High-Yielding and Divergent Paradigm for the Synthesis of D2h-Symmetric Octakis-Substituted Pentiptycenequinones.

With a rigid fused polyaromatic framework and a well-defined, highly symmetric molecular geometry, pentiptycenes are appealing building blocks for a variety of materials applications. Unfortunately, their use has been limited by the lengthy syntheses of their functionalized derivatives. This communication describes a highly efficient, brief, divergent paradigm for the preparation of octakis-substituted pentiptycene derivatives that starts with the preparation of an octakis(bromo) compound, which can be used as a Pd(0)-catalyzed coupling partner with suitable organometallic compounds to install a range of groups in high yields at the peripheral 2,3,6,7,14,15,19,20 positions, including methyl, allyl, vinyl, alkynyl, aryl, heteroaryl, and even bulky 4-(triphenylmethyl)phenyl substituents.