Dimethylsilane

Me3SiCH2CH=CH2, TsOH, CH3CN, 70-80°, 1-2 h, 90-95% yield. " This silylating reagent is stable to moisture. Allylsilanes can be used to protect alcohols, phenols, and carboxylic acids there is no reaction with thio-phenol, except when Cp3S03H is used as a catalyst. The method is also applicable to the formation of r-butyldimethylsilyl derivatives the silyl ether of cyclohexanol was prepared in 95% yield from allyl-r-butyl-dimethylsilane. Iodine, bromine, trimethylsilyl bromide, and trimethylsilyl iodide have also been used as catalysts. Nafion-H has been shown to be an effective catalyst. ... 

Fig. 12. H1 NMR spectrum of [2-(p-methylphenyi)ethyl]dimethylsilane recovered from experiment III.G.l...

QiiHioiNOioSij I286S4-97-9) see Tacrolimus Ar-(l,l-dimethylethyl)pyrazinecarboxamide (C,H jNjO 121885-10-7) see Indinavir sulfate (l,l-dimethylethyl)[[(3P E,7E,22 )-9,10-secoergosta-5,7,10(19),22-tetraen-3-yl]oxy]dimethylsilane (CMHjgOSi 104846-63-1) see Calcipotriol iV-(l,l-dimethylethyl)-l,4,5,6-tetrahydropyrazine-carboxamide... 

C4(,H 202S 39668-35-4) see Betacarotene [[(la3P,7 ,22 -6,19-sulfonyl-9,10-secoergosta-5(10),7,22-triene-13-diyl]bis(oxy)]bis[(l,l-dimethyl-ethyl)dimethylsilane]... 

It has also been shown that dimethylsilyl enolates can be activated by diisopropylamine and water and exhibit a high reactivity toward iV-tosyl imines to give Mannich-type reaction products in the absence of a Fewis acid or a Bronsted acid.51 For example, the reaction of [(1-cyclohexen-l-yl)oxy]dimethylsilane with 4-methyl-A -(phenylmethylene)benzene sulfonamide gave re/-4-methyl-N- (f )-[(15)-(2-oxocyclohexyl)phenyl-methyl] benzenesulfonamide (anti-isomer) in 91% yield stereoselectively (99 1 anti syn) (Eq. 11.30). On the other hand, Fi and co-workers reported a ruthenium-catalyzed tandem olefin migration/aldol and Mannich-type reactions by reacting allyl alcohol and imine in protic solvents.52... 

For the preparation of Ila and lib see (20 ). Compounds Ilc-e were prepared in reasonably good yields from aniline and 1,7-dichlorooctamethyltetrasiloxane (He), bis-(phenylamino)-dimethylsilane and 1,5-dichlorohexamethyltrisiloxane (Hd), and aniline and 1,3-dichlorotetramethyldisiloxane (He). All syntheses were carried out in DMF and in the presence of stoichiometric amounts of triethylamine as hydrogen chloride acceptor (21). 

Similar results were obtained when o-phenylenediamine was reacted with mb. A range of low boiling compounds were separated from the reaction mixture after 10-12 hr heating at 220°C. These have been identified as diazadimethylsilaindane Vb (m.p. 76-78°C lit. (321 m.p. 75-83°C) and bis(phenylamino)dimethylsilane VIb (m.p. 46-48°C lit. (331 m.p, 45 2°C). They are probably formed by thermal decomposition of the intermediate unsymmetrical disilazane IVb". At 190-225°C/0.3 torr, a crystalline fraction with... 

VUIb is formed by dimerization of the diazasilaindane, Vb, and subsequent reaction of the cyclic dimer, Vllb, with bis(phenylamino)-dimethylsilane, VIb, as it was shown in separate experiments starting from Vb and VIb. It was subsequently found that VUIb is formed in fairly good yield whenever o-phenylenediamine is brought into reaction with difunctional silanes, such as dichlorodimethylsilane, bis(diethylamino)dimethylsilane and hexamethyl-cyclotrisilazane. 

When Illb is heated with p-phenylenediamine at 200-300°C under conditions similar to the other phenylenediamines, mainly insoluble, probably crosslinked, oligomers (rubber-like solid) are formed. On the other hand, p-phenylenediamine with bis(diethylamino)dimethylsilane at 180°C yielded a toluene-soluble solid whose molecular weight and elemental analysis agree well with the probable cyclophane structure IX for C32H48NsSi4 Mcaic. 657.16, found Mcryoscopic 648, m/e 657.16 calc. % C, 58.49 H, 7.36 N, 17.05 Si, 17.10 found % C, 58.40 H, 7.42 N, 17.10 Si, 17.16. The structure of this compound is being further investigated. 

While the Olin efforts on the production of high-temperature polymers were centered mainly on FeCl3-catalyzed condensation reactions, subsequent efforts from Union Carbide, Inc. utilized an aminosilane route and a ureidosilane route (Fig. 3) to synthesize carboranylenesiloxane polymers of high molecular weights. Using the former route, the polymer was produced by a condensation reaction between a carborane-disilanol and bis(dimethylamino)dimethylsilane, during which an expulsion of a... 

The self-assembly of di[4-(5-pyrimidyl)phenyl]dimethylsilane and -germane with (ethylenediamine)palladium dinitrate in an 1 2 ratio generated a new octahedral supramolecule containing group 14 elements <06ICC50>. 

Both the dimethylsilanes and germanes are much more reactive than the tetraalkyls and hydrolyze readily. 

Historically, the polysilanes are old materials and the first diaryl derivatives were probably prepared in 1924 by Kipping (12). The simplest dialkyl representative poly(dimethylsilane) (PDMS) was described in 1949 (12). These materials were,... 

Figure 12 shows DSC curves for poly(phenylmethylsilane-co-dimethylsilane), polysilane(II) and polysilane(III)s. The... 

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