1
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Oiarbide M, Palomo C. Brønsted Base-Catalyzed Enantioselective α-Functionalization of Carbonyl Compounds Involving π-Extended Enolates. CHEM REC 2023; 23:e202300164. [PMID: 37350363 DOI: 10.1002/tcr.202300164] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/06/2023] [Indexed: 06/24/2023]
Abstract
Chiral Brønsted base (BB) catalyzed asymmetric transformations constitute an important tool for synthesis. A meaningful fraction of these transformations proceeds through transiently generated enolate intermediates, which display quite versatile reactivity against a variety of electrophiles. Some years ago, our group became interested in developing BB-catalyzed asymmetric reactions of enolizable carbonyl substrates that involve π-extended enolates in which, besides control of reaction diastereo and enantioselectivity, the site-selectivity control is an additional issue in most cases. In the examples covered in this account the opportunities deployed, and the challenges posed, by these methods are illustrated, with a focus on the generation of quaternary carbon stereocenters. In the way, new bifunctional BB catalysts as well as achiral templates were developed that may find further applications.
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Affiliation(s)
- Mikel Oiarbide
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018 San Sebastián, Spain
| | - Claudio Palomo
- Departamento de Química Orgánica I, Universidad del País Vasco UPV/EHU, Manuel Lardizabal 3, 20018 San Sebastián, Spain
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2
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Kondoh A, Hirozane T, Terada M. Formal Umpolung Addition of Phosphites to 2‐Azaaryl Ketones under Chiral Brønsted Base Catalysis: Enantioselective Protonation Utilizing [1,2]‐Phospha‐Brook Rearrangement. Chemistry 2022; 28:e202201240. [DOI: 10.1002/chem.202201240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Indexed: 11/06/2022]
Affiliation(s)
- Azusa Kondoh
- Research and Analytical Center for Giant Molecules Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
| | - Takayuki Hirozane
- Department of Chemistry Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
| | - Masahiro Terada
- Department of Chemistry Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
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3
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Bai YJ, Cheng ML, Zheng XH, Zhang SY, Wang PA. Chiral Cyclopropenimine-catalyzed Asymmetric Michael Addition of Bulky Glycine Imine to α,β-Unsaturated Isoxazoles. Chem Asian J 2022; 17:e202200131. [PMID: 35415949 DOI: 10.1002/asia.202200131] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2022] [Revised: 03/26/2022] [Indexed: 11/11/2022]
Abstract
A highly efficient asymmetric Michael addition of bulky glycine imine to α,β-unsaturated isoxazoles has been achieved by using 5 mol% of chiral cyclopropenimine as a chiral organo-superbase catalyst under mild conditions. Michael adducts were obtained in excellent yields (up to 97%) and stereoselectivities (up to>99 : 1 dr and 98% ee). A significant solvent effect was found in these chiral organosuperbase catalyzed asymmetric Michael reactions. Gram-scale preparation of Michael adducts and their transformations are realized to provide corresponding products without loss of stereoselectivities. The configurations of Michael adduct was determined by single-crystal X-ray diffraction analysis.
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Affiliation(s)
- Yu-Jun Bai
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi'an, 710069, P. R. China) E-mails.,Department of Medicinal Chemistry and Pharmaceutical Analysis, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, P. R. China
| | - Mei-Ling Cheng
- Department of Medicinal Chemistry and Pharmaceutical Analysis, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, P. R. China
| | - Xiao-Hui Zheng
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi'an, 710069, P. R. China) E-mails
| | - Sheng-Yong Zhang
- Key Laboratory of Resource Biology and Biotechnology in Western China, Ministry of Education, The College of Life Sciences, Northwest University, Xi'an, 710069, P. R. China) E-mails.,Department of Medicinal Chemistry and Pharmaceutical Analysis, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, P. R. China
| | - Ping-An Wang
- Department of Medicinal Chemistry and Pharmaceutical Analysis, School of Pharmacy, Fourth Military Medical University, Xi'an, 710032, P. R. China
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4
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Saha A, Ganguly B. The design of C2-chiral bases with dual basic sites predicted to exceed the range of superbasicity: a computational study. NEW J CHEM 2022. [DOI: 10.1039/d2nj03537e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A set of C2-chiral bases with bis-protonation sites (1–9) on dimethyl-binaphthalene derivatives have been explored using the B3LYP/6-311+G(d,p) level and the proton affinities calculated are in the range of superbases for both the sites.
