Transition-Metal-Promoted Direct C-H Cyanoalkylation and Cyanoalkoxylation of Internal Alkenes via Radical C-C Bond Cleavage of Cycloketone Oxime Esters

Transition-metal-catalyzed alkyl-Heck-type cross-coupling of olefinic C-H bonds has been a challenge in the C-H activation area. Herein, we report FeCl3-promoted efficient direct C-H cyanoalkylation of internal alkenes, that is, ketene dithioacetals, with cycloketone oxime esters via radical C-C bond cleavage under the redox-neutral conditions. With CuCl2 as the catalyst under a dioxygen atmosphere direct C-H cyanoalkoxylation of the same internal alkenes was achieved. The cyanoalkylated tetrasubstituted alkene products could be diversely transformed to cyanoalkyl-funtionalized N- and S-heterocyclic compounds. The mechanistic studies have revealed that these C-H cyanoalkylation and cyanoalkoxylation reactions proceed through a radical pathway