Synthesis and Characterization of Functionalized [12]Cycloparaphenylenes Containing Four Alternating Biphenyl and Naphthyl Units

Functionalized [12]­cycloparaphenylenes ([12]­CPPs) containing four alternating biphenyl and naphthyl units were synthesized. A macrocyclic furan-containing CPP precursor was used for the Diels–Alder reaction with the parent benzyne or 3,6-dimethoxybenzyne to form the corresponding macrocyclic carbon frameworks. The subsequent reductive deoxygenation of the Diels–Alder adducts with Fe2(CO)9 followed by oxidative aromatization with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone produced the functionalized [12]­CPPs. The effect of macrocyclic ring size on the reaction rate of oxidative aromatization was investigated.