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  • 1.
    Biswas, Srijit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Dahlstrand, Christian
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Watile, Rahul A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Kalek, Marcin
    Himo, Fahmi
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Atom-Efficient Gold(I)-Chloride-Catalyzed Synthesis of alpha-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols: Substrate Scope and Experimental and Theoretical Mechanistic Investigation2013In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 19, no 52, p. 17939-17950Article in journal (Refereed)
    Abstract [en]

    Gold(I)-chloride-catalyzed synthesis of -sulfenylated carbonyl compounds from propargylic alcohols and aryl thiols showed a wide substrate scope with respect to both propargylic alcohols and aryl thiols. Primary and secondary aromatic propargylic alcohols generated -sulfenylated aldehydes and ketones in 60-97% yield. Secondary aliphatic propargylic alcohols generated -sulfenylated ketones in yields of 47-71%. Different gold sources and ligand effects were studied, and it was shown that gold(I) chloride gave the highest product yields. Experimental and theoretical studies demonstrated that the reaction proceeds in two separate steps. A sulfenylated allylic alcohol, generated by initial regioselective attack of the aryl thiol on the triple bond of the propargylic alcohol, was isolated, evaluated, and found to be an intermediate in the reaction. Deuterium labeling experiments showed that the protons from the propargylic alcohol and aryl thiol were transferred to the 3-position, and that the hydride from the alcohol was transferred to the 2-position of the product. Density functional theory (DFT) calculations showed that the observed regioselectivity of the aryl thiol attack towards the 2-position of propargylic alcohol was determined by a low-energy, five-membered cyclic protodeauration transition state instead of the strained, four-membered cyclic transition state found for attack at the 3-position. Experimental data and DFT calculations supported that the second step of the reaction is initiated by protonation of the double bond of the sulfenylated allylic alcohol with a proton donor coordinated to gold(I) chloride. This in turn allows for a 1,2-hydride shift, generating the final product of the reaction.

  • 2.
    Biswas, Srijit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    A Gold(I)-Catalyzed Route to α-Sulfenylated Carbonyl Compounds from Propargylic Alcohols and Aryl Thiols2012In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 48, no 52, p. 6586-6588Article in journal (Refereed)
    Abstract [en]

    A one-step atom efficient gold(I)-catalyzed route to α-sulfenylated ketones and aldehydes from propargylic alcohols and aryl thiols is described.

  • 3.
    Biswas, Srijit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    The Efficiency of the Metal Catalysts in the Nucleophilic Substitution of Alcohols is Dependent on the Nucleophile and Not on the Electrophile2013In: Chemistry - An Asian Journal, ISSN 1861-4728, E-ISSN 1861-471X, Vol. 8, no 5, p. 974-981Article in journal (Refereed)
    Abstract [en]

    In this study, we investigate the effect of the electrophiles and the nucleophiles for eight catalysts in the catalytic SN1 type substitution of alcohols with different degree of activation by sulfur-, carbon-, oxygen-, and nitrogen-centered nucleophiles. The catalysts do not show any general variance in efficiency or selectivity with respect to the alcohols and follow the trend of alcohol reactivity. However, when it comes to the nucleophile, the eight catalysts show general and specific variances in the efficiency and selectivity to perform the desired substitution. Interestingly, the selectivity of the alcohols to produce the desired substitution products was found to be independent of the electrophilicity of the generated carbocations but highly dependent on the ease of formation of the cation. Catalysts based on iron(III), bismuth(III), and gold(III) show higher conversions for S-, C-, and N-centered nucleophiles, and BiIII was the most efficient catalyst in all combinations. Catalysts based on rhenium(I) or rhenium(VII), palladium(II), and lanthanum(III) were the most efficient in performing the nucleophilic substitution on the various alcohols with the O-centered nucleophiles. These catalysts generate the symmetrical ether as a by-product from the reactions of S-, C-, and N-centered nucleophiles as well, resulting in lower chemoselectivity.

  • 4.
    Biswas, Srijit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Gold-catalyzed route to alpha-sulfenylated carbonyl compounds from propargylic alcohols and thiophenol: Scope, limitations, and mechanism2013In: Abstract of Papers of the American Chemical Society, ISSN 0065-7727, Vol. 245, p. 382-ORGN-Article in journal (Other academic)
  • 5.
    Biswas, Srijit
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Watile, Rahul A.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Tandem Pd/Au-Catalyzed Route to alpha-Sulfenylated Carbonyl Compounds from Terminal Propargylic Alcohols and Thiols2014In: Chemistry - A European Journal, ISSN 0947-6539, E-ISSN 1521-3765, Vol. 20, no 8, p. 2159-2163Article in journal (Refereed)
    Abstract [en]

    An efficient and highly atom-economical tandem Pd/Au-catalyzed route to -sulfenylated carbonyl compounds from terminal propargylic alcohols and thiols has been developed. This one-step procedure has a wide substrate scope with respect to substituents at the -position of the alcohol. Both aromatic and aliphatic thiols generated the -sulfenylated carbonyl products in good to excellent yields. A mechanism is proposed in which the reaction proceeds through a Pd-catalyzed regioselective hydrothiolation at the terminal triple bond of the propargyl alcohol followed by an Au-catalyzed 1,2-hydride migration.

