Through the Maze: Cross-Coupling Pathways to a Helical Hexaphenyl "Geländer" Molecule

This paper highlights a new concept on how to induce chirality in a hexaphenyl Geländer-type system. Bridging a terphenyl backbone with a considerably longer benzyl ether oligomer enforces a continuous twist of the molecule, while preventing an achiral meso form. By highlighting cross-coupling strategies and explored synthetic pathways, this report aims to serve as an Ariadne`s thread for the synthesis of precisely functionalized, complex polyaromatic systems. The synthetic challenges and considerations required to access the designed target are outlined and solutions to each step of the assembly are presented. Encountered isomerizations are discussed as much as synthetic tools to access highly functionalized intermediates with multiorthogonal moieties. A strong focus is made on the employment of Suzuki–Miyaura protocols for the targeted connection of polyaromatic fragments and ultimately the desired oligomeric structure.