NHSi/NHGe-Supported Copper Halide and Pseudohalide Complexes: Synthesis and Application

Herein, we have demonstrated the complexation reaction
of silylene
and germylene [PhC(NtBu)2EN(TMS)2; E = Si (A) and Ge (B)] with several copper(I)
salts and further utilized them (1–6) as efficient
catalysts in CuAAC reaction. The copper complexes (2 and 4–6) were synthesized from the reaction of [PhC(NtBu)2EN(TMS)2] [E = Si (A) or Ge (B)] and CuX (X = Br, I, and SCN). The molecular
structures of 2, 4, 5, and 6 were established by single-crystal X-ray diffraction studies.
The density functional theory studies indicate that the bimetallic
Cu catalyst facilitates the cycloaddition reaction by anchoring the
reactants to the close proximity and reducing the energy gap between
the frontier orbitals of the dipole and dipolarophile.