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Affiliation(s)
- Anusuya Saha
- Computation and Simulation Unit, Analytical and Environmental Science Division and Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat-364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Bishwajit Ganguly
- Computation and Simulation Unit, Analytical and Environmental Science Division and Centralized Instrument Facility, CSIR-Central Salt & Marine Chemicals Research Institute, Bhavnagar, Gujarat-364002, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
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5
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Leonardi C, Brandolese A, Preti L, Bortolini O, Polo E, Dambruoso P, Ragno D, Di Carmine G, Massi A. Expanding the Toolbox of Heterogeneous Asymmetric Organocatalysts: Bifunctional Cyclopropenimine Superbases for Enantioselective Catalysis in Batch and Continuous Flow. Adv Synth Catal 2021. [DOI: 10.1002/adsc.202100757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Costanza Leonardi
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Arianna Brandolese
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Lorenzo Preti
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Olga Bortolini
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Eleonora Polo
- Istituto per la Sintesi Organica e la Fotoreattività Consiglio Nazionale delle Ricerche Via P. Gobetti, 101 40129 Bologna Italy
| | - Paolo Dambruoso
- Istituto per la Sintesi Organica e la Fotoreattività Consiglio Nazionale delle Ricerche Via P. Gobetti, 101 40129 Bologna Italy
| | - Daniele Ragno
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Graziano Di Carmine
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
| | - Alessandro Massi
- Department of Chemical, Pharmaceutical and Agricultural Sciences University of Ferrara Via L. Borsari 46 44121 Ferrara Italy
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6
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Push–Pull Effect on the Gas-Phase Basicity of Nitriles: Transmission of the Resonance Effects by Methylenecyclopropene and Cyclopropenimine π-Systems Substituted by Two Identical Strong Electron Donors. Symmetry (Basel) 2021. [DOI: 10.3390/sym13091554] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The gas-phase basicity of nitriles can be enhanced by a push–pull effect. The role of the intercalated scaffold between the pushing group (electron-donor) and the pulling (electron-acceptor) nitrile group is crucial in the basicity enhancement, simultaneously having a transmission function and an intrinsic contribution to the basicity. In this study, we examine the methylenecyclopropene and the N-analog, cyclopropenimine, as the smallest cyclic π systems that can be considered for resonance propagation in a push–pull system, as well as their derivatives possessing two strong pushing groups (X) attached symmetrically to the cyclopropene scaffold. For basicity and push–pull effect investigations, we apply theoretical methods (DFT and G2). The effects of geometrical and rotational isomerism on the basicity are explored. We establish that the protonation of the cyano group is always favored. The push–pull effect of strong electron donor X substituents is very similar and the two π-systems appear to be good relays for this effect. The effects of groups in the two cyclopropene series are found to be proportional to the effects in the directly substituted nitrile series X–C≡N. In parallel to the basicity, changes in electron delocalization caused by protonation are also assessed on the basis of aromaticity indices. The calculated proton affinities of the nitrile series reported in this study enrich the gas-phase basicity scale of nitriles to around 1000 kJ mol−1.
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7
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Weitkamp RF, Neumann B, Stammler H, Hoge B. Phosphorus-Containing Superbases: Recent Progress in the Chemistry of Electron-Abundant Phosphines and Phosphazenes. Chemistry 2021; 27:10807-10825. [PMID: 34032319 PMCID: PMC8362139 DOI: 10.1002/chem.202101065] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Indexed: 01/11/2023]
Abstract
The renaissance of Brønsted superbases is primarily based on their pronounced capacity for a large variety of chemical transformations under mild reaction conditions. Four major set screws are available for the selective tuning of the basicity: the nature of the basic center (N, P, …), the degree of electron donation by substituents to the central atom, the possibility of charge delocalization, and the energy gain by hydrogen bonding. Within the past decades, a plethora of neutral electron-rich phosphine and phosphazene bases have appeared in the literature. Their outstanding properties and advantages over inorganic or charged bases have now made them indispensable as auxiliary bases in deprotonation processes. Herein, an update of the chemistry of basic phosphines and phosphazenes is given. In addition, due to widespread interest, their use in catalysis or as ligands in coordination chemistry is highlighted.
