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Light-Driven Enantioselective Organocatalytic ?-Benzylation of Enals.

ABSTRACT: A photochemical organocatalytic strategy for the direct enantioselective ?-benzylation of ?,?-unsaturated aldehydes is reported. The chemistry capitalizes upon the light-triggered enolization of 2-alkyl-benzophenones to afford hydroxy-o-quinodinomethanes. These fleeting intermediates are stereoselectively intercepted by chiral iminium ions, transiently formed upon condensation of a secondary amine catalyst with enals. Density functional theory (DFT) studies provided an explanation for why the reaction proceeds through an unconventional Michael-type addition manifold, instead of a classical cycloaddition mechanism and subsequent ring-opening.

SUBMITTER: Dell'Amico L

PROVIDER: S-EPMC5412672 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature

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Light-Driven Enantioselective Organocatalytic β-Benzylation of Enals.

Dell'Amico Luca L Fernández-Alvarez Victor M VM Maseras Feliu F Melchiorre Paolo P

Angewandte Chemie (International ed. in English) 20170210 12

A photochemical organocatalytic strategy for the direct enantioselective β-benzylation of α,β-unsaturated aldehydes is reported. The chemistry capitalizes upon the light-triggered enolization of 2-alkyl-benzophenones to afford hydroxy-o-quinodinomethanes. These fleeting intermediates are stereoselectively intercepted by chiral iminium ions, transiently formed upon condensation of a secondary amine catalyst with enals. Density functional theory (DFT) studies provided an explanation for why the re ...[more]

PMID: 28185401

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