Synthesis and Characterization of Cyanobutadiene Isomers—Molecules of Astrochemical Significance
Synthesis and Characterization of Cyanobutadiene Isomers—Molecules of Astrochemical Significance
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氰基丁二烯异构体——具有天体化学意义的分子的合成和表征
DOI：
10.1021/acs.joc.9b03388
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
McMahon, Robert J.
中科院分区：
文献类型：
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作者：
Kougias, Samuel M.;Knezz, Stephanie N.;Owen, Andrew N.;Sanchez, Rodrigo A.;Hyland, Grace E.;Lee, Daniel J.;Patel, Aatmik R.;Esselman, Brian J.;Woods, R. Claude;McMahon, Robert J.
以良好的收率合成了有机化学、分子光谱学和天体化学界非常感兴趣的四种氰基丁二烯异构体，并分离为纯化合物：(E)-1-氰基-1,3-丁二烯 (E-1)、(Z)-1-氰基-1,3-丁二烯 (Z-1)、4-氰基-1,2-丁二烯 (2) 和 2-氰基-1,3-丁二烯（3）。开发了一种非对映选择性合成方法，通过串联 SN2 和 E2' 反应生成 (E)-1-氰基-1,3-丁二烯 (1) (10:1E/Z)。通过密度泛函理论计算分析了导致 (E)- 和 (Z)-1-氰基-1,3-丁二烯 (1) 的 E2' 反应的势能面，并在科廷-哈米特原理的背景下对观察到的非对映选择性进行了合理化。制备这些活性化合物的纯样品可以测量它们的实验室旋转光谱，这是通过射电天文学在太空中搜索这些物质所需的关键数据。
Four cyanobutadiene isomers of considerable interest to the organic chemistry, molecular spectroscopy, and astrochemistry communities were synthesized in good yields and isolated as pure compounds: (E)-1-cyano-1,3-butadiene (E-1), (Z)-1-cyano-1,3-butadiene (Z-1), 4-cyano-1,2-butadiene (2), and 2-cyano-1,3-butadiene (3). A diastereoselective synthesis was developed to generate (E)-1-cyano-1,3-butadiene (1) (10:1E/Z)viatandem SN2 and E2′ reactions. The potential energy surfaces of the E2′ reactions leading to (E)- and (Z)-1-cyano-1,3-butadiene (1) were analyzed by density functional theory calculations, and the observed diastereoselectivity was rationalized in the context of the Curtin–Hammett principle. The preparation of pure samples of these reactive compounds enables measurement of their laboratory rotational spectra, which are the critical data needed to search for these species in space by radioastronomy.