Development of regioselective [2 + 3] cycloaddition reactions of nitrile oxides with alkenes using intramolecular reactions through oxime groups [1]
作者:Nao Umemoto、Ayumi Imayoshi、Kazunori Tsubaki
DOI:10.1016/j.tet.2022.132833
日期:2022.8
oxime group and demonstrated their intramolecular [2 + 3] cycloaddition reactions. The desired cycloadducts were obtained in high yields and as single regioisomers. Furthermore, face-selective cycloaddition reactions were achieved by introducing a stereocenter into the linker moiety, affording the desired cycloadducts with good diastereoselectivity.
腈氧化物通过与烯烃的 [2 + 3] 环加成反应提供 2-异恶唑啉杂环。这些杂环可以转化为有用的中间体,例如 β-羟基酮和 γ-氨基醇,从而产生药物和农用化合物。然而,由于偶极子 HOMO 的能量降低,直接与羰基连接的腈氧化物显示出低反应性。此外,当使用不对称内烯烃时,区域选择性控制很困难。在此,我们设计了通过肟基团与烯烃结合的腈氧化物,并展示了它们的分子内 [2 + 3] 环加成反应。以高产率和单一区域异构体形式获得所需的环加合物。此外,通过在接头部分引入立体中心来实现面选择性环加成反应,