Rigid hydrocarbon scaffolds such as cubane and bicyclo[1.1.1]pentane (BCP) exhibit interesting but poorly understood chemistry, perhaps due to the exoticness of structures and prejudices about their thermal stability. Since the introduction of the ‘Rule of Five’ (RO5) and ‘Escape from Flatland’ concepts, medicinal chemists have frequently explored the bioisosteric replacement of phenyl rings with BCP or cubane in pharmacologically relevant drugs. Not only in drug development is the use of rigid scaffolds promising, but also for organic materials due to their ability to arrange chromophores in a spatially defined manner and to allow an efficient singlet fission process. Despite these promising properties, the use of rigid scaffolds in material applications has not yet been fully realized. Considerable scope remains to unlock the potential of BCP- or cubane-linked chromophores in organic semiconductor materials. The Senge group focuses efforts towards the investigation of transition metal-catalyzed coupling reactions at bridgehead carbons of the cubane and BCP motifs. We introduced an improved radical cross-coupling protocol as a promising tool for the functionalization of the cubane framework. Magnesium and zinc derivatives of the bicyclo[1.1.1]pentyl unit were successfully used for Pd-catalyzed coupling reactions. Radical and Negishi cross-coupling reactions were used for the synthesis of cubane-porphyrin and BCP-porphyrin arrays, respectively. In summary, electronically isolated, yet structurally defined BCP/cubane linked porphyrin, arrays were synthesized and their properties were delineated.

Bicyclo[1.1.1]pentane- and cubane-linked porphyrin arrays

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.