A fascinating Suzuki homo-coupling reaction over anchored gold Schiff base complexes on mesoporous host

Abstract

We present a study of the use of chloro-functionalized mesoporous silicas as supports for immobilization of Au(III) Schiff base complex, and use of this composite material as heterogeneous catalyst for homocoupling of aryl boronic acid. The catalyst was characterised by XRD, FTIR, UV-vis DRS, TG-DTA, etc. Catalyst was initially tested using the coupling of phenylboronic acid with bromo benzene in the presence of K(2)CO(3) and with xylene as solvent. The reaction was also tested in the absence of the aryl halide and K(2)CO(3). The results indicate that in our catalytic system base is not needed for the activation of phenylboronic acid, and its only role is to neutralize the boric acid. The optimized catalysts are also active in the coupling of a range of aryl boronic acids, and after four catalytic runs they show virtually no drop in activity. (C) 2011 Elsevier B.V. All rights reserved.