Palladium-Catalyzed Oxidative C–h Alkoxycarbonylation of Arenes with Alkylcarbazates Directed by N-Heterocyclic Substituents

Abstract

With alkyl carbazates as the green ester source, a novel palladium-catalyzed oxidative free radical carbonylative transformation of the C–H bond on aromatic rings to produce esters has been developed. Good yields of the corresponding products have been obtained with wide functional group tolerance and excellent regioselectivity. A variety of alkyl carbazates are found to be suitable reactants for the ortho-alkoxycarbonylation on the aromatic ring. We report an environmentally benign protocol for the C–H alkoxycarbonylation of arenes with alkylcarbazates directed by N-heterocyclic substituents. Pd(OAc)2 is used to catalyze this oxidative free radical carbonylative transformation. The reaction is tolerant to a wide variety of functional groups to give the products in good yields and excellent regioselectivity