A non-cross-coupling approach to arene-bridged macrocycles: synthesis, structure, and direct, regioselective functionalization of a cycloparaphenylene fragment.

A new synthetic strategy that employs a relatively unstrained, 1,4-diketo-bridged macrocycle as a precursor to a strained, 1,4-arene-bridged (bent para-phenylene) macrocycle has been developed. The distorted p-terphenyl nucleus (CPP fragment) of the macrocycle has been characterized by X-ray crystallography, and a direct, regioselective bromination protocol of the macrocyclic system is reported.