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  • 1.
    Abbas, Alaa
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Palladium-Catalysed Carbonylative Synthesis of Acylamidines2014Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 2. Abdel-Hamid, Mohammed K
    et al.
    Macgregor, Kylie A
    Odell, Luke R
    Chau, Ngoc
    Mariana, Anna
    Whiting, Ainslie
    Robinson, Phillip J
    McCluskey, Adam
    1,8-Naphthalimide derivatives: new leads against dynamin I GTPase activity.2015Ingår i: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, nr 29Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Fragment-based in silico screening against dynamin I (dynI) GTPase activity identified the 1,8-naphthalimide framework as a potential scaffold for the design of new inhibitors targeting the GTP binding pocket of dynI. Structure-based design, synthesis and subsequent optimization resulted in the development of a library of 1,8-naphthalimide derivatives, called the Naphthaladyn™ series, with compounds 23 and 29 being the most active (IC50 of 19.1 ± 0.3 and 18.5 ± 1.7 μM respectively). Compound 29 showed effective inhibition of clathrin-mediated endocytosis (IC50(CME) 66 μM). The results introduce 29 as an optimised GTP-competitive lead Naphthaladyn™ compound for the further development of naphthalimide-based dynI GTPase inhibitors.

  • 3.
    Acharya, P
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Chattopadhyaya, J
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    The Hydrogen Bonding and Hydration of 2'-OH in Adenosine and Adenosine 3'-ethylphosphate.2002Ingår i: J. Org. Chem., Vol. 67, s. 1852-1865Artikel i tidskrift (Refereegranskat)
  • 4.
    Acharya, Parag
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Studies on the Non-covalent Interactions (Stereoelectronics, Stacking and Hydrogen Bonding) in the Self-assembly of DNA and RNA2003Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis is based on ten publications (Papers I-X). The phosphodiester backbone makes DNA or RNA to behave as polyelectrolyte, the pentose sugar gives the flexibility, and the aglycones promote the self-assembly or the ligand-binding process. The hydrogen bonding, stacking, stereoelectronics and hydration are few of the important non-covalent forces dictating the self-assembly of DNA/RNA. The pH-dependent thermodynamics clearly show (Papers I and II) that a change of the electronic character of aglycone modulates the conformation of the sugar moiety by the tunable interplay of stereoelectronic anomeric and gauche effects, which are further transmitted to steer the sugar-phosphate backbone conformation in a cooperative manner. 3'-anthraniloyl adenosine (a mimic of 3'-teminal CCAOH of the aminoacyl-tRNAPhe) binds to EF-Tu*GTP in preference over 2'-anthraniloyl adenosine, thereby showing (Paper III) that the 2’-endo sugar conformation is a more suitable mimic of the transition state geometry than the 3’-endo conformation in discriminating between correctly and incorrectly charged aminoacyl-tRNAPhe by EF-Tu during protein synthesis. The presence of 2'-OH in RNA distinguishes it from DNA both functionally as well as structurally. This work (Paper IV) provides straightforward NMR evidence to show that the 2'-OH is intramolecularly hydrogen bonded with the vicinal 3'-oxygen, and the exposure of the 3'-phosphate of the ribonucleotides to the bulk water determines the availability of the bound water around the vicinal 2'-OH, which then can play various functional role through inter- or intramolecular interactions. The pH-dependent 1H NMR study with nicotinamide derivatives demonstrates (Paper V) that the cascade of intramolecular cation (pyridinium)-π(phenyl)-CH(methyl) interaction in edge-to-face geometry is responsible for perturbing the pKa of the pyridine-nitrogen as well as for the modulation of the aromatic character of the neighboring phenyl moiety, which is also supported by the T1 relaxation studies and ab initio calculations. It has been found (Papers VI-IX) that the variable intramolecular electrostatic interaction between electronically coupled nearest neighbor nucleobases (steered by their respective microenvironments) can modulate their respective pseudoaromatic characters. The net result of this pseudoaromatic cross-modulation is the creation of a unique set of aglycones in an oligo or polynucleotide, whose physico-chemical properties are completely dependent upon the propensity and geometry of the nearest neighbor interactions (extended genetic code). The propagation of the interplay of these electrostatic interactions across the hexameric ssDNA chain is considerably less favoured (effectively up to the fourth nucleobase) compared to that of the isosequential ssRNA (up to the sixth nucleobase). The dissection of the relative strength of basepairing and stacking in a duplex shows that stability of DNA-DNA duplex weakens over the corresponding RNA-RNA duplexes with the increasing content of A-T/U base pairs, while the strength of stacking of A-T rich DNA-DNA duplex increases in comparison with A-U rich sequence in RNA-RNA duplexes (Paper X).

