Palladium-catalyzed biaryl-coupling reaction of arylboronic acids in water using hydrophilic phosphine ligands

Hydrophilic phosphine ligands possessing a carbohydrate side-chain, such as N-(4-diphenylphosphinophenyl)methyl gluconamide (), N-[4-(2′-dicyclohexylphosphinobiphenyl)phenylmethyl] gluconamide (), and N-[4-(2′-di-t-butylphosphinobiphenyl)]phenylmethyl gluconamide (), were newly synthesized to carry out palladium-catalyzed biaryl coupling of arylboronic acids in a single aqueous medium. The catalyst prepared in situ from Pd(OAc)2 and exhibited a higher efficiency than that of , , Ph2P(m-C6H4SO3Na) (TPPMS) or P(m-C6H4SO3Na)3 (TPPTS) for representative aryl bromides, chlorides, or triflates. The catalyst prepared in situ from Pd(OAc)2 (0.001 mol%) and (0.002 mol%) achieved 96,000 TON in the reaction of p-tolylboronic acid with 4-bromoacetophenone in water.