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 Cu I and Pd II 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 Cu I ions to Cu II . The obtained Cu I and Pd II complexes with polymer ligands had high catalytic activity in the reaction of aryl halides with phenylacetylene giving rise to a C(sp 2 )-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% depend ing on the nature of the aryl halide.

Polymer biquinolyl-containing complexes of Pd(ii) as efficient catalysts for cyanation of aryl and vinyl halides with K4Fe(CN)6

“…The presence of the CH 2 -group between two aromatic rings ensures plasticity, and imide fragments in the copolymer are responsible for the tensile strength of the polymer. The biquinolyl (biQ) fragments in the main chain of the polymer backbone provide an opportunity for coordination to transition metal ions, e.g., Ni(II), 13,14 Cu(I), [15][16][17][18] Pd(II), 17,19 yielding polymer complexes which show excellent efficiency in electrocatalytic aerobic oxidation of aliphatic alcohols 15 and amines 16 to corresponding carbonyl compounds as well as in catalysis for C-C bond formation (Suzuki-Miyaura 19 and Sonogashira 17,18 couplings).…”