    Delarbeten
    1. The Transmission of the Electronic Character of Guanin-9-yl Drives the Sugar-phosphate Backbone Torsions in Guanosine 3',5'-bisphosphate.
    Öppna denna publikation i ny flik eller fönster >>The Transmission of the Electronic Character of Guanin-9-yl Drives the Sugar-phosphate Backbone Torsions in Guanosine 3',5'-bisphosphate.
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    1999 Ingår i: Angew. Chem. Int. Ed., Vol. 38, nr 24, s. 3645-3650Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91143 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    2. The RNA Molecular Wire: The pH-Dependent Change in Electronic Character of Adenine-9-yl is Transmitted to Drive the Sugar-Phosphate Backbone Torsions in Adenosine 3', 5'-bisphosphate
    Öppna denna publikation i ny flik eller fönster >>The RNA Molecular Wire: The pH-Dependent Change in Electronic Character of Adenine-9-yl is Transmitted to Drive the Sugar-Phosphate Backbone Torsions in Adenosine 3', 5'-bisphosphate
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    2000 Ingår i: J. Phys. Org. Chem., Vol. 13, s. 300-305Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91144 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    3. The Strength of the 3'-gauche effect Dictates the Structure of 3'-anthraniloyladenosine and its 5'-phosphate, Two Analogues of the 3'-end of Aminoacyl tRNA
    Öppna denna publikation i ny flik eller fönster >>The Strength of the 3'-gauche effect Dictates the Structure of 3'-anthraniloyladenosine and its 5'-phosphate, Two Analogues of the 3'-end of Aminoacyl tRNA
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    1999 Ingår i: J. Chem. Soc. Perkin 2, s. 1531-1536Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91145 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    4. The Hydrogen Bonding and Hydration of 2'-OH in Adenosine and Adenosine 3'-ethylphosphate
    Öppna denna publikation i ny flik eller fönster >>The Hydrogen Bonding and Hydration of 2'-OH in Adenosine and Adenosine 3'-ethylphosphate
    2002 Ingår i: J. Org. Chem., Vol. 67, nr 6, s. 1852-1865Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91146 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    5. A Repertoire of Pyridinium-Phenyl-Methyl Cross-Talk through a Cascade of Intramolecular Electrostatic Interactions
    Öppna denna publikation i ny flik eller fönster >>A Repertoire of Pyridinium-Phenyl-Methyl Cross-Talk through a Cascade of Intramolecular Electrostatic Interactions
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    2003 Ingår i: J. Org. Chem., Vol. 68, nr 4, s. 1529-1538Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91147 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    6. Cross-Modulation of Physicochemical Character of Aglycones in Dinucleoside (3'→5') monophosphates by the Nearest Neighbor Interaction in the Stacked State
    Öppna denna publikation i ny flik eller fönster >>Cross-Modulation of Physicochemical Character of Aglycones in Dinucleoside (3'→5') monophosphates by the Nearest Neighbor Interaction in the Stacked State
    2002 Ingår i: J. Am. Chem. Soc., Vol. 124, nr 46, s. 13722-13730Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91148 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    7. Tandem Electrostatic Effect From the First to the Third Aglycon in the Trimeric RNA Owing to the Nearest-neighbor Stacking
    Öppna denna publikation i ny flik eller fönster >>Tandem Electrostatic Effect From the First to the Third Aglycon in the Trimeric RNA Owing to the Nearest-neighbor Stacking
    2003 Ingår i: J. Am. Chem. Soc., Vol. 125, nr 8, s. 2094-2100Artikel i tidskrift (Refereegranskat) Published
    Identifikatorer
    urn:nbn:se:uu:diva-91149 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    8. Cross-Modulation of the pKa of Nucleobases in a Single-Stranded Hexameric-RNA Due to Tandem Electrostatic Nearest-Neighbor Interactions
    Öppna denna publikation i ny flik eller fönster >>Cross-Modulation of the pKa of Nucleobases in a Single-Stranded Hexameric-RNA Due to Tandem Electrostatic Nearest-Neighbor Interactions
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    2003 (Engelska)Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 125, nr 33, s. 9948-9961Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The pH titration studies (pH 6.7-12.1) in a series of dimeric, trimeric, tetrameric, pentameric, and hexameric oligo-RNA molecules [GpA (2a), GpC (3a), GpApC (5), GpA(1)pA(2)pC (6), GpA(1)pA(2)pA(3)pC (7), GpA(1)pA(2)pA(3)pA(4)pC (8)] have shown that the pK(a) of N(1)-H of 9-guaninyl could be measured not only from its own deltaH8G, but also from the aromatic marker protons of other constituent nucleobases. The relative chemical shift differences [Deltadelta((N)(-)(D))] between the protons in various nucleotide residues in the oligo-RNAs at the neutral (N) and deprotonated (D) states of the guanine moiety show that the generation of the 5'-(9-guanylate ion) in oligo-RNAs 2-8 reduces the stability of the stacked helical RNA conformation owing to the destabilizing anion(G(-))-pi/dipole(Im(delta)(-)) interaction. This destabilizing effect in the deprotonated RNA is, however, opposed by the electrostatically attractive atom-pisigma (major) as well as the anion(G(-))-pi/dipole(Py(delta)(+)) (minor) interactions. Our studies have demonstrated that the electrostatically repulsive anion(G(-))-pi/dipole(Im(delta)(-)) interaction propagates from the first to the third nucleobase quite strongly in the oligo-RNAs 6-8, causing destacking of the helix, and then its effect is gradually reduced, although it is clearly NMR detectable along the RNA chain. Thus, such specific generation of a charge at a single nucleobase moiety allows us to explore the relative strength of stacking within a single-stranded helix. The pK(a) of 5'-Gp residue from its own deltaH8G in the hexameric RNA 8 is found to be 9.76 +/- 0.01; it, however, varies from 9.65 +/- 0.01 to 10.5 +/- 0.07 along the RNA chain as measured from the other marker protons (H2, H8, H5, and H6) of 9-adeninyl and 1-cytosinyl residues. This nucleobase-dependent modulation of pK(a)s (DeltapK(a) +/- 0.9) of 9-guaninyl obtained from other nucleobases in the hexameric RNA 8 represents a difference of ca. 5.1 kJ mol(-)(1), which has been attributed to the variable strength of electrostatic interactions between the electron densities of the involved atoms in the offset stacked nucleobases as well as with that of the phosphates. The chemical implication of this variable pK(a) for guanin-9-yl deprotonation as obtained from all other marker protons of each nucleotide residue within a ssRNA molecule is that it enables us to experimentally understand the variation of the electronic microenvironment around each constituent nucleobase along the RNA chain in a stepwise manner with very high accuracy without having to make any assumption. This means that the pseudoaromaticity of neighboring 9-adeninyl and next-neighbor nucleobases within a polyanionic sugar-phosphate backbone of a ssRNA can vary from one case to another due to cross-modulation of an electronically coupled pi system by a neighboring nucleobase. This modulation may depend on the sequence context, spatial proximity of the negatively charged phosphates, as well as whether the offset stacking is ON or OFF. The net outcome of this electrostatic interaction between the neighbors is creation of new sequence-dependent hybrid nucleobases in an oligo- or polynucleotide whose properties are unlike the monomeric counterpart, which may have considerable biological implications.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-91150 (URN)10.1021/ja034651h (DOI)12914458 (PubMedID)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
    9. The Nucleobases in Single-stranded DNA are Better Stacked and Yet Their Pseudoaromatic Characters are More Poorly Cross-modulated Than in the RNA Counterparts Due to Variable Tandem Nearest-neighbour Electrostatic Interactions
    Öppna denna publikation i ny flik eller fönster >>The Nucleobases in Single-stranded DNA are Better Stacked and Yet Their Pseudoaromatic Characters are More Poorly Cross-modulated Than in the RNA Counterparts Due to Variable Tandem Nearest-neighbour Electrostatic Interactions
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    Ingår i: J. Am. Chem. Soc.Artikel i tidskrift (Refereegranskat) Submitted
    Identifikatorer
    urn:nbn:se:uu:diva-91151 (URN)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26Bibliografiskt granskad
    10. Measurement of nucleobase pKa values in model mononucleotides shows RNA-RNA duplexes to be more stable than DNA-DNA duplexes
    Öppna denna publikation i ny flik eller fönster >>Measurement of nucleobase pKa values in model mononucleotides shows RNA-RNA duplexes to be more stable than DNA-DNA duplexes
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    2004 (Engelska)Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 126, nr 9, s. 2862-2869Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    To understand why the RNA-RNA duplexes in general has a higher thermodynamic stability over the corresponding DNA-DNA duplexes, we have measured the pK(a) values of both nucleoside 3',5'-bis-ethyl phosphates [Etp(d/rN)pEt] and nucleoside 3'-ethyl phosphates [(d/rN)pEt] (N = A, G, C, or T/U), modeling as donors and acceptors of base pairs in duplexes. While the 3',5'-bis-phosphates, Etp(d/rN)pEt, mimic the internucleotidic monomeric units of DNA and RNA, in which the stacking contribution is completely absent, the 3'-ethyl phosphates, (d/rN)pEt, mimic the nucleotide at the 5'-end. The pK(a) values of the nucleobase in each of these model nucleoside phosphates have been determined with low pK(a) error (sigma = +/-0.01 to 0.02) by (1)H NMR (at 500 MHz) with 20-33 different pH measurements for each compound. This study has led us to show the following: (1) All monomeric DNA nucleobases are more basic than the corresponding RNA nucleobases in their respective Etp(d/rN)pEt and (d/rN)pEt. (2) The pK(a) values of the monomeric nucleotide blocks as well as Delta pK(a) values between the donor and acceptor can be used to understand the relative base-pairing strength in the oligomeric duplexes in the RNA and DNA series. (3) The Delta G*(pKa) of the donor and acceptor of the base pair in duplexes enables a qualitative dissection of the relative strength of the base-pairing and stacking in the RNA-RNA over the DNA-DNA duplexes. (4) It is also found that the relative contribution of base-pairing strength and nucleobase stacking in RNA-RNA over DNA-DNA is mutually compensating as the % A-T/U content increases or decreases. This interdependency of stacking and hydrogen bonding can be potentially important in the molecular design of the base-pair mimics to expand the alphabet of the genetic code.

    Nationell ämneskategori
    Naturvetenskap
    Identifikatorer
    urn:nbn:se:uu:diva-91152 (URN)10.1021/ja0386546 (DOI)14995203 (PubMedID)
    Tillgänglig från: 2003-11-26 Skapad: 2003-11-26 Senast uppdaterad: 2017-12-14Bibliografiskt granskad
  • 5.
    Ahlgren, Joakim
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi. Institutionen för biokemi och organisk kemi, Organisk kemi I. Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi.
    Reitzel, Kasper
    Danielsson, Rolf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi. Institutionen för biokemi och organisk kemi, Organisk kemi I. Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi.
    Gogoll, Adolf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi. Institutionen för biokemi och organisk kemi, Organisk kemi I. Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Rydin, Emil
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för fysikalisk och analytisk kemi, Analytisk kemi. Institutionen för biokemi och organisk kemi, Organisk kemi I. Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Biogenic phosphorus in oligotropic mountain lake sediments: Differences in composition measured with NMR spectroscopy2006Ingår i: Water Research, nr 40, s. 3705-3712Artikel i tidskrift (Refereegranskat)
  • 6.
    Ahlgren, Joakim
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Tranvik, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Gogoll, Adolf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Waldebäck, Monica
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Markides, Karin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen, Avdelningen för analytisk kemi.
    Rydin, Emil
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution, Limnologi.
    Sediment Depth Attenuation of Biogenic Phosphorus Compounds Measured by 31P NMR2005Ingår i: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 39, nr 3, s. 867-872Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Being a major cause of eutrophication and subsequent loss of water quality, the turnover of phosphorus (P) in lake sediments is in need of deeper understanding. A major part of the flux of P to eutrophic lake sediments is organically bound or of biogenic origin. This P is incorporated in a poorly described mixture of autochthonous and allochthonous sediment and forms the primary storage of P available for recycling to the water column, thus regulating lake trophic status. To identify and quantify biogenic sediment P and assess its lability, we analyzed sediment cores from Lake Erken, Sweden, using traditional P fractionation, and in parallel, NaOH extracts were analyzed using 31P NMR. The surface sediments contain orthophosphates (ortho-P) and pyrophosphates (pyro-P), as well as phosphate mono- and diesters. The first group of compounds to disappear with increased sediment depth is pyrophosphate, followed by a steady decline of the different ester compounds. Estimated half-life times of these compound groups are about 10 yr for pyrophosphate and 2 decades for mono- and diesters. Probably, these compounds will be mineralized to ortho-P and is thus potentially available for recycling to the water column, supporting further growth of phytoplankton. In conclusion, 31P NMR is a useful tool to asses the bioavailability of certain P compound groups, and the combination with traditional fractionation techniques makes quantification possible.

