Kuroki Kaito, Ito Tatsuyoshi, Takaya Jun
Department of Chemistry, School of Science, Tokyo Institute of Technology O-okayama, Meguro-ku, Tokyo, 152-8551, Japan.
Angew Chem Int Ed Engl. 2023 Nov 27;62(48):e202312980. doi: 10.1002/anie.202312980. Epub 2023 Oct 9.
Formation of borabicyclo[3.2.0]heptadiene derivatives was achieved via boron-insertion into aromatic C-C bonds in the photo-promoted skeletal rearrangement reaction of triarylboranes bearing an ortho-phosphino substituent (ambiphilic phosphine-boranes). The borabicyclo[3.2.0]heptadiene derivatives were fully characterized by NMR and X-ray analyses. The dearomatized products were demonstrated to undergo the reverse reaction in the dark at room temperature, realizing photochemical and thermal interconversion between triarylboranes and boron-doped bicyclic systems. Experimental and theoretical studies revealed that sequential two electrocyclic reactions involving E/Z-isomerization of an alkene moiety proceed via a highly strained trans-borepin intermediate.
通过将硼插入到带有邻位膦取代基的三芳基硼烷（双亲性膦硼烷）的光促进骨架重排反应中的芳族C-C键中，实现了硼双环[3.2.0]庚二烯衍生物的形成。通过核磁共振（NMR）和X射线分析对硼双环[3.2.0]庚二烯衍生物进行了全面表征。结果表明，脱芳构化产物在室温黑暗条件下会发生逆反应，实现了三芳基硼烷与硼掺杂双环体系之间的光化学和热相互转化。实验和理论研究表明，涉及烯烃部分E/Z异构化的连续两个电环化反应通过高度应变的反式硼戊搭烯中间体进行。
