Versatile and highly efficient oxidative C(sp3)–H bond functionalization of tetrahydroisoquinoline promoted by bifunctional diethyl azodicarboxylate (DEAD): scope and mechanistic insights

Abstract

Oxidative C(sp³)–H bond functionalization of the 1-position of tetrahydroisoquinoline (THIQ) derivatives was performed by using diethyl azodicarboxylate (DEAD) as the oxidant. A wide range of nucleophiles, including ketene silyl acetal, silyl enol ether, nitroalkane, dimethyl malonate, terminal alkyne, ketone, phosphonate, trimethylsilyl cyanide, and allylstannane gave very high yields without their excessive use. A mechanistic study revealed that the oxidative and basic nature of DEAD is responsible for its high efficiency.