Merging Visible Light Photoredox and Chiral Phosphate Catalysis for Asymmetric Friedel Crafts Reaction with in Situ Generation of N Acyl Imines.
In the presence of visible light photoredox and chiral phosphate catalysts, a novel asymmetric Friedel Crafts reaction of indoles and readily accessible a amino acid derived redox active esters is established to afford enantioenriched 1 indolyl 1 alkylamine derivatives in moderate to high yields and with high levels of enantioselectivities. This method not only shows a mild and efficient alternative for the in situ generation of N acyl imines but also indicates the feasibility of a multicatalyst system for asymmetric photoredox catalysis.
Organic letters