Diphenyldichlorosilane, reaction with

Li and co-workers also reported a highly efficient conjugate addition reaction with arylsilanes as nucleophilic reagents. The reaction of 2-cyclohexenone with 4 equiv. of either diphenyldichlorosilane or phenylmethyldichlorosilane in water generated the conjugate addition product in 97% and 95% yields, respectively (Scheme 55).143 An excess of sodium fluoride additive was important in this reaction. 

Protection of amines. Reagent 1 is prepared from diphenyldichlorosilane by the following sequence reaction with vinylmagnesium bromide, hydroboration of the resulting divinylsilane, and tosylation. The 4-diphenylsilapiperidines that are formed with primary amines can be cleaved by exposure to CsF, BU4NF in THF or DMF. 

Diphenyldichlorosilane is thought to react with hemiacetal 1 to afford silyl heraiac-etal 22 and thereby liberate HC1 to perpetuate the reaction. The investigators design... 

The discussion continues regarding the role of silanone and cyclodisiloxanes as reactive intermediates in the formation of Si-O-Si bond.25 In studies of the reaction of dimethyldichlorosilane, phenylmethyldichlorosilane, or diphenyldichlorosilane with dimethyl sulfoxide in the presence of 2,2,5,5-tetramethyl-l-oxa-2,5-disilacyclopentane, Weber and co-workers obtained products of the insertion of diorganosiloxy unit into the cyclic siloxane, accompanied... 

Scheme 1. Silylation reactions on MCM-41 surface a) silylation of the outer surface by diphenyldichlorosilane in THF at ambient temperature and b) functionalization of the inner surface with APTES in CH2C12 at ambient temperature and toluene at reflux. APTES is not neccessarily bonded on three silanol groups.

Silylation of the outer surface with diphenyldichlorosilane does practically not influence the texture of MCM-41. As previously indicated by TEM micrographs only the external surface is effected.8 It is noteworthy, too, that the pre-silylation is independent on the offered amount of silane (Table 2) and, thus, does not result in a bonding at the inner surface at ambient temperature. A shrinking of pore diameter by utilizing diphenyldichlorosilane is only observed at higher reaction temperatures. 

The mixture of chromium trioxide with one equivalent of trimethylsilyl chloride, with no solvent added, results in the formation of an explosive red liquid that is soluble in dichloromethane or tetrachloromethane.428 It is suggested, with no spectroscopic evidence, that it consists of trimethylsilyl chlorochromate [Me3Si-0-Cr(0)2-Cl]. This compound, which can safely be used in organic solvents, is able to oxidize alcohols to aldehydes or ketones, and interacts with r-butyldimethylsilyl ethers producing deprotection, followed by oxidation of the liberated alcohol.138 Compounds analogue to trimethylsilyl chlorochromate are also able to oxidize alcohols, although they possess lesser reactivity. They can be prepared by reaction of chromium trioxide with dimethyldichlorosilane and diphenyldichlorosilane.428b... 

The first reported examples, Fe(C5H4)2SiPh2 (47) and the spiro compound Si(H4C5FeC5H4)2 (52)131, were synthesized by a classical procedure (see Section II) via the reaction of dilithioferrocene-TMEDA with diphenyldichlorosilane and tetrachlorosilane, respectively. The other members in this class were prepared analogously or via the reaction of ferrous chloride with the corresponding dilithiated bis(cyclopentadienyl)dimethylsilane11°,132 134. 

To increase the diphenyldichlorosilane content in the condensate, it is advisable to conduct the direct synthesis of phenylchlorosilanes not with copper-silicon alloy but with a mechanical mixture of silicon and copper powders, promoted by zinc oxide. The introduction of zinc oxide seems to inhibit the undesirable reactions of diphenyl and benzene formation, creating favourable conditions to attach phenyl radicals to the silicon atom, i.t. to form diphenyldichlorosilane. 

Treatment of the allylic alcohols with diphenyldichlorosilane and 2,6-lutidine afforded the bis-alkoxysilanes 195 in excellent yield. These silicon-tethered compounds were treated with Grubbs catalyst to induce RCM reaction, furnishing the seven-membered silacycles 196 in 87-95% yield (Equation 37) <1998JOC6768>. 

Two fullerenes were also joined in different fashion by mechanochanical reactions of fullerene with diphenyldichlorosilane and diphenyldichlorogeimane (4.2 equiv.), in the presence of lithium (5.8 equiv.), in milling vessel filled with argon which gives novel bisfullerene products 46 aud 47 possessing silicon (or germanium) bridges (Scheme 7.13) [24,25]. 

The reactions of tris(methylsilyl) phosphine illustrate some of the properties of the P-Si bond in this type of compound (Figure 9.9). The bond is cleaved by water, oxygen, alkyl iodides, cobalt chloride and so forth. With diphenyldichlorosilane, long-chain polymeric material is formed (9.196a). Phosphines with only two Si atoms attached to P are known (9.196b) [17]. 

Solid catalyst [Mg-Ti] was analyzed for its composition and specific surface area (Table 2). A 3.0 wt. % of titanium is incorporated on active support. BET surface area of crystalline magnesium dichloride is found to be 10 mVg. The treatment of magnesium dichloride with 2-ethyl-1-hexanol and DBPh followed by diphenyldichlorosilane gives a product [Mg-Ti I] with improved surface area characteristics (50 mVg). The reaction of [Mg-Ti I] with titanium tetrachloride increases the surface area to 115 m /g. These results show that the present process of catalyst synthesis gives approximately tenfold improvement in the surface area of the Mg-Ti catalyst as compared to the starting anhydrous magnesium dichloride. 

The foundation of polysilane chemistry was laid by F. S. Kipping and his coworkers. Investigations by these researchers on the reactions of alkali metals with diorganodichlorosilanes in general and diphenyldichlorosilane in particular led them to isolate a number of cyclic rings. For example, the cyclotetrasilane [Ph2Si]4 was a prominent product that was isolated by Kipping and his coworkers (see Eq. 7.1) [1,4]. 

This direct process has been the focus of much research, particularly in Industrial laboratories during the last 40 years [8]. Published results show that it an extremely complex process with many competing reactions which is difficult to apply to systems other than methylchlorosilanes and trlchlorosllane. Key monomers for productfon of linear polydimethyl-siloxane are dimethyldichlorosilane and trimethylchlorosllane so in general the process has been optimized to produce these materials. Other monomers such as, phenylmethyldichlorosilane, methylvinyldichlorosilane, diphenyldichlorosilane and trlfluoropropylmethyldichlorosilane are required to modify the propertfes of polydimethylsiloxane as described later. These are produced by a variety of approaches depending upon the producer. 

A soln. of diphenyldichlorosilane in methyl acetate as an inert solvent added portion wise with shaking to a mixture of 1.5-2 moles of ZnO and methyl acetate, then gently refluxed for ca. 11 min. until color change of crystal violet indicates completion of the reaction hexaphenylcyclotrisiloxane. Y 97%. T. Takiguchi et al., J. Org. Ghem. 25, 310 (1960). 

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