  • 7. Aili, Daniel
    et al.
    Enander, Karin
    Rydberg, Johan
    Lundström, Ingemar
    Baltzer, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi II.
    Liedberg, Bo
    Aggregation-Induced Folding of a de novo Designed Polypeptide Immobilized on Gold Nanoparticles2006Ingår i: J. Am. Chem. Soc., nr 128, s. 2194-2195Artikel i tidskrift (Refereegranskat)
  • 8. Aili, Daniel
    et al.
    Enander, Karin
    Rydberg, Johan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi II.
    Nesterenko, Irina
    Björefors, Fredrik
    Baltzer, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi II.
    Liedberg, Bo
    Folding Induced Assembly of Polypeptide Decorated Gold Nanoparticles2008Ingår i: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 130, nr 17, s. 5780-5788Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Reversible assembly of gold nanoparticles controlled by the homodimerization and folding of an immobilized de novo designed synthetic polypeptide is described. In solution at neutral pH, the polypeptide folds into a helix-loop-helix four-helix bundle in the presence of zinc ions. When immobilized on gold nanoparticles, the addition of zinc ions induces dimerization and folding between peptide monomers located on separate particles, resulting in rapid particle aggregation. The particles can be completely redispersed by removal of the zinc ions from the peptide upon addition of EDTA. Calcium ions, which do not induce folding in solution, have no effect on the stability of the peptide decorated particles. The contribution from folding on particle assembly was further determined utilizing a reference peptide with the same primary sequence but containing both D and L amino acids. Particles functionalized with the reference peptide do not aggregate, as the peptides are unable to fold. The two peptides, linked to the nanoparticle surface via a cysteine residue located in the loop region, form submonolayers on planar gold with comparable properties regarding surface density, orientation, and ability to interact with zinc ions. These results demonstrate that nanoparticle assembly can be induced, controlled, and to some extent tuned, by exploiting specific molecular interactions involved in polypeptide folding.

  • 9.
    Akkarasamiyo, Sunisa
    et al.
    Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Sawadjoon, Supaporn
    Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Orthaber, Andreas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Molekylär biomimetik.
    Samec, Joseph S. M.
    Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Tsuji-Trost Reaction of Non-Derivatized Allylic Alcohols2018Ingår i: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 24, nr 14, s. 3488-3498Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Palladium-catalyzed allylic substitution of non-derivatized enantioenriched allylic alcohols with a variety of uncharged N-, S-, C- and O-centered nucleophiles using a bidentate BiPhePhos ligand is described. A remarkable effect of the counter ion (X) of the XPd[kappa(2)-BiPhePhos][kappa(3)-C3H5] was observed. When ClPd[kappa(2)-BiPhePhos][eta(3)-C3H5] (complexI) was used as catalyst, non-reproducible results were obtained. Study of the complex by X-ray crystallography, (PNMR)-P-31 spectroscopy, and ESI-MS showed that a decomposition occurred where one of the phosphite ligands was oxidized to the corresponding phosphate, generating ClPd[kappa(1)-BiPhePhosphite-phosphate][eta(3)-C3H5] species (complexII). When the chloride was exchanged to the weaker coordinating OTf- counter ion the more stable Pd[kappa(2)-BiPhePhos][eta(3)-C3H5](+)+[OTf] (-) (complexIII) was formed. ComplexIII performed better and gave higher enantiospecificities in the substitution reactions. ComplexIII was evaluated in Tsuji-Trost reactions of stereogenic non-derivatized allylic alcohols. The desired products were obtained in good to excellent yields (71-98%) and enantiospecificities (73-99%) for both inter- and intramolecular substitution reactions with only water generated as a by-product. The methodology was applied to key steps in total synthesis of (S)-cuspareine and (+)-lentiginosine. A reaction mechanism involving a palladium hydride as a key intermediate in the activation of the hydroxyl group is proposed in the overall transformation.

  • 10. Albrecht, Christiane
    et al.
    Fechner, Peter
    Honcharenko, Dmytro
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Baltzer, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi.
    Gauglitz, Günther
    A new assay design for clinical diagnostics based on alternative recognition elements2010Ingår i: Biosensors & bioelectronics, ISSN 0956-5663, E-ISSN 1873-4235, Vol. 25, nr 10, s. 2302-2308Artikel i tidskrift (Refereegranskat)
  • 11. Alogheli, Hiba
    Pan-NS3 protease inhibitors of hepatitis C virus based on an R3-elongated pyrazinone scaffoldIngår i: Artikel i tidskrift (Refereegranskat)
  • 12. Alonso, Diego
    et al.
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Deprotection of Sulfonyl Aziridines1998Ingår i: J. Org. Chem., nr 63, s. 9455-9461Artikel i tidskrift (Refereegranskat)
  • 13. Alonso, Diego
    et al.
    Bertilsson, Sophie
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Johnsson, Sandra
    Nordin, Sofia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Södergren, Mikael
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    New Expedient Route to Both Enantiomers of Nonproteinogenic a-Amino Acid Derivatives from the Unsaturated 2-Aza-Bicyclo Moiety1999Ingår i: J. Org. Chem., nr 64, s. 2276-2280Artikel i tidskrift (Refereegranskat)
  • 14. Alonso, Diego
    et al.
    Brandt, Peter
    Nordin, Sofia
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Ru(arene)(amino alcohol)-Catalyzed Transfer Hydrogenation of Ketones: Mechanism and Origin of Enantioselectivity1999Ingår i: J. Am. Chem. Soc., nr 121, s. 9580-9588Artikel i tidskrift (Refereegranskat)
    Abstract
  • 15. Alonso, Diego
    et al.
    Guijarro, David
    Pinho, Pedro
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Temme, Oliver
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    (1S,3R,4R)-2-Azanorbornylmethanol, an Efficient Ligand for Ruthenium-Catalyzed Asymmetric Transfer Hydrogenation of Ketones1998Ingår i: J. Org. Chem., nr 63, s. 2749-2751Artikel i tidskrift (Refereegranskat)
  • 16.
    Al-Smadi, Derar
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Organisk kemi.
    Enugala, Thilak Reddy
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Biokemi.
    Norberg, Thomas
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Organisk kemi.
    Kihlberg, Jan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Organisk kemi.
    Widersten, Mikael
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Biokemi.
    Synthesis of substrates for aldolase-catalyzed reactions - A comparison of methods for the synthesis of substituted phenylacetaldehydes2018Ingår i: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, Vol. 29, s. 1187-1190Artikel i tidskrift (Refereegranskat)
  • 17.
    Alvi, Muhammad Rouf
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Low-coordinate Organosilicon Chemistry: Fundamentals, Excursions Outside the Field, and Potential Applications2012Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis reports on unsaturated silicon compounds, as well as excursions from these into germanium chemistry, single molecule electronics, and silyl protective group chemistry. Both experimental and computational investigations were performed.

    Potassium germenolates were synthesized through reactions of tris(timethylsilyl) substituted acyl- and carbamylgermanes with potassium tert-butoxide. The potassium germenolates calculated by density functional theory have pyramidal structures at the Ge atoms, similar to the Si in the corresponding potassium silenolates, indicating negative charge on germanium rather than on oxygen. Germenolates also display germyl anion-like reactivity instead of germene-like reactivity as they are alkylated at Ge and initiate anionic polymerization of dienes rather than form [4+2] cycloadducts. The NMR chemical shifts reveal more negative charge at Ge in germenolates than at Si in analogous silenolates.

