Synthesis of heteropolynuclear CuI and PdII complexes with polymeric 2,2′-biquinoline-containing ligands and investigation of their catalytic activity in the Sonogashira couplings

Abstract

A method for electrosynthesis of heteropolynuclear biquinoline-containing CuI and PdII complexes using sacrificial Cu and Pd anodes was developed. The sequence of anode dissolution (first Pd and then Cu) was important for the synthesis of the complex. The opposite sequence of dissolution resulted in oxidation of the initially formed CuI ions to CuII. The obtained CuI and PdII complexes with polymer ligands had high catalytic activity in the reaction of aryl halides with phenylacetylene giving rise to a C(sp2)-C(sp) bond. The yield of arylphenylacetylene in the presence of 0.1 mol.% of Pd catalyst in relation to the starting halide was 50–90% depending on the nature of the aryl halide.