HSiR3/CO as the Potent Reactant Combination in Developing New Transition-Metal-Catalyzed Reactions
31 December 2000 (online)
Transition-metal-catalyzed reactions of various organic compounds with HSiR3 and CO are reviewed. A brief summary of the earlier works using Co2(CO)8 as the catalyst is given and an extensive review of recent studies using transition metal catalysts other than Co2(CO)8 is described. The Co2(CO)8-catalyzed reactions of olefins or oxygen-containing compounds with HSiR3 and CO can be classified into four categories; formylation, 1,2-bis(siloxy)vinylation, siloxymethylenation, and siloxymethylation depending on the structure of the substrates used as well as reaction conditions employed. Ring-opening silylformylation of cyclic ethers is accomplished by the presence of rhodium complexes. Rhodium complexes catalyze silylformylation of acetylenes leading to β-silylacrylaldehydes. The reaction of acetylenes with HSiR3 and CO is applied to the preparation of β-lactones, β-lactams, bicyclo[3.3.0]octenones, and so on. C-Formylation of aldehydes takes place in the presence of a rhodium catalyst. Rhodium complexes also catalyze the regioselective incorporation of CO into enamines. The reaction of N,N-acetals with HSiR3 and CO in the presence of rhodium complexes leads to several types of CO-incorporating transformations, depending on the structure of the substrates. The iridium-catalyzed reaction of olefins with HSiR3 and CO gives acylsilane derivatives. Ruthenium complexes catalyze the conversion of 1,6-diynes to catechol derivatives, in which two molecules of CO are incorporated. Various types of new catalytic reactions have been developed by the use of the reagent combination of HSiR3 and CO, many of them being useful in organic synthesis.
carbon monoxide - hydrosilane - cobalt - iridium - rhodium - ruthenium