Visible-Light-Induced Dehydrohalogenative Coupling for Intramolecular α-Alkenylation: A Way to Build Seven- and Eight-Membered Rings
作者:Dawen Xu、Han Li、Guangxing Pan、Pan Huang、Jens Oberkofler、Robert M. Reich、Fritz E. Kühn、Hao Guo
DOI:10.1021/acs.orglett.0c01391
日期:2020.6.5
with cyclobutane and cyclobutene being involved as key intermediates. This transformation is broadly applicable and highly stereoselective, yielding exclusively cyclic (1Z,3Z)-1,3-diene via photochemically allowed disrotation. This protocol excavates new applications of [2 + 2]-photocycloadditions, which may find their way in future olefin–olefin coupling reactions and medium-sized ring synthesis.
可见光诱导的分子内α-烯基化反应是通过无金属的脱卤化氢的C(sp 2)–C(sp 2)偶联反应发展而得到的七元和八元环。广泛的机理研究证明,该反应通过[2 + 2]-光环加成,消除和逆-[2 + 2]-光环加成过程进行,其中环丁烷和环丁烯为关键中间体。这种转换具有广泛的应用范围和高度立体选择性,仅产生环状(1 Z,3 Z)-1,3-二烯经光化学作用允许旋转。该协议开辟了[2 + 2]-光环加成的新应用,它们可能会在未来的烯烃-烯烃偶联反应和中型环合成中找到应用。