Photocatalyzed Metal-Free Alkylheteroarylation of Unactivated Olefins via Direct Acidic C(sp3)-H Bond Activation.

A visible-light-promoted metal-free alkylheteroarylation of unactivated olefins was developed by using readily available ketones/esters as the alkyl radical source. With this strategy, both linear and cyclic ketones/esters could be conveniently converted to corresponding α-carbonyl alkyl radical species by using commonly found diacylperoxide (LPO) as the hydrogen atom transfer reagent, and heteroaryl-containing 1,7-carbonyl compounds were synthesized via distal heteroaryl ipso-migration in good to excellent yields with high functional group tolerance and a broad substrate scope. In addition, this approach was also amenable to C-H functionalization of acetonitrile, dichloromethane, 1,2-dichloroethane, and chloroform.