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  • 1.
    Abbas, Alaa
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Palladium-Catalysed Carbonylative Synthesis of Acylamidines2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
  • 2.
    Alvi, Muhammad Rouf
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Anas, Saithalavi
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Emanuelsson, Rikard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - 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 University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Scope and Limitations of an Acid Catalyzed Protocol for Hypersilyl Protection of Alcohols Manuscript (preprint) (Other academic)
    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.

  • 3.
    Alvi, Muhammad Rouf
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Burkhard O., Jahn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Computational Investigation of Brook-Type Silabenzenes and Their Possible Formation through [1,3]-Si -> O Silyl Shifts2013In: Organometallics, ISSN 0276-7333, E-ISSN 1520-6041, Vol. 32, no 1, p. 16-28Article in journal (Refereed)
    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.

  • 4.
    Alvi, Muhammad Rouf
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Jahn, Burkhard O.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Tibbelin, Julius
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Baumgartner, Judith
    Institut für Anorganische Chemie, Technische Universität Graz, Stremayrgasse 9, A-8010 Graz, Austria.
    Gómez, Cesar Pay
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Highly Efficient and Convenient Acid Catalyzed Hypersilyl Protection of Alcohols and Thiols by Tris(trimethylsilyl)silyl-N,N-dimethylmethaneamide2012Article in journal (Other academic)
    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.

  • 5.
    Ayub, Rabia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Jorner, Kjell
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    The silacyclobutene ring: An indicator of triplet state Baird-aromaticityManuscript (preprint) (Other academic)
  • 6.
    Ayub, Rabia
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Papadakis, Raffaello
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Jorner, Kjell
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. uppsala university.
    Zietz, Burkhard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Physical Chemistry.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics. uppsala university.
    Cyclopropyl Group: An Excited-State Aromaticity Indicator?2017In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 23, no 55, p. 13684-13695Article in journal (Refereed)
    Abstract [en]

    The cyclopropyl (cPr) group, which is a well-known probe for detecting radical character at atoms to which it is connected, is tested as an indicator for aromaticity in the first * triplet and singlet excited states (T-1 and S-1). Baird's rule says that the -electron counts for aromaticity and antiaromaticity in the T-1 and S-1 states are opposite to Huckel's rule in the ground state (S-0). Our hypothesis is that the cPr group, as a result of Baird's rule, will remain closed when attached to an excited-state aromatic ring, enabling it to be used as an indicator to distinguish excited-state aromatic rings from excited-state antiaromatic and nonaromatic rings. Quantum chemical calculations and photoreactivity experiments support our hypothesis; calculated aromaticity indices reveal that openings of cPr substituents on [4n]annulenes ruin the excited-state aromaticity in energetically unfavorable processes. Yet, polycyclic compounds influenced by excited-state aromaticity (e.g., biphenylene), as well as 4n-electron heterocycles with two or more heteroatoms represent limitations.

  • 7.
    Belfrage, Anna Karin
    et al.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Abdurakhmanov, Eldar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Åkerblom, Eva
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Brandt, Peter
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Oshalim, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Gising, Johan
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Skogh, Anna
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Neyts, Johan
    Danielson, U. Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Sandström, Anja
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Discovery of pyrazinone based compounds that potently inhibit the drug resistant enzyme variant R155K of the hepatitis C virus NS3 protease2016In: Bioorganic & Medicinal Chemistry, ISSN 0968-0896, E-ISSN 1464-3391, Vol. 24, no 12, p. 2603-2620Article in journal (Refereed)
    Abstract [en]

    Herein, we present the design and synthesis of 2(1H)-pyrazinone based HCV NS3 protease inhibitors with variations in the C-terminus. Biochemical evaluation was performed using genotype 1a, both the wildtype and the drug resistant enzyme variant, R155K. Surprisingly, compounds without an acidic sulfonamide retained good inhibition, challenging our previous molecular docking model. Moreover, selected compounds in this series showed nanomolar potency against R155K NS3 protease; which generally confer resistance to all HCV NS3 protease inhibitors approved or in clinical trials. These results further strengthen the potential of this novel substance class, being very different to the approved drugs and clinical candidates, in the development of inhibitors less sensitive to drug resistance.

  • 8.
    Bunrit, Anon
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Dahlstrand, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Srifa, Pemikar
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Olsson, Sandra K.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Huang, Genping
    Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden.;Tianjin Univ, Sch Sci, Dept Chem, Tianjin 300072, Peoples R China..
    Biswas, Srijit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Ctr Biomed Res, Lucknow 226014, Uttar Pradesh, India..
    Himo, Fahmi
    Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Nucleophilic Substitution of the Hydroxyl Group in Stereogenic Alcohols with Chirality Transfer2016In: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, Vol. 27, no 2, p. 173-176Article in journal (Refereed)
    Abstract [en]

    A brief overview of the development of direct substitution of the hydroxyl (OH) group of alcohols in our research group is presented. By applying a BrOnsted acid, an intramolecular substitution of the OH group in stereogenic alcohols with chirality transfer was achieved. Noteworthy, the intramolecular substitution has a wide scope in respect to both the nucleophile and also the nucleofuge. A mechanistic study by both experiments and DFT calculations revealed a unique reaction pathway in which the BrOnsted acid operates in a bifunctional manner to promote an S(N)2-type reaction mechanism.

