Gold/Palladium Bimetallic Alloy Nanoclusters Stabilized by Chitosan as Highly Efficient and Selective Catalysts for Homocoupling of Arylboronic Acid

Aerobic oxidative homocoupling of arylboronic acid under acidic aqueous conditions (pH 4.0) using bimetallic Au/Pd alloy nanoclusters stabilized by chitosan has been investigated. It was found that a Au0.81Pd0.19 catalyst (3.1 +/- 0.8 nm) exhibited superior catalytic activities as compared to monometallic Au (2.3 +/- 0.3 nm) and other series of bimetallic nanoclusters, giving the corresponding biaryls in nearly quantitative yield.