  • 6.
    Blom, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Light-Triggered Conformational Switches for Modulation of Molecular Recognition: Applications for Peptidomimetics and Supramolecular Systems2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The main focus of this thesis is on photochemical modulation of molecular recognition in various host-guest systems. This involves the design, synthesis and integration of light-triggered conformational switches into peptidomimetic guests and molecular tweezer hosts. The impact of the switches on guest and host structures has been assessed by spectroscopic and computational conformational analysis. Effects of photochemical structure modulation on molecular recognition in protein-ligand and supramolecular host-guest systems are discussed.

    Phototriggerable peptidomimetic inhibitors of the enzyme M. tuberculosis ribonucleotide reductase (RNR) were obtained by incorporation of a stilbene based amino acid moiety into oligopeptides between 3-9 residues long (Paper I). Interstrand hydrogen bond probability in the E and Z forms of the peptidomimetics was used as a tool for predicting conformational preferences. Considerable differences in inhibitory potency for the E and Z photoisomers were demonstrated in a binding assay.

    In order to advance the concept of photomodulable inhibitors, synthetic routes towards amino acid derivatives based on the more rigid stiff-stilbene chromophore were developed (Paper II).  The effect of E-Z isomerization on the conformational properties of peptidomimetic inhibitors incorporating the stiff-stilbene chromophore was also assessed computationally (Paper III). It was indicated that inhibitors with the more rigid amino acid derivative should display larger conformational divergence between photoisomers than corresponding stilbene derivatives.

    Bisporphyrin tweezers with enediyne and stiff-stilbene spacers have been synthesized, and the conformational characteristics imposed by the spacers have been studied and compared to a glycoluril linked tweezer. The effects of spacers on tweezer binding of diamine guests and helicity induction by chiral guests have been investigated (Paper IV). Connections between spacer flexibility and host-guest binding strength have been established. The structural properties of the stiff-stilbene spaced tweezer made it particularly susceptible to helicity induction by both monotopic and bitopic chiral guests. Finally, the possibility of photochemical bite-size variation of tweezers with photoswitchable spacers has been assessed. Initial studies have shown that photoisomerization of the tweezers is possible without photochemical decomposition. Conformational analyses indicate that isomerization should impact binding characteristics of the tweezers to a significant extent (Paper V).

    List of papers
    1. Phototriggerable peptidomimetics for the inhibition of Mycobacterium turberculosis ribonucleotide reductase by targeting protein-protein binding
    Open this publication in new window or tab >>Phototriggerable peptidomimetics for the inhibition of Mycobacterium turberculosis ribonucleotide reductase by targeting protein-protein binding
    Show others...
    2015 (English)In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 13, no 9, p. 2612-2621Article in journal (Refereed) Published
    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.

    National Category
    Organic Chemistry Medicinal Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry; Medicinal Chemistry
    Identifiers
    urn:nbn:se:uu:diva-239491 (URN)10.1039/C4OB01926A (DOI)000350144600018 ()25580895 (PubMedID)
    Funder
    Swedish Research Council
    Available from: 2014-12-28 Created: 2014-12-28 Last updated: 2018-01-11Bibliographically approved
    2. Synthesis and characterization of photoswitchable stiff-stilbene based amino acid derivatives
    Open this publication in new window or tab >>Synthesis and characterization of photoswitchable stiff-stilbene based amino acid derivatives
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Synthetic routes towards the Boc-protected amino acids 1 and 2 incorporating the stiff stilbene chromophore via the corresponding indanone carboxylic acids have been devised. Crucial steps are a reductive McMurry coupling of the indanone carboxylic acids, yielding stiff stilbene dicarboxylic acid esters. Hydrolysis to the monoester and conversion to the azides, followed by a Curtius rearrangement afforded the Boc-protected amino acid ester 1.

    Keywords
    Peptidomimetics
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-267829 (URN)
    Funder
    Swedish Research Council, 621-2012-3379
    Available from: 2015-11-27 Created: 2015-11-27 Last updated: 2016-01-13
    3. Photoswitchable peptidomimetics with a stiff-stilbene chromophore for inhibition of Mycobacterium tuberculosis RNR
    Open this publication in new window or tab >>Photoswitchable peptidomimetics with a stiff-stilbene chromophore for inhibition of Mycobacterium tuberculosis RNR
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Peptidomimetics incorporating two amino acids 1 and 2 with a stiff stilbene chromophore have been screened by a computational study and compared to a previously investigated analog 3 with stilbene chromophore. The effect of E-Z isomerization of the chromophores on the conformational properties of the petidomimetics was assessed via the frequency of hydrogen bonding between the two peptide strands attached to either side of the chromophore. Substantial differences between the three amino acids were thus indicated, in line with the anticipated effect of chromophore rigidity variation.

    Keywords
    Peptidomimetics, conformational analysis
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-267830 (URN)
    Funder
    Swedish Research Council, 621-2012-3379
    Available from: 2015-11-27 Created: 2015-11-27 Last updated: 2016-01-13
    4. Synthesis and Properties of Bis-Porphyrin Molecular Tweezers: Effects of Spacer Flexibility on Binding and Supramolecular Chirogenesis
    Open this publication in new window or tab >>Synthesis and Properties of Bis-Porphyrin Molecular Tweezers: Effects of Spacer Flexibility on Binding and Supramolecular Chirogenesis
    Show others...
    2016 (English)In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 21, no 1Article in journal (Refereed) Published
    Abstract [en]

    Abstract: Ditopic binding of various dinitrogen compounds to three bisporphyrin molecular tweezers with spacers of varying conformational rigidity, incorporating the planar ene-diyne (1), the helical stiff stilbene (2), or the semirigid glycoluril motif fused to  the porphyrins (3) are compared. Binding constants Ka = 10^4 to 10^6 M^-1 reveal subtle  differences between these tweezers, that are discussed in terms of porphyrin dislocation  modes. Exciton coupled circular dichroism (ECCD) of complexes with chiral dinitrogen  guests provides experimental evidence for the conformational properties of the tweezers. The results are further supported and rationalized by conformational analysis.

