Hydrocarbon Belts with Truncated Cone Structures

We report in this communication the synthesis, structure, and application of a novel type of hydrocarbon belts. Starting from inexpensive and easily available resorcin[n]arenes, a closing-all-fjords strategy featuring exhaustive triflation of phenolic hydroxyl groups followed by consecutively the transition-metal-catalyzed vinylation and intramolecular olefin metathesis allowed facile construction of belt[n]arene[n]tropilidenes (n = 4, 6), which adopt double-stranded macrocyclic belt structures with unique truncated cone cavities. Selective hydrogenation reactions of olefin and benzene subunits led to diverse hydrocarbon belts with varied structures. Moreover, the resulting molecular belts acted as synthetic host materials to include selectively small molecules such as nitromethane and p-xylene.