Vicinal Functionalization of Propiolate Esters via Catalytic Carbocupration: Stereoselective Formation of Substituted Vinyl Silanes
作者:Amanda J. Mueller Hendrix、Michael P. Jennings
DOI:10.1021/ol100854j
日期:2010.6.18
The vicinal functionalization of propiolate esters via a catalytic carbocupration−silicon group migration sequence has been investigated. We have observed that catalyst loadings as low as 5 mol % allow for good yields and excellent diastereoselectivities (>20:1) with a series of Grignard reagents for the synthesis of substituted E-vinyl silanes.
Stereoselective Halo-Succinimide Facilitated α-Halogenations of Substituted α-Trialkylsilyl-β-Substituted-α,β-Unsaturated Esters
作者:Kristina C. Probasco、Michael P. Jennings
DOI:10.1021/acs.joc.1c00876
日期:2021.7.2
halogenation of a series of (E)-α-trimethylsilyl-β-alkyl(aryl)-α,β-unsaturated esters in dimethylformamide (DMF) has furnished (Z)-β-substituted-α-halogenated-α,β-unsaturated ester products in moderate to high isolated yields (58–90%) with dr values of >20:1 coupled with the inversion of olefin stereochemistry. The reaction process was hypothesized to include an initial halonium cation intermediate,
NXS (X = Cl, Br) 介导的一系列 ( E )-α-三甲基甲硅烷基-β-烷基(芳基)-α,β-不饱和酯在二甲基甲酰胺 (DMF) 中的卤化提供了 ( Z )-β-取代-α-卤代-α,β-不饱和酯产物的分离产率中等至高(58-90%),dr 值大于 20:1,并伴有烯烃立体化学的反转。假设反应过程包括最初的卤阳离子中间体,然后是区域选择性的 DMF 开环。随后的抗-E2-型伴随消除允许产物乙烯基溴和氯酯的立体选择性形成。
Diastereoselective Syntheses of (<i>E</i>)-α-Trialkylsilyl α,β-Unsaturated Esters, α-Silane-Substituted Conjugated Silyl Ketene Acetals, and α,γ-Substituted Allylsilanes
作者:David A. Johnson、Amanda J. Mueller Hendrix、Michael P. Jennings
DOI:10.1021/acs.joc.8b01209
日期:2018.9.7
functionalization of propiolate estersvia a catalytic carbocupration/silicon group migration sequence has been further investigated to include the syntheses of a wide variety of β-alkyl- and β-aryl-substituted (E)-α-silyl α,β-unsaturated esters. The ester substrates were transformed into their β,γ-unsaturated isomers by means of an LDA-mediated γ-deprotonation, extended silylketeneacetal formation, and final