    Keywords
    Bisporphyrin tweezers, metalloporphyrins, porphyrinoids, host-guest chemistry, supramolecular chemistry, chirogenesis, chirality transfer, exciton coupled circular dichroism, conformational analysis
    National Category
    Organic Chemistry Engineering and Technology
    Research subject
    Chemistry with specialization in Organic Chemistry; Engineering Science with specialization in Nanotechnology and Functional Materials
    Identifiers
    urn:nbn:se:uu:diva-267826 (URN)10.3390/molecules21010016 (DOI)000369485600001 ()
    Funder
    Swedish Research Council, 621-2012-3379Swedish Research Council, 621-2011-4423
    Available from: 2015-11-27 Created: 2015-11-27 Last updated: 2017-12-01Bibliographically approved
    5. Photomodulable bis-porphyrin molecular tweezers as dynamic host systems for diamine guests
    Open this publication in new window or tab >>Photomodulable bis-porphyrin molecular tweezers as dynamic host systems for diamine guests
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Bisporphyrin molecular tweezers with an enediyne (1) or a stiff stilbene (2) photoswitchable spacer are proposed as systems for modulation of bitopic binding to diamine guests via E/Z photoisomerization. The photoisomerization has been monitored by UV-Vis and 1H NMR spectroscopy and occurs without side reactions such as Bergman cyclization. Possible applications are rationalized in terms of competitive binding involving monoamine/diamine mixtures, and are supported by conformational analysis of the envisioned host-guest complexes. Binding dynamics for conformationally flexible guests show significantly different performance of aliphatic 1,w-diamine guests with varying N-N distance.

    Keywords
    Bisporphyrin tweezers, supramolecular chemistry, photochemistry
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-267833 (URN)
    Funder
    Swedish Research Council, 621-2012-3379
    Available from: 2015-11-27 Created: 2015-11-27 Last updated: 2016-01-13
  • 7.
    Blom, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Huang, Hao
    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 Biochemistry and Organic Chemistry, Organic Chemistry I.
    Photoswitchable peptidomimetics with a stiff-stilbene chromophore for inhibition of Mycobacterium tuberculosis RNRManuscript (preprint) (Other academic)
    Abstract [en]

    Peptidomimetics incorporating two amino acids 1 and 2 with a stiff stilbene chromophore have been screened by a computational study and compared to a previously investigated analog 3 with stilbene chromophore. The effect of E-Z isomerization of the chromophores on the conformational properties of the petidomimetics was assessed via the frequency of hydrogen bonding between the two peptide strands attached to either side of the chromophore. Substantial differences between the three amino acids were thus indicated, in line with the anticipated effect of chromophore rigidity variation.

  • 8.
    Blom, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Huang, Hao
    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, Synthetical Organic Chemistry.
    Synthesis and characterization of photoswitchable stiff-stilbene based amino acid derivativesManuscript (preprint) (Other academic)
    Abstract [en]

    Synthetic routes towards the Boc-protected amino acids 1 and 2 incorporating the stiff stilbene chromophore via the corresponding indanone carboxylic acids have been devised. Crucial steps are a reductive McMurry coupling of the indanone carboxylic acids, yielding stiff stilbene dicarboxylic acid esters. Hydrolysis to the monoester and conversion to the azides, followed by a Curtius rearrangement afforded the Boc-protected amino acid ester 1.

  • 9.
    Blom, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Norrehed, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Huang, Hao
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Light, Mark E.
    Department of Chemistry, University of Southampton, Highfield, Southampton SO17 1BJ, U.K.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Synthesis and Properties of Bis-Porphyrin Molecular Tweezers: Effects of Spacer Flexibility on Binding and Supramolecular Chirogenesis2016In: Molecules, ISSN 1420-3049, E-ISSN 1420-3049, Vol. 21, no 1Article in journal (Refereed)
    Abstract [en]

    Abstract: Ditopic binding of various dinitrogen compounds to three bisporphyrin molecular tweezers with spacers of varying conformational rigidity, incorporating the planar ene-diyne (1), the helical stiff stilbene (2), or the semirigid glycoluril motif fused to  the porphyrins (3) are compared. Binding constants Ka = 10^4 to 10^6 M^-1 reveal subtle  differences between these tweezers, that are discussed in terms of porphyrin dislocation  modes. Exciton coupled circular dichroism (ECCD) of complexes with chiral dinitrogen  guests provides experimental evidence for the conformational properties of the tweezers. The results are further supported and rationalized by conformational analysis.

  • 10.
    Blom, Magnus
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Olsson, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Norrehed, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Andersson, Claes-Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Grennberg, Helena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Physical Organic Chemistry.
    Gogoll, Adolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry I.
    Photomodulable bis-porphyrin molecular tweezers as dynamic host systems for diamine guestsManuscript (preprint) (Other academic)
    Abstract [en]

    Bisporphyrin molecular tweezers with an enediyne (1) or a stiff stilbene (2) photoswitchable spacer are proposed as systems for modulation of bitopic binding to diamine guests via E/Z photoisomerization. The photoisomerization has been monitored by UV-Vis and 1H NMR spectroscopy and occurs without side reactions such as Bergman cyclization. Possible applications are rationalized in terms of competitive binding involving monoamine/diamine mixtures, and are supported by conformational analysis of the envisioned host-guest complexes. Binding dynamics for conformationally flexible guests show significantly different performance of aliphatic 1,w-diamine guests with varying N-N distance.

