Organosilicon reagents allylsilanes

Treatment of triarylbismuth difluorides with organosilicon reagents, such as silyl enol ethers [94JCS(P1)1739], siloxycyclopropanes [95JCS(P1)2543], ketene silyl acetals [99JOC6924, 95JCS(P1)2543] or allylsilanes... 

The derivatization method is compensated by the electrophihc addition reaction using organosilicon reagents [40-43]. Thus, the squaric acid family of derivatives, e.g., dichloride 17, methyl ester chloride 18, amide chloride 19, and diester 5 are the partners of the reactions with allylsilanes, silyl enol ethers, and silyl ketene acetals (Scheme 3). In this case, 1,2- and 1,4-addition to 20 and 21, respectively, are regulated by the substitution pattern of unsaturated organosilanes, kind of Lewis acid catalysts, and the reactivity of acid derivatives. The less congested is the reaction site, the more preferable is 1,2-... 

Olefin metathesis has been established as a standard tool in organic synthesis, and is also applicable to the synthesis of organosilicon reagents. For example, crossmetathesis of allylsilanes provides an efficient access to more substituted and functionalized allylsilanes (Scheme 3-64). ° The cross-metathesis of vinylsilanes is a convenient method to prepare substituted vinylsilanes.For example, the reaction of... 

Nucleophilic substitution reaction is another class of important transformations that organosilicon reagents play key roles in organic synthesis. Electrophiles such as acyl and alkyl halides activated by a Lewis acid in a stoichiometric amount readily react with silyl enol ethers, allylsilanes, and alkenylsilanes. ... 

Since the preparation of anionic species or organosilicon compounds is largely restricted by its reaction conditions, the synthetic utility of silyl anions for the synthesis of organosilicon compounds is limited. However silyllithiums possessing one or more phenyl groups on a silicon atom are readily prepared by the reductive metallation of the corresponding halosilanes with lithium. Allylsilanes are synthesized by the reaction of allyl acetates with the cuprate prepared from such a reagent (eq (47)) [43]. 

---