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

A one-pot protocol for the synthesis of 1,2,3-triazoles has been developed starting from inactivated alkenes and based on two click reactions: the azidosulfenylation of the carbon–carbon double bond and the copper-catalyzed azide–alkyne cycloaddition (CuAAC). High yields of the β-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 direct access to 1-vinyl and 4-monosubstituted triazoles.Spanish Ministerio de Economía y Competitividad (MINECO; CTQ2007-65218, CTQ2011-24151 and Consolider Ingenio 2010-CSD2007-00006), the Generalitat Valenciana (GV; PROMETEO/2009/039), and Fondo Europeo de Desarrollo Regional (FEDER)

Multicomponent click synthesis of 1,2,3-triazoles from epoxides in water catalyzed by Copper nanoparticles on activated carbon

Copper nanoparticles on activated carbon have been found to effectively catalyze the multicomponent synthesis of β-hydroxy-1,2,3-triazoles from a variety of epoxides and alkynes in water. The catalyst is easy to prepare, reusable at a low copper loading (0.5 mol %), and exhibits higher catalytic activity than some commercially available copper sources. The regio- and stereochemistry of the reaction has been revised and unequivocally established on the basis of X-ray crystallographic analyses. An NMR experiment has been implemented for the rapid and unmistakable determination of the regiochemistry of the process. Some mechanistic aspects of the reaction have been also undertaken which unveil the participation of copper(I) acetylides.This work was generously supported by the Spanish Ministerio de Ciencia e Innovación (MICINN; CTQ2007-65218 and Consolider Ingenio 2010-CSD2007-00006), the Generalitat Valenciana (GV; PROMETEO/2009/039), and FEDER. Y.M. acknowledges the ISO of the Universidad de Alicante for a grant