  • 11.
    Cadu, Alban
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Iridium Catalysed Asymmetric Hydrogenation of Pyridines2013Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents the hydrogenation of substituted pyridines using N,P-ligated iridium catalystsin homogeneous media. These iridium catalysts were developed within this research group in thepast decade. This method of hydrogenation is highly stereoselective, and in several cases good to excellent ees were obtained.The hydrogenation of substituted pyridines was studied: by screening for the catalyst giving thehighest conversion and ee, by optimising the reaction conditions and by attempting to improve existingcatalysts. New substrates were synthesised for this process, in particular alkyl substituted Nprotectedpyridines. Their reduction provided chiral piperidines, which could be used as chiralbuilding blocks once deprotected.

    List of papers
    1. Iridium-Catalyzed Asymmetric Hydrogenation of Substituted Pyridines
    Open this publication in new window or tab >>Iridium-Catalyzed Asymmetric Hydrogenation of Substituted Pyridines
    2013 (English)In: Asian Journal of Organic Chemistry, ISSN 2193-5807, Vol. 2, no 12, p. 1061-1065Article in journal (Refereed) Published
    Abstract [en]

    Asymmetric hydrogenation of ortho-substituted pyridines catalyzed by N,P-ligated iridium is demonstrated. To facilitate this reaction, the aromaticity of the pyridines was weakened by forming N-iminopyridium ylides. The reactions give very high conversions, and after a single recrystallization, excellent ee of up to 98 % was obtained. This method lends itself to the synthesis of chiral piperidine building blocks.

    Keywords
    hydrogenation, iridium, N-iminopyridium ylides, pyridines, selective catalysis
    National Category
    Organic Chemistry Inorganic Chemistry
    Research subject
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-212412 (URN)10.1002/ajoc.201300160 (DOI)000328218000008 ()
    Available from: 2013-12-10 Created: 2013-12-10 Last updated: 2017-01-25Bibliographically approved
  • 12.
    Cadu, Alban
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Noble Metal Catalysed Reductions and Rearrangements2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The focus of this thesis has been organometallic catalysis applied to compounds containing heteroatoms which are usually poisonous to metal catalysts, by channelling their innate reactivity advantageously. The studies described in this thesis concentrate, in the first part, on iridium catalysed asymmetric hydrogenation (papers I and II) and in the second part, on gold catalysed internal rearrangements (papers III and IV). In each case, two classes of compounds are studied: pyridinium salts or sulphurous compounds. The asymmetric hydrogenation of pyridinium compounds was performed with 2% loading of N,P-ligated Ir catalyst with I2 additive (paper I) to achieve moderate to good enantiomeric excess (up to 98%). In paper II, olefinic sulphones were hydrogenated with an efficient 0.5% catalytic loading. In most cases full conversion was obtained and with good to excellent ees (up to 99%). The products of these reductions are chiral compounds, which could constitute further chemical building blocks. Palladium and gold were used sequentially in paper III, in order to perform a “Click” thiol-yne reaction followed by a semi-Pinacol rearrangement, leading to isolated yields of up to 98%. In paper IV The gold catalysed rearrangement of alkyl-pyridinium diynes was conducted, with a number of substrates providing >90% NMR yield. A highly selective hydrogenation was performed with a heterogeneous palladium catalyst to yield single diastereomer products. This methodology consists of up to three steps, with two catalysts in one pot.

    List of papers
    1. Iridium-Catalyzed Asymmetric Hydrogenation of Substituted Pyridines
    Open this publication in new window or tab >>Iridium-Catalyzed Asymmetric Hydrogenation of Substituted Pyridines
    2013 (English)In: Asian Journal of Organic Chemistry, ISSN 2193-5807, Vol. 2, no 12, p. 1061-1065Article in journal (Refereed) Published
    Abstract [en]

    Asymmetric hydrogenation of ortho-substituted pyridines catalyzed by N,P-ligated iridium is demonstrated. To facilitate this reaction, the aromaticity of the pyridines was weakened by forming N-iminopyridium ylides. The reactions give very high conversions, and after a single recrystallization, excellent ee of up to 98 % was obtained. This method lends itself to the synthesis of chiral piperidine building blocks.

    Keywords
    hydrogenation, iridium, N-iminopyridium ylides, pyridines, selective catalysis
    National Category
    Organic Chemistry Inorganic Chemistry
    Research subject
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-212412 (URN)10.1002/ajoc.201300160 (DOI)000328218000008 ()
    Available from: 2013-12-10 Created: 2013-12-10 Last updated: 2017-01-25Bibliographically approved
    2. An Enantioselective Approach to the Preparation of Chiral Sulfones by Ir-Catalyzed Asymmetric Hydrogenation
    Open this publication in new window or tab >>An Enantioselective Approach to the Preparation of Chiral Sulfones by Ir-Catalyzed Asymmetric Hydrogenation
    Show others...
    2014 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 136, no 47, p. 16557-16562Article in journal (Refereed) Published
    Abstract [en]

