构象受限的环状γ-氨基酸的高度立体选择性合成已被设计。关键步骤涉及在双功能硫脲催化剂的促进下,硝基酸酯在共轭酯上的分子内环化。该方法已成功应用于生成多种 γ-氨基酸,包括一些含有三个连续立体中心的氨基酸,具有非常高的非对映选择性和出色的对映选择性。据推测,该过程成功的关键是硫脲官能团与共轭酯和硝基酯的同时配位。最后,这些化合物的合成效用在源自 C 和 N 末端的两种二肽的合成中得到证明。
Bifunctional Iminophosphorane‐Catalyzed Enantioselective Nitroalkane Addition to Unactivated α,β‐Unsaturated Esters
作者:Daniel Rozsar、Alistair J. M. Farley、Iain McLauchlan、Benjamin D. A. Shennan、Ken Yamazaki、Darren James Dixon
DOI:10.1002/anie.202303391
日期:——
The first intermolecular enantioselectiveaddition of nitroalkanes to unactivated α,β-unsaturated esters is described, catalyzed by a bifunctional iminophosphorane (BIMP) superbase. This fundamental synthetically relevant transformation proceeds with high enantiomeric excesses and yields over a wide range of feedstock substrates, providing pharmaceutically relevant building blocks in a single step