    Computations indicate that silabenzenes and silapyridines are reachable via [1,3]-silyl shifts from cyclic conjugated acylsilanes. Differently sized substituents were considered to prevent dimerizations, and 1-triisopropylsilyl-2-triisopropylsiloxy-6-tert-butylsilabenzene is a good synthetic target. Computations also show that silaphenolates are species with negative charge primarily localized at oxygen atom. Their planar structures, bond lengths, and NICS values reveal significant influence of aromaticity. Electrostatic repulsion should increase their stability, however, steric bulk is also important.

    Furthermore, it was found computationally that [1,3]-silyl shift from an acylsilane to a silene can function as a molecular switch reaction. Conductance calculations support this proposition.  

    Finally, tris(trimethylsilyl)silylmethaneamide (hypersilylamide) together with catalytic amounts of triflic acid were found to be efficient for protection of a range of alkyl and aryl alcohols and thiols in good to excellent yields. The protocol can be used to protect the less hindered OH group of a diol and has a broad functional group tolerance. A catalytic cycle is proposed. Hypersilyl protected alcohols and thiols are deprotected efficiently under photolytic conditions.

    Delarbeten
    1. Remarkably Stable Silicon Analogues of Amide Enolates: Synthesis, Structural Characterization, and Reactivity Studies
    Öppna denna publikation i ny flik eller fönster >>Remarkably Stable Silicon Analogues of Amide Enolates: Synthesis, Structural Characterization, and Reactivity Studies
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Potassium 2-N,N-dialkylamino-1,1-bis(trimethylsilyl)silen-2-olates (or amide silenolates, silicon analogues of amide enolates) were synthesized through reaction of N,N-dialkyl-tris(trimethylsilyl)silylmethaneamides with potassium tert-butoxide, and these 2-N,N-dialkylaminosilen-2-olates display remarkable thermal stabilities (e.g., merely 37% decomposition after 8 h at 90 ºC).  The crystal structure of one of the potassium 2-N,N-dialkylaminosilen-2-olates, without potassium ion chelating agent, reveals a more pyramidal configuration around the Si atom than found in previously reported silenolates, indicating a strong localization of the negative charge to this atom. The reactivities of the potassium 2-N,N-dialkylaminosilen-2-olates are in part similar to those of previous lithium and potassium silenolates as they are alkylated with MeI at Si. However, they do not react with dienes to yield [4+2] cycloadducts, the customary adducts of silenolates and reverse polarized silenes, but instead initiate anionic diene polymerization.  Consequently, they display silyl anion-like rather than silene-like reactivities. Finally, we find that potassium 2-aminosilen-2-olates with N,N-diphenylamino instead of N,N-dialkylamino substitution decompose rapidly to potassium diphenylamide, carbon monoxide, and silylenes. Clearly, if the substituent at the 2-position of a silenolate is able to accept and stabilize negative charge, such as NPh2, then this silenolate will be prone to decompose.

    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169783 (URN)
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2012-04-19
    2. Formation and Fundamental Properties of Potassium Germen-2-olates
    Öppna denna publikation i ny flik eller fönster >>Formation and Fundamental Properties of Potassium Germen-2-olates
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    Potassium 1,1-bis(trimethylsilyl)germen-2-olates (2a - 2d) with different substituents at the carbon atom were generated in good yields through the treatment of the correspondingly substituted tris(trimethylsilyl)acyl- and tris(trimethylsilyl)carbamyl-germanes (1a - 1d) with potassium tert-butoxide at room temperature in dry THF. Comparisons between the 29Si and 13C NMR chemical shifts of the germenolates and the analogous silenolates (4a4d) were performed. The recorded 13C and 29Si NMR chemical shifts of the potassium germenolates were also compared to those obtained from GIAO-B3LYP/6-31+G(d)//B3LYP/LANL2DZp calculations. The chemical reactivities of potassium germenolates were compared with silenolates. In this regard, the reactions of 2a - 2d were performed with methyliodide at -40 oC and the germanium methylated products (5a - 5c) were obtained in yields of 54 - 77 %. The reactions of these germenolates with 1,3-butadiene at low temperatures, however, lead to polymerization of dienes (2,3-dimethyl-1,3-butadiene, isoprene, and 1,3-pentadiene) revealing a reactivity resemblance to aminosilenolates, species which in return are comparable to silyl anions in reactivity.

    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169795 (URN)
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2012-04-19
    3. Computational Investigation of Brook-Type Silabenzenes and Their Possible Formation through [1,3]-Si -> O Silyl Shifts
    Öppna denna publikation i ny flik eller fönster >>Computational Investigation of Brook-Type Silabenzenes and Their Possible Formation through [1,3]-Si -> O Silyl Shifts
    2013 (Engelska)Ingår i: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 32, nr 1, s. 16-28Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Quantum chemical calculations with the M062X hybrid meta density functional theory method were performed in order to examine formation of Brook-type silabenzenes 4a 4l, silapyridines 6a 6d, and five-membered ring silaheteroaromatics 8a8d through [1,3]-trimethylsilyl (TMS) and [1,3]-tri(isopropyl)silyl (TIPS) shifts from a tetrahedral silicon atom to an adjacent carbonyl oxygen of cyclic conjugated acylsilane precursors. All Brook-type silabenzenes and silapyridines, having a 2-trialkylsiloxy substituent, are at lower relative energies than their precursors, whereas silaheteroaromatics 8a 8d are found at slightly higher energies. The free energies of activation for the thermal [1,3]-TMS shifts range from 29 to 44 kcal/mol, with the lowest for a Brook-type silapyridine and the highest for a silafuran. The geometries of the Brook-type silabenzenes, silapyridines, silafuran and silathiophene indicate aromatic character, but the silapyrroles are nonaromatic. At M062X/6-311+G(d)//M062X/6-31G(d) level all Brook-type silabenzene dimers studied herein are more stable than two silabenzenes, also for a silabenzene with bulky TIPS, OTIPS and tert-butyl substituents (4l). Yet, comparisons of the B3LYP/6-31G(d) dimerization energies of 4l with that of the isolable 1-Tbt-silabenzene (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) of Tokitoh [J. Chin. Chem. Soc. 2008, 55, 487] indicate that 4l will also be a monomeric silabenzene, and thus, a suitable synthetic target.

    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169784 (URN)10.1021/om300023s (DOI)000313606200005 ()
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2017-12-07Bibliografiskt granskad
    4. Silaphenolates and Silaphenylthiolates: Two Unexplored Unsaturated Silicon Compound Classes Influenced by Aromaticity
    Öppna denna publikation i ny flik eller fönster >>Silaphenolates and Silaphenylthiolates: Two Unexplored Unsaturated Silicon Compound Classes Influenced by Aromaticity
    2012 (Engelska)Ingår i: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 17, nr 1, s. 369-389Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Monosilicon analogs of phenolates and phenylthiolates are studied by quantum chemical calculations. Three different silaphenolates and three different silaphenylthiolates are possible; the ortho-, meta-, and para-isomers. For the silaphenolates, the meta- isomer is the thermodynamically most stable, regardless if the substituent R at Si is H, t-Bu or SiMe3. However, with R = H and SiMe3 the energy differences between the three isomers are small, whereas with R = t-Bu the meta- isomer is similar to 5 kcal/mol more stable than the ortho- isomer. For the silaphenylthiolates the ortho- isomer is of lowest energy, although with R = H the ortho- and meta- isomers are isoenergetic. The calculated nucleus independent chemical shifts (NICS) indicate that the silaphenolates and silaphenylthiolates are influenced by aromaticity, but they are less aromatic than the parent silabenzene. The geometries and charge distributions suggest that all silaphenolates and silaphenylthiolates to substantial degrees are described by resonance structures with an exocyclic C=O double bond and a silapentadienyl anionic segment. Indeed, they resemble the all-carbon phenolate and phenylthiolate. Silaphenylthiolates are less bond alternate and have slightly more negative NICS values than analogous silaphenolates, suggesting that this compound class is a bit more aromatic. Dimerization of the silaphenolates and silaphenylthiolates is hampered due to intramolecular Coulomb repulsion in the dimers, and silaphenolates with a moderately bulky SiMe3 group as substituent at Si should prefer the monomeric form.

