화학공학소재연구정보센터
Journal of the American Chemical Society, Vol.137, No.19, 6120-6123, 2015
Enantioselective Organocatalytic Alkylation of Aldehydes and Enals Driven by the Direct Photoexcitation of Enamines
Disclosed herein is a photo-organocatalytic enantioselective alpha- and gamma-alkylation of aldehydes and enals, respectively, with bromomalonates. The chemistry uses a Commercially available aminocatalyst and occurs under Illumination by a fluorescent light bulb in the absence of any external photoredox catalyst. Mechanistic investigations reveal the previously hidden ability of transiently generated enamines to directly reach an electronically excited state upon light absorption while successively triggering the formation of reactive radical species from the organic halides. At the same time, the ground state chiral enamines provide effective stereochemical induction for the enantioselective alkylation process.