Fluoro-Ene Reaction Versus [2+2] Cycloaddition in the Thermal C<sup>2</sup>-C<sup>6</sup>Cyclization of Enyne-Allenes: An Experimental and Theoretical Investigation
作者:M. Emin Cinar、Chandrasekhar Vavilala、Ralph Jaquet、Jan W. Bats、Michael Schmittel
DOI:10.1002/ejoc.201402438
日期:2014.8
A series of fluoroalkyl-substituted enyne-allenes have been synthesized by a new route with the aim of elucidating the possibility of a fluoro-ene reaction via an intermediate fulvenyl diradical generated in the thermal C2–C6 (Schmittel) cyclization reaction. As a result of the strong C–F bond, fluorine atom transfer was not observed. Instead, 1H-cyclobuta[a]indenes were formed in good yields despite
一系列氟代烷基取代的烯炔-丙二烯通过新途径合成,目的是阐明氟烯反应的可能性,该反应通过在热 C2-C6(施密特尔)环化反应中产生的中间体富烯基双自由基进行。由于强 C-F 键,没有观察到氟原子转移。相反,尽管应变能很高,但仍以良好的产率形成了 1H-环丁 [a] 茚。B3LYP 理论水平的 DFT 计算表明,尽管氟-烯反应是可用的放热反应最多的反应,但在各种模型化合物中,环丁烯的形成在动力学上比 [1,5]-氟位移 5-15 kcal mol-1 更有利.