    Nyckelord
    silicon, aromaticity, quantum chemical calculations
    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-166896 (URN)10.3390/molecules17010369 (DOI)000299535700025 ()
    Tillgänglig från: 2012-01-16 Skapad: 2012-01-16 Senast uppdaterad: 2017-12-08Bibliografiskt granskad
    5. The [1,3]-Si→O Silyl Shift from a Nonconducting Acylsilane to a Conducting Brook-Silene as Basis for a Molecular Switch
    Öppna denna publikation i ny flik eller fönster >>The [1,3]-Si→O Silyl Shift from a Nonconducting Acylsilane to a Conducting Brook-Silene as Basis for a Molecular Switch
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    By usage of density functional theory (DFT) calculations we explored if the [1,3]-silyl shift leading from an acylsilane with two p-conjugated substituents to a silene (a Si=C double bonded compound) can be used as a basis for a molecular conductance switch. In such a switch, the acylsilane, with a tetrahedral saturated silicon atom disrupting the conjugation through the molecule, acts as the OFF state, whereas the silene with a conjugated path running through the complete molecule represents the ON state. Our requirements are (i) the silenes should be slightly higher in relative energy than the acylsilane so as to promote a thermal backrearragment, (ii) the barrier for the backtransfer of the silyl group should be 25-30 kcal/mol, (iii) the ON/OFF conductance ratio should be high, and (iv) the switch should be realistic. According to our calculations using non-equilibrium Green’s function theory, a 1,2-bis(4-thiophenylethynyl)silene has a conductance which is 270 times higher than that of the corresponding acylsilane at zero bias voltage. However, at a voltage of +1 V the ON/OFF ratio decreases to ~40.

    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169782 (URN)
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2012-04-19
    6. Highly Efficient and Convenient Acid Catalyzed Hypersilyl Protection of Alcohols and Thiols by Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide
    Öppna denna publikation i ny flik eller fönster >>Highly Efficient and Convenient Acid Catalyzed Hypersilyl Protection of Alcohols and Thiols by Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide
    Visa övriga...
    2012 (Engelska)Artikel i tidskrift (Övrigt vetenskapligt) Submitted
    Abstract [en]

    Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide, herein named hypersilylamide, is a convenient and efficient source of the hypersilyl group in the first widely applicable acid catalyzed protocol for silyl group protection of primary, secondary, tertiary alkyl as well as aryl alcohols and thiols in high yields. The sole by-product is N,N-dimethylformamide (DMF) and a range of solvents can be used, including DMF. A high selectivity in the protection of diols can be achieved, also for diols with very small differences in the steric demands at the two hydroxyl groups. Moreover, in the protection of equivalent alcohol and thiol sites the protection of the alcohol is faster, allowing for selective protection in high yields. Quantum chemical calculations at the M062X hybrid meta density functional theory level give insights on the mechanism for the catalytic process. Finally, the hypersilyl group is easily removed from all protected alcohols and thiols examined herein by irradiation at 254 nm.

    Nationell ämneskategori
    Organisk kemi Oorganisk kemi
    Forskningsämne
    Kemi med inriktning mot oorganisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169781 (URN)
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2013-03-07Bibliografiskt granskad
    7. Scope and Limitations of an Acid Catalyzed Protocol for Hypersilyl Protection of Alcohols
    Öppna denna publikation i ny flik eller fönster >>Scope and Limitations of an Acid Catalyzed Protocol for Hypersilyl Protection of Alcohols
    Visa övriga...
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A highly efficient and convenient triflic acid (TfOH) catalyzed protocol for the protection of various functionalized alcohols in CH2Cl2 at ambient temperature using tris(trimethylsilyl)silyl-N,N-dimethyl-methaneamide (hypersilylamide) 1 as the protecting reagent is developed. Herein, results on the scope and limitations of this protocol for a number of functionalized alcohols are presented. This method was found to be effective for the selective protection of less hindered OH groups in different classes of diols containing both pri/tert, sec/tert, or aromatic/aliphatic hydroxyl groups. In general, our protocol exhibited excellent functional group tolerance in the protection of alcohols containing alkoxy, keto, amino, as well as halo substituents in good to excellent yields.

    Nationell ämneskategori
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-169780 (URN)
    Tillgänglig från: 2012-03-06 Skapad: 2012-03-06 Senast uppdaterad: 2012-04-19
  • 18.
    Alvi, Muhammad Rouf
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Anas, Saithalavi
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Emanuelsson, Rikard
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Lozinski, Kaitlin
    Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC) and Department of Chemistry, University of Richmond, UR 1099, 28 Westhampton Way, VA 23173, USA.
    Ottosson, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Scope and Limitations of an Acid Catalyzed Protocol for Hypersilyl Protection of Alcohols Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A highly efficient and convenient triflic acid (TfOH) catalyzed protocol for the protection of various functionalized alcohols in CH2Cl2 at ambient temperature using tris(trimethylsilyl)silyl-N,N-dimethyl-methaneamide (hypersilylamide) 1 as the protecting reagent is developed. Herein, results on the scope and limitations of this protocol for a number of functionalized alcohols are presented. This method was found to be effective for the selective protection of less hindered OH groups in different classes of diols containing both pri/tert, sec/tert, or aromatic/aliphatic hydroxyl groups. In general, our protocol exhibited excellent functional group tolerance in the protection of alcohols containing alkoxy, keto, amino, as well as halo substituents in good to excellent yields.

  • 19.
    Alvi, Muhammad Rouf
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Burkhard O., Jahn
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Ottosson, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Computational Investigation of Brook-Type Silabenzenes and Their Possible Formation through [1,3]-Si -> O Silyl Shifts2013Ingår i: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 32, nr 1, s. 16-28Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Quantum chemical calculations with the M062X hybrid meta density functional theory method were performed in order to examine formation of Brook-type silabenzenes 4a 4l, silapyridines 6a 6d, and five-membered ring silaheteroaromatics 8a8d through [1,3]-trimethylsilyl (TMS) and [1,3]-tri(isopropyl)silyl (TIPS) shifts from a tetrahedral silicon atom to an adjacent carbonyl oxygen of cyclic conjugated acylsilane precursors. All Brook-type silabenzenes and silapyridines, having a 2-trialkylsiloxy substituent, are at lower relative energies than their precursors, whereas silaheteroaromatics 8a 8d are found at slightly higher energies. The free energies of activation for the thermal [1,3]-TMS shifts range from 29 to 44 kcal/mol, with the lowest for a Brook-type silapyridine and the highest for a silafuran. The geometries of the Brook-type silabenzenes, silapyridines, silafuran and silathiophene indicate aromatic character, but the silapyrroles are nonaromatic. At M062X/6-311+G(d)//M062X/6-31G(d) level all Brook-type silabenzene dimers studied herein are more stable than two silabenzenes, also for a silabenzene with bulky TIPS, OTIPS and tert-butyl substituents (4l). Yet, comparisons of the B3LYP/6-31G(d) dimerization energies of 4l with that of the isolable 1-Tbt-silabenzene (Tbt = 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl) of Tokitoh [J. Chin. Chem. Soc. 2008, 55, 487] indicate that 4l will also be a monomeric silabenzene, and thus, a suitable synthetic target.

  • 20.
    Alvi, Muhammad Rouf
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Jahn, Burkhard O.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Tibbelin, Julius
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC.
    Baumgartner, Judith
    Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria.
    Gómez, Cesar Pay
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Strukturkemi.
    Ottosson, Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Highly Efficient and Convenient Acid Catalyzed Hypersilyl Protection of Alcohols and Thiols by Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide2012Artikel i tidskrift (Övrigt vetenskapligt)
    Abstract [en]

    Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide, herein named hypersilylamide, is a convenient and efficient source of the hypersilyl group in the first widely applicable acid catalyzed protocol for silyl group protection of primary, secondary, tertiary alkyl as well as aryl alcohols and thiols in high yields. The sole by-product is N,N-dimethylformamide (DMF) and a range of solvents can be used, including DMF. A high selectivity in the protection of diols can be achieved, also for diols with very small differences in the steric demands at the two hydroxyl groups. Moreover, in the protection of equivalent alcohol and thiol sites the protection of the alcohol is faster, allowing for selective protection in high yields. Quantum chemical calculations at the M062X hybrid meta density functional theory level give insights on the mechanism for the catalytic process. Finally, the hypersilyl group is easily removed from all protected alcohols and thiols examined herein by irradiation at 254 nm.

