Anti-Markovnikov Hydroacylation of Aryl Alkenes with Aldehydes Enabled by Photo/Cobalt Dual Catalysis.

Herein we describe a dual photo/cobalt-catalyzed anti-Markovnikov hydroacylation of aryl alkenes using aldehyde as acyl source. The key to success is the cobalt catalyzed hydrogen atom transfer, which enables effective formation of the desired products and efficient regeneration of the photocatalyst under mild conditions. This protocol features broad substrate scopes, good functional group tolerance, high efficiency and regioselectivity.