Silicon—mercury bonds reactions with

The formation of mercury-silicon bonds has been observed in the reaction of the mercury halides HgCP, HgBr2 and Hg2Cl2 with decamethylsilicocene, Cp 2Si. The reaction products are a consequence on single or double insertion reactions. An example of a product is shown as 2. ... 

The first mercury(I) silyl complex [(Me3SiMe2Si)3Si]2Hg2 was prepared by the reaction of an excess of (Me3SiMe2Si)3SiH with (t-Bu)2Hg. The solid structure of the complex displays linear Si—Hg—Hg—Si fragment with regular metal-silicon bond lengths... 

When a thin film prepared from poly[(tetraethyldisilanylene)bis(2,5-thienylene)] was irradiated in air with a 6-W low pressure mercury lamp bearing a Vycor filter, the absorption maximum near 340 nm disappeared within 40 min. Poly[(tetraethyldisilanylene)(2,5-thienylene)] also exhibited a rapid UV change when its thin film was irradiated. IR spectra of the resulting films reveal strong absorption bands due to Si-O-H and Si-O-Si bonds at 3300 and 1100 cm [. The formation of the Si-O-H and Si-O-Si bonds can be best explained by the reaction of the silyl radicals generated by homolytic scission of the silicon-silicon bonds in the polymer backbone with oxygen in air. The other polymers are also photoactive,... 

Examples of carbene insertions into the carbon-silicon bond of SCBs have been known since 1967, when Seyferth studied the behavior of SCBs exposed to dichlorocarbene, which was generated by thermolytic activation of phenyl(bromodichloromethyl)mercury <1967JA1538>. The reaction produces a mixture of products arising from Si-C and C-H bond insertions, with the major products being the ring-expanded silacyclopentanes that result from Si-C bond insertions (Scheme 30). 

The reaction of heterocyclic lithium derivatives with organic halides to form a C-C bond has been discussed in Section 3.3.3.8.2. This cannot, however, be extended to aryl, alkenyl or heteroaryl halides in which the halogen is attached to an sp2 carbon. Such cross-coupling can be successfully achieved by nickel or palladium-catalyzed reaction of the unsaturated organohalide with a suitable heterocyclic metal derivative. The metal is usually zinc, magnesium, boron or tin occasionally lithium, mercury, copper, and silicon derivatives of thiophene have also found application in such reactions. In addition to this type, the Pd-catalyzed reaction of halogenated heterocycles with suitable alkenes and alkynes, usually referred to as the Heck reaction, is also discussed in this section. 

In 1975, we discovered that photolysis of aryldisilanes produces a novel type of the silicon-carbon double-bonded intermediate (83). The structure of this intermediate is quite different from that of the diphenylsilaeth-ene reported by Sommer et al. A transient formation of the reactive intermediate can be confirmed by trapping experiments. Thus, the photolysis of p-tolylpentamethyldisilane with a low-pressure mercury lamp in the presence of methanol- affords 1,4- and 1,6-adducts, 1-methoxydimeth-ylsilyl-4-methyl-5-deutero-6-trimethylsilyl-1,3-cyclohexadiene, and 1-methoxydimethylsilyl-3-deutero-4-methyl-6-trimethylsilyl-l,4-cyclohexa-diene in 27 and 28% yield (Scheme 11). In this photolysis, monodeutero methoxydimethylsilyltoluene to be expected from the reaction of the sila-ethene intermediate, p-CHsC6H4Si(Me)=CH2, with methanol- produces in only 2% yield (84). 

The reaction of the silicon-carbon double-bonded intermediate generated from phenylpentamethyldisilane with methyllithium and with methylmagnesium bromide leads to the formation of wholly unexpected products (92). Thus, irradiation of 34 in the presence of methyllithium with a low-pressure mercury lamp in diethyl ether followed by hydrolysis produces l,3-bis(trimethylsilyl)benzene (42) and 1,2-bis(trimethylsilyl)-benzene (43) in 60 and 20% yield, respectively, in addition to an 8% yield of phenyltrimethylsilane (Scheme 13). Surprisingly, no disilyl-substituted cyclohexadienes that might be expected from addition of methyllithium to the intermediate followed by hydrolysis are observed. In this photolysis,... 

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