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  • 1.
    Cadu, Alban
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Paptchikhine, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Andersson, Pher G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Birch Reaction Followed by Asymmetric Iridium-Catalysed Hydrogenation2011In: Synthesis (Stuttgart), ISSN 0039-7881, E-ISSN 1437-210X, no 23, p. 3796-3800Article in journal (Refereed)
    Abstract [en]

    Birch reaction products are asymmetrically hydrogenated with high enantio- and diastereoselectivity via iridium catalysts. This new method of producing chiral compounds was explored for a variety of 1,3-di- and 1,2,4-tri-substituted cyclohexadienes.

  • 2.
    Paptchikhine, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - BMC, Synthetical Organic Chemistry.
    Asymmetric Hydrogenations using N, P - Ligated Iridium Complexes2012Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The research described in this thesis focuses on the catalytic asymmetric hydrogenation of prochiral olefins using N, P – chelated iridium catalysts. This catalytic system is tolerant to a wide range of substrates and performs better than the well-known ruthenium- and rhodium-catalytic systems for substrates devoid of coordinating groups in proximity of the olefin. Low catalytic loadings (often <1 %) and the high atom efficiency of this reaction make it a synthetically useful method of chiral molecule synthesis. The primary aim of this thesis was to develop new catalysts that rapidly and efficiently hydrogenate a broad range of alkenes asymmetrically. Papers I and II describe the synthesis and evaluation of new, highly efficient, chiral N, P – ligated iridium complexes. These catalysts were obtained in relatively few steps, while leaving open possibilities to modify and fine-tune their structure. Their versatility is ideally suited to both industrial uses and to equip any catalyst box. Paper III deals with a common problem of defluorination of vinylic fluorides during the hydrogenation. The catalyst designed in that work performs well for several substrates giving very low defluorination rates making it a good starting point for further improvements to cover a broader scope of vinyl fluorides. The structures of the catalysts from papers I and III also offers an easy approach to attach the catalyst ligands to a solid support. Paper IV explores hydrogenation of vinyl boronates, which gives synthetically interesting borane compounds with high enantioselectivities. Taking into account the rich chemistry of organic boranes, these compounds are very important. Paper V deals with hydrogenation of diphenylvinylphosphine oxides and vinyl phosphonates, another important classes of substrates that give chiral phosphorous containing compounds of interest in many fields of chemistry: such as medicinal chemistry and organocatalysis. In papers VI and VII we explore the Birch reaction as a source of prochiral olefins. By combining asymmetric hydrogenation with it, we obtain a powerful method to create chiral compounds with excellent enantioselectivities that are next to impossible to make by other routes. The products of the asymmetric hydrogenation are further modified by other well-known transformation to create other induced stereogenic centres.

    List of papers
    1. Development of new thiazole-based iridium catalysts and their applications in the asymmetric hydrogenation of trisubstituted olefins
    Open this publication in new window or tab >>Development of new thiazole-based iridium catalysts and their applications in the asymmetric hydrogenation of trisubstituted olefins
    Show others...
    2008 (English)In: Organic and biomolecular chemistry, ISSN 1477-0520, E-ISSN 1477-0539, Vol. 6, p. 366-373Article in journal (Refereed) Published
    National Category
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-173458 (URN)
    Available from: 2012-04-24 Created: 2012-04-24 Last updated: 2017-12-07
    2. Bicyclic phosphine-thiazole ligands for the asymmetric hydrogenation of olefins
    Open this publication in new window or tab >>Bicyclic phosphine-thiazole ligands for the asymmetric hydrogenation of olefins
    2010 (English)In: Tetrahedron: asymmetry, ISSN 0957-4166, E-ISSN 1362-511X, Vol. 21, no 11-12, p. 1328-1333Article in journal (Refereed) Published
    Abstract [en]

    New bicyclic thiazole-based chiral N,P-chelating ligands were developed. High activities and enantioselectivities were achieved in the iridium-catalyzed asymmetric hydrogenation of olefins with the new ligands.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-135190 (URN)10.1016/j.tetasy.2010.03.023 (DOI)000281095300002 ()
    Available from: 2010-12-06 Created: 2010-12-06 Last updated: 2017-12-11Bibliographically approved
    3. Iridium-Catalyzed Asymmetric Hydrogenation of Fluorinated Olefins Using N,P-Ligands: A struggle with hydrogenolysis and selectivity
    Open this publication in new window or tab >>Iridium-Catalyzed Asymmetric Hydrogenation of Fluorinated Olefins Using N,P-Ligands: A struggle with hydrogenolysis and selectivity
    2007 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 129, no 15, p. 4536-4537Article in journal (Refereed) Published
    Abstract [en]

