Zhang Zhi-Jun, Zhou Xu, Li Dashan, Chen Yang, Xiao Wen-Wen, Li Rong-Tao, Shao Li-Dong
Faculty of Life Science and Technology, Kunming University of Science and Technology, Kunming 650500, China.
Yunnan Key Laboratory of Southern Medicinal Utilization, School of Chinese Materia Medica, Yunnan University of Chinese Medicine, Kunming 650500, China.
J Org Chem. 2021 Jun 4;86(11):7609-7624. doi: 10.1021/acs.joc.1c00656. Epub 2021 Apr 27.
An aerobic copper-catalyzed cascade oxidative isomerization/[4+4] cyclization of 2,2'-disubstituted stilbenes is described. Under the mild CuCl/DBED/air catalytic system, various 5,10-heteroatom-containing tetrahydroindeno[2,1-]indenes were efficiently prepared through the difunctionalizations of alkenes in a highly atom economic manner. Mechanistic investigations suggested the bicyclic product was likely formed through a sequence of rapid single-electron oxidation/[4+4] cyclization from 2,2'-disubstituted stilbene. The antarafacial manner of the thermally allowed [4+4] cyclization was further proven by series of control experiments and density functional theory calculations. Our findings provide an important addition to the aerobic copper-catalyzed oxidative cyclization.
本文描述了一种有氧铜催化的2,2'-二取代芪的串联氧化异构化/[4+4]环化反应。在温和的CuCl/DBED/空气催化体系下，通过烯烃的双官能化反应，以高度原子经济性的方式高效制备了各种含5,10-杂原子的四氢茚并[2,1-]茚。机理研究表明，双环产物可能是由2,2'-二取代芪通过一系列快速单电子氧化/[4+4]环化反应形成的。一系列对照实验和密度泛函理论计算进一步证明了热允许的[4+4]环化反应的异面方式。我们的研究结果为有氧铜催化的氧化环化反应提供了重要补充。