  • 9.
    Bunrit, Anon
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    Sawadjoon, Supaporn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Tsupova, Svetlana
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Sjöberg, Per J. R.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Stockholm Univ, Dept Organ Chem, S-10691 Stockholm, Sweden..
    A General Route to beta-Substituted Pyrroles by Transition-Metal Catalysis2016In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 81, no 4, p. 1450-1460Article in journal (Refereed)
    Abstract [en]

    An atom-efficient route to pyrroles substituted in the beta-position has been achieved in four high yielding steps by a combination of Pd, Ru, and Fe catalysis with only water and ethene as side-products. The reaction is general and gives pyrroles substituted in the beta-position with linear and branched alkyl, benzyl, or aryl groups in overall good yields. The synthetic route includes a Pd-catalyzed monoallylation step of amines with substituted allylic alcohols that proceeds to yield the monoallylated products in moderate to excellent yields. In a second step, unsymmetrical diallylated aromatic amines are generated from the reaction of a second allylic alcohol with high selectivity in moderate to good yields by control of the reaction temperature. Ru-catalyzed ring-closing metathesis performed on the diallylated aromatic amines yields the pyrrolines substituted in the beta-position in excellent yields. By addition of ferric chloride to the reaction mixture, a selective aromatization to yield the corresponding pyrroles substituted in the beta-position was achieved. A reaction mechanism involving a palladium hydride, generated from insertion of palladium to O-H of an allyl alcohol, that is responsible for the C-O bond cleavage to generate the pi-allyl intermediate is proposed.

  • 10.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Watile, Rahul
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Biswas, Srijit
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Orthaber, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Sjöberg, Per J
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Samec, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    One-Pot Synthesis of Keto Thioethers by Palladium/Gold-Catalyzed Click and Pinacol Reactions2014In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 16, no 21, p. 5556-5559Article in journal (Refereed)
    Abstract [en]

    An atom-efficient synthesis of keto thioethers was devised via tandem gold/palladium catalysis. The reaction proceeds through a regioselective thiol attack at the β-position of the alcohol, followed by an alkyl, aryl, or benzyl 1,2-shift. Both acyclic and cyclic systems were studied, in the latter case leading to the ring expansion of cyclic substrates.

  • 11.
    Díaz-Álvarez, Alba E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Mesas Sanchez, Laura
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Dinér, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Non-Enzymatic Dynamic Kinetic Resolution of Secondary Aryl Alcohols: Planar Chiral Ferrocene and Ruthenium Catalysts in Cooperation2013In: Angewandte Chemie International Edition, ISSN 1433-7851, E-ISSN 1521-3773, Vol. 52, no 2, p. 502-504Article in journal (Refereed)
  • 12.
    Díaz-Álvarez, Alba E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Mesas-Sánchez, Laura
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Dinér, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. KTH-Royal Institute of Technology.
    Access to optically pure β-hydroxy esters via non-enzymatic kinetic resolution by a planar-chiral DMAP catalyst2014In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 19, no 9, p. 14273-14291Article in journal (Refereed)
    Abstract [en]

    The development of new approaches to obtain optically pure β-hydroxy esters is an important area in synthetic organic chemistry since they are precursors of other high value compounds. Herein, the kinetic resolution of racemic β-hydroxy esters using a planar-chiral DMAP derivative catalyst is presented. Following this procedure, a range of aromatic β-hydroxy esters was obtained in excellent selectivities (up to = 107) and high enantiomeric excess (up to 99% ee). Furthermore, the utility of the present method was demonstrated in the synthesis of (S)-3-hydroxy-N-methyl-3-phenylpropanamide, a key intermediate for bioactive molecules such as fluoxetine, tomoxetine or nisoxetine, in its enantiomerically pure form.

  • 13.
    Díaz-Álvarez, Alba E.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Mesas-Sánchez, Laura
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Dinér, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Nichtenzymatische dynamische kinetische Racematspaltung sekundärer Arylalkohole: planar-chirale Ferrocen- und Rutheniumkatalysatoren im Zusammenspiel2013In: Angewandte Chemie, ISSN 1521-3757, Vol. 125, no 2, p. 522-524Article in journal (Refereed)
  • 14.
    Fällman, Tove
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Capturing of the carbonyl oxide intermediate in ozonolysis using aldehydes and ketones2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 15.
    Guliashvili, Tamaz
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Martel, Arnaud
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Alvi, Muhammad Rouf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Fischer, Andreas
    Department of Chemistry (Inorganic Chemistry), Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Akselsson, Patrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Remarkably Stable Silicon Analogues of Amide Enolates: Synthesis, Structural Characterization, and Reactivity StudiesManuscript (preprint) (Other academic)
    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.

  • 16.
    Hao, Huang
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strømme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Potential Tuning in Quinone-pyrrole Dyad Based Conducting Redox PolymersManuscript (preprint) (Other academic)
    Abstract [en]

    In this study, conducting redox polymers (CRPs), which consist of a polypyrrole conducting polymer (CP) backbone with attached quinone pendant groups (PGs), have been explored as electrode materials for organic batteries. A modular organic synthetic approach allows the assembly of the pyrrole and quinone units into quinone-pyrrole dyads. These dyad monomers were copolymerized electrochemically with pyrrole to yield the CRPs. DFT calculations were used to predict the formal potentials of the dyads, showing excellent agreement with the experimental values of the corresponding CRPs. Moreover, it is shown that the matching between the redox potential of PGs and the conductive region of CPs is an absolute requirement for good performance of these materials. With access to CRP materials with varying quinone formal potentials a prototype of a full organic based battery was constructed by choosing two CRPs with different quinone potentials. A galvanostatic charge-discharge study showed that the cell potentials coincided well with the difference in redox potential between the quinone substituents used in the anode and cathode CRP.

  • 17.
    Jorner, Kjell
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Jahn, Burkhard O.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. SciClus GmbH & Co. KG, Moritz-von-Rohr-Str. 1a, 07745 Jena, Germany .
    Bultinck, Patrick
    SciClus GmbH & Co. KG, Moritz-von-Rohr-Str. 1a, 07745 Jena, Germany.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Triplet state homoaromaticity: concept, computational validation and experimental relevance2018In: Chemical Science, ISSN 2041-6520, E-ISSN 2041-6539, Vol. 9, no 12, p. 3165-3176Article in journal (Refereed)
    Abstract [en]

    Cyclic conjugation that occurs through-space and leads to aromatic properties is called homoaromaticity. Here we formulate the homoaromaticity concept for the triplet excited state (T1) based on Baird's 4n rule and validate it through extensive quantum-chemical calculations on a range of different species (neutral, cationic and anionic). By comparison to well-known ground state homoaromatic molecules we reveal that five of the investigated compounds show strong T1 homoaromaticity, four show weak homoaromaticity and two are non-aromatic. Two of the compounds have previously been identified as excited state intermediates in photochemical reactions and our calculations indicate that they are also homoaromatic in the first singlet excited state. Homoaromaticity should therefore have broad implications in photochemistry. We further demonstrate this by computational design of a photomechanical “lever” that is powered by relief of homoantiaromatic destabilization in the first singlet excited state.

