Hydrosilylation trimethylsilane

The hydrosilylation of butadiene proceeds with palladium compounds even in the absence of phosphines. Other ligands, such as glyoxime, benzonitrile, and 1,5-cyclooctadiene, can be used as effective ligands for the hydrosilylation of butadiene (65, 67). The reaction of trichlorosilane and dichlorosilane with isoprene proceeded regioselectively and stereo-selectively to give Z-l-trichlorosilyl-2-methyl-2-butene (67) (65, 66, 68). No reaction of trimethylsilane with isoprene took place, and this shows the lower reactivity of trialkylsilane. 

Hydrosilylation of butadiene gives rise to different products depending on the kinds of hydrosilanes and the reaction conditions. Trimethylsilane produces the 1 2 adduct, namely 1-trimethylsilyl-2,6-octadiene (231) in high yields [100,101], Unlike other telomers, which have the 2,7-octadienyl chain, the 2,6-octadienyl chain is formed by the hydrosilylation. However, 1-trichlorosilyl-2-butene (230) as the 1 1 adduct is formed selectively with trichlorosilane, which is more reactive than trialkylsilanes. The... 

Dimethylketene trimethylsilyl acetals.1 Hydrosilylation of methacrylates with trimethylsilane catalyzed by rhodium(III) chloride results in rearrangement to di-methylketene trimethylsilyl acetals in 65-85% yield. 

Catalytic hydrosilylation of alkenes performed in the presence of a chiral catalyst results in the formation of chiral silanes. Initially platinium catalysts of the type L PtCl2, L = (/ )-benzyl-(methyl)phenylphosphine (BMPP) or (/ )-methyl(phenyl)propylphosphine and 1,1-disubstituted prostereogenic alkenes, such as a-methylstyrene, 2,3-dimethyl-l-butene and 2-methyl-l-butene, were used however, the stereoselectivity was low4,5. A slightly higher stereoselectivity is obtained when dichlorobis[(/ )-benzyl(methyl)phenylphosphine]nickel [Ni(BMPP)2Cl2] is used as the catalyst. Note that two chiral silanes are formed in this reaction, both of which are products of anti-Markovnikov addition. The major product is the expected dichlorosilane 3, while the byproduct is an anomalous chlorosilane 4 both products were separated by fractional distillation and the major product methylated to give the trimethylsilanes 56 7. 

Hydrosilylation of aryl alkyl ketones with trimethylsilane, catalyzed by a [PtCl2 (/f)-BMPP ] complex, gave (R)-silyl ethers (91) with low enantiomeric excesses,but a combination of dimethylphe-nylsilane and a Rh /(S)-BMPP complex gave (R)-silyl ethers (92) in 44-56% ee.ii-Mn use of a [ Rh(COD)Cl 2]/(-)-DI0P complex and a-naphthylphenylsilane" is effective for the reaction of a-keto esters, giving (/ )-a-hydroxy esters (93)." - ... 

The Pt-catalyzed hydrosilylation of trimethyl silane and alkenols or alkenyl-polyethers lead to nonionic silane surfactants, whereas the addition of allylglycidyl ether to trimethylsilane results in a precursor for ionic derivatives. The epoxy group is highly reactive towards nucleophilic agents and can be easily transformed into quaternary ammonium, betaine, or sulfonate complexes. Additionally, cation-anion complexes can be formed by the transformation of two equivalents of epoxy silane with one equivalent of trialkyl ammonium hydrogen sulfite. The reaction of hydroxyalkyltrimethylsilane... 

The hydrosilylation of butadiene with phosphine-palladium catalysts proceeds in an entirely different manner from that of platinum catalysts to give 2,6-octadienylsilane or 2-butenylsilane selectively depending upon the structure of the hydrosilane employed. For instance, trimethylsilane and other trialkylsilanes reacted with butadiene to give the 1 2 adduct, 2,6-octadienyltrialkylsilanes, in excellent yield77,78 whereas trichlorosilane... 

The hydrosilylation of isoprene with palladium catalysts using chlorohydrosilanes affords only 1 1 adducts. Trimethylsilane does not add to isoprene at all. In most cases, the reaction gives 2-methyl-2-butenylsilane exclusively in excellent yield (equation 38)90,91, but at a higher temperature the formation of a small amount of 3-methyl-2-butenylsilane is detected89. 

The hydrosilylation of butadiene with trimethylsilane catalyzed by nickel(O) complexes, such as Ni(PR3)2(CO)2, Ni(COD)2, Ni(CO)4 and Ni(CH2 = CHCN)PPh3, gives a mixture of 2-butenyltrimethylsilane and 2,6-octadienyltrimethylsilane together with a considerable amount of cyclooctadiene88,96. The product ratio is markedly affected by the sort of donor ligand employed88. 

Trimethylsilane in the presence of palladium gives 1,4-dihydro-1-trimethylsilylpyr-idine, together with silylated dimer titanium-catalysed hydrosilylation produces a tetrahydro-derivative cleanly. ... 

The extent of asymmetric hydrosilylation depends strongly upon the structure of hydrosilanes employed in a similar manner to the cases of other chiral rhodium complex-catalyzed reactions with dimethylphenylsilane optical yields are generally more than several times as high as with trimethylsilane. Most remarkable is the fact that the addition of dimethylphenylsilane to pivalophenone gave the silyl ether of (iS)-2,2-dimethyH-phenylpropanol, while that of trimethylsilane led to the (R)-enantiomer. 

The availability of trimethylsilane in larger amounts and reproducible quality by the reduction of chlorotrimethylsilane to trimethylsilane with magnesium hydride [91] in a milling reactor provided a better method in silane surfactant chemistry [92]. By using trimethylsilane in hydrosilylation reactions with a, 5-unsaturated compounds such as alkenols, allyl glycidyl ether, or alkenyl polyethers, a whole range of amphiphilic trimethylsilane compounds can be easily obtained (Fig. 8). 

The silane alcohol can serve as an intermediate for further reactions with sulfamic acid to give sulfates or EO leading to anionic or nonionic silane surfactants (Fig. 26), respectively. Alternatively, the nonionic derivatives can be obtained by hydrosilylation of the trimethylsilane with an alkenol polyether (Fig. 26). The hydrosilylation reaction with allyl glycidyl ether (Fig. 8)... 

More recently, Gacal and coworkers used Wilkinson s catalyst in the hydrosilylation of polyisoprene-f)/ocfe-poly(vinyl trimethylsilane) (PIP-6-PVTMS)." They achieved 80% hydrosilylation of the PIP unit and then... 

Figure 13 Hydrosilylation and hydrogenation of polyisoprene-b/ocfc-poly(vinyl trimethylsilane).

Gacal BN, Fdiz V, Shishatskiy S, Rangou S, Neumarm S, Abetz V. Modification of polyisoprene-block-poly(vinyl trimethylsilane) block copolymers via hydrosilylation and hydrogenation, and their gas transport properties. J Polym Sd B Polym Phys. 2013 51 1252-1261. 

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