C−H Bond Activation Relay (CHAR) of Proline Ester Derivatives Promoted by In Situ Triarylamine Radical Cation: Selective Synthesis of 4‐Bromopyrrole Derivatives

Abstract

AbstractUsing the in situ generated triarylamine radical cation as an initiator, the sp3 C−H bond of proline esters was smoothly oxidized and brominated through C−H activation relay (CHAR), giving a series of 4‐bromopyrroles in good yields with high regioselectivity. The mechanistic study revealed that the oxidation of the active C−H bond initiated the followed 1,5‐HAT and bromination, which provides a new method to realize the functionalization of the remote C−H bond.