© 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 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 reaction proceeds through an unconventional Michael-type addition manifold, instead of a classical cycloaddition mechanism and subsequent ring-opening.
- asymmetric catalysis
- synthetic methods
Dell'Amico, L., Fernández-Alvarez, V. M., Maseras, F., & Melchiorre, P. (2017). Light-Driven Enantioselective Organocatalytic β-Benzylation of Enals. Angewandte Chemie - International Edition, 56(12), 3304-3308. https://doi.org/10.1002/anie.201612159