Chloromethyl dimethylsilane

Rearrangement of 1-alkenylsilanesf Alkenyl(chloromethyl)dimethylsilanes, readily available from hydrosilylation of alkynes with (chloromethyl)dimethylsilane, rearrange in the presence of aluminum chloride to allyl- and/or cyclopropylsilanes. (Z)-l-Alken-ylsilanes rearrange exclusively to (Z)-allylsilanes (equation I). (E)-l-Alkenylsilanes rearrange to (E)-allylsilanes as the major product (equation II). Cyclopropylsilanes are formed... 

A silacyclopropane 69 was proposed as an intermediate in one of two possible pathways involving the Grignard reaction of bis(chloromethyl)dimethylsilane with trimethylchlorosilane in THF. The intermediate was obtained from the intramolecular cyclization of GlCH2Me2SiCH2MgCl, which undergoes a ring-opening polymerization by nucleophilic attack (Scheme 17) <19998KC422>. 

Method A and C have been used for intramolecular cyclopropanation reactions. Thus, 2-silabicyclo[3.1.0]hexanes 5b,c and 2-silabicyclo[4.1.0]heptane 5d have been prepared in moderate yields by treatment of alkenyl(chloromethyl)dimethylsilanes 4b-d with sodium. In the case of 4d, C-H insertion of the intermediate carbene competes with cyclopropanation, and for 4e, it becomes the sole carbene reaction. The corresponding allylsilane 4a does not undergo intramolecular cyclopropanation, and in the case of vinylsilane 6, intramolecular cyclopropanation is probably involved in the formation of silylcyclopropane 7. 

The reaction of bis(chloromethyl)dimethylsilane with bis[(dimethylsodiumstannyl)methyl]di-methylsilane afforded a mixture of l,l,3,3,5,5,7,7-octamethyl-l,5-distanna-3,7-disila-cyclooctane (1), its dimer 1,1,3,3,5,5,7,7,9,9,1 l,ll,13,13,15,15-hexadecamethyl-l,5,9,13-tetrastanna-3,7,l 1,15-tetrasilacyclohexadecane (2) and unidentified polymeric compounds (Eq. 1). The ring system 1 could be isolated by distillation and the macrocycle 2 by size exclusion chromatography [4]. 

Chloromethyl) isocyanatodimethyhilane 504, triethylisocyanatosilane 508, and various silane diisoqranates were prepared by heating chloro(chloromethyl)dimethylsilane or dichlorodialkyl silanes with urea in the presence of SnCU or hexamethyldisila-zane for 5-6 h at 115-125 °C [356]. 

Preparative Methods can be prepared either by the reaction of phenylmagnesium bromide with chloro(chloromethyl)di-methylsilane in ether at reflux, or by the reaction of phenylmagnesium bromide with chloro(chloromethyl)dimethylsilane in the presence of catalytic (Al,Al,lY,iV -tetramethylethylenedi-amine)zinc in 1,4-dioxane at 20 °C ... 

Scheme 33 Reaction of O-trimethylsilylated hydrazides with chloro(chloromethyl)dimethylsilane...

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