ACTIVITY OF HOMOGENEOUS TRANSITION-METAL CATALYSTS FOR OXIDATIVE CARBONYLATION OF ANILINE TO N,N'DIPHENYL UREA

Oxidative carbonylation of aniline to N,N'diphenyl urea was achieved a t 100 degrees C and atmospheric pressure conditions. The screening of several homogeneous transition metal complexes was carried out. The be st catalytic activity was shown by [Ru(CO)(3)I-3]NBu4 catalyst. The ef fect of solvents, temperature, aniline and promoter concentration etc. on the activity and selectivity of this catalyst was studied. The act ivation energy of the reaction is evaluated as 26.6 kcal/mol. A plausi ble mechanistic pathway for oxidative carbonylation of aniline to diph enyl urea has also been proposed. (C) 1997 Published by Elsevier Scien ce B.V.