Transition Metal-Free <i>Trans</i> Hydroboration of Alkynoic Acid Derivatives: Experimental and Theoretical Studies
作者:Russell Fritzemeier、Ashley Gates、Xueying Guo、Zhenyang Lin、Webster L. Santos
DOI:10.1021/acs.joc.8b01493
日期:2018.9.7
(E)-β-boryl acrylamides in good to excellent yields. The reaction is tolerant of a variety of functional groups and allows efficient access to novel oxaboroles as well as a pargyline derivative (MAO inhibitor). Theoretical calculations suggest an internal hydride generates a phosphonium allenoxyborane followed by the formation of a key phosphonocyclobutene intermediate that collapses in a stereoselective
我们报告了膦酸酯催化的炔烃酯和酰胺的反式氢硼化。该反应在温和的条件下以排他的(E)选择性进行,以良好至极好的收率得到(E)-β-硼基丙烯酸酯和(E)-β-硼基丙烯酰胺。该反应可耐受多种官能团,并可以有效地获得新的草并五氢硼烷以及一种精氨酸衍生物(MAO抑制剂)。理论计算表明,内部氢化物会生成all烯丙氧基硼烷,然后形成关键的膦酰基环丁烯中间体,该中间体在立体选择性的限速步骤中会崩溃。