Cu(OTf)2-triggered benzotriazole ring cleavage (BtRC) approach for the synthesis of 2-aryl/alkyl benzoxazoles from N-acylbenzotriazoles

Cu(OTf) is introduced as a novel reagent for the benzotriazole ring cleavage (BtRC) of N-acylbenzotriazoles (RCOBt), followed by cyclization to the corresponding benzoxazoles.This method exhibits unprecedented efficiency, achieving high yields across a broad substrate scope, including aryl and alkyl derivatives, and is scalable from milligram to gram quantities.