Lewis Acid-Activated Reactions of Silyl Ketenes for the Preparation of α-Silyl Carbonyl Compounds
作者:Sarah M. Mitchell、Yuanhui Xiang、Rachael Matthews、Alexis M. Amburgey、Emily B. Pentzer
DOI:10.1021/acs.joc.9b01859
日期:2019.11.15
Silyl-substituted ketenes are attractive molecular building blocks due to their stability and ease of storage, as opposed to unstable alkyl and aryl ketenes. To better understand the reactivity of silyl ketenes and, in turn, their use in the preparation of highly functionalized small molecules, the reaction of silyl ketenes with different nucleophiles was studied. The addition of alcohol, amine, or
Hetero [4 + 2] Cycloadditions of (Trialkylsilyl)vinylketenes. Synthesis of α,β-Unsaturated δ-Valerolactones and -Lactams
作者:Dawn M. Bennett、Iwao Okamoto、Rick L. Danheiser
DOI:10.1021/ol9907217
日期:1999.8.1
[formula: see text] HeteroDiels-Alderreactions of (trialkylsilyl)vinylketenes (TAS-vinylketenes) with carbonyl and imino dienophiles are described. TAS-vinylketenes participate as electron-rich dienes in [4 + 2] cycloadditions with diethyl ketomalonate to afford alpha,beta-unsaturated delta-valerolactones in good yield. Nonenolizable N-alkyl- and N-(trimethylsilyl)imines combine with TAS-vinylketenes
作者:Svetlana N. Nikolaeva、Sergei V. Ponomarev、Valery S. Petrosyan、Jörg Lorberth
DOI:10.1016/s0022-328x(97)00006-5
日期:1997.5
Silylation of silylketenes RSiCH=C=O 1 (a, R=Et-3; b, R=(BuMe2)-Bu-t; c, :R=Pr-i(3)) with trimethylsilyltriflate in the presence of triethylamine was studied. Mixtures of the corresponding 1-trimethylsiloxy-2-silylethynes RSiC=COSiMe3 2 and trimethylsilyl(silyl)ketenes RSi(Me3Si)C=C=O 3 in the case of la and Ib were obtained. By this reaction only 2c was prepared from Ic. Heating of mixtures of 2a, 3a and 2b, 3b at 100-110 degrees C affords pure ketenes 3a and 3b respectively; heating of 2c under the same conditions takes place practically without rearrangement. (C) 1997 Elsevier Science S.A.
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作者:S. V. Ponomarev、A. S. Zolotareva、R. N. Ezhov、Yu. V. Kuznetsov、V. S. Petrosyan
DOI:10.1023/a:1011346024964
日期:——
Silylation of silyl- and germylketenes with trialkylsilyl triflates was studied. Either the corresponding bis-organoelement-substituted ketenes or mixtures of these compounds with isomeric (silyloxy)silylacetylenes were formed depending on the size of the substituents at the silicon or germanium atom (both in ketenes and triflates) and on the nature of the heteroelement. The resulting (silyloxy)silylacetylenes were isomerized into the corresponding bis-sitylketenes upon prolonged storage.