Oxidative C5−H amination of imidazo[1,2-a]pyrimidines via iodine catalysis

Abstract

An iodine-catalyzed oxidative C−H amination of imidazo[1,2-a]pyrimidine at its C5 position with secondary cyclic amines using tert-butyl hydroperoxide as an oxidant under an open atmosphere at 60 °C has been accomplished. This simple protocol features metal-free reaction conditions, operational simplicity, and a broad substrate scope with high tolerance for various functional groups. Mechanistic studies suggest an ionic pathway for the regioselective amination reaction, proceeding through in situ formation of an active N-iodoamine intermediate.