Highly <i>syn</i>-Selective Elimination of Peterson <i>anti</i>-Adducts to Give <i>Z</i>-α,β-Unsaturated Esters
作者:Yutaka Murai、Akira Nakagawa、Satoshi Kojima
DOI:10.1246/cl.160975
日期:2017.2.5
Peterson adducts have been known to stereospecifically give syn-elimination products upon treatment with base except when the product olefin is in conjugation with an electron-withdrawing group. The missing piece has been put in place by using a catalytic amount of DBU, by which syn-elimination could be effected to provide the thermally less stable Z-olefin from the anti-adduct with high selectivity
Si-H insertion of a carbenoid, generated by decomposition of N2CHCO2Et, followed by a nucleophilic attack onto the Si-Cl bond by an alcohol. Alkylation of the title esters, reduction of the ester function and finally oxidation of the C-Si bond provide a facileentry to 1,2-diols.
Silver-catalyzed silicon–hydrogen bond functionalization by carbene insertion
作者:M. José Iglesias、M. Carmen Nicasio、Ana Caballero、Pedro J. Pérez
DOI:10.1039/c2dt31460f
日期:——
functionalization of silicon–hydrogen bonds by means of the insertion of carbene units :CHCO2Et from ethyl diazoacetate (EDA) has been achieved using a silver-based catalyst, constituting the first example of this metal to promote this transformation. Competition experiments have revealed that the relative reactivity of substituted silanes depends on the bond dissociation energy of the Si–H bond (tertiary >
作者:N. Ya. Grigorieva、O. A. Pinsker、A. V. Buevich、A. M. Moiseenkov
DOI:10.1007/bf00702395
日期:1995.3
A highly-stereoselective method (90 % of theZ-isomer) was developed for the Petersonolefination of ketones with nerylacetone (1) as an example. The method is based on the introduction of a PhS group, which is removed after completion of the reaction, at the ketone C(3) atom.
Solvolysisrates of 2-(aryldimethylsilyl)ethyl chlorides were determined conductimetrically in 60% (v/v) aqueous ethanol. The effects of aryl substituents at the silyl atom on the solvolysisrates ...