Super fast cobalt carbonyl-mediated synthesis of ureas

Fast cobalt carbonyl-mediated generation of ureas from primary amines was performed using high-density microwave irradiation. This enhanced method permitted the preparation of symmetrical ureas in good yields and unsymmetrical ureas in moderate yields. The reaction times varied between 10 s and 40 min. The proposed mechanism for the reaction includes in situ generation of an intermediate isocyanate that subsequently traps the free amine, producing the urea product.