Synthesis of (Z)-Vinylsilanes with High Diastereoselectivity by Using Samarium Diiodide
摘要:
[GRAPHICS]Beta-Elimination of O-acetyl 1-chloro-1-trimethylsilylalkan-2-ols 1 was achieved by using samarium diiodide as a metaling reagent and afforded the corresponding (Z)-vinylsilanes with high stereoselectivity. The starting compounds 1 were easily prepared by treatment of different aldehydes with (chlorolithiomethyl)trimethylsilane and further acetylation.
One-pot, cis-selective synthesis of α-substituted β-trimethylsilyl-α,β-epoxyesters from α-ketoesters and diazo(trimethylsilyl)methyl magnesium bromide
作者:Yoshiyuki Hari、Susumu Tsuchida、Toyohiko Aoyama
DOI:10.1016/j.tetlet.2006.01.067
日期:2006.3
Reaction of α-ketoesters with diazo(trimethylsilyl)methyl magnesium bromide followed by in situ treatment with pivalic acid gave α-substituted β-trimethylsilyl-α,β-epoxyesters in an efficient and cis-selective manner.
Additions of functionalized α-substituted allylboronates to aldehydes under the novel Lewis and Brønsted acid catalyzed manifolds
作者:Lisa Carosi、Hugo Lachance、Dennis G. Hall
DOI:10.1016/j.tetlet.2005.10.115
日期:2005.12
stereo- and chemoselectivity in the additions of four model α-substituted allylboronates to benzaldehyde was examined under the standard thermal (uncatalyzed) conditions and the novel Lewis and Brønsted acid-catalyzed conditions. With either of Sc(OTf)3 or triflic acid as catalysts, an α-ethyl allylboronate, 1a, led to a surprising inversion of stereoselectivity that can be tentatively rationalized through
Homologation of boronic esters with trimethylsilylchloromethyllithium
作者:Donald S. Matteson、Debesh Majumdar
DOI:10.1016/s0022-328x(00)83500-7
日期:1980.1
Trimethylsilylchloromethyllithium adds to boronicesters to form ate complexes which rearrange with displacement of chloride to form the homologous α-trimethylsilyl boronicesters in high yields.
Migratory insertion reactions of organometallics. 3. Carbon-carbon bond forming reactions of organotransition metals with .alpha.- or .gamma.-haloorganolithium reagents