  • 21.
    Amirkhanov, N V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Chattopadhyaya, J
    The RNase H Affinity and Cleavage of the target RNA in the Antisense-RNA Hybrid Duplexes Containing various 3’-Tethered Substituents in the Antisense Strand.2002Ingår i: J. Chem. Soc. Perkin 2, Vol. 2, s. 271-281Artikel i tidskrift (Refereegranskat)
  • 22.
    Amirkhanov, N V
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Pradeepkumar, P I
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Chattopadhyaya, J
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Teknisk-naturvetenskapliga fakulteten, Biologiska sektionen, Institutionen för bioorganisk kemi.
    Kinetic Analysis of the RNA Cleavage of the oxetane modified Antisense-RNA Hybrid Duplex by RNase H.2002Ingår i: J. Chem. Soc. Perkin 2, Vol. 5, s. 976-984Artikel i tidskrift (Refereegranskat)
  • 23.
    Andersson, Claes-Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Fysikalisk-organisk kemi.
      Appendix: Experimental details for tricarbonyl chromium complexes2011Övrigt (Övrigt vetenskapligt)
  • 24.
    Andersson, Claes-Henrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Fysikalisk-organisk kemi.
    Chemistry of Carbon Nanostructures: Functionalization of Carbon Nanotubes and Synthesis of Organometallic Fullerene Derivatives2011Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis is based on two main parts. The first part concerns purification and functionalization of carbon nanotubes (papers I-III), and the second part is related to the synthesis of organometallic fullerene derivatives (papers IV-VII):

    Two oxidative methods involving aqueous nitric acid were compared with respect to their capability to introduce carboxylic groups into single walled carbon nanotubes, and several literature methods for esterification and amidation of these groups have been evaluated with focus on efficiency and reproducibility in forming covalently functionalized products soluble in organic media. Amidation proceeding via a SWNT-(COCl)n intermediate yielded the expected covalent product, whereas carboxylate salt formation dominated with other attempted methods. Esterification was achieved via the acyl chloride method and via alkylation of SWNT-(COO)n, the latter being the more efficient method.

    A new, reagent-free method for purification of single- and multi walled carbon nanotubes has been developed. Microwave treatment dissociates non-nanotube carbon and disperses it into an organic solvent, resulting in very pure carbon nanotubes within a few minutes of heating, without the involvement of acidic/oxidative reagents. According to thermogravimetric analysis, Raman and IR spectroscopy, as well as SEM, the process yields nanotubes with a low degree of defects.

    A non-covalent approach has been employed to prepare nanotubes functionalized with glycosides. Derivatives of galactose and lactose were covalently linked to a pyrene moiety and the thus formed pyrene-glycosides were non-covalently attached to single- and multi walled carbon nanotubes by π-π interactions. Fluorescence titrations have been used to quantify the formed supramolecular assemblies, which for SWNTs exhibits increased water solubility.

    A fulleropyrrolidine-(tricarbonyl)chromium complex was synthesized and fully characterized. IR spectroelectrochemistry was used to probe the redox state of the fullerene and provided evidence for electronic communication between the two electroacive moieties. A C60-ferrocene-C60 triad system was synthesized and characterized. Cyclic voltammetry and fluorescence studies suggested electronic communication between ferrocene and the two fullerenes. Finally, the synthesis and initial characterization of short fullerene-ferrocene oligomers are presented.

    Delarbeten
    1. Reproducibility and efficiency of carbon nanotube end-group generation and functionalization
    Öppna denna publikation i ny flik eller fönster >>Reproducibility and efficiency of carbon nanotube end-group generation and functionalization
    2009 (Engelska)Ingår i: European Journal of Organic Chemistry, ISSN 1434-193X, E-ISSN 1099-0690, Vol. 26, s. 4421-4428Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    In a systematic fashion, several methods for esterification and  amidation of single-walled carbon nanotubes have been evaluated with   focus on efficiency and reproducibility in forming covalently   functionalized products soluble in organic media. The outcome of   transformations was determined using IR, Raman and NMR spectroscopy and   by thermogravimetric analysis (TGA). Amidation proceeding via a   SWNT-(COCl)(n) intermediate yielded the expected covalent product,  whereas carboxylate salt formation dominated with other attempted   methods. Esterification was achieved via the acyl chloride method and   via alkylation of SWNT-(COO-)(n), the latter being the more efficient   method. A non-covalent solubilizing interaction was obtained for RNH2   but not for ROH (R = octadecyl), proving that the most important   non-covalent interaction between oxidatively cleaned SWNTs and   octadecylamine is a salt formation. The outcome of the secondary   functionalization of carboxyl units is highly reproducible for   experiments carried out on the same batch of SWNT-(COOH)(n). Normalization of the outcome of the secondary functionalization to the   composition of the different batches of starting materials reveals an overall high reproducibility of the secondary function alizations. The   differences in outcome related to different commercial SWNT batches   from the same synthetic procedure is negligible compared to that   resulting from differences in overall carboxyl content after the   primary HNO3 oxidative cleaning step. Hence, the composition of   purified SWNT starting materials always needs to be assessed, in particular before drawing any conclusions concerning differences in   outcome from reaction systems involving different sources of SWNT  material.

    Nyckelord
    Nanotubes, Nanotechnology, Functionalization, Esterification, Amidation
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-112369 (URN)10.1002/ejoc.200900534 (DOI)000270014700006 ()
    Tillgänglig från: 2010-01-13 Skapad: 2010-01-13 Senast uppdaterad: 2017-12-12Bibliografiskt granskad
    2. The reagent-free, microwave-assisted purification of carbon nanotubes
    Öppna denna publikation i ny flik eller fönster >>The reagent-free, microwave-assisted purification of carbon nanotubes
    Visa övriga...
    2010 (Engelska)Ingår i: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 34, nr 10, s. 2275-2280Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    We have developed a microwave-assisted, reagent-free method for the efficient primary purification of MW and SW carbon nanotubes that is extremely fast compared to previously reported processes. The treatment dissociates and disperses non-nanotube carbon in an organic solvent to yield very pure carbon nanotubes within a few minutes of heating and a simple filtration, without the involvement of acidic/oxidative reagents. According to thermogravimetric analysis, Raman and IR spectroscopy, as well as scanning and transmission electron microscopy, the process yields pure nanotubes with a low degree of defects.

    Nationell ämneskategori
    Kemi Oorganisk kemi Teknik och teknologier
    Forskningsämne
    Kemi med inriktning mot oorganisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-134674 (URN)10.1039/c0nj00087f (DOI)000282219600029 ()
    Tillgänglig från: 2010-12-01 Skapad: 2010-11-30 Senast uppdaterad: 2017-12-12Bibliografiskt granskad
    3. Reversible Non-Covalent Derivatisation of Carbon Nanotubes with Glycosides
    Öppna denna publikation i ny flik eller fönster >>Reversible Non-Covalent Derivatisation of Carbon Nanotubes with Glycosides
    2009 (Engelska)Ingår i: Soft Matter, ISSN 1744-683X, Vol. 5, nr 14, s. 2713-2716Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    SWNTs and MWNTs have been non-covalently functionalized with glycosides   in a reversible manner, and fluorescence titrations have been used to   quantify the formed supramolecular assemblies which for SWNTs exhibits   increased water solubility.

    Nyckelord
    carbon nanotube
    Nationell ämneskategori
    Kemi
    Identifikatorer
    urn:nbn:se:uu:diva-112366 (URN)10.1039/ B907791J (DOI)000268783500006 ()
    Tillgänglig från: 2010-01-13 Skapad: 2010-01-13 Senast uppdaterad: 2011-11-04Bibliografiskt granskad
    4. Synthesis and IR Spectroelectrochemical Studies of a [60]Fulleropyrrolidine-(tricarbonyl)chromium Complex: Probing C-60 Redox States by IR Spectroscopy
    Öppna denna publikation i ny flik eller fönster >>Synthesis and IR Spectroelectrochemical Studies of a [60]Fulleropyrrolidine-(tricarbonyl)chromium Complex: Probing C-60 Redox States by IR Spectroscopy
    2011 (Engelska)Ingår i: European Journal of Inorganic Chemistry, ISSN 1434-1948, E-ISSN 1099-1948, nr 11, s. 1744-1749Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    The synthesis of a new fulleropyrrolidine-(tricarbonyl)chromium complex: 1-methyl-2-(4-methoxyphenyl)-3,4-[60]fulleropyrrolidine-(tricarbonyl)chromium is described together with its characterization by IR, NMR and cyclic voltammetry. IR spectro-electrochemistry has been used to probe the redox level of the fullerene derivative via the relative position of the vibrational bands of the CO ligands, which are sensitive to the electronic state of the complex. Other strategies to incorporate a tricarbonylchromium moiety to fullerene C60 are also briefly discussed and evaluated.