  • 18.
    Karlsson, Christoffer
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Blom, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Johansson, Miranda
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Jansson, Anna M.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Scifo, Enzo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Cell and Molecular Biology.
    Karlén, Anders
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Organic Pharmaceutical Chemistry.
    Govender, Thavendran
    Catalysis and Peptide Research Unit, University of KwaZulu Natal, South Africa.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Phototriggerable peptidomimetics for the inhibition of Mycobacterium turberculosis ribonucleotide reductase by targeting protein-protein binding2015In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, no 9, p. 2612-2621Article in journal (Refereed)
    Abstract [en]

    Incorporation of an artificial amino acid 2 with a stilbene chromophore into peptidomimetics with three to nine amino acids yields phototriggerable candidates for inhibition of the binding between the R1 and R2 subunits of the M. tuberculosis ribonucleotide reductase (RNR). Interstrand hydrogen bond probability was used as a guideline for predicting conformational preferences of the photoisomers. Binding of these inhibitors has been rationalized by docking studies with the R1 unit. Significant differences in binding of the photoisomers were observed. For the shorter peptidomimetics, stronger binding of the Z isomer might indicate hydrophobic interactions between the stilbene chromophore and the binding site.

  • 19.
    Kathiravan, Subban
    et al.
    Linnaeus Univ, Dept Chem & Biomed Sci, Bioorgan & Biophys Chem Lab, SE-39182 Kalmar, Sweden.;Linnaeus Univ, Ctr Biomat Chem, SE-39182 Kalmar, Sweden..
    Nicholls, Ian A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Linnaeus Univ, Dept Chem & Biomed Sci, Bioorgan & Biophys Chem Lab, SE-39182 Kalmar, Sweden.;Linnaeus Univ, Ctr Biomat Chem, SE-39182 Kalmar, Sweden..
    Cobalt Catalyzed, Regioselective C(sp(2))-H Activation of Amides with 1,3-Diynes2017In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 19, no 18, p. 4758-4761Article in journal (Refereed)
    Abstract [en]

    The development of a first row transition metal (cobalt)-based catalyst for the as yet unexplored CH activation-driven reaction of 1,3-diynes, themselves a functional class of interest in a range of application areas, to form isoquinolinonesan important structural motif in a number of biologically active substancesis presented. This versatile and inexpensive catalyst employs a covalently attached bidendate-directing group, 8-aminoquinoline. The template directs the CH activation and facilitates the synthesis of a wide range of alkynylated heterocycles under mild conditions and with excellent regioselectivity. This strategy provides a novel and efficient route to diverse heterocyclic frameworks as demonstrated by its late stage application in bisheterocycle syntheses.

  • 20. Larsson, Johanna
    et al.
    Demory, Emilien
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Devaraj, Karthik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Sollert, Carina
    Pilarski, Lukasz
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Selective Activation of Arylboronate or Aryne Reactivity as a Versatile Postfunctionalization Strateg2016In: Synlett: Accounts and Rapid Communications in Synthetic Organic Chemistry, ISSN 0936-5214, E-ISSN 1437-2096, Vol. 27, no 7, p. 969-976Article in journal (Refereed)
  • 21.
    Lundstedt, Anna
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Development of Mild Methods for Selective Covalent Functionalization of Graphene2017Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis discusses methods for the comparatively mild covalent functionalization of graphene. Several graphene models were investigated: polycyclic aromatic hydrocarbons (PAHs), chemical vapor deposition (CVD)-graphene on SiO2/Si substrate, graphite foil, graphite flakes, kish graphite and highly oriented pyrolytic graphite. The PAHs were viewed as graphene edge analogs with the following molecules representing different edge motifs: pyrene, perylene, benzo[a]pyrene, benzo[e]pyrene, triphenylene, acenapthylene, and anthracene.

    Ozone was used in combination with different solvents to functionalize PAHs, graphite, and CVD-graphene on SiO2/Si. Ozonation in water or methanol resulted in trapping of the carbonyl oxide intermediate that was formed in the reaction, producing a variety of functional groups. Ozonation in hydrogen peroxide solution with sonication promoted radical formation, possibly resulting in edge-oxidation of graphite. The regioselectivity for addition reactions (ozonolysis) and electrophilic aromatic substitution reactions with graphene edges is discussed.

    To achieve functionalization of the basal plane of graphite or graphene, white light irradiation was used in combination with several transfer hydrogenation reagents. Formic acid treatment under irradiation resulted in the expected hydrogenation, whereas iso-propanol treatment resulted in iso-propanol attachment to the graphene.

    The developed methods provide opportunities for graphene functionalization without the need for metal based reagents or harsh conditions.

    List of papers
    1. Ozonolysis of triphenylene in acetone
    Open this publication in new window or tab >>Ozonolysis of triphenylene in acetone
    (English)Manuscript (preprint) (Other academic)
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-332003 (URN)
    Available from: 2017-10-20 Created: 2017-10-20 Last updated: 2017-10-24
    2. Ozonolysis of polycyclic aromatic hydrocarbons in participating solvents
    Open this publication in new window or tab >>Ozonolysis of polycyclic aromatic hydrocarbons in participating solvents
    2017 (English)In: RSC Advances, ISSN 2046-2069, E-ISSN 2046-2069, Vol. 7, no 10, p. 6152-6159Article in journal (Refereed) Published
    Abstract [en]

    Seven polycyclic aromatic hydrocarbon (PAH) compounds that can be considered small models for graphene edges have been treated with ozone in solution. The presence of participating solvents such as water or methanol had a pronounced influence on conversion and identity of the functional groups formed, whereas the regioselectivity of the ozonation remained unaffected. Six previously unreported compounds have been isolated from the ozonolysis of pyrene 1, perylene 2 and benzo[e] pyrene 4. Comparison of the experimental data with calculated local ionization energy surfaces (IES) shows a good correlation, and indicates that this computational tool would be useful to predict the regioselectivity of ozone also for larger PAHs, including graphene and graphene nanoribbons.

