Stille Cross‐Coupling Reactions with Tin Reagents Supported on Ionic Liquids

New ionic-liquid-supported tin reagents were synthesized and used in Stille cross-coupling reactions. High yields of biaryls were obtained under low-temperature, solvent-free, ligand-free conditions, with simple purification techniques. Moreover, the tin compound could be recycled up to five times without significant loss of reactivity. An expanded catalytic cycle for the Stille cross coupling reaction is proposed in order to explain side products that were formed under certain reaction conditions.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)