1,2,3-Triazoles by a [3+2] Cycloaddition of Azides and Alkynes

Significance

A very mild and convenient Huisgen cycloaddition reaction to triazoles in high yields and with high regioselectivity is reported. The reaction proceeds with a copper complex [(SIMes)CuBr] as the catalyst (0.8 mol%) and without further solvents at room temperature to generate the desired products which can be isolated in high purity after simple filtration or extraction. Additionally to the use of previously prepared organic azides, the in situ generation of the azides from bromides in water has also been developed by using the same copper complex. A mechanistic proposal starting with a coordination of the copper complex to the alkyne, followed by Huisgen cycloaddition, also supported by DFT calculations, is given.