BrØnsted/Lewis acids-promoted selective preparations of 3-hetero quinolines or 4/5-hetero triazoles from azides and hetero-alkynes

Construction of hetero-quinoline and triazole derivatives from hetero-alkynes and arylmethyl azides was herein demonstrated. And the formation of the six- or five-membered rings relied on the use of a BrØnsted acid (TfOH) or a Lewis acid (CuSO4). alkynyl phosphonates provided high regio-selectivity whereas alkynyl sulfides offered high efficiency. And together 39 six or five-membered aza-cyclic compounds were readily obtained in up to 94% yields. Moreover, proposed mechanism gave a good explanation for the region-selectivities of the methodologies.127