    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-316964 (URN)10.1039/c6ra26248a (DOI)000393754100073 ()
    Funder
    Swedish Research CouncilKnut and Alice Wallenberg Foundation
    Available from: 2017-03-08 Created: 2017-03-08 Last updated: 2017-11-29Bibliographically approved
    3. Edge oxidation of graphite using a combined hydrogen peroxide - ozone treatment under sonication conditions
    Open this publication in new window or tab >>Edge oxidation of graphite using a combined hydrogen peroxide - ozone treatment under sonication conditions
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    A mild method for edge oxidation of graphite using ultrasonication in the presence of ozone and hydrogen peroxide is described. The method benefits from sustainable reagents - no metals or oxidising mineral acids are involved; and easy purification of the resulting material. Initial characterisation of the material and its dispersibility by spectroscopic methods and thermogravimetric analysis is presented.

    Keywords
    Edge oxidation, Graphite, Graphene, Hydrogen peroxide, Ozone
    National Category
    Materials Chemistry Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-327165 (URN)
    Available from: 2017-08-06 Created: 2017-08-06 Last updated: 2017-10-24
    4. Metal-free photochemical silylations and transfer hydrogenations of benzenoid hydrocarbons and graphene
    Open this publication in new window or tab >>Metal-free photochemical silylations and transfer hydrogenations of benzenoid hydrocarbons and graphene
    Show others...
    2016 (English)In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723Article in journal (Refereed) Published
    Abstract [en]

    The first hydrogenation step of benzene, which is endergonic in the electronic ground state (S0), becomes exergonic in the first triplet state (T1). This is in line with Baird’s rule, which tells that benzene is antiaromatic and destabilized in its T1 state and also in its first singlet excited state (S1), opposite to S0, where it is aromatic and remarkably unreactive. Here we utilized this feature to show that benzene and several polycyclic aromatic hydrocarbons (PAHs) to various extents undergo metal-free photochemical (hydro)silylations and transfer-hydrogenations at mild conditions, with the highest yield for naphthalene (photosilylation: 21%). Quantum chemical computations reveal that T1-state benzene is excellent at H-atom abstraction, while COT, aromatic in the T1 and S1 states according to Baird’s rule, is unreactive. Remarkably, also CVD-graphene on SiO2 is efficiently transfer-photohydrogenated using formic acid/water mixtures together with white light or solar irradiation under metal-free conditions.

    National Category
    Chemical Sciences Chemical Engineering
    Identifiers
    urn:nbn:se:uu:diva-303639 (URN)10.1038/ncomms12962 (DOI)000385553900001 ()27708336 (PubMedID)
    Funder
    Wenner-Gren FoundationsSwedish Research CouncilKnut and Alice Wallenberg FoundationÅForsk (Ångpanneföreningen's Foundation for Research and Development)Magnus Bergvall Foundation
    Available from: 2016-09-21 Created: 2016-09-21 Last updated: 2018-04-23Bibliographically approved
    5. White-light photoassisted covalent functionalization of graphene using 2-propanol
    Open this publication in new window or tab >>White-light photoassisted covalent functionalization of graphene using 2-propanol
    Show others...
    2017 (English)In: Small Methods, ISSN 2366-9608, Vol. 1, no 11, article id 1700214Article in journal (Refereed) Published
    Abstract [en]

    Herein, a photochemical method for functionalization of graphene using 2-propanol is reported. The functionalization method which is catalyst-free operates at ambient temperature in neat 2-propanol under an inert atmosphere of argon. The equipment requirement is a white-light source for the irradiation. The same methodology when applied to kish graphite results in a novel material, exhibiting significantly higher wettability than the starting material according to water contact angle measurements. Furthermore, the materials generated from both graphene and kish graphite exhibit increased adhesion energy, attributed to the fixation of isopropyl alcohol fragments onto graphene and graphite, respectively. The presence of hydroxyl groups and the possibility for further reactions on the functionalized graphene material are demonstrated through a substitution reaction with thionyl chloride, where the hydroxyl groups are replaced with chlorides, as confirmed through X-ray photoelectron spectroscopy analysis.

    Place, publisher, year, edition, pages
    John Wiley & Sons, 2017
    National Category
    Materials Engineering Materials Chemistry
    Identifiers
    urn:nbn:se:uu:diva-314171 (URN)10.1002/smtd.201700214 (DOI)000417488900006 ()
    Funder
    Wenner-Gren FoundationsSwedish Research CouncilKnut and Alice Wallenberg FoundationÅForsk (Ångpanneföreningen's Foundation for Research and Development)Magnus Bergvall Foundation
    Available from: 2017-01-29 Created: 2017-01-29 Last updated: 2018-03-09Bibliographically approved
  • 22.
    Lundstedt, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ozonolysis of triphenylene in acetoneManuscript (preprint) (Other academic)
  • 23.
    Lundstedt, Anna
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Nordlund, Michael
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ahlberg, Patrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Electronics.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Edge oxidation of graphite using a combined hydrogen peroxide - ozone treatment under sonication conditionsManuscript (preprint) (Other academic)
    Abstract [en]

    A mild method for edge oxidation of graphite using ultrasonication in the presence of ozone and hydrogen peroxide is described. The method benefits from sustainable reagents - no metals or oxidising mineral acids are involved; and easy purification of the resulting material. Initial characterisation of the material and its dispersibility by spectroscopic methods and thermogravimetric analysis is presented.

