Rapid access to triptycene-like naphthopleiadenes for use in supramolecular and materials chemistry

Triptycene derivatives are used extensively in supramolecular and materials chemistry, however, most are prepared using a multi-step synthesis that involves the generation of a benzyne intermediate, which hinders scale-up. Inspired by the ease of resorcinarene synthesis, we report the rapid and efficient preparation of triptycene-like 1,6,2’,7’-tetrahydroxynaphthopleiadene directly from 2,7-dihydroxynaphthalene and phthalaldehyde. Structural characterisation confirms the novel bridged bicyclic framework, within which the planes of the single benzene ring and two naphthalene units are fixed at an angle of ~120° relative to each other. Several simple variations of aromatic 1,2-dialdehydes and 2,7-disubstituted naphthalenes also provided triptycene-like products. The low cost of the precursors and undemanding reaction conditions allows for rapid multigram synthesis of 1,6,2’,7’-tetrahydroxynaphthopleiadene with product isolation by simple filtration. The potential for its use in supramolecular and polymer chemistry was demonstrated by the preparation of a very rigid novel cavitand, a microporous network polymer, and a solution-processable polymer of Intrinsic microporosity.