Copper-Catalyzed Three-Component Domino Cyclization for the Synthesis of 4-Aryl-5-(arythio)-2-(trifluoromethyl)oxazoles

Abstract

A copper-catalyzed oxidative cyclization of oxime, arylthiol, and trifluoroacetic anhydride for the construction of trisubstituted oxazoles has been developed. This transformation combines N–O bond cleavage, C–H functionalization, and intramolecular annulation, providing a practical protocol for the introduction of a trifluoromethyl (−CF3) group at oxazole rings.

Recent developments and perspectives in the copper-catalyzed multicomponent synthesis of heterocycles

“…An efficient synthetic strategy for the incorporation of a trifluoromethyl group at oxazole ring was established by Xiao et al 18 This protocol involved oxidative cyclization of arylthiol, oxime and trifluoroacetic anhydride using a copper( ii ) catalyst, and a series of trisubstituted oxazoles was developed ( Scheme 5 ). The reaction proceeded via N–O bond breaking, C–H functionalization, and an intramolecular annulation.…”

Recent Progress in Iodine‐Catalysed C−O/C−N Bond Formation of 1,3‐Oxazoles: A Comprehensive Review

“…Deng et al [67] . research group developed copper‐catalysed cyclization of oximes 93 , aryl thiols 94 , and trifluoroacetic anhydrides 95 into oxazoles 96 through oxidative annulation reaction (Scheme 36).…”

“…Deng et al [67] research group developed copper-catalysed cyclization of oximes 93, aryl thiols 94, and trifluoroacetic anhydrides 95 into oxazoles 96 through oxidative annulation reaction (Scheme 36). With the optimised catalytic system of Cu(OTf) 2 , a variety of oximes could be transformed into structurally diverse oxazoles in good to excellent yield.…”

Convergent Domino Cyclization: Oxidative [3+1+1] Annulation for One‐Pot Synthesis of 2‐Quinoline‐4,5‐diaryl‐oxazoles from Methyl Azaarenes, Benzoins and NH4OAc

“…Visible‐light catalyzed approaches were achieved through the cyclization of 2H‐azirines with aldehydes or alkynyl bromides, α‐bromoketones with benzylamines [8] . Copper catalyzed three‐component domino cyclization of oxime, arylthiol, and trifluoroacetic anhydride was demonstrated for the synthesis of trifluoromethyl attached oxazoles [9] . The intramolecular cyclization of 2H‐azirines, enaminones and N ‐propargylamides was also efficient approach [10]…”