  • 24.
    Löfås, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Alvi, Muhammad Rouf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grigoriev, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    The [1,3]-Si→O Silyl Shift from a Nonconducting Acylsilane to a Conducting Brook-Silene as Basis for a Molecular SwitchManuscript (preprint) (Other academic)
    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.

  • 25.
    Löfås, Henrik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Jahn, B. O.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Wärnå, John
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Emanuelsson, Rikard
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Ahuja, Rajeev
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Grigoriev, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    A computational study of potential molecular switches that exploit Baird's rule on excited-state aromaticity and antiaromaticity2014In: Faraday discussions (Online), ISSN 1359-6640, E-ISSN 1364-5498, Vol. 174, p. 105-124Article in journal (Refereed)
    Abstract [en]

    A series of tentative single-molecule conductance switches which could be triggered by light were examined by computational means using density functional theory (DFT) with non-equilibrium Green's functions (NEGF). The switches exploit the reversal in electron counting rules for aromaticity and antiaromaticity upon excitation from the electronic ground state (S0) to the lowest [small pi][small pi]* excited singlet and triplet states (S1 or T1), as described by Huckel's and Baird's rules, respectively. Four different switches and one antifuse were designed which rely on various photoreactions that either lead from the OFF to the ON states (switches 1, 2 and 4, and antifuse 5) or from the ON to the OFF state (switch 3). The highest and lowest ideal calculated switching ratios are 1175 and 5, respectively, observed for switches 1 and 4. Increased thermal stability of the 1-ON isomer is achieved by benzannulation (switch 1B-OFF/ON). The effects of constrained electrode-electrode distances on activation energies for thermal hydrogen back-transfer from 1-ON to 1-OFF and the relative energies of 1-ON and 1-OFF at constrained geometries were also studied. The switching ratio is strongly distance-dependent as revealed for 1B-ON/OFF where it equals 711 and 148 when the ON and OFF isomers are calculated in electrode gaps with distances confined to either that of the OFF isomer or to that of the ON isomer, respectively.

  • 26.
    Mesas-Sanchez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Diaz-Alvarez, Alba E.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Koukal, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Diner, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Kinetic resolution of 2-hydroxy-2-aryl-ethylphosphonates by a non-enzymatic acylation catalyst2014In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 70, no 24, p. 3807-3811Article in journal (Refereed)
    Abstract [en]

    Optically pure hydroxyphosphonates are widely used as derivatizable compounds that can be incorporated into a variety of synthetic strategies for the preparation of other high value organic products. A non-enzymatic kinetic resolution procedure to obtain chiral 2-hydroxy-2-arylethylphosphonates from the easily available racemic counterparts is described. A range of 2-hydroxy-2-arylethylphosphonates was efficiently resolved employing a planar-chiral DMAP derived catalyst with good selectivities (up to S=68). The chiral hydroxyphosphonates were isolated in good yields and high enantiomeric excess (>94% ee).

  • 27.
    Mesas-Sánchez, Laura
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Díaz-Álvarez, Alba Estrella
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Dinér, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Non-enzymatic kinetic resolution of 1,2-azidoalcohols using a planar-chiral DMAP derivative catalyst2013In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 69, no 2, p. 753-757Article in journal (Refereed)
    Abstract [en]

    Optically pure 1,2-azidoalcohols are widely used as precursors for other high value organic products. A non-enzymatic kinetic resolution procedure for the stereoselective synthesis of chiral 1,2-azidoalcohols from the readily available racemic counterparts has been developed, employing a planar-chiral DMAP derivative catalyst. Following this procedure, a range of aromatic 1,2-azidoalcohols was obtained in good selectivities (up to S=45) and high enantiomeric excess (up to 99% ee).

  • 28.
    Mohamed, Rana K.
    et al.
    Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
    Mondal, Sayantan
    Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
    Jorner, Kjell
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Delgado, Thais Faria
    Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
    Lobodin, Vladislav V.
    Natl High Magnet Field Lab, Tallahassee, FL 32310 USA.;Florida State Univ, Future Fuels Inst, Tallahassee, FL 32310 USA..
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Alabugin, Igor V.
    Florida State Univ, Dept Chem & Biochem, Tallahassee, FL 32310 USA..
    The Missing C-1-C-5 Cycloaromatization Reaction: Triplet State Antiaromaticity Relief and Self-Terminating Photorelease of Formaldehyde for Synthesis of Fulvenes from Enynes2015In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 137, no 49, p. 15441-15450Article in journal (Refereed)
    Abstract [en]

    The last missing example of the four archetypical cycloaromatizations of enediynes and enynes was discovered by combining a twisted alkene excited state with a new self-terminating path for intramolecular conversion of diradicals into closed-shell products. Photoexcitation of aromatic enynes to a twisted alkene triplet state creates a unique stereoelectronic situation, which is facilitated by the relief of excited state antiaromaticity of the benzene ring. This enables the usually unfavorable 5-endo-trig cyclization and merges it with 5-exo-dig closure. The 1,4-diradical product of the C1-C5 cyclization undergoes internal H atom transfer that is coupled with the fragmentation of an exocyclic C-C bond. This sequence provides efficient access to benzofulvenes from enynes and expands the utility of self-terminating aromatizing enyne cascades to photochemical reactions. The key feature of this self-terminating reaction is that, despite the involvement of radical species in the key cyclization step, no external radical sources or quenchers are needed to provide the products. In these cascades, both radical centers are formed transiently and converted to the closed-shell products via intramolecular H-transfer and C-C bond fragmentation. Furthermore, incorporating C-C bond cleavage into the photochemical self-terminating cyclizations of enynes opens a new way for the use of alkenes as alkyne equivalents in organic synthesis.

