Alkenes as Azido Precursors for the One-Pot Synthesis of 1,2,3-Triazoles Catalyzed by Copper Nanoparticles on Activated Carbon

F. ALONSO; Y. MOGLIE; G. RADIVOY; M. YUS

Alicante

Congreso; VI International School on Organometallic Chemistry "Marcial Moreno Mañas"; 2013

Universidad de Alicante

Recently, we introduced a catalyst consisting of oxidized copper nanoparticles on activated carbon (CuNPs/C), readily prepared under mild conditions, which exhibited a high versatility in the multicomponent click synthesis of 1,2,3-triazoles in water. Not only organic halides but diazonium salts, anilines, and epoxides were successfully used as azide precursors in the CuAAC. We want to present herein the first one-pot transformation of inactivated olefins into 1,2,3-triazoles by taking advantage of two consecutive click reactions: (a) the ring opening of in-situ generated episulfonium ions by the azide anion and (b) the reaction of the in-situ generated azides with alkynes catalyzed by CuNPs/C. High yields of the beta-methylsulfanyl triazoles have been attained using CuNPs/C as catalyst, with other commercial copper catalysts being completely inactive. The versatility of the methylsulfanyl group has been demonstrated through a series of synthetic transformations, including the direct access to 1-vinyl and 4-monosubstituted triazoles (Scheme 1).