    Several chiral sulfonyl compounds were prepared using the iridium catalyzed asymmetric hydrogenation reaction. Vinylic, allylic and homoallylic sulfone substitutions were investigated, and high enantioselectivity is maintained regardless of the location of the olefin with respect to the sulfone. Impressive stereoselectivity was obtained for dialkyl substitutions, which typically are challenging substrates in the hydrogenation. As expected, the more bulky Z-substrates were hydrogenated slower than the corresponding E isomers, and in slightly lower enantioselectivity.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2014
    National Category
    Organic Chemistry
    Research subject
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-236862 (URN)10.1021/ja5079877 (DOI)000345720500016 ()25300238 (PubMedID)
    Available from: 2014-11-24 Created: 2014-11-24 Last updated: 2017-12-05Bibliographically approved
    3. One-Pot Synthesis of Keto Thioethers by Palladium/Gold-Catalyzed Click and Pinacol Reactions
    Open this publication in new window or tab >>One-Pot Synthesis of Keto Thioethers by Palladium/Gold-Catalyzed Click and Pinacol Reactions
    Show others...
    2014 (English)In: Organic Letters, ISSN 1523-7060, E-ISSN 1523-7052, Vol. 16, no 21, p. 5556-5559Article in journal (Refereed) Published
    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.

    Place, publisher, year, edition, pages
    American Chemical Society (ACS), 2014
    Keywords
    Gold, Palladium, thioether, catalysis, synthesis
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-236857 (URN)10.1021/ol502553p (DOI)000344635200013 ()25325145 (PubMedID)
    Available from: 2014-11-24 Created: 2014-11-24 Last updated: 2017-12-05Bibliographically approved
    4. Dual Gold (I) Catalysed Cyclisation of Dialkynyl Pyridinium salts
    Open this publication in new window or tab >>Dual Gold (I) Catalysed Cyclisation of Dialkynyl Pyridinium salts
    Show others...
    (English)Manuscript (preprint) (Other academic)
    Abstract [en]

    Novel dialkynyl pyridines were synthesised and protected as alkyl salts for dual gold (I) catalysed cycloisomerisation. Different alkyl groups and counter ions were screened for the salts, with benzyl and PF6- providing the best results. The cyclisation led to NMR yields of >95% being obtained for a number of substrates. Step-wise hydrogenation of products could be carried out in one-pot by Pd/C, with selective reduction of the double bonds, followed by deprotection of the Bn group.

    Keywords
    chemistry
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-272369 (URN)
    Available from: 2016-01-13 Created: 2016-01-13 Last updated: 2016-02-12Bibliographically approved
  • 13.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Andersson, Pher G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Development of iridium-catalyzed asymmetric hydrogenation: New catalysts, new substrate scope2012In: Journal of Organometallic Chemistry, ISSN 0022-328X, E-ISSN 1872-8561, Vol. 714, p. 3-11Article, review/survey (Refereed)
    Abstract [en]

    A review. The asym. hydrogenation of olefins is a tremendously powerful tool used to synthesize chiral mols. The field was pioneered using rhodium- and ruthenium- based catalysts; however, catalysts based on both of these metals suffer from limitations, such as the need for directing substituents near or even adjacent to the olefin. Iridium-based catalysts do not suffer from this flaw and can thus hydrogenate a wide variety of olefins, including some tetra substituted ones. It is also possible for iridium-based catalysts to hydrogenate hetero-π bonds such as those found in heteroarom. rings. This review summarizes the contributions made to this field by the authors in the past few years. [on SciFinder(R)]

  • 14.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Andersson, Pher G
    Iridium catalysis: Application of asymmetric reductive hydrogenation2013In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 42, no 40, p. 14345-14356Article in journal (Refereed)
    Abstract [en]

    Iridium, despite being one of the least abundant transition metals, has found several uses. N,P-ligated iridium catalysts are used to perform many highly selective reactions. These methodologies have been developed extensively over the past 15 years. More recently, the application of iridium N,P catalysts in asymmetric hydrogenation has been a focus of research to find novel applications and to expand on their current synthetic utility. The aim of this perspective is to highlight the advances made by the Andersson group.

  • 15.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Upadhyay, Puspesh K.
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry.
    Andersson, Pher G.
    Stockholm University.
    Iridium-Catalyzed Asymmetric Hydrogenation of Substituted Pyridines2013In: Asian Journal of Organic Chemistry, ISSN 2193-5807, Vol. 2, no 12, p. 1061-1065Article in journal (Refereed)
    Abstract [en]

    Asymmetric hydrogenation of ortho-substituted pyridines catalyzed by N,P-ligated iridium is demonstrated. To facilitate this reaction, the aromaticity of the pyridines was weakened by forming N-iminopyridium ylides. The reactions give very high conversions, and after a single recrystallization, excellent ee of up to 98 % was obtained. This method lends itself to the synthesis of chiral piperidine building blocks.

  • 16.
    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.

  • 17.
    Dinér, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Superacid-Promoted Ionization of Alkanes Without Carbonium Ion Formation: A Density Functional Theory Study2012In: Journal of Physical Chemistry A, ISSN 1089-5639, E-ISSN 1520-5215, Vol. 116, no 40, p. 9979-9984Article in journal (Refereed)
    Abstract [en]

    The carbonium ion has been suggested to be the intermediate in superacid-promoted reactions (SbF5-HF) such as hydrogen-deuterium exchange and in the electrophilic C-H cleavage into hydrogen and the carbenium ion. In this study, the superacid-promoted C-H cleavage into hydrogen and the carbenium ion was studied using density functional theory (B3LYP and M062X) and ab initio methods (MP2 and CCSD). The calculations suggest that the superacid-promoted C-H cleavage proceeds via a concerted transition state leading to hydrogen (H-2) and the carbenium ion without the formation of the elusive carbonium ion. The reactivity for the superacid promoted C-H cleavage decreases upon going from isobutane (tertiary) > propane (secondary) > isobutane (primary) > propane (primary) > ethane >> methane.

