ABSTRACT
Invited for the cover of this issue is the group of Takayuki Iwata, Mitsuru Shindo, and co-workers at Kyushu University. The image depicts ring-opening of triptycenes to afford corresponding anthrones by acid treatment. Read the full text of the article at 10.1002/chem.202104160.
ABSTRACT
The triptycene scaffold has been ring-opened by using a retro-Friedel-Crafts-type reaction under acidic conditions to give its corresponding anthrone product. 9-Hydroxytriptycenes and unsubstituted triptycene undergo ring-opening reaction under strongly acidic conditions, such as with TfOH. An investigation of the substitution effect has revealed that the electron-donating group on the arene moiety allows the reaction to proceed in the presence of a weaker acid, such as TFA. In addition, the reaction has been successfully applied toward the synthesis of tetracene.
ABSTRACT
We report herein an efficient method to synthesize triptycenes by the reaction of benzynes and anthranoxides, which are electron-rich and readily prepared from the corresponding anthrones. Using this method, 1,9-syn-substituted triptycenes were regioselectively obtained employing 3-methoxybenzynes. This method was also applied to synthesize pentiptycenes. A DFT study revealed that the cycloaddition of lithium anthranoxide and benzyne proceeds stepwise.