    To broaden the substrate scope of asymmetric iridium-catalyzed hydrogenation, fluorine-functionalized olefins were synthesized and hydrogenated with iridium complexes. Preliminary results showed high levels of fluorine elimination together with low selectivity. The loss of vinylic fluorine at first seemed difficult to handle, but further studies revealed that a catalyst with an azanorbornyl scaffold in the ligand gave more promising results. With this in mind, a new ligand was developed. This gave among the best results published to date for fluorine asymmetric hydrogenation, yielding high conversion and very high ee's with very little fluorine elimination. Further increasing the selectivity, the trials also revealed that tetrasubstituted fluorine-containing olefins can be hydrogenated with high ee's, despite that this class of compounds has usually shown low reactivity in this reaction type.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-97352 (URN)10.1021/ja0686763 (DOI)000245739700016 ()17375924 (PubMedID)
    Available from: 2008-05-13 Created: 2008-05-13 Last updated: 2017-12-14Bibliographically approved
    4. Iridium-catalyzed enantioselective hydrogenation of vinyl boronates
    Open this publication in new window or tab >>Iridium-catalyzed enantioselective hydrogenation of vinyl boronates
    2009 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, no 40, p. 5996-5998Article in journal (Refereed) Published
    Abstract [en]

    The first Ir-catalyzed asymmetric hydrogenations of vinyl boronates have been performed using low catalyst loadings (0.5 mol%) and pressure (as low as 1 bar). Good selectivities (76-98% ee) were obtained for a range of substrates.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-121862 (URN)10.1039/b912590f (DOI)000270542300008 ()19809622 (PubMedID)
    Available from: 2010-03-31 Created: 2010-03-31 Last updated: 2017-12-12Bibliographically approved
    5. Iridium-N,P-ligand-catalyzed enantioselective hydrogenation of diphenylvinylphosphine oxides and vinylphosphonates
    Open this publication in new window or tab >>Iridium-N,P-ligand-catalyzed enantioselective hydrogenation of diphenylvinylphosphine oxides and vinylphosphonates
    2009 (English)In: Journal of the American Chemical Society, ISSN 0002-7863, E-ISSN 1520-5126, Vol. 131, no 23, p. 8285-8289Article in journal (Refereed) Published
    Abstract [en]

    Diphenylvinylphosphine oxides and di- and trisubstituted vinylphosphonates have been employed as substrates in iridium-catalyzed asymmetric hydrogenations. Complete conversions and excellent enantioselectivities (up to and above 99% ee) were observed for a range of substrates with both aromatic and aliphatic groups at the prochiral carbon. We have also hydrogenated electron-deficient carboxyethylvinylphosphonates with excellent stereoselectivity (up to and above 99% ee). The hydrogenated products of both classes of substrates are synthetically useful intermediates.

    National Category
    Chemical Sciences
    Identifiers
    urn:nbn:se:uu:diva-121865 (URN)10.1021/ja901437t (DOI)000267623100057 ()19462955 (PubMedID)
    Available from: 2010-03-31 Created: 2010-03-31 Last updated: 2017-12-12Bibliographically approved
    6. Sequential Birch reaction and asymmetric Ir-catalyzed hydrogenation as a route to chiral building blocks
    Open this publication in new window or tab >>Sequential Birch reaction and asymmetric Ir-catalyzed hydrogenation as a route to chiral building blocks
    2011 (English)In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 47, no 13, p. 3989-3991Article in journal (Refereed) Published
    Abstract [en]

    A range of 1,2,4-trisubstituted cyclohexadienes obtained from the Birch reaction were hydrogenated asymmetrically to produce synthetically valuable chiral compounds in high enantio- and diastereoselectivity.

    National Category
    Biochemistry and Molecular Biology
    Identifiers
    urn:nbn:se:uu:diva-150770 (URN)10.1039/c0cc05619g (DOI)000288386600089 ()21327284 (PubMedID)
    Available from: 2011-04-06 Created: 2011-04-06 Last updated: 2017-12-11Bibliographically approved
    7. The Birch reaction as a source of substrates for asymmetric hydrogenation
    Open this publication in new window or tab >>The Birch reaction as a source of substrates for asymmetric hydrogenation
    (English)Manuscript (preprint) (Other academic)
    Keywords
    birch reaction, asymmetric hydrogenation, cyclohexanes, 1, 6-diketone
    National Category
    Organic Chemistry
    Research subject
    Organic Chemistry
    Identifiers
    urn:nbn:se:uu:diva-173230 (URN)
    Available from: 2012-04-20 Created: 2012-04-20 Last updated: 2012-08-01
  • 3.
    Paptchikhine, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry.
    Itto, Kaori
    Andersson, Pher G.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry, Organic Chemistry.
    Sequential Birch reaction and asymmetric Ir-catalyzed hydrogenation as a route to chiral building blocks2011In: Chemical Communications, ISSN 1359-7345, E-ISSN 1364-548X, Vol. 47, no 13, p. 3989-3991Article in journal (Refereed)
    Abstract [en]

    A range of 1,2,4-trisubstituted cyclohexadienes obtained from the Birch reaction were hydrogenated asymmetrically to produce synthetically valuable chiral compounds in high enantio- and diastereoselectivity.

  • 4.
    Paptchikhine, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Källström, Klas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    Andersson, Pher
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Biochemistry and Organic Chemistry.
    New ligands for the RuCp*-diamine catalysed asymmetric hydrogenation of aryl ketones2007In: Comptes rendus. Chimie, ISSN 1631-0748, E-ISSN 1878-1543, Vol. 10, no 3, p. 213-219Article in journal (Refereed)
    Abstract [en]

    New chiral diamine ligands have been synthesized and evaluated in the asymmetric Ru-catalyzed hydrogenation of prochiral aryl ketones. All catalysts showed good conversions with observed enantioselectivities ranging from moderate to good.

1 - 4 of 4
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