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Affiliation(s)
- Robin F. Weitkamp
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Beate Neumann
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Hans‐Georg Stammler
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
| | - Berthold Hoge
- Centrum für Molekulare MaterialienFakultät für ChemieUniversität BielefeldUniversitätsstraße 2533615BielefeldGermany
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8
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Antenucci A, Dughera S, Renzi P. Green Chemistry Meets Asymmetric Organocatalysis: A Critical Overview on Catalysts Synthesis. CHEMSUSCHEM 2021; 14:2785-2853. [PMID: 33984187 PMCID: PMC8362219 DOI: 10.1002/cssc.202100573] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2021] [Revised: 04/30/2021] [Indexed: 05/30/2023]
Abstract
Can green chemistry be the right reading key to let organocatalyst design take a step forward towards sustainable catalysis? What if the intriguing chemistry promoted by more engineered organocatalysts was carried on by using renewable and naturally occurring molecular scaffolds, or at least synthetic catalysts more respectful towards the principles of green chemistry? Within the frame of these questions, this Review will tackle the most commonly occurring organic chiral catalysts from the perspective of their synthesis rather than their employment in chemical methodologies or processes. A classification of the catalyst scaffolds based on their E factor will be provided, and the global E factor (EG factor) will be proposed as a new green chemistry metric to consider, also, the synthetic route to the catalyst within a given organocatalytic process.
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Affiliation(s)
- Achille Antenucci
- Department of ChemistryUniversity of TurinVia Pietro Giuria, 710125TurinItaly
- NIS Interdeprtmental CentreINSTM Reference CentreUniversity of TurinVia Gioacchino Quarello 15/A10135TurinItaly
| | - Stefano Dughera
- Department of ChemistryUniversity of TurinVia Pietro Giuria, 710125TurinItaly
| | - Polyssena Renzi
- Department of ChemistryUniversity of TurinVia Pietro Giuria, 710125TurinItaly
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9
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Meninno S, Carratù M, Overgaard J, Lattanzi A. Diastereoselective Synthesis of Functionalized 5-Amino-3,4-Dihydro-2H-Pyrrole-2-Carboxylic Acid Esters: One-Pot Approach Using Commercially Available Compounds and Benign Solvents. Chemistry 2021; 27:4573-4577. [PMID: 33464645 DOI: 10.1002/chem.202005262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 01/18/2021] [Indexed: 11/08/2022]
Abstract
A novel three-step four-transformation approach to highly functionalized 5-amino-3,4-dihydro-2H-pyrrole-2-carboxylic acid esters, starting from commercially available phenylsulfonylacetonitrile, aldehydes, and N-(diphenylmethylene)glycine tert-butyl ester, was developed. The one-pot strategy delivered this class of amidines bearing, for the first time, three contiguous stereocenters, in good to high yield and diastereoselectivity. The entire sequence was carried out using diethyl carbonate and 2-methyl tetrahydrofuran as benign solvents, operating under metal-free conditions. The process could be conveniently scaled-up, and the synthetic utility of the products was demonstrated.
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Affiliation(s)
- Sara Meninno
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, Italy
| | - Mario Carratù
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, Italy
| | - Jacob Overgaard
- Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus, Denmark
| | - Alessandra Lattanzi
- Dipartimento di Chimica e Biologia "A. Zambelli", Università di Salerno, Via Giovanni Paolo II 132, 84084, Fisciano, Italy
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10
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Das S, Hu Q, Kondoh A, Terada M. Enantioselective Protonation: Hydrophosphinylation of 1,1-Vinyl Azaheterocycle N-Oxides Catalyzed by Chiral Bis(guanidino)iminophosphorane Organosuperbase. Angew Chem Int Ed Engl 2021; 60:1417-1422. [PMID: 33030798 DOI: 10.1002/anie.202012492] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Indexed: 12/30/2022]
Abstract
Enantioselective protonation by hydrophosphinylation of diarylphosphine oxides with 2-vinyl azaheterocycle N-oxide derivatives was demonstrated using chiral bis(guanidino)iminophosphorane as the higher-order organosuperbase catalyst. It was confirmed by several control experiments that a chiral weak conjugate acid of the chiral bis(guanidino)iminophosphorane, instead of achiral diarylphosphine oxides, directly functioned as the proton source to afford the corresponding product in a highly enantioselective manner in most cases. Enantioselective protonation by a weak conjugate acid generated from the higher-order organosuperbase would broaden the scope of enantioselective reaction systems because of utilization of a range of less acidic pronucleophiles. This method is highlighted by the valuable synthesis of a series of chiral P,N-ligands for chiral metal complexes through the reduction of phosphine oxide and N-oxide units of the corresponding product without loss of enantiomeric purity.
