[3+3] Annulation of vinyl sulfoxonium ylides and difluoroacetohydrazonoyl bromides for synthesis of 3-difluoromethyl 1,6-dihydropyridazine derivatives

Abstract

A novel strategy was developed for the efficient construction of 3-difluoromethyl 1,6-dihydropyridazine derivatives via a [3+3] annulation reaction between vinyl sulfonium ylides and difluoroacetohydrazonoyl bromides in the presence of Na₂CO₃ under transition-metal-free conditions. This process features mild reaction conditions and broad substrate compatibility. The resulting 3-difluoromethyl 1,6-dihydropyridazine derivatives exhibit distinct aggregation-induced emission (AIE) properties, demonstrating potential applications in latent fingerprint visualization and information encryption.