ISSN:
1434-193X
Keywords:
Dilithiovinylsilanes
;
Lithium hydride eliminations
;
Reductive metalations
;
Solvent effects
;
Vinyllithium dimerizations
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Vinylsilanes are known to react with lithium metal to form either 1,2-dilithioethanes by reduction or 1,4-dilithiobutanes by reductive dimerization. The reaction of the substituted vinylsilanes 3, (Z)-13b, 17b, c, 42b, c, 44, and 51 with lithium has been investigated. Depending on the substituents on the vinylsilane and the solvent employed, several new reaction pathways are observed, which have been proved by independent syntheses of the reactive intermediates (E)-14b, 18d, and 25-27. Thus, besides the known elimination of lithium hydride, either a 1,4-proton shift of 25 to 26 or a Grovenstein-Zimmerman rearrangement of 45 to 47 can occur as follow-up reactions. Furthermore, two different types of dimerization of the silyl-substituted vinyllithium compounds have been identified. Either the vinyllithium compound 18d adds to the starting vinylsilane leading to the monolithiumorganic species 41, or lithium metal catalyzed dimerization to the 1,4-dilithio-2-butene derivative 49 takes place, which is without precedence.
Type of Medium:
Electronic Resource
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