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

YANINA MOGLIE; FRANCISCO ALONSO; GABRIEL RADIVOY; MIGUEL YUS

Alicante

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

Universidad de Alicante, Equipo de Consolider Ingenio 2010-Orfeo Team CSD2007-00006

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 b-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.