Copper(II)-Catalyzed Ortho-Acyloxylation of the 2-Arylpyridines sp2 C−H Bonds with Anhydrides, Using O2 as Terminal Oxidant
摘要:
A chelation-assisted copper(II)-catalyzed ortho-acyloxylation of the 2-arylpyridine sp(2) C-H bond with anhydride is described. The procedure tolerates various functional groups, such as carbomethoxyl, methoxyl fluoro, bromo, chloro, and cyano groups, affording the mono- or diacyloxylated products in moderate to good yields. Importantly, this procedure uses O-2 as a clean terminal oxidant.