Immobilized [Cu(cdsalMeen)] on silica gel: a highly efficient heterogeneous catalyst for 'Click' [3+2] Huisgen cycloaddition

A facile and simple protocol for the 'Click' cycloaddition of organic azides with terminal alkynes catalyzed by immobilized [Cu(cdsalMeen)] on silica as a new and convenient heterogeneous catalyst is described. In this synthetic methodology, [Cu(cdsalMeen)]-SiO2 catalyzes 1,3-dipolar Huisgen cycloaddition of different functionalized beta-azido alcohols and alkynes in the presence of ascorbic acid and a solution of THF/H2O (2:1, V/V) at room temperature. Good to excellent yields of beta-hydroxytriazolylalkyl derivatives were afforded using [Cu(cdsalMeen)]-SiO2. Immobilization of [Cu(cdsalMeen)] on silica was approved as a chemically and thermally stable catalyst that can be reused for many consecutive trials without a significant decline in its reactivity. [GRAPHICS] .