Revised Theoretical Model on Enantiocontrol in Phosphoric Acid Catalyzed H -Transfer Hydrogenation of Quinoline
| Autor: | Angela Marinetti, Elixabete Rezabal, Julien Pastor, Jean-François Betzer, Gilles Frison, Arnaud Voituriez |
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| Přispěvatelé: | Laboratoire de chimie moléculaire (LCM), Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-École polytechnique (X), Universidad del Pais Vasco / Euskal Herriko Unibertsitatea [Espagne] (UPV/EHU), Institut de Chimie des Substances Naturelles (ICSN), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC) |
| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
010405 organic chemistry
[CHIM.ORGA]Chemical Sciences/Organic chemistry Aryl Organic Chemistry Quinoline Substituent Enantioselective synthesis [CHIM.CATA]Chemical Sciences/Catalysis 010402 general chemistry Transfer hydrogenation 01 natural sciences 0104 chemical sciences Catalysis [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry chemistry.chemical_compound chemistry Computational chemistry Brønsted–Lowry acid–base theory Phosphoric acid |
| Zdroj: | Journal of Organic Chemistry Journal of Organic Chemistry, American Chemical Society, 2018, 83 (5), pp.2779-2787. ⟨10.1021/acs.joc.7b03248⟩ |
| ISSN: | 0022-3263 1520-6904 |
| Popis: | International audience; The enantioselective H-transfer hydrogenation of quinoline by Hantzsch ester is a relevant example of Brønsted acid catalyzed cascade reactions, with phosphoric acid being a privileged catalyst. The generally accepted mechanism points out the hydride transfer step as the rate- and stereodetermining step, however computations based on these models do not totally fit with experimental observations. We hereby present a computational study that enlightens the stereochemical outcome and quantitatively reproduces the experimental enantiomeric excesses in a series of H-transfer hydrogenations. Our calculations suggest that the high stereocontrol usually attained with BINOL-derived phosphoric acids results mostly from the steric constraints generated by an aryl substituent of the catalyst, which hinders the access of the Hantzsch ester to the catalytic site and enforces approach through a specific way. It relies on a new model involving the preferential assembly of one of the stereomeric complexes formed by the chiral phosphoric acid and the two reaction partners. The stereodetermining step thus occurs prior to the H-transfer step. |
| Databáze: | OpenAIRE |
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