Reference
Wang, L., Zhang, D., & Luo, G. (2017). Enantioselective Decarboxylative α-Alkynylation of β-Ketocarbonyls via a Catalytic α-Imino Radical Intermediate. 19(18). https://doi.org/10.1021/acs.orglett.7b02386
Abstract
A distinctive aminocatalysis via α-imino radical is reported on the basis of SET oxidation of a secondary enamine. The combination of chiral primary amine catalysis and visible-light photoredox catalysis enables the enantioselective decarboxylative coupling of propiolic acid and β-ketocarbonyls to afford alkynylation adducts with high enantioselectivity. Mechanism studies indicate the reaction proceeds via an α-imino radical addition.