Transition-Metal Catalyzed Rapid Synthesis of Imidiazo[2,1-b]thiazoles: Access to Aza-Fused Heterocycles via Aerobic Oxidative Coupling of 2-Aminothiazoles and Acetophenones

We report an efficient synthesis of 6-substituted imidazo[2,1-b]thiazoles through intramolecular cyclization of in situ generated thiazolium ylide from 2-aminothiazole and acetophenone. This one-pot cascade process efficiently forms two C-N bonds and is facilitated by Cu(OTf)2 and KI, both of which play key roles in the mechanism. The method utilizes commercially available starting materials and features mild reaction conditions, tolerance to different functional groups, and ease of operation. The synthetic applicability has further been demonstrated through post-modification of imidazo[2,1-b]thiazole analogues.