Halide-bridged tetranuclear organocopper(I) clusters supported by indolyl-based NCN pincer ligands and their catalytic activities towards the hydrophosphination of alkenes.

Novel tetranuclear organocopper(I) clusters bridged by two halides and two indolyl-based NCN pincer ligands were synthesized through the reactions of Cu(I) halides with lithiated ligands. Single-crystal X-ray diffraction revealed that the structure of these complexes included a [Cu 4 X 2 ] 2+ cluster unit wherein the four copper ions were stabilized by multiple Cu-Cu interactions, arranged in a distorted tetrahedral fashion and the halide anions μ 3 -bridged with metal centers. Meanwhile, these clusters displayed excellent catalytic activities towards the hydrophosphination of alkenes under solvent-free conditions with wide functional group tolerance.