| The primary focus of this thesis is the investigation of the catalytic formation of 1,3-dialkyl ureas. The process involves a reaction between nitrobenzene, an alkylamine and carbon monoxide in the presence of (bis(diphenylphosphino)ethane) ruthenium(0)tricarbonyl producing dialkyl urea, aniline and carbon dioxide. After optimization of the catalytic conditions, the reaction was found to produce high yields of a variety of dialkyl ureas.;The kinetics of the overall catalytic cycle, spectroscopy of catalytic solutions, and reactivity of product forming intermediates were investigated. The rates of reaction as a function of catalyst, amine, and nitrobenzene concentrations were determined as well as the dependence on carbon monoxide pressure and temperature resulting in a rate expression for the formation of aniline and urea. Spectroscopy of reaction solutions showed the presence of two catalytic intermediates and a kinetic study of their product forming reactions was conducted and compared to the overall kinetic expression.;The reaction of a four-membered metallacyclic complex with aryl and alkylamines produced two five-membered metallacyclic species and one bis(carbamoyl) complex which were spectroscopically and crystallographically characterized. The mechanism of their formation was investigated using ;The reactivity of the catalyst was studied with o- and p-quinones to explore their use as alternate oxidants in the catalytic reaction. The p-quinones substituted with electron-withdrawing groups were found to oxidize the catalyst readily, producing uncharacterized products which further reacted with amines to produce a bis(carbamoyl) complex, observed previously in catalytic solutions. Reaction of the catalyst with an 3,5-di-t-butyl-o-quinone resulted in a metallacyclic species in which the quinone had formally added across the ruthenium-carbon bond of a metal carbonyl. This complex also reacted with amines to produce a catalytically important bis(carbamoyl) complex. |
