Role of C, S, Se and P donor ligands in copper(i) mediated C–N and C–Si bond formation reactions

摘要

The first comparative study of C, S, Se and P donor ligands-supported copper( I ) complexes for C–N and C–Si bond formation reactions are described. The syntheses and characterization of eight mononuclear copper( I ) chalcogenone complexes, two polynuclear copper( I ) chalcogenone complexes and one tetranuclear copper( I ) phosphine complex are reported. All these new complexes were characterized by CHN analysis, FT-IR, UV-vis, multinuclear NMR and single crystal X-ray diffraction techniques. The single crystal X-ray structures of these complexes depict the existence of a wide range of coordination environments for the copper( I ) center. This is the first comparative study of metal–phosphine, metal–NHC and metal–imidazolin-2-chalcogenones in C–N and C–Si bond formation reactions. Among all the catalysts, mononuclear copper( I ) thione, mononuclear copper( I ) N-heterocyclic carbene and tetranuclear copper( I ) phosphine are exceedingly active towards the synthesis of 1,2,3-triazoles as well as for the cross-dehydrogenative coupling of alkynes with silanes. The cross-dehydrogenative coupling of terminal alkynes with silanes represents the first report of a catalytic process mediated by metal–imidazolin-2-chalcogenones.