Germylene stabilized copper(I) halide complexes as catalysts for click and C-S coupling reactions

Aminotroponiminato(chloro)germylene stabilized mononuclear copper(I) iodide complex [{(i-Bu)2ATIGeCl}(CuI)(C5H5N)2] (1) was used as catalyst for regioselective cycloaddition reactions and found that it works efficiently. To realize how the halogen atom (X), the nuclearity of the CuX core, and the number of germylene donors in the copper complexes can affect their catalytic potential, a series of copper complexes [{(t-Bu)2ATIGePh}2(CuX)] (X = Cl 3, Br 4, I 5) with monomeric CuX core and [{(t-Bu)2ATIGePh}3(CuCl)3] (6) containing trimeric Cu3Cl3 core were prepared and used as catalysts. The results indicated that complex 1 is a better catalyst than complexes 3-6. Given this, the catalytic utility of complex 1 in the C-S coupling reactions was tested to find that it functions effectively for a wide variety of substrates. Complexes 3-6 were characterized in the solid-state through single-crystal X-ray diffraction studies.