Rhodium-catalyzed formal [4+3] annulation reaction of N-methoxybenzamides with gem-difluorocyclopropenes: A combination of experimental and theoretical studies

Authors：He, Yimiao^*; Tian, Limei; Chang, Xuexue; Qu, Zeming; Huang, Yanmin; Huang, Chusheng; Sun, Qing^*; Wang, Honggen^*

Source：CHINESE CHEMICAL LETTERS, 2022, 33(6): 2987-2992.

DOI：10.1016/j.cclet.2022.01.068

• gem-Difluorocyclopropene
• Fluorinated 2H-azepin-2-one
• C-H functionalization
• Oxidizing directing group
• Rhodium
• [4+3] Annulation

A rhodium-catalyzed [4+3] cycloaddition reaction between N-methoxybenzamides and gem-difluorocyclopropenes is described. The reaction offers a mild and efficient approach towards the synthesis of fluorinated 2H-azepin-2-ones with broad substrate scope. A consecutive HOAc-assisted C-N bond formation and fluorine elimination are involved as key steps for success as illustrated by detailed DFT studies.

• Institution
  南昌航空大学; 中山大学