Abstract
The introduction of rigid‐rod molecules as privileged scaffolds has opened routes to otherwise problematic supramolecular architecture like artificial β‐barrels and functional supramolecules covering pores, hosts, sensors, and catalysts. The usefulness of __p‐__oligophenyls for the construction of functional barrel‐stave architecture has, however, been limited by uniform substitution along the rigid‐rod scaffold. The objective of this report is to overcome this obstacle for the synthesis of p‐octiphenyls with orthogonally protected carboxylic acid groups along the rigid‐rod scaffold. In the reported {242}‐p‐octiphenyl 1, the two peripheral arene moieties carry carboxylic acid groups protected as benzyl esters, whereas the four central carboxylic acid groups are protected orthogonally as tert‐butyl esters (Scheme 2). The complementary orthogonal protection of the three peripheral and the two central arenes is achieved in the {323}‐p‐octiphenyl 2 (Scheme 3). The realized {242}‐ and {323}‐p‐octiphenyls 1 and 2, respectively, provide a complete set for the general access to refined rigid‐rod barrel‐stave architecture with maximized functional plasticity. The need for resolution‐enhanced (aliased) HMBC 2D‐NMR spectroscopy to characterize these refined oligomers is described in the following publication in this issue of Helv. Chim. Acta.