Metal-free regioselective C–H amination for the synthesis of pyrazole-containing 2H-indazoles

Abstract

A general and practical regioselective approach for the C–H amination of 2H-indazoles under transition-metal-free conditions was developed. A series of substrates were tested showing eminent functional group tolerance and affording the C–N functionalization products in good to excellent yields. Mechanism studies revealed that a radical process was involved in this transformation.