LIGANDLESS PALLADIUM-CATALYZED REACTIONS OF ARYLBORONIC ACIDS AND SODIUM TETRAPHENYLBORATE WITH ARYL HALIDES IN AQUEOUS-MEDIA

Polyfunctional biaryls are prepared by a modified Suzuki cross-couplin g reaction between arylboronic acids or sodium tetraphenylborate and a ryl halides ArX, X= 1, Br, Cl in aqueous solvents or neat water using a phosphine-free palladium catalyst, and in the presence of bases (Na2 CO3 or NaOH). All four phenyl groups of Ph4BNa participate in the reac tion. The reaction of Ph4BNa with aryl halides proceeds in water with high catalytic efficiency (250,000 catalytic cycles). (C) 1997 Elsevie r Science Ltd.