Department of Chemistry, M.V. Lomonosov Moscow State University , Leninskie Gory 1-3, Moscow 119991, Russian Federation.
Dmitry Rogachev National Research Center of Pediatric Hematology , Oncology and Immunology, Samory Mashela 1, Moscow 117997, Russian Federation.
J Org Chem. 2018 Jan 19;83(2):543-560. doi: 10.1021/acs.joc.7b02351. Epub 2017 Nov 10.
We report a mild Lewis acid induced isomerization of donor-acceptor cyclopropanes, containing an alkenyl moiety and diverse electron-withdrawing group(s) at the adjacent positions, into substituted cyclopentenes. We have found that 1,1,2-trisubstituted cyclopent-3-enes were exclusively obtained in yield of 51-99% when cyclopropanes with a 2-substituted alkenyl group as a donor underwent isomerization. For cyclopropanes bearing a trisubstituted alkenyl group either the corresponding cyclopent-3-enes or isomeric cyclopent-2-enes having two acceptor groups at the C(1) atom were formed, with the reaction selectivity being determined by the applied Lewis acid. We have shown that the reactivity of the donor-acceptor cyclopropane increases with the increase of the electron-donating character of (hetero)aromatic group attached to the alkenyl moiety. The synthetic utility of the developed methodology was also demonstrated through the synthesis of polysubstituted cyclopentane and piperidine derivatives.
我们报告了一种温和的路易斯酸诱导的给体-受体环丙烷的异构化反应，其中包含烯基部分和相邻位置的各种吸电子基团，生成取代的环戊烯。我们发现，当具有 2-取代烯基作为给体的环丙烷进行异构化时，以 51-99%的产率得到了 1,1,2-三取代的环戊-3-烯。对于带有三取代烯基的环丙烷，得到的是相应的环戊-3-烯或具有两个吸电子基团在 C(1)原子上的异构的环戊-2-烯，反应选择性取决于所应用的路易斯酸。我们已经表明，与烯基部分连接的（杂）芳基的给电子特性的增加会增加给体-受体环丙烷的反应性。通过合成多取代的环戊烷和哌啶衍生物，也展示了所开发方法的合成实用性。
