Catalytic Generation and Use of Ketyl Radical from Unactivated Aliphatic Carbonyl Compounds.

Generation of a ketyl radical from unactivated aliphatic carbonyl compounds is an important strategy in organic synthesis. Herein, catalytic generation and use of a ketyl radical for the reductive coupling of aliphatic carbonyl compounds and styrenes by organic photoredox catalysis is described. The method is applicable to both aliphatic ketones and aldehydes to afford the corresponding tertiary and secondary alcohols in continuous flow and batch. Preliminary mechanistic investigation suggests the catalytic formation of a ketyl radical intermediate.