- Homogeneous catalytic hydrosilylation of the C=C double bond in the presence of transition metal catalysts
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Hydrosilylation of unsaturated esters and other vinyl- and vinylidene type olefins has been carried out with PtCl2(PhCN)2, RhCl(PPh3)3 and platinum-phosphine catalysts.With PtCl2(PhCN)2 and platinum(0)-phosphine complexes as catalysts the hydrosilylation of methyl methacrylate gave the linear product 2a, whereas in the RhCl(PPh3)-catalyzed reaction the silyl ketene acetal derivative 4a was formed selectively.In the reactions of other esters and unsaturated hydrocarbons the main product is highly dependent on the structure of the substrate, but the catalyst used is also very important.With unsaturated hydrocarbons the selectivity is rather poor, but in the case of 1-vinyl-2-pyrrolidinone the linear- (9e) and the branched hydrosilylated derivative (10e) are formed in high yields depending on the catalyst used.The platinum(II)-phosphine complexes are inactive in the absence of air, but some platinum(0)-phosphine catalysts are also effective under argon in the hydrosilylation of methyl methacrylate.
- Skoda-Foeldes, Rita,Kollar, Laszlo,Heil, Balint
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p. 297 - 304
(2007/10/02)
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- Homogeneous catalytic hydrosilylation of the C=C double bond with platinum catalysts
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Hydrosilylation of vinyl- and vinylidene-type olefins (styrene (1a), 2-phenyl-propene (1b), methyl methacrylate (6)) has been carried out with either PtCl2 (dissolved in the substrate) or a platinum-phosphine catalyst prepared in situ.The activity and regioselectivity of the platinum-phosphine catalysts depend strongly on the phosphine structure and the metal/ligand ratio.Complexes involving chelating phosphines are inactive.Although mainly linear regioisomers are formed (2 and 7 respectively) in the reaction of 6, some 1,4-addition of the silane to the conjugated system also takes place to give a silyl ketene acetal derivative (8).A marked decrease in the reaction rate is observed if Ph3SiH instead of Et3SiH is used as the hydrosilylating agent.
- Skoda-Foeldes, Rita,Kollar, Laszlo,Heil, Balint
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p. 275 - 280
(2007/10/02)
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