  • 29.
    MRIDHA, MD MONIRUZZAMAN
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    HIGHLY STEREOSELECTIVE ALDOL REACTION BY THE COMBINATION OF AMINOACID AND HYDROGEN BOND DONATING CATALYSTS IN WATER AND APPLICATION FOR CONCISE SYNTHESIS OF D-Lyxo-PHYTOSPHINGOSINE.2012Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
  • 30.
    Mridha, Moniruzzaman
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, S-85170 Sundsvall, Sweden..
    Ma, Guangning
    Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, S-85170 Sundsvall, Sweden..
    Palo-Nieto, Carlos
    Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, S-85170 Sundsvall, Sweden..
    Afewerki, Samson
    Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, S-85170 Sundsvall, Sweden.;Stockholm Univ, Arrhenius Lab, Berzelii Ctr EXSELENT, S-10691 Stockholm, Sweden..
    Cordova, Armando
    Mid Sweden Univ, Dept Nat Sci, Holmgatan 10, S-85170 Sundsvall, Sweden.;Stockholm Univ, Arrhenius Lab, Berzelii Ctr EXSELENT, S-10691 Stockholm, Sweden..
    Development of an Amino Acid/Hydroxy Oxime Dual Catalyst System for Highly Stereoselective Direct Asymmetric Aldol Reactions in the Presence of Water2017In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, Vol. 49, no 2, p. 383-390Article in journal (Refereed)
    Abstract [en]

    An eco-friendly dual catalyst system for stereoselective aldol reactions in the presence of water is described. It is based on the cooperative action of acyclic amino acids and H-bond donating hydroxy oxime catalysts. The synthetic utility of this dual catalyst system was further demonstrated by applying it as the key step in the expeditious and highly stereoselective total synthesis of D-lyxo-phytosphingosine (29% overall yield). Here the amino acid/hydroxy oxime system significantly accelerated the direct aldol reactions in the presence of water as compared to organic solvents. The stereo-and chemoselectivity were also significantly increased.

  • 31.
    Nicholls, Ian A.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC. Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Chavan, Swapnil
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Golker, Kerstin
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Karlsson, Björn C. G.
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Olsson, Gustaf D.
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Rosengren, Annika M.
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Suriyanarayanan, Subramanian
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Wiklander, Jesper G.
    Linnaeus Univ, Bioorgan & Biophys Chem Lab, Ctr Biomat Chem, Dept Chem & Biomed, S-39182 Kalmar, Sweden..
    Theoretical and Computational Strategies for the Study of the Molecular Imprinting Process and Polymer Performance2015In: Molecularly Imprinted Polymers In Biotechnology, Cham, Switzerland: Springer, 2015, p. 25-50Chapter in book (Refereed)
    Abstract [en]

    The development of in silico strategies for the study of the molecular imprinting process and the properties of molecularly imprinted materials has been driven by a growing awareness of the inherent complexity of these systems and even by an increased awareness of the potential of these materials for use in a range of application areas. Here we highlight the development of theoretical and computational strategies that are contributing to an improved understanding of the mechanisms underlying molecularly imprinted material synthesis and performance, and even their rational design.

  • 32.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Mono- and diamides of 1,1’-dicarboxyferrocene: a stepwise approach to ferrocene-linked triadsManuscript (preprint) (Other academic)
    Abstract [en]

    An improved route to the monomethyl ester of 1,1´-dicarboxyferrocene is described. The compound is a key intermediate for the assembly of ferrocene-bridged triads by stepwise amidation. This renders possible symmetric as well as non-symmetric diamides, exemplified by the preparaton of a symmetric ferrocene-linked fulleropyrrolidine dumbbell and a non-symmetric fulleropyrrolidine-ferrocene-tryptophan triad.

  • 33.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Organometallic Fullerene Derivatives: Synthesis of a Ferrocene-[60]Fulleropyrrolidine Trimer2016Conference paper (Refereed)
  • 34.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Organometallic Fullerene Derivatives: Towards Ferrocene-[60]Fulleropyrrolidine Trimer2014Conference paper (Refereed)
  • 35.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Synthesis of Organometallic Fullerene Derivatives: Ferrocene- [60]Fulleropyrrolidine Trimer2014Conference paper (Refereed)
  • 36.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Towards [60]fullerene-based molecular wires: amide-interlinked ferrocene-[60]fullerene oligomersManuscript (preprint) (Other academic)
    Abstract [en]

    Design and synthesis of amide-linked ferrocene-fulleropyrrolidine oligomers is presented, with initial characterisation that confirms products containing three or four ferrocene-bridged fullerene units. Side-products have been identified; the encountered issues concerning their formation and general solubility motivated modifications of the synthesis strategy.

  • 37.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Bhandary, Sumanta
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy.
    Sanyal, Biplab
    Uppsala University, Disciplinary Domain of Science and Technology, Physics, Department of Physics and Astronomy, Materials Theory.
    Almqvist, Nils
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Löfqvist, Torbjörn
    Luleå tekniska universitet, Institutionen för system- och rymdteknik.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Side-selective self-assembly of graphene and FLG on piezoelectric PVDF from suspension2016In: Journal of Physics D: Applied Physics, ISSN 0022-3727, E-ISSN 1361-6463, Vol. 49, no 7, article id 07LT01Article in journal (Refereed)
    Abstract [en]

    The deposition of few-layer graphene by self-assembly from suspension onto a piezoelectric polymer substrate is presented. The graphene self-assembles with negligible overlap between flakes, and with high selectivity for one of the faces of the substrate, an observation which is discussed and rationalized. A computational study on a model system further confirms the theory and supports the experimental results. The highest obtained degree of surface coverage was estimated to 77%.

  • 38.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Günther, Tyran
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Catenane dimer formation in tether-assisted trans-bis-pyrrolidination of [60]fullereneManuscript (preprint) (Other academic)
    Abstract [en]

    Trans-bis-pyrrolidination of [60]fullerene employing a new bis-aldehyde tether with appended octadecyloxy substituents proceeded to give the desired product as well as catenane dimers. For pyrrolidinations employing sarcosine, the products were separable, and characterisation by NMR spectroscopy, including diffusion-ordered spectroscopy (DOSY), provided unambiguous proof that the high-mass product was a symmetric non-covalent catenane. No catenane or other high-mass products were observed for reactions employing a tether without the octadecyloxy substituents.

