Catalytic Asymmetric exo'-Selective [3+2] Cycloaddition of Iminoesters with Nitroalkenes
Catalytic Asymmetric exo'-Selective [3+2] Cycloaddition of Iminoesters with Nitroalkenes
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DOI：
10.1002/anie.201004098
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发表时间：
2010-01-01
影响因子：
16.6
通讯作者：
Sato, Hiroyasu
中科院分区：
文献类型：
--
作者：
Arai, Takayoshi;Yokoyama, Naota;Sato, Hiroyasu
高度功能化的复杂分子是促进生物化学研究和开发药物化合物的关键工具，因为分子中杂原子的位置和孤对电子的方向与其生物活性密切相关。催化不对称合成是以立体选择性方式提供这些复杂化合物的基本技术。催化不对称1，3-偶极环化反应是合成多取代吡咯烷类化合物的一个典型例子。[1]由亚氨基酯和硝基烯烃生成的偶氮甲碱叶立德可用于在吡咯烷环上引入额外的硝基官能团，从而提供四个立体中心和多达八个非对映异构体。当使用反式硝基烯烃时，3-和4-位之间的立体连接以反式构象固定，并且可能有四种非对映异构体，分为内、外、内'和外'异构体（方案1）。
Highly functionalized complex molecules are key tools for promoting biochemical research and developing pharmaceutical compounds because the positions of the heteroatoms and the direction of lone pairs in the molecules are closely linked to their biological activities. Catalytic asymmetric synthesis is a fundamental technique to supply these complex compounds in a stereoselective manner. As a representative example, the catalytic asymmetric 1, 3-dipolar cyclization reaction has been widely studied for the synthesis of multisubstituted pyrrolidines.[1] Azomethine ylides, generated from an iminoester and a nitroalkene, can be used to introduce an additional nitro functionality onto the pyrrolidine ring, thus affording four stereogenic centers and up to eight diastereomers. When a trans nitroalkene is used, the stereoconjunction between the 3-and 4-positions is fixed in a trans conformation, and four diastereomers are possible, classified as endo, exo, endo’, and exo’isomers (Scheme 1).