Carbonates siloxides

Scheme 7.3 Reaction of surface Jt-allyl rhodium siloxide complex with carbon monoxide.

Characterization of 6 by solid-state NMR spectroscopy as well as elemental analysis (only 28% decrease of rhodium content in samples after 20 cycles in the hydrosilylation) are convincing evidence of the high efficiency of surface rhodium siloxide complexes in the hydrosilylation of carbon-carbon multiple bonds as well as, presumably, in other reactions catalyzed by late transition metal siloxides syn-... 

There are a few reports of silyl-carbonyl complexes that decompose by processes that may involve a migratory insertion. These reactions lead to siloxide derivatives by ill-defined processes that involve inter- or intramolecular silyl migration6,7 1014 and most commonly result in cleavage of the carbon monoxide C-O bond (e.g. equation 93)247. 

Mc3Si)3SiO as opposed to MesSiO". This in turn might facilitate nucleophilic attack of CO2 by the siloxide ligand (see section 5.3). It should be noted that CO2 readily inserts into rare earth phenoxides to generate stable carbonate complexes. These species could be involved as the actual catalysts in the copolymerization of CO2 with epoxides. ... 

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