  • 39.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Kazen Orrefur, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Diarylacetyene-linked [60]fullerene dumbbells via metal-catalyzed couplingsManuscript (preprint) (Other academic)
    Abstract [en]

    This preliminary manuscript describes the synthesis and characterization of new di(4-bromoaryl)acetylenes by Sonogashira cross-coupling, initial attempts to transform model aryl bromides to aryl boronic acids as well as a model study of Rh-catalysed hydroarylation of [60]fullerene with aryl boronic acids, aiming towards “all carbon”-linked [60]fullerene dumbbells.

  • 40.
    Nordlund, Michael
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Kazen Orrefur, Johannes
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Organic Chemistry.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Functionalization of fullerenes via metal catalyzed hydroarylation2016Conference paper (Refereed)
  • 41.
    Norrehed, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Erdélyi, Maté
    Light, Mark E.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Protonation-triggered Conformational Modulation of an N,N´‑Dialkylbispidine: First observation of the elusive boat-boat conformer2013In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 11, p. 6292-6299Article in journal (Refereed)
    Abstract [en]

    Modulation of the solution conformations of N,N′-bis(benzhydryl)bispidine has been achieved by protonation. Conformers have been characterized by NMR spectroscopy using nuclear Overhauser effects and residual dipolar couplings. In contrast to the preference for the chair–chair conformation for the free base and the monoprotonated species, the diprotonated bispidine is revealed to exist as a mixture of chair–boat and boat–boat conformers. While boat–boat conformers of bispidines have previously not been detected, they are here observed to constitute up to 70% of the bispidine population.

  • 42.
    Norrehed, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Polavarapu, Prasad
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Yang, Wenzhi
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Conformational restriction of flexible molecules in solution by a semirigid bis-porphyrin molecular tweezer2013In: Tetrahedron, ISSN 0040-4020, E-ISSN 1464-5416, Vol. 69, no 34, p. 7131-7138Article in journal (Refereed)
    Abstract [en]

    A semirigid bis-porphyrin molecular clip with a glycoluril backbone has been synthesized. The clip provides an adaptable molecular cavity for binding of diamines. Binding constants for diamines of 104–107 M−1 are orders of magnitude higher than those for monoamines of 103 M−1, indicating a preference to bidentate binding. NMR studies confirmed that binding of bidentate guests occurs inside the clip. Short- and medium-size acyclic molecular guests are locked into a single, extended conformation, and also guests with longer flexible chains exhibit considerably less conformational mobility than when free in solution. The size of the cavity adapts to the guest size, as indicated by modelling studies and self diffusion constants of the complexes.

  • 43. Oh, Juwon
    et al.
    Sung, Young Mo
    Mori, Hirotaka
    Park, Seongchul
    Jorner, Kjell
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Lim, Manho
    Osuka, Atsuhiro
    Kim, Dongho
    Unraveling Excited-Singlet-State Aromaticity via Vibrational Analysis2017In: Chem, ISSN 24519294, Vol. 3, no 5, p. 870-880Article in journal (Refereed)
    Abstract [en]

    Summary

    The concept of excited-state aromaticity is receiving much attention in that completely reversed aromaticity in the excited state (so-called aromaticity reversal) provides crucial insight into photostability, photoreactivity, and its application to the photosynthetic mechanism and photoactive materials. Despite this significance, experimental elucidation of excited-state aromaticity is still unsolved, particularly for the excited singlet state. Here, as an unconventional approach, time-resolved IR (TRIR) spectroscopy on aromatic and anti-aromatic hexaphyrin congeners shed light on excited-singlet-state aromaticity. The contrasting spectral features between the Fourier transform IR and TRIR spectra reveal the aromaticity-driven structural changes, corroborating aromaticity reversal in the excited singlet states. Our paradigm for excited-state aromaticity, the correlation of IR spectral features with aromaticity reversal, provides another fundamental key to understanding the role of (anti)aromaticity in the stability, dynamics, and reactivity in the excited singlet state of π-conjugated molecular systems.

  • 44.
    Ragnarsson, Ulf
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Biochemistry.
    Grehn, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Pehk, Tonis
    An unprecedented rearrangement of a 1,1-diprotected hydrazine derivative. Structure revision of a catalyst-containing by-product2014In: Tetrahedron Letters, ISSN 0040-4039, E-ISSN 1359-8562, Vol. 55, no 51, p. 7019-7022Article in journal (Refereed)
    Abstract [en]

    Treatment of 1-Boc-1-tosyl-hydrazine with 1,1,3,3-tetramethylguanidine (TMG) gave rise to twoproducts, one containing and the other not containing TMG. The latter was identified as 1-Boc-2-tosylhydrazine.This rearrangement provided useful insight into the nature of the first product that had previouslybeen isolated and assigned an incorrect tentative structure. To rationalize the results a plausiblemechanism via a common intermediate, involving TMG as a nucleophilic catalyst is proposed. A simplerprocedure for the preparation of the starting material is also presented.

  • 45.
    Singh, Vijay P.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Poon, Jia-fei
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Yan, Jiajie
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Lu, Xi
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Karlsson Ott, Marjam
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Materials Sciences.
    Butcher, Ray J.
    Howard Univ, Dept Chem, Washington, DC 20059 USA.
    Gates, Paul J.
    Univ Bristol, Sch Chem, Bristol BS8 1TS, Avon, England.
    Engman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Nitro-, Azo-, and Amino Derivatives of Ebselen: Synthesis, Structure, and Cytoprotective Effects2017In: Journal of Organic Chemistry, ISSN 0022-3263, E-ISSN 1520-6904, Vol. 82, no 1, p. 313-321Article in journal (Refereed)
    Abstract [en]

