Silicon-phenyl groups

Likewise, reaction of chlorotrimethylsilane with the silyllithium reagent resulting from cleavage of a silicon-phenyl group of bis(trimethylsilyl)-... 

Silicone. SiHcone elastomers have a sdoxy backbone with methyl, vinyl, and phenyl groups attached. The elastomers are designated by their chemical composition, as foUows methyl siHcone (MQ), methyl vinyl siHcone (VMQ), methyl phenyl siHcone (PMQ), methyl phenyl vinyl siHcone (PVMQ), and fluorovinyl methyl siHcone (FVMQ). 

PMQ Silicone rubbers having both methyl and phenyl groups on the polymer chain. 

Phenyl or mixed alkyl/phenyl substituted silicon hydrides show similar reactivities to trialkylsilanes. Indeed, by replacing one alkyl by a phenyl group the effect on the hydrogen donating ability of SiH moiety increases only slightly. ... 

Silicon compounds substituted by 2-(dimethylaminomethyl)phenyl groups [C6H4CH2N(CH3)2]nSiX4 n (X = Cl, H, organo group, n = 1 - 4) are available by the reaction of the appropriate chlorosilanes with 2-(dimethylaminomethyl)phenyllithium [4],... 

We found a new route for preparing larger amounts of these disilanes. The stepwise substitution of the phenyl groups at the silicon atoms with triflic acid and the additional conversion to Si-H and Si-C1 functions at low temperatures leads to pure chloro-hydrogen disilanes. The synthetic routes to 1,1,1-trichlorodisilane 2 and 1,1-dichlorodisilane 3 [7] are shown in Eq.(4). 

The replacement of 5-10% of the methyl groups on the silicon atom with phenyl groups gives polymers which exhibit superior low temperature properties. Brittleness temperatures of approximately -117 °C can be achieved compared to the approximately -70 °C for the VMQ types. The ISO designation for the phenyl modified silicones is either PMQ or PVMQ depending on whether the grade is vinyl modified. 

The resistance of the E14-S bond in cyclotrimetallathianes toward nucleophilic reagents, for example, water and alcohol,62 increases on going from the silicon compounds to the corresponding germanium and tin derivatives. This is due, most likely, to the fact that the reaction of less nucleophilic ylides with phenyl groups at the phosphorus atom with trithianes (R2MS)3 (M = Ge, Sn) occurs slowly and is impeded by several side processes. 

Organic groups are bound to the silica surface after grinding silica in organic liquids (277). A more controlled substitution of surface silanol groups was reported by Wartmann and Deuel (194). Silica gel which had been treated with thionyl chloride was allowed to react with phenyl lithium. Silicon-phenyl bonds could be detected by infrared spectroscopy. The phenyl content of Aerosil treated in this way as estimated from carbon analysis corresponded to 85% of the silanol groups (188). However, it is not certain whether the reaction... 

The catalyst, although applied in 1.5 equiv., also worked well with heteroarenes in the alkylation reactions. A simple and most plausible mode for the enantioselectivity of the Friedel-Crafts reaction has been shown in Scheme 33. It is evident from the model that the arene would approach from the front (Si) face, as the back (Re) face is blocked by the phenyl group present on the silicon. 

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