  • 18.
    Galkin, Maxim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Palladium-catalyzed lignin valorization: Towards a lignin-based biorefinery2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The work described in this thesis focuses on the cleavage of the β-O-4′ bond, which is the most abundant interunit linkage in the lignin polymer.

    In the first part, three methods based on palladium catalysis have been developed and their applicability has been verified using lignin model compounds. A transfer hydrogenolysis of the β-O-4′ bond using formic acid as a mild hydrogen donor together with a base. An aerobic oxidation of the benzylic alcohol motif in the β-O-4′ linkage to generate a key intermediate in the cleavage reaction was performed. A redox neutral cleavage of the β-O-4′ bond was accomplished in which no stoichiometric reducing or oxidizing agents were added.

    In the second part of the thesis, a mechanistic study is presented. The corresponding ketone from a dehydrogenation reaction of the benzylic alcohol motif was identified to be the key intermediate. This ketone and its enol tautomer was found to be responsible for the β-O-4′ bond cleavage reaction under the employed reaction conditions.

    In the final part of this thesis, the methodologies have been applied to native lignin. The depolymerization reaction was combined with organosolv pulping. This approach was successful, and together with cellulose and hemicellulose, propenyl aryls were generated in excellent yields directly from wood. In this transformation, the lignin derived molecules have been reduced by an endogenous hydrogen donor from the wood.

    List of papers
    1. Mild Heterogeneous Palladium-Catalyzed Cleavage of beta-O-4 '-Ether Linkages of Lignin Model Compounds and Native Lignin in Air
    Open this publication in new window or tab >>Mild Heterogeneous Palladium-Catalyzed Cleavage of beta-O-4 '-Ether Linkages of Lignin Model Compounds and Native Lignin in Air
    Show others...
    2014 (English)In: ChemCatChem, ISSN 1867-3880, E-ISSN 1867-3899, Vol. 6, no 1, p. 179-184Article in journal (Refereed) Published
    Abstract [en]

    A mild and robust heterogeneous palladium-catalyzed CO bond cleavage of 2-aryloxy-1-arylethanols using formic acid as reducing agent in air was developed. The cleaved products were isolated in 92-98% yield; and by slightly varying the reaction conditions, a ketone, an alcohol, or an alkane can be generated in near-quantitative yield. This reaction is applicable to cleaving the -O-4-ether bond found in lignin polymers of different origin. The reaction was performed on a lignin polymer model to generate either the monomeric aryl ketone or alkane in a quantitative yield. Moderate depolymerization was achieved with native lignin at similar reaction conditions. Mechanistic studies under kinetic control indicate that an initial palladium-catalyzed dehydrogenation of the alcohol is followed by insertion of palladium to an enol equivalent. A palladium-formato complex reductively cleaves the palladium-enolate complex to generate the ketone.

    Keywords
    heterogeneous catalysis, cleavage reactions, green chemistry, palladium, polymers, lignin
    National Category
    Natural Sciences
    Identifiers
    urn:nbn:se:uu:diva-220309 (URN)10.1002/cctc.201300540 (DOI)000330636800023 ()
    Note

    De två första författarna delar första författarskapet.

    Available from: 2014-03-17 Created: 2014-03-12 Last updated: 2017-12-05Bibliographically approved
    2. Selective Aerobic Benzylic Alcohol Oxidation of Lignin Model Compounds: Route to Aryl Ketones
    Open this publication in new window or tab >>Selective Aerobic Benzylic Alcohol Oxidation of Lignin Model Compounds: Route to Aryl Ketones
    2015 (English)In: ChemCatChem, ISSN 1867-3880, E-ISSN 1867-3899, Vol. 7, no 3, p. 401-404Article in journal (Refereed) Published
    Abstract [en]

    A mild and chemoselective oxidation of the -alcohol in -O-4-ethanoaryl and -O-4-glycerolaryl ethers has been developed. The benzylic alcohols were selectively dehydrogenated to the corresponding ketones in 60-93% yield. A one-pot selective route to aryl ethyl ketones was performed. The catalytic system comprises recyclable heterogeneous palladium, mild reaction conditions, green solvents, and oxygen in air as oxidant. Catalytic amounts of a coordinating polyol were found pivotal for an efficient aerobic oxidation.

    Keywords
    biomass valorization, heterogeneous catalysis, lignin, oxidation, palladium
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-246820 (URN)10.1002/cctc.201402825 (DOI)000349147100005 ()
    Available from: 2015-03-11 Created: 2015-03-10 Last updated: 2017-12-04Bibliographically approved
    3. Mild and Robust Redox-Neutral Pd/C-Catalyzed Lignol -O-4 Bond Cleavage Through a Low-Energy-Barrier Pathway
    Open this publication in new window or tab >>Mild and Robust Redox-Neutral Pd/C-Catalyzed Lignol -O-4 Bond Cleavage Through a Low-Energy-Barrier Pathway
    2015 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 8, no 13, p. 2187-2192Article in journal (Refereed) Published
    Abstract [en]

    A Pd/C catalyzed redox neutral CO bond cleavage of 2-aryloxy-1-arylethanols has been developed. The reactions are carried out at 80 degrees C, in air, using a green solvent system to yield the aryl ketones in near quantitative yields. Addition of catalytic amounts of a hydrogen source to the reaction mixture activates the catalyst to proceed through a low energy barrier pathway. Initial studies support a transfer hydrogenolysis reaction mechanism that proceeds through an initial dehydrogenation followed by an enol adsorption to Pd/C and a reductive CO bond cleavage.

