Access to Thiazole via Copper-Catalyzed [3+1+1]-Type Condensation Reaction under Redox-Neutral Conditions.

A new strategy for thiazoles via copper-catalyzed [3+1+1]-type condensation reaction from oximes, anhydrides and potassiumthiocyanate (KSCN) is developed herein. The transformation has good functional group tolerance and various thiazoles were formed smoothly in good to excellent yields under mild reaction conditions. This process involves copper-catalyzed N-O/C-S bond cleavages, activation of vinyl sp C-H bond, and C-S/C-N bond formations which are under redox-neutral conditions as well as operational simplicity.