Iridium complexes silicon compounds

I 14 Tran omations of (Organo)silicon Compounds Catalyzed by Iridium Complexes... 

Among the latter group, iridium complexes (though less common than rhodium) and perhaps also ruthenium play crucial roles in many of the above-mentioned transformations of silicon compounds, leading to the creahon of sihcon-carbon bonds. Examples include the hydrosilylation or dehydrogenahve silylation of alkenes and alkynes, the hydroformylahon of vinylsilanes, and the silyhbrmylation of alkynes as well as activation of the sp C—H of arenes (by disilanes) and alkenes (by vinylsilanes). 

By contrast, the isomerization of silyl olefins and addition of silylacetylenes =C—H bond into imines catalyzed by iridium complexes appears to serve as a suitable route for the synthesis of silylfunctionahzed organic compounds. Hence, the acquisition of experimental data on catalysis by iridium complexes in silicon chemistry may be regarded as an initial stage in the quest for catalytic processes leading to the synthesis of other p-block (e.g. B, Ge, Sn, P)-carbon bond-containing compounds. 

Several examples of oxidative addition reactions of compounds involving group (iv) elements, silicon and germanium, with iridium(i) complexes have been described and reviewed. In the reaction of silicon hydrides (CH3) (C2H50)3 SiH with bis(bis-l, 2-diphenylphosphinoethane)iridium(i), [Ir (diphos)2],... 

The following metal compounds are used for the preparation of the catalysts oxides, metal carbonyls, halides, alkyl and allyl complexes, as well as molybdenum, tungsten, and rhenium sulfides. Oxides of iridium, osmium, ruthenium, rhodium, niobium, tantalum, lanthanum, tellurium, and tin are effective promoters, although their catalytic activity is considerably lower. Oxides of aluminum, silicon, titanium, manganese, zirconium as well as silicates and phosphates of these elements are utilized as supports. Also, mixtures of oxides are used. The best supports are those of alumina oxide and silica. 

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