CHLOROMETHYLDIMETHYLPHENYLSILANE

bp 106–107°C/15 mmHg; d 1.024 g cm3

The first reported preparation and use of (chloromethyl)dimethylphenylsilane was in 1949.At the time, the main utility of (chloromethyl)dimethylphenylsilane was as the starting material for conversion to the corresponding Grignard reagent (see below). Since then, it has also been used for heteroatom alkylation, carbon alkylation, and conversion to a variety of organometallic and organolanthanide reagents. The main advantage of this reagent over the closely related (chloromethyl)trimethylsilane is the ability of (chloromethyl)dimethylphenylsilane to undergo a Fleming oxidation, thus allowing (chloromethyl)dimethylphenylsilane to serve as a masked hydroxyl group. This utility has been exploited for both the C-substituted and Nsubstituted adducts. A major disadvantage of the use of (chloromethyl)dimethylphenylsilane is its propensity to undergo rearrangements under a variety of conditions (see below). (Chloromethyl) dimethylphenylsilane is used as the precursor for the preparation of (phenyldimethylsilyl)methoxymethyl chloride (SMOM-Cl), a hydroxyl protecting group.
(Chloromethyl)dimethylphenylsilane (1) can be utilized to install a silylmethyl group on carbon via base promoted C-alkylation of terminal alkynes,dihydropyrazines,malonic esters,phenylacetonitriles,sulfoxides,and imines.Although has been used directly in the alkylation, conversion to the corresponding iodide via Finkelstein displacement (eq 1) prior to alkylation is sometimeswarranted. Except for the malonic esters (eq 2), strongly basic conditions and lowtemperatures (with slow warming) are generally employed in the transformation (eqs 3 and 4).

can be prepared either by the reaction of phenylmagnesium bromide with chloro(chloromethyl)dimethylsilane in ether at reflux,or by the reaction of phenylmagnesium bromide with chloro(chloromethyl)dimethylsilane in the presence of catalytic (N,N,N,N-tetramethylethylenediamine) zinc in 1,4-dioxane at 20°C.