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 steric effects. 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。