Abstract The reaction of β-diketones, ethylacetoacetare and malononitrile with α, β-insaturated β, β-difunctionnalized phosphonates constitutes a performant newroute leading to the formation of substituted 2-amino-4-phosphono-4H-pynnes. Moreover the reaction of dialkylphosphonates with 2-hydroxybenzylidenemalononitrile affords a new series of phosphorylated benzopyranes.
Chemo-, Regio-, and Stereoselective Synthesis of Polysusbtituted Oxazolo[3,2-<i>d</i>][1,4]oxazepin-5(3<i>H</i>)ones via a Domino oxa-Michael/aza-Michael/Williamson Cycloetherification Sequence
作者:Abderrahman El Bouakher、Jordan Tasserie、Ronan Le Goff、Jérôme Lhoste、Arnaud Martel、Sébastien Comesse
DOI:10.1021/acs.joc.7b00629
日期:2017.6.2
proved to be chemo-, regio-, and stereoselective and allows the formation of a large diversity of highly functional 7-membered rings in good yields up to 95%. The complete shift of the regioselectivity of the intermediate enolate from a C–C to a C–O bond formation, contrary to the already known alkylations of such ambident nucleophiles, is mostly triggered by stericeffects. The last step of the sequence
提出了在温和条件下从α-溴酰胺基醇和Michael受体开始合成新的oxazolo [3,2- d ] [1,4] oxazepin-5(3 H)-的方法。事实证明,这种多米诺骨牌工艺具有化学选择性,区域选择性和立体选择性,并且可以形成高达95%的高收率的多种多样的高功能7元环。中间烯醇的区域选择性从C–C到C–O键形成的完全转变与这种环境友好的亲核试剂的已知烷基化相反,主要是由空间效应触发的。序列的最后一步是通过DFT建模的,从而给出了该C–C与C–O键移位的一些重要见解。
2,3‐Epoxyamide‐alcohols in Domino Reactions: En Route to Molecular Diversity
作者:Abderrahman El Bouakher、Jérôme Lhoste、Arnaud Martel、Sébastien Comesse
DOI:10.1002/open.202400115
日期:——
Molecular diversity was achieved by reaction between easily accessible 2,3-epoxyamido-alcohols and Michaelacceptors. 4 different γ- and δ-lactam skeletons were selectively synthesized in good yields with up to 4 contiguous stereo-centres fully controlled. Depending on the R substituent and the electron-withdrawing groups different domino pathways, all triggered by an an oxa-Michael/aza-Michael/epoxide
通过易于接近的 2,3-环氧酰胺醇和 Michael 受体之间的反应实现分子多样性。选择性合成 4 种不同的 γ 和 δ-内酰胺骨架,产量高,多达 4 个连续的立体中心完全受控。根据 R 取代基和吸电子基团,发生了不同的多米诺骨牌通路,这些通路均由 oxa-Michael/aza-Michael/环氧化物开放序列触发。
Tandem aza-Michael/spiro-ring closure sequence: access to a versatile scaffold and total synthesis of (±)-coerulescine
作者:Meral Görmen、Ronan Le Goff、Ata Martin Lawson、Adam Daïch、Sébastien Comesse
DOI:10.1016/j.tetlet.2013.02.047
日期:2013.4
The total synthesis of the alkaloid (+/-)-coerulescine is presented. The key step of this approach is an efficient tandem aza-Michael initiated ring closure (aza-MIRC) process between ethoxymethylene-oxindole and benzyl(2-bromoethyl)carbamate. The potency of the aza-MIRC reaction was first tested onto less challenging Michael acceptors and led in good yields to the corresponding N-Cbz alpha-alkoxy-beta-gem-disubstituted pyrrolidines. The resulting N-acyliminium precursor obtained from ethoxymethylidene-oxindole was efficiently converted in four steps, including 2 deprotections, into the targeted (+/-)-coerulescine. (C) 2013 Elsevier Ltd. All rights reserved.