Synthesis and Fluoride-Promoted Wittig Rearrangements of α-Alkoxysilanes
摘要:
[GRAPHICS]Lewis acid-catalyzed reaction of allyl and benzyl trichloroacetimidates with alpha-silyl alcohols was found to be a general method for the synthesis of alpha-alkoxysllanes. Upon exposure to CsF, these alpha-alkoxysilanes could be made to undergo [2,3]-Wittig rearrangement with an efficiency similar to that realized by the analogous but inherently more toxic alpha-alkoxystannanes.
Synthesis and Fluoride-Promoted Wittig Rearrangements of α-Alkoxysilanes
摘要:
[GRAPHICS]Lewis acid-catalyzed reaction of allyl and benzyl trichloroacetimidates with alpha-silyl alcohols was found to be a general method for the synthesis of alpha-alkoxysllanes. Upon exposure to CsF, these alpha-alkoxysilanes could be made to undergo [2,3]-Wittig rearrangement with an efficiency similar to that realized by the analogous but inherently more toxic alpha-alkoxystannanes.
Methyllithium-Promoted Wittig Rearrangements of α-Alkoxysilanes
作者:Robert E. Maleczka,、Feng Geng
DOI:10.1021/ol990912+
日期:1999.10.1
[formula: see text] The Wittig rearrangements of alpha-alkoxysilanes, promoted by the action of methyllithium were studied. Depending on both the substrate and reaction conditions employed, [2,3]-, [1,2]-, or [1,4]-Wittigrearrangements can be realized. These rearrangements were shown to be initiated by either Si/Li exchange or deprotonation alpha to the silane. Furthermore the sigmatropic shifts can