    Ort, förlag, år, upplaga, sidor
    John Wiley & Sons, 2011
    Nyckelord
    Fullerenes, Chromium, IR spectroscopy, Cyclic voltammetry, Redox chemistry, Electrochemistry
    Nationell ämneskategori
    Kemi
    Forskningsämne
    Kemi med inriktning mot organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-148456 (URN)10.1002/ejic.201100011 (DOI)000289354900008 ()
    Tillgänglig från: 2011-03-07 Skapad: 2011-03-07 Senast uppdaterad: 2017-12-11
    5. Synthesis and characterization of a ferrocene-linked bis-fullerene[60] dumbbell
    Öppna denna publikation i ny flik eller fönster >>Synthesis and characterization of a ferrocene-linked bis-fullerene[60] dumbbell
    2012 (Engelska)Ingår i: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 41, nr 8, s. 2374-2381Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    A new [60]fullerene dumbbell consisting of two fulleropyrrolidines connected to a central ferrocene unit by amide linkages has been prepared and fully characterized by elemental analysis, 1H NMR, UV/Vis, fluorescence and mass spectrometry. The electrochemical properties as determined by cyclic voltammetry show ground state electronic communication between the ferrocene and the fullerene units. In addition, the preparaton of a ferrocene building block for an alternative linking approach is presented.

    Nyckelord
    Fullerenes, Ferrocene, Dumbbell, Cyclic voltammetry
    Nationell ämneskategori
    Organisk kemi Oorganisk kemi
    Forskningsämne
    Kemi med inriktning mot organisk kemi; Kemi med inriktning mot oorganisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-158905 (URN)10.1039/C2DT12097F (DOI)000300186100022 ()
    Tillgänglig från: 2011-09-19 Skapad: 2011-09-19 Senast uppdaterad: 2017-12-08Bibliografiskt granskad
    6. Short ferrocene-[60]fulleropyrrolidine oligomers. A preliminary account on synthetic studies
    Öppna denna publikation i ny flik eller fönster >>Short ferrocene-[60]fulleropyrrolidine oligomers. A preliminary account on synthetic studies
    (Engelska)Manuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A synthetic strategy towards short fullerene based organometallic oligomers is reported. The synthetic approach is based on the secondary functionalization of N-unsubstituted fulleropyrrolidines with ferrocene dicarboxylic acid chloride. Preliminary characterization by mass spectrometry, UV/Vis and NMR suggest a trimer or tetramer structure.

    Nyckelord
    Fullerenes / Oligomers / Ferrocene
    Nationell ämneskategori
    Organisk kemi
    Forskningsämne
    Organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-159308 (URN)
    Anmärkning
    preliminärt manuskriptTillgänglig från: 2011-09-27 Skapad: 2011-09-27 Senast uppdaterad: 2011-11-04
    7.   Appendix: Experimental details for tricarbonyl chromium complexes
    Öppna denna publikation i ny flik eller fönster >>  Appendix: Experimental details for tricarbonyl chromium complexes
    2011 (Engelska)Övrigt (Övrigt vetenskapligt)
    Ort, förlag, år, sidor
    Uppsala: Acta Universitatis Upsaliensis, 2011
    Nationell ämneskategori
    Organisk kemi
    Forskningsämne
    Kemi med inriktning mot organisk kemi
    Identifikatorer
    urn:nbn:se:uu:diva-159309 (URN)
    Tillgänglig från: 2011-09-27 Skapad: 2011-09-27 Senast uppdaterad: 2011-11-04
  • 25.
    Andersson, Claes-Henrik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Fysikalisk-organisk kemi.
    Grennberg, Helena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Fysikalisk-organisk kemi.
    Short ferrocene-[60]fulleropyrrolidine oligomers. A preliminary account on synthetic studiesManuskript (preprint) (Övrigt vetenskapligt)
    Abstract [en]

    A synthetic strategy towards short fullerene based organometallic oligomers is reported. The synthetic approach is based on the secondary functionalization of N-unsubstituted fulleropyrrolidines with ferrocene dicarboxylic acid chloride. Preliminary characterization by mass spectrometry, UV/Vis and NMR suggest a trimer or tetramer structure.

  • 26.
    Andersson, Claes-Henrik
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Nyholm, Leif
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - Ångström, Oorganisk kemi.
    Grennberg, Helena
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Fysikalisk-organisk kemi.
    Synthesis and characterization of a ferrocene-linked bis-fullerene[60] dumbbell2012Ingår i: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 41, nr 8, s. 2374-2381Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new [60]fullerene dumbbell consisting of two fulleropyrrolidines connected to a central ferrocene unit by amide linkages has been prepared and fully characterized by elemental analysis, 1H NMR, UV/Vis, fluorescence and mass spectrometry. The electrochemical properties as determined by cyclic voltammetry show ground state electronic communication between the ferrocene and the fullerene units. In addition, the preparaton of a ferrocene building block for an alternative linking approach is presented.

  • 27.
    Andersson, Hanna
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Organisk kemi.
    Carlsson, Anna-Carin C.
    University of Gothenburg, Gothenburg, Sweden.
    Nekoueishahraki, Bijan
    University of Gothenburg, Gothenburg, Sweden.
    Brath, Ulrika
    University of Gothenburg, Gothenburg, Sweden.
    Erdélyi, Máté
    University of Gothenburg, Gothenburg, Sweden.
    Chapter Two - Solvent Effects on Nitrogen Chemical Shifts2015Ingår i: Annual Reports on NMR Spectroscopy, Academic Press , 2015, Vol. 86, s. 73-210Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Due to significant developments in cryogenic probe technology and the easy access to inverse detection pulse programmes (HSQC, HMBC), the sensitivity of nitrogen NMR has lately vastly improved. As a consequence, nitrogen NMR has turned into a useful and commonly available tool for solution studies of molecular structure and properties for small organic compounds likewise biopolymers. The high sensitivity of the nitrogen lone pair to changes in the molecular environment, alterations in intra- and intermolecular interactions, and in molecular conformation along with its wide, up to 1200ppm chemical shift dispersion make nitrogen NMR to an exceptionally sensitive reporter tool. The nitrogen chemical shift has been applied in various fields of chemistry, including for instance the studies of transition metal complexes, chemical reactions such as N-alkylation and N-oxidation, tautomerization, protonation–deprotonation equilibria, hydrogen and halogen bonding, and elucidation of molecular conformation and configuration. The 15N NMR data observed in the investigation of these molecular properties and processes is influenced by the medium it is acquired in. This influence may be due to direct coordination of solvent molecules to transition metal complexes, alteration of tautomerization equilibria, and solvent polarity induced electron density changes of conjugated systems, for example. Thus, the solvent may significantly alter the observed nitrogen NMR shifts. This review aims to provide an overview of solvent effects of practical importance, and discusses selected experimental reports from various subfields of chemistry.

  • 28. Andersson, Hanna
    et al.
    Danelius, Emma
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Jarvoll, Patrik
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Niebling, Stephan
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Hughes, Ashley J
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Westenhoff, Sebastian
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Brath, Ulrika
    University of Gothenburg, Kemivägen 10, SE-412 96 Gothenburg, Sweden.
    Erdélyi, Máté
    The Swedish NMR Centre, Medicinaregatan 5c, SE-413 96 Gothenburg, Sweden.
    Assessing the Ability of Spectroscopic Methods to Determine the Difference in the Folding Propensities of Highly Similar β-Hairpins2017Ingår i: ACS omega, ISSN 2470-1343, Vol. 2, nr 2, s. 508-516Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We have evaluated the ability of nuclear magnetic resonance (NMR) and circular dichroism (CD) spectroscopies to describe the difference in the folding propensities of two structurally highly similar cyclic β-hairpins, comparing the outcome to that of molecular dynamics simulations. NAMFIS-type NMR ensemble analysis and CD spectroscopy were observed to accurately describe the consequence of altering a single interaction site, whereas a single-site 13C NMR chemical shift melting curve-based technique was not.

