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

Abstract

AbstractTransition‐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.magnified image