Palladium(II) complex of an organotellurium ligand as a catalyst for Suzuki Miyaura coupling: Generation and role of nano-sized Pd3Te2

Organotellurium ligand (L = (C6H5)(2-HOC6H4)CHNH(CH2)(3)TeeC(6)H(4)-4-OMe) and its palladium complex [PdCl(L-H)](1) have been synthesized and characterized by multinuclei NMR and mass spectra. The L coordinates with Pd(II) in a (N,Te,C-) mode. The complex 1 has been used to catalyze Suzuki-Miyaura coupling (SMC) reaction. The conversions at 0.1 mol% loading of the complex catalyst were good for coupling of phenylboronic acid with various aryl bromides. In case of 4-formylphenylboronic acid catalyst loading needed was higher. In the course of catalysis nanoparticles (NPs) were generated. They were isolated and characterized as Pd3Te2 species (similar to 1-2 nm size). Catalytic activity of 1 has been ascribed via these NPs. A cocktail process involving both homogeneous and heterogeneous routes appears to carry out catalysis. (C) 2013 Elsevier B. V. All rights reserved.