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Affiliation(s)
- Saikat Das
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Qiupeng Hu
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Azusa Kondoh
- Research and Analytical Center for Giant Molecules, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
| | - Masahiro Terada
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan
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11
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Puleo TR, Sujansky SJ, Wright SE, Bandar JS. Organic Superbases in Recent Synthetic Methodology Research. Chemistry 2021; 27:4216-4229. [DOI: 10.1002/chem.202003580] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Indexed: 12/23/2022]
Affiliation(s)
- Thomas R. Puleo
- Department of Chemistry Colorado State University Fort Collins Colorado 80523 USA
| | - Stephen J. Sujansky
- Department of Chemistry Colorado State University Fort Collins Colorado 80523 USA
| | - Shawn E. Wright
- Department of Chemistry Colorado State University Fort Collins Colorado 80523 USA
| | - Jeffrey S. Bandar
- Department of Chemistry Colorado State University Fort Collins Colorado 80523 USA
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12
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Das S, Hu Q, Kondoh A, Terada M. Enantioselective Protonation: Hydrophosphinylation of 1,1‐Vinyl Azaheterocycle
N
‐Oxides Catalyzed by Chiral Bis(guanidino)iminophosphorane Organosuperbase. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202012492] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Saikat Das
- Department of Chemistry Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
| | - Qiupeng Hu
- Department of Chemistry Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
| | - Azusa Kondoh
- Research and Analytical Center for Giant Molecules Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
| | - Masahiro Terada
- Department of Chemistry Graduate School of Science Tohoku University Aramaki, Aoba-ku Sendai 980-8578 Japan
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13
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Golec JC, Carter EM, Ward JW, Whittingham WG, Simón L, Paton RS, Dixon DJ. BIMP-Catalyzed 1,3-Prototropic Shift for the Highly Enantioselective Synthesis of Conjugated Cyclohexenones. Angew Chem Int Ed Engl 2020; 59:17417-17422. [PMID: 32558981 PMCID: PMC7540019 DOI: 10.1002/anie.202006202] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/03/2020] [Indexed: 12/18/2022]
Abstract
A bifunctional iminophosphorane (BIMP)-catalysed enantioselective synthesis of α,β-unsaturated cyclohexenones through a facially selective 1,3-prototropic shift of β,γ-unsaturated prochiral isomers, under mild reaction conditions and in short reaction times, on a range of structurally diverse substrates, is reported. α,β-Unsaturated cyclohexenone products primed for downstream derivatisation were obtained in high yields (up to 99 %) and consistently high enantioselectivity (up to 99 % ee). Computational studies into the reaction mechanism and origins of enantioselectivity, including multivariate linear regression of TS energy, were carried out and the obtained data were found to be in good agreement with experimental findings.
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Affiliation(s)
- Jonathan C. Golec
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - Eve M. Carter
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
| | - John W. Ward
- Leverhulme Research Centre for Functional Materials DesignThe Materials Innovation FactoryDepartment of ChemistryUniversity of LiverpoolLiverpoolL7 3NYUK
| | | | - Luis Simón
- Facultad de Ciencias QuímicasUniversidad de SalamancaPlaza de los Caídos 1–537008SalamancaSpain
| | - Robert S. Paton
- Department of ChemistryColorado State University1301 Center AveFt. CollinsCO80523-1872USA
| | - Darren J. Dixon
- Department of ChemistryChemistry Research LaboratoryUniversity of OxfordMansfield RoadOxfordOX1 3TAUK
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14
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Golec JC, Carter EM, Ward JW, Whittingham WG, Simón L, Paton RS, Dixon DJ. BIMP‐Catalyzed 1,3‐Prototropic Shift for the Highly Enantioselective Synthesis of Conjugated Cyclohexenones. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202006202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Jonathan C. Golec
- Department of Chemistry Chemistry Research Laboratory University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - Eve M. Carter
- Department of Chemistry Chemistry Research Laboratory University of Oxford Mansfield Road Oxford OX1 3TA UK
| | - John W. Ward
- Leverhulme Research Centre for Functional Materials Design The Materials Innovation Factory Department of Chemistry University of Liverpool Liverpool L7 3NY UK
| | | | - Luis Simón
- Facultad de Ciencias Químicas Universidad de Salamanca Plaza de los Caídos 1–5 37008 Salamanca Spain
| | - Robert S. Paton
- Department of Chemistry Colorado State University 1301 Center Ave Ft. Collins CO 80523-1872 USA
| | - Darren J. Dixon
- Department of Chemistry Chemistry Research Laboratory University of Oxford Mansfield Road Oxford OX1 3TA UK
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