A potentially general method to control relative stereochemistry in enone-olefin 2+2-photocycloaddition reactions by using eniminium salt surrogates
A potentially general method to control relative stereochemistry in enone-olefin 2+2-photocycloaddition reactions by using eniminium salt surrogates
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DOI：
10.1016/s0040-4039(00)01581-1
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发表时间：
2000-12-02
影响因子：
1.8
通讯作者：
Mariano, PS
中科院分区：
文献类型：
--
作者：
Cai, XL;Chang, V;Mariano, PS
实验测试了一种基于烯胺盐替代物的控制烯酮-烯烃 2+2-光环加成反应立体化学的新策略。烯酮-烯烃光环加成反应由烯酮三重激发态产生并遵循非协同途径，与之相反，共轭烯胺盐的类似反应可以通过单线态、协同途径发生，因此，将产生含有环丁烷环的产物，并完全控制相对立体化学。该提议通过使用一系列含有富电子和贫电子烯烃系链的烯胺盐进行了测试。结果表明，这些底物的分子内 2+2-光环加成显示出中度至高度的立体特异性。 (C) 2000 Elsevier Science Ltd. 保留所有权利。
A new strategy to control the stereochemistry of enone-olefin 2+2-photocycloaddition reactions, based on the use of eniminium salt surrogates, is experimentally tested. In contrast to enone-olefin photocycloadditions, which emanate from enone triplet excited states and follow non-concerted pathways, analogous reactions of conjugated eniminium salts can occur by singlet, concerted routes and, as a result, would deliver cyclobutane ring containing products with complete control of relative stereochemistry. This proposal was tested by using a series of eniminium salts, which contain electron rich and electron poor olefin tethers. The results show that intramolecular 2+2-photocycloadditions of these substrates display moderate to high degrees of stereospecificity. (C) 2000 Elsevier Science Ltd. All rights reserved.