Allylsilanes, Allenylsilanes, and Propargylsilanes

Since the discovery of the Hosomi-Sakurai allylation reaction [332] much attention 

In 1976 we reported that aldehydes and ketones are efficiently allylated with allyl-trimethylsilane in the presence of a substoichiometric amount of I iLf, [332]. Subsequently, BU4NF, a fluoride ion source, was found to be an effective catalyst of this allylation reaction [333]. After these initial reports of the Hosomi-Sakurai reaction, several allylsilanes, including highly functionalized compounds, were used for regio- and stereoselective allylation of a variety of carbon electrophiles [6, 13, 14, 334]. In the nineteen-eighties, some Lewis acids (TMSOTf [335], TMSI [336] 

1 Lewis Acid-promoted Reactions of Aidehydes, Ketones, and Acetais 

Woerpel et al. have reported the stereoselective allylation of 5- and 6-membered 

The aUylation of acetals with y-substituted allylsilanes is occasionally highly syn-selective [362]. Panek et al. have succeeded in highly diastereo- and enantioselective synthesis of homoallyl ethers by aUylation using homochiral a,y-disubstituted allylsilanes [334] (Section 10.3.1.3). 

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Intramolecular allylsilylation of alkynes is a convenient route to cyclic vinylsilanes.211 Propargylsilanes are available for Lewis acid-promoted carbosilylation of alkynes.212 Unlike allylsilanes, both cr-substituted and unsubstituted propargylsilanes react at the a-position, which can be rationalized by in situ isomerization of these reagents to allenylsilanes (Equation (55)). 

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