Dehydrogenative C(sp)-H bond functionalization of tetrahydroisoquinolines mediated by organic oxidants under mild conditions.

The organocatalyzed Mannich reaction of unsubstituted and N-aryl-substituted tetrahydroisoquinolines (THIQs) and the Strecker reaction of several N-aryl-substituted THIQs through dehydrogenative C(sp3)-H bond functionalization (cross-dehydrogenative coupling) promoted by organic single electron oxidants DDQ and IBX are presented. The C-H oxidation/Mannich reaction of less reactive N-aryl substituted pyrrolidines is achieved via metal catalyzed photoredox catalysis. Operationally simple procedures provide desired products in an effective and time preserving manner.