Department of Chemistry , University of Virginia , Charlottesville , Virginia 22904-4319 , United States.
Org Lett. 2019 Apr 5;21(7):2307-2311. doi: 10.1021/acs.orglett.9b00594. Epub 2019 Mar 25.
Formal [5 + 1] cycloadditions between aryl-substituted vinylcyclopropanes and nitrenoid precursors are reported. The method, which employs Rh(esp) as a catalyst, leads to the highly regioselective formation of substituted tetrahydropyridines. Preliminary mechanistic studies support a stepwise, polar mechanism enabled by the previously observed Lewis acidity of Rh-nitrenoids. Overall, this work expands the application of nitrene-transfer cycloaddition, a relatively underexplored approach to heterocycle synthesis, to the formation of six-membered rings.
报道了芳基取代的乙烯基环丙烷和氮宾前体之间的[5 + 1]环加成反应。该方法采用 Rh(esp)作为催化剂，可高度区域选择性地形成取代的四氢吡啶。初步的机理研究支持通过先前观察到的 Rh-氮宾的路易斯酸度实现的分步、极性机理。总的来说，这项工作扩展了氮宾转移环加成的应用，这是一种相对未被充分探索的杂环合成方法，用于六元环的形成。
