Alkene hydrosilation, homogeneous

Ammonia N-donor Ligands Asymmetric Synthesis by Homogeneous Catalysis Decarbonylation Catalysis Hydride Complexes of the Transition Metals Hydroboration Catalysis Hydrogenation Isomerization of Alkenes Hydrosilation Catalysis P-donor Ligands Rhodium Organometallic Chemistry. 

Rhodium(II) acetate catalyzes C—H insertion, olefin addition, heteroatom-H insertion, and ylide formation of a-diazocarbonyls via a rhodium carbenoid species (144—147). Intramolecular cyclopentane formation via C—H insertion occurs with retention of stereochemistry (143). Chiral rhodium (TT) carboxamides catalyze enantioselective cyclopropanation and intramolecular C—N insertions of CC-diazoketones (148). Other reactions catalyzed by rhodium complexes include double-bond migration (140), hydrogenation of aromatic aldehydes and ketones to hydrocarbons (150), homologation of esters (151), carbonylation of formaldehyde (152) and amines (140), reductive carbonylation of dimethyl ether or methyl acetate to 1,1-diacetoxy ethane (153), decarbonylation of aldehydes (140), water gas shift reaction (69,154), C—C skeletal rearrangements (132,140), oxidation of olefins to ketones (155) and aldehydes (156), and oxidation of substituted anthracenes to anthraquinones (157). Rhodium-catalyzed hydrosilation of olefins, alkynes, carbonyls, alcohols, and imines is facile and may also be accomplished enantioselectively (140). Rhodium complexes are moderately active alkene and alkyne polymerization catalysts (140). In some cases polymer-supported versions of homogeneous rhodium catalysts have improved activity, compared to their homogenous counterparts. This is the case for the conversion of alkenes direcdy to alcohols under oxo conditions by rhodium—amine polymer catalysts... 

Despite its few binary compounds, the element gives rise to many complexes. Table 1 indicates the diversity of complexes formed. Several low oxidation state complexes of the element are important homogeneous catalysts, particularly in the oligomerization, isomerization. Hydrogenation, Hydro-formylation, Hydroboration, or Hydrosilation of alkenes. lodorhodium complexes catalyze the industrial-scale carbony-lation of methanol to acetic acid. 

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