One-Pot Synthesis of Bis(arylamino)pentiptycenes by TiCl 4 -DABCO Assisted Reductive Amination of Pentiptycene Quinone.

The previously eight-step synthesis of bis(arylamino)pentiptycenes ( 2 ) from pentiptycene quinone ( 1 ) can now be achieved in a single step with 18-90% yields through TiCl 4 -DABCO assisted reductive amination with anilines. Both the dual amination of 1 and the in situ reduction of quinone diimines are unprecedented. The π system of 2 can be further expanded, including the formation of bis(diarylamino)pentiptycenes. This work also provides mechanistic insights into the challenges encountered in the dual reductive amination of 1 with other amines.