Base- and phosphine-free palladium-catalyzed homocoupling of arylboronic acid derivatives under air

In the presence of a catalytic amount of Pd(OAC)(2), various arylboronic acids underwent homocoupling in MeOH at ambient temperature under air to give rise to symmetrical biaryls. The homocoupling of arylboronic acids was also carried out using polyurea-encapsulated Pd(OAC)(2) as a recyclable catalyst.