    Novel azo-bis-ebselen compounds 7 were prepared by reduction of 7-nitro-2-aryl-1,2-benzisoselenazol-3(2H)ones 3 and 6 with sodium benzenetellurolate; NaTeC6H5, and by reaction of 2-bromo-3-nitrobenzamides with Na2Se2. The X-ray structure of 7b showed that the molecule, due to strong intramolecular secondary Se center dot center dot center dot N interactions, is completely planar. Azo-compounds 7 upon further reaction with NaTeC6H5 were reductively cleaved to provide 2 equiv of the corresponding aromatic amine. The weak Se-N bond was not stable enough to survive the reaction conditions, and diselenides 8 were isolated after workup. Whereas azo-bis-ebselens 7 were poor mimics of the glutathione peroxidase (GPx)-enzymes, nitroebselens 3, 6, and 11b and diselenides 8 were 3-6-fold more active than ebselen. Based on Se-77 NMR. spectroscopy, a catalytic cycle for diselenide 8b, involving aminoebselen 14, was proposed. As assessed by chemiluminescence measurements, the good GPx-mimics could reduce production of reactive oxygen species (ROS) in stimulated human mononuclear cells more efficiently than Trolox. No toxic effects of the, compounds were seen in MC3T3-cells at 25 mu M.

  • 46.
    Sollert, Carina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Hribersek, Matic
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ingner, Fredric
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Wang, Ying
    Division of Theoretical Chemistry & Biology, School of Biotechnology, KTH Royal Institute of Technology, 10691 Stockholm, Sweden.
    Ahlquist, Mårten S. G.
    Division of Theoretical Chemistry & Biology, School of Biotechnology, KTH Royal Institute of Technology, 10691 Stockholm, Sweden.
    Gates, Paul J.
    School of Chemistry, University of Bristol, Cantock’s Close, Clifton, Bristol, BS8 1TS, United Kingdom.
    Pilarski, Lukasz T.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Distal Fluoroboronate Substituents for Remote Control of Aryne Distortion and RegioselectivityManuscript (preprint) (Other academic)
  • 47.
    Sollert, Carina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Orthaber, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Molecular Biomimetics.
    Pilarski, Lukasz T.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Crystal structure of acetonitrile[eta(6)-1-methyl-4-(1-methylethyl)benzene][1-(pyrimidin-2-yl )-3H-indol-1-ium-2-yl-kappa N-2,C]ruthenium(II) bis-(hexafluoridoantimonate)2015In: ACTA CRYSTALLOGRAPHICA SECTION E-CRYSTALLOGRAPHIC COMMUNICATIONS, ISSN 2056-9890, Vol. 71, p. 1190-+Article in journal (Refereed)
    Abstract [en]

    In the title compound, [Ru(C10H14)(C12H9N3)(CH3CN)][SbF6](2), the ruthenium(II) cation is eta(6)-coordinated by the para-cymene ligand with a Ru-centroid(eta(6)-benzene) distance of 1.746 (2) angstrom. Furthermore, ruthenium coordinations to the C and N atoms of the pyrimidyl indole ligand are found to be 1.986 (4) and 2.082 (3) angstrom, respectively. The typical piano-stool coordination environment is saturated with an acetonitrile solvent molecule with a Ru-N distance of 2.044 (3) angstrom. The indolyl ligand is protonated at the C3 position with the N=C imine bond length appropriate to that of related 3H-indole-based complexes. In the crystal, the complex cation is linked to the SbF6- ions through weak C-H center dot center dot center dot F hydrogen bonds.

  • 48.
    Tibbelin, Julius
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Alvi, Muhammad Rouf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Björklund, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Hui, Tong
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Lach, Jochen
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Ottosson, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Formation and Fundamental Properties of Potassium Germen-2-olatesManuscript (preprint) (Other academic)
    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.

  • 49.
    Xiong, Ruisheng
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Andres, Julien
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Scheffler, Kira
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Borbas, Eszter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström.
    Synthesis and characterisation of lanthanide-hydroporphyrin dyads2015In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 44, p. 2541-2553Article in journal (Refereed)
    Abstract [en]

    Fluorescence spectroscopy is in many ways the ideal tool for the interrogation of complex biological systems, as it is non-invasive, sensitive, and offers high spatiotemporal resolution. For biomedical imaging luminescent probes absorbing and emitting in the red-to-near infrared (NIR) region are best suited to maximise tissue penetration and minimise damage to cellular components. NIR-emitting lanthanides (Ln) sensitised with red-absorbing antennae are promising candidates for these applications, assuming the challenges of poor photophysical properties and tedious syntheses of the complexes are overcome. Chlorins are porphyrin-type tetrapyrroles with intense red absorption. Recently chlorins have been shown to sensitise Yb and Nd emission when incorporated into Ln-complexes. Here we expand on our previous work, and explore the effect of chlorin structure, metallation state, chlorin-Ln-complex linker length and mode of attachment on the properties of chlorin-Ln complexes. As chlorin absorption bands are approximately 20 nm fwhm and readily tunable, a deeper understanding of structure-property relationships would enable the use of chlorin-Ln complexes in multicolour imaging using antenna-specific excitation. A detailed description of antenna and complex syntheses and photophysical characterisation is given. A number of challenges were identified, which will have to be addressed in future studies to enable multicolour imaging using the NIR-emitting lanthanides.

  • 50.
    Yan, Jiajie
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Poon, Jia-fei
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Singh, Vijay P
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Gates, Paul
    Engman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC.
    Regenerable thiophenolic radical-trapping antioxidants2015In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 17, no 24, p. 6162-6165Article in journal (Refereed)
    Abstract [en]

    Diphenyl disulfides carrying alkyltelluro groups in the o-, m-, and p-positions were prepared using ortho-lithiation and lithium halogen exchange reactions. The novel antioxidants showed only minimal inhibitory effect on the azo-initiated peroxidation of linoleic acid in chlorobenzene until reduced to the corresponding thiophenols by tris(2-carboxyethyl)phosphine (TCEP). The best in situ generated thiophenol (from 7c) under these conditions quenched peroxyl radicals more efficiently than α-tocopherol with an almost 3-fold increase in inhibition time.

12 1 - 50 of 51
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