    Keywords
    heterogeneous catalysis, lignin, palladium, reaction mechanisms, transfer hydrogenolysis
    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-259649 (URN)10.1002/cssc.201500117 (DOI)000357619000004 ()25925736 (PubMedID)
    Funder
    Swedish Energy Agency
    Available from: 2015-08-20 Created: 2015-08-10 Last updated: 2017-12-04Bibliographically approved
    4. Selective Route to 2-Propenyl Aryls Directly from Wood by a Tandem Organosolv and Palladium-Catalysed Transfer Hydrogenolysis
    Open this publication in new window or tab >>Selective Route to 2-Propenyl Aryls Directly from Wood by a Tandem Organosolv and Palladium-Catalysed Transfer Hydrogenolysis
    2014 (English)In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 8, p. 2154-2158Article in journal (Refereed) Published
    Abstract [en]

    A tandem organosolv pulping and Pd-catalysed transfer hydrogenolysis depolymerisation and deoxygenation has been developed. The tandem process generated 2-methoxy-4-(prop-1-enyl)phenol in 23 % yield (92 % theoretical monomer yield) starting from pine wood and 2,6-dimethoxy-4-(prop-1-enyl)phenol in 49 % yield (92 % theoretical monomer yield) starting from birch wood. Only endogenous hydrogen from wood was consumed, and the reaction was performed using green solvents.

    Keywords
    Biomass, Lignin Green, Chemistry, Palladium, catalysis
    National Category
    Organic Chemistry
    Research subject
    Chemistry with specialization in Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-226637 (URN)10.1002/cssc.201402017 (DOI)000340519500016 ()
    Funder
    Swedish Energy Agency
    Available from: 2014-06-18 Created: 2014-06-18 Last updated: 2017-12-05Bibliographically approved
  • 19.
    Galkin, Maxim
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Selective Route to 2-Propenyl Aryls Directly from Wood by a Tandem Organosolv and Palladium-Catalysed Transfer Hydrogenolysis2014In: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 7, no 8, p. 2154-2158Article in journal (Refereed)
    Abstract [en]

    A tandem organosolv pulping and Pd-catalysed transfer hydrogenolysis depolymerisation and deoxygenation has been developed. The tandem process generated 2-methoxy-4-(prop-1-enyl)phenol in 23 % yield (92 % theoretical monomer yield) starting from pine wood and 2,6-dimethoxy-4-(prop-1-enyl)phenol in 49 % yield (92 % theoretical monomer yield) starting from birch wood. Only endogenous hydrogen from wood was consumed, and the reaction was performed using green solvents.

  • 20.
    Galkin, Maxim V.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Sawadjoon, Supaporn
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Rohde, Volker
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Dawange, Monali
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Samec, Joseph S. M.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Mild Heterogeneous Palladium-Catalyzed Cleavage of beta-O-4 '-Ether Linkages of Lignin Model Compounds and Native Lignin in Air2014In: ChemCatChem, ISSN 1867-3880, E-ISSN 1867-3899, Vol. 6, no 1, p. 179-184Article in journal (Refereed)
    Abstract [en]

    A mild and robust heterogeneous palladium-catalyzed CO bond cleavage of 2-aryloxy-1-arylethanols using formic acid as reducing agent in air was developed. The cleaved products were isolated in 92-98% yield; and by slightly varying the reaction conditions, a ketone, an alcohol, or an alkane can be generated in near-quantitative yield. This reaction is applicable to cleaving the -O-4-ether bond found in lignin polymers of different origin. The reaction was performed on a lignin polymer model to generate either the monomeric aryl ketone or alkane in a quantitative yield. Moderate depolymerization was achieved with native lignin at similar reaction conditions. Mechanistic studies under kinetic control indicate that an initial palladium-catalyzed dehydrogenation of the alcohol is followed by insertion of palladium to an enol equivalent. A palladium-formato complex reductively cleaves the palladium-enolate complex to generate the ketone.

  • 21.
    Gustafsson, Tomas
    et al.
    Karolinska Inst, Div Biochem, Dept Med Biochem & Biophys, Scheeles Vag 2, SE-17177 Stockholm, Sweden.; Umea Univ, Sunderby Res Unit, Dept Clin Microbiol, Clin Bacteriol, Umea, Sweden.
    Osman, Harer
    Karolinska Inst, Div Biochem, Dept Med Biochem & Biophys, Scheeles Vag 2, SE-17177 Stockholm, Sweden.
    Werngren, Jim
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden.
    Hoffner, Sven
    Publ Hlth Agcy Sweden, Dept Microbiol, Solna, Sweden.
    Engman, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Holmgren, Arne
    Karolinska Inst, Div Biochem, Dept Med Biochem & Biophys, Scheeles Vag 2, SE-17177 Stockholm, Sweden.
    Ebselen and analogs as inhibitors of Bacillus anthracis thioredoxin reductase and bactericidal antibacterials targeting Bacillus species, Staphylococcus aureus and Mycobacterium tuberculosis2016In: Biochimica et Biophysica Acta - General Subjects, ISSN 0304-4165, E-ISSN 1872-8006, Vol. 1860, no 6, p. 1265-1271Article in journal (Refereed)
    Abstract [en]

    Background: Bacillus anthracis is the causative agent of anthrax, a disease associated with a very high mortality rate in its invasive forms.