  • 29.
    Andersson, Hanna
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för kemi - BMC, Organisk kemi. University of Gothenburg, SE-412 96 Gothenburg, Sweden.
    Gräfenstein, Jürgen
    National Sun Yat-Sen University, Kaohsiung, Taiwan.
    Isobe, Minoru
    National Sun Yat-Sen University, Kaohsiung, Taiwan.
    Erdélyi, Máté
    University of Gothenburg, SE-412 96 Gothenburg, Sweden; The Swedish NMR Centre, SE-413 96 Gothenburg, Sweden.
    Sydnes, Magne O
    University of Stavanger, NO-4036 Stavanger, Norway.
    Photochemically Induced Aryl Azide Rearrangement: Solution NMR Spectroscopic Identification of the Rearrangement Product2017Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 82, nr 3, s. 1812-1816Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Photolysis of ethyl 3-azido-4,6-difluorobenzoate at room temperature in the presence of oxygen results in the regioselective formation of ethyl 5,7-difluoro-4-azaspiro[2.4]hepta-1,4,6-triene-1-carboxylate, presumably via the corresponding ketenimine intermediate which undergoes a photochemical four-electron electrocyclization followed by a rearrangement. The photorearrangement product was identified by multinuclear solution NMR spectroscopic techniques supported by DFT calculations.

  • 30.
    Andersson, M.
    et al.
    YKI Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden.
    Hillerström, A.
    YKI Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden.
    Svensk, A.
    YKI Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden.
    Younesi, S. R.
    YKI Institute for Surface Chemistry, Box 5607, SE-114 86 Stockholm, Sweden.
    Sjöström, E.
    Blute, I.
    Kjellin, M.
    Kizilng, J.
    Kronberg, B.
    Oldgren, J.
    Hansson, A.
    Sjöstrand, S.
    A New Class of Labile Surfactants that Break Down to Non-surface Active Products upon Heating or after a Pre-set Time, without the Need for a pH Change2007Ingår i: Tenside Surfactants Detergents, ISSN 0932-3414, E-ISSN 2195-8564, Vol. 44, nr 6, s. 366-372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new class of labile surfactants that break down at a controllable rate without the need for a change in pH will be presented. The invention has been patented by YKI Institute for Surface Chemistry, and is based on use of β-keto acids or their salts as surface-active compounds. These surfactants spontaneously break down through decarboxylation, to form an oil-like ketone and CO 2/HCO 3 -/CO 32 - depending on pH. The rate of breakdown can be controlled within a wide range by temperature or by certain additives, but, unlike most cleavable surfactants, a change in pH is not needed. Furthermore the surfactants can be conveniently activated from a stabile precursor just before use, and one (of many possible) precursors of this kind is already available on the industrial scale in the form of a wellknown chemical that is FDA-approved in other, non-surfactant, applications. The compound in question, alkyl ketene dimer (AKD), is produced in large scale by a number of large chemical producers today, and used for hydrophobization of paper. The present article gives an overview of the surfactant chemistry, with focus on recent studies of the kinetics of activation of the surfactant precursor and breakdown kinetics of the labile surfactant at different conditions. Furthermore, possible industrial applications of the surfactant will be discussed, with one example taken from a recent feasibility study performed within the car washing area. © Carl Hanser Publisher.

  • 31.
    Andersson, P.G.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen.
    Development of New Methodology for th Preparation of Optically Active Alcohols2004Ingår i: Pure Appl. Chem., nr 76, s. 547-Artikel i tidskrift (Refereegranskat)
  • 32.
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Development of a new methodology for the preparation of optically active alcohols*2004Ingår i: Pure Appl. Chem., Vol. 76, nr 3, s. 547-555Artikel i tidskrift (Refereegranskat)
  • 33.
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    On the Stereochemical Outcome of the McMurry Coupling of Acetophenone. A Reinvestigation1994Ingår i: Tetrahedron Letters, Vol. 35, nr 16, s. 2609-2610Artikel i tidskrift (Refereegranskat)
  • 34.
    Andersson, Pher
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Regio- and Stereoselective Deuteration of Allylic Chlorides Controlled by Neighboring Alcohol or Ether Groups1996Ingår i: J. Org. Chem., nr 61, s. 4154-4156Artikel i tidskrift (Refereegranskat)
  • 35.
    Andersson, Pher
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Aranyos, Attila
    Palladium-Mediated Stereo- and Regioselective Tandem-Cyclization-Carbonylations of 1,3-dienes1994Ingår i: Tetrahedron Letters, Vol. 35, nr 25, s. 4441-4444Artikel i tidskrift (Refereegranskat)
  • 36.
    Andersson, Pher
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Bäckvall, Jan-E.
    Palladium-Catalyzed Tandem Cyclization of 4,6- and 5,7-Diene Amides. A New Route towards the Pyrrolizidine and Indolizidine Alkaloids1992Ingår i: J. Am. Chem. Soc., Vol. 114, nr 22, s. 8696-8698Artikel i tidskrift (Refereegranskat)
  • 37.
    Andersson, Pher
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen. Institutionen för biokemi och organisk kemi, Organisk kemi I.
    Bäckvall, Jan-E.
    Synthesis of Furanoid Terpenes via an Efficient Palladium-Catalyzed Cyclization of 4,6-Dienols1991Ingår i: J. Org. Chem., Vol. 56, nr 18, s. 5349-5353Artikel i tidskrift (Refereegranskat)
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    Synthesis of Heterocyclic Natural Products via Regio- and Stereocontrolled Palladium-Catalyzed Reactions1996Ingår i: Advances in Heterocyclic Natural Product Synthesis, JAI Press Inc, Greenwich , 1996, s. 179-215Kapitel i bok, del av antologi (Refereegranskat)
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    Regio- and Stereoselective Deuteration of Allylic Chlorides Controlled by Neighboring Alcohol or Ether Groups1996Ingår i: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 61, nr 12, s. 4154-4156Artikel i tidskrift (Refereegranskat)
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    Preparation and Use of Aziridino Alcohols as Promoters for the Enantioselective Addition of Dialkylzinc Reagents to N-(Diphenylphosphinoyl) Imines1997Ingår i: J. Org. Chem., nr 62, s. 7364-7375Artikel i tidskrift (Refereegranskat)
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    Simple Aziridino Alcohols as Chiral Ligands. Enantioselective Additions of Diethylzinc to N-Diphenylphosphinoylimines1996Ingår i: Synlett, nr 8, s. 727-728Artikel i tidskrift (Refereegranskat)
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    Studies of Allylic Substitution Catalysed by a Palladium Complex of a C2-Symmetric Bis(aziridine): Preparation and NMR Spectroscopic Investigation of a Chiral n-Allyl Species1995Ingår i: Chem. Eur. J., nr 1, s. 12-16Artikel i tidskrift (Refereegranskat)
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    Mechanism of the Palladium-Catalyzed Elimination of Acetic Acid from Allylic Acetates1995Ingår i: Organometallics, Vol. 14, nr 1, s. 1-Artikel i tidskrift (Refereegranskat)
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    Asymmetric Total Synthesis of (+)-Tolterodine, a New Muscarinic Receptor Antagonist, via Copper-Assisted Asymmetric Conjugate Addition of Aryl Grignard Reagents to 3-Phenyl-prop-2-enoyl-oxazolidinones1998Ingår i: J. Org. Chem., nr 63, s. 8067-8070Artikel i tidskrift (Refereegranskat)
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    A Dramatic Ligand Effect on the Relative Reactive Reactivites of Substituted Alkenes with Osmium Tetroxide1993Ingår i: J. Am. Chem. Soc., nr 115, s. 7047-7048Artikel i tidskrift (Refereegranskat)
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    Cooperative binding of human Carbonic Anhydrase II by functionalized folded polypeptide receptors2005Ingår i: Chem. Biol., nr 12, s. 1245-1252Artikel i tidskrift (Refereegranskat)
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    Synthesis of [18F]labelled roflumilast using difluoro[18F]bromo methane as alkylating agent2001Ingår i: Synthesis and Applications of Isotopically LabelledArtikel i tidskrift (Refereegranskat)
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    Antoni G., Ögren M., Långström B.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Kemiska institutionen.
    Enzymes as catalysts in labelling synthesis using short-lived radionuclides2001Ingår i: Synthesis and Applications of Isotopically LabelledArtikel i tidskrift (Refereegranskat)
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