The application of carbonylation and related reactions to fatty acid derivatives

Abstract

The work detailed in this thesis is mainly concerned with the carbonylation of fatty acid derivatives, using carbon monoxide atmospheres in the presence of a transition metal. The two systems under study were the conversion of oleonitrile to a cyano-ester using a cobalt catalyst, and formation of isocyanates from amines in the presence of a palladium salt. The objectives of each study were: (i) to assess the influence of physical conditions on the reaction (i.e. pressure, time and temperature);(ii) to examine the effect of various additives on the system (i.e. phosphines, iodides and bases); and (iii) to identify any catalytic species observed under reaction conditions.Three major techniques were employed in each study: autoclave reactions, high pressure infra-red studies and atmospheric pressure nitrogen-line chemistry. The proposed underlying reaction mechanism was examined critically for each system, comparisons being drawn between the postulated catalytic species and those actually observed by high pressure infra-red spectroscopy. The chemical properties of the proposed catalytic intermediates are discussed in relation to the effect of co-reactants on the system. In the case of the carbonylation of oleonitrile the high pressure infra-red studies are consistent with the proposed reaction mechanism based upon the acyl complex RCOCo(CO)(_4). Although the infra-red study on the carbonylation of amines did not reveal any definite information, the results of other experiments were found to be consistent with a system based upon a carboxamido species L(_2)Pd(Cl)(CONRR').