The half‐sandwich titanocene CpTi
<sup>III</sup>
Cl
<sub>2</sub>
as efficient system for the preparation of 2,5‐dihydrofurans
<i>via</i>
α‐allenols
作者:Irene Torres‐García、Josefa L. López‐Martínez、Raquel Martínez‐Martínez、J. Enrique Oltra、Manuel Muñoz‐Dorado、Ignacio Rodríguez‐García、Miriam Álvarez‐Corral
DOI:10.1002/aoc.5244
日期:2020.1
excellent system for the Barbier‐type reaction between aldehydes and propargylic halides, leading to homopropargylic alcohols and α‐allenols. An efficient and straightforward methodology for the conversion of aldehydes into 2,5‐dihydrofurans involving a two‐step sequence (TiIII addition‐AgI cyclization) is presented. The usefulness of the method is proved by the preparation of a Natural Product: a dihydrofuranic
半夹心钛茂试剂CpTi III Cl 2是通过用锰原位还原商用CpTiCl 3而获得的,它是醛与炔丙基卤化物之间的Barbier型反应的极佳系统,可导致均炔丙基醇和α-烯丙醇。提出了一种高效,直接的方法,将醛转化为2,5-二氢呋喃涉及两个步骤(Ti III加成-Ag I环化)。该方法的有用性通过制备天然产物:从Mikania sp。的叶子中分离出来的二氢呋喃丹丹证明。十一月