A novel tandem single-electron oxidative ring expansion reaction has been developed for the construction of the saddle-shaped polycyclic arenes fused with cyclooctatetraene, that is, dibenzo[3,4:7,8]cycloocta[1,2-l]phenanthrenes (dbCOTPs). The combination of Cu(OTf)₂ catalyst with DDQ triggered the selective oxidation of o-biphenyl-tethered methylenecirculenes fused with a seven-membered ring, giving rise to the formation of the corresponding eight-membered ring fused dbCOTPs. The present tandem ring expansion of a seven- to an eight-membered ring takes place via the selective single-electron oxidation of the benzylidene moiety, intramolecular spirocyclization, and 1,2-aryl migration sequence.

中文翻译：

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用于合成二苯并环八苯菲的串联氧化环扩环。

已经开发了一种新颖的串联单电子氧化环扩环反应，用于构建与环辛酸酯，即二苯并[3,4：7,8]环辛[1,2- l ]菲（ dbCOTP）。Cu（OTf）₂催化剂与DDQ的结合触发了与七元环稠合的邻联苯系留亚甲基环的选择性氧化，从而形成了相应的八元环稠合的dbCOTP。当前的七元环到八元环的串联扩环是通过亚苄基部分的选择性单电子氧化，分子内螺环化和1,2-芳基迁移序列发生的。