Fluoride Ion Induced Peterson-Type Reactions

1 Generation of a-Silyl Carbanions by Fluoride Ion Induced Desilylation 

Fluoride ion induced desilylation of -hydroxyalkylsilanes followed by elimination of the oxy group represents a modified methodology for carrying out Peterson re- 

2 Fluoride Ion Induced Peterson Reactions of Bis(trimethylsilyl)methane Derivatives 

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Scheme 2.95. Synthesis of cyclopropenes by fluoride ion induced Peterson-type reaction.

There is another variation of fluoride ion induced Peterson-type reaction that utilizes two silyl groups. The reactions between bis(trimethylsilyl)methyl derivatives 157 and carbonyl compounds using fluoride ion as a catalyst give the corresponding alkenes (Scheme 2.99) [281-283]. This reaction is usefiil for many bis(trimethylsilyl)methane derivatives, bearing a variety of substituents, with many ketones and aldehydes. As regards the stereoselectivity of the reaction, E- and Z-isomers are mostly produced in equal amounts. 

Scheme 2.99. Fluoride ion induced Peterson-type reaction of bis(trimethylsilyl) methane derivatives.

The fluoride ion induced Peterson-type reaction is most widely and effectively utilized in the synthesis of enamines from N-bis(trimethylsilyl)raethylamide derivatives such as 159 [285]. It has been especially exploited to prepare N-1-alkenyl phthalimides and N-l-alkenyl amides 160 (Scheme 2.102) [286-288]. 

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