    Methods: We studied a number of ebselen analogs as inhibitors of B. anthracis thioredoxin reductase and their antibacterial activity on Bacillus subtilis, Staphylococcus aureus, Bacillus cereus and Mycobacterium tuberculosis.

    Results: The most potent compounds in the series gave IC50 values down to 70 nM for the pure enzyme and minimal inhibitory concentrations (MICs) down to 0.4 mu M (0.12 mu g/ml) for B. subtilis,1.5 mu M (0.64 mu g/ml) for S. aureus, 2 mu M (0.86 mu g/ml) for B. cereus and 10 mu g/ml for M. tuberculosis. Minimal bactericidal concentrations (MBCs) were found at 1-1.5 times the MIC, indicating a general, class-dependent, bactericidal mode of action. The combined bacteriological and enzymological data were used to construct a preliminary structure-activity-relationship for the benzoisoselenazol class of compounds. When S. aureus and B. subtilis were exposed to ebselen, we were unable to isolate resistant mutants on both solid and in liquid medium suggesting a high resistance barrier.

    Conclusions: These results suggest that ebselen and analogs thereof could be developed into a novel antibiotic class, useful for the treatment of infections caused by B. anthracis, S. aureus, M. tuberculosis and other clinically important bacteria. Furthermore, the high barrier against resistance development is encouraging for further drug development.

    General significance: We have characterized the thioredoxin system from B. anthracis as a novel drug target and ebselen and analogs thereof as a potential new class of antibiotics targeting several important human pathogens.

  • 22.
    Hao, Huang
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Karlsson, Christoffer
    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, Synthetical Organic Chemistry.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Quinone Based Polypyrroles for Energy Storage Materials2015Conference paper (Refereed)
  • 23.
    Huang, Hao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Karlsson, Christoffer
    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.
    Sjödin, Martin
    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 Biochemistry and Organic Chemistry, Organic Chemistry I. Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Hydroquinone–pyrrole dyads with varied linkers2016In: Beilstein Journal of Organic Chemistry, ISSN 2195-951X, E-ISSN 1860-5397, Vol. 12, p. 89-96Article in journal (Refereed)
    Abstract [en]

    A series of pyrroles functionalized in the 3-position with p-dimethoxybenzene via various linkers (CH2, CH2CH2, CH=CH, C≡C) has been synthesized. Their electronic properties have been deduced from 1H NMR, 13C NMR, and UV–vis spectra to detect possible interactions between the two aromatic subunits. The extent of conjugation between the subunits is largely controlled by the nature of the linker, with the largest conjugation found with the trans-ethene linker and the weakest with the aliphatic linkers. DFT calculations revealed substantial changes in the HOMO–LUMO gap that correlated with the extent of conjugation found experimentally. The results of this work are expected to open up for use of the investigated compounds as components of redox-active materials in sustainable, organic electrical energy storage devices.

  • 24.
    Huang, Xiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Yang, Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Bergquist, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Analytical Chemistry.
    Strömme, 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, Synthetical Organic Chemistry.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Synthesis and Redox Properties of Thiophene Terephthalate Building Blocks for Low-Potential Conducting Redox Polymers2015In: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 119, no 49, p. 27247-27254Article in journal (Refereed)
    Abstract [en]

    Terephthalate-substituted thiophene derivatives are promising redox-active components for anode materials in lithium-ion batteries. In this study, we present the synthesis of substituted 2-(thiophen-3-yl)terephthalate derivatives (TTDs) as suitable monomers for thiophene-based conducting redox polymers, along with their characterization by electrochemical and spectroscopic techniques. Density functional theory (DFT) calculations, utilizing the universal solvation model based on solute electron density (SMD), were used to predict both the first and the second reduction potentials of these TTDs. The computational results showed good agreement with the experimental data in nonaqueous acetonitrile solvent, with mean absolute errors of 30 and 40 mV for the first and second reduction steps, respectively. Time-dependent (TD) DFT calculations on TTDs indicated terephthalate local transitions at both 200 and 240 nm and charge-transfer transitions above 300 nm by examination of the involved molecular orbitals.

  • 25.
    Huang, Xiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Yang, Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, 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, Synthetical Organic Chemistry.
    The n-type polymers pending with terephthalate group attempt for organic anode material2014Conference paper (Refereed)
  • 26.
    Huang, Xiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Yang, Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, 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, Synthetical Organic Chemistry.
    The n-type polymers with terephthalate group attempt for organic anode material2014Conference paper (Refereed)
  • 27.
    Huang, Xiao
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Yang, Li
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Strömme, 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, Synthetical Organic Chemistry.
    Sjödin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Synthesis and Redox Properties of Thiophene-Terephthalate Building Blocks for Low Potential Conducting Redox Polymers2015In: 66th Annual Meeting of the International Society of Electrochemistry Proceeding., 2015Conference paper (Refereed)
  • 28.
    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.

  • 29.
    Karlsson, Christoffer
    et al.
    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, Synthetical Organic Chemistry.
    Strømme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Sjödin, Ma