Highly Active Dinuclear Copper Catalysts for Homogeneous Azide-Alkyne Cycloadditions

The main feature of the herein presented class of molecularly defined catalysts for the copper-catalyzed azidealkyne cycloaddition reaction is the presence of two copper centres in one catalyst molecule. We report the facile three-step synthesis of two representative bis-NHC-dicopper complexes as well as their catalytic performance in the azidealkyne cycloaddition. A screening with one of these complexes has proved its wide applicability and excellent performance as homogeneous catalyst in various organic solvents and with different alkyne and azide substrates.