Soluble rhodium catalyst for carbonylation reaction: Kinetics and mechanism of diphenylurea formation

Authors
Citation
Dk. Mukherjee, Soluble rhodium catalyst for carbonylation reaction: Kinetics and mechanism of diphenylurea formation, I J CHEM A, 40(11), 2001, pp. 1176-1181
Citations number
30
Categorie Soggetti
Chemistry
Journal title
INDIAN JOURNAL OF CHEMISTRY SECTION A-INORGANIC BIO-INORGANIC PHYSICAL THEORETICAL & ANALYTICAL CHEMISTRY
ISSN journal
03764710 → ACNP
Volume
40
Issue
11
Year of publication
2001
Pages
1176 - 1181
Database
ISI
SICI code
0376-4710(200111)40:11<1176:SRCFCR>2.0.ZU;2-P
Abstract
The preparation of [RhA(CO)Py], having the same coordination environment as [RhA(CO)PPh3], has been reported. Its catalytic behaviour under various re action conditions and methanol concentrations for the carbonylation of nitr obenzene at low temperature and atmospheric or elevated pressure has been s tudied. N,N'-diphenylurea (DPU) is the main product under moderate carbon m onoxide pressure (P-co), while methyl-N-phenyl carbamate (MPC) is formed pr edominantly as P-co and methanol concentration is increased. Spectroscopic and kinetic studies show that the reaction proceeds through a species [Rh(A )(C(O)OCH3)(2)] and the isocyanate formed at an intermediate stage is immed iately scavenged by excess amine to form N,N'-diphenylurea. A tentative rea ction mechanism based on the identification of reactive intermediates has b een proposed for the carbonylation process.