February 2023

A novel structurally constrained nanobelt, methylene-bridged [6]cyclo-2,6-naphthylene ([6]MCN), has been synthesized by the nickel-mediated intramolecular aryl–aryl coupling of a triflated prism[6]arene. The structural and electronic properties of [6]MCN were revealed through NMR studies and photophysical measurements. In contrast to methylene-bridged [6]cycloparaphenylene, our previously synthesized benzene-based analogue, [6]MCN has a low strain energy (77.4 kcal·mol–1) and displays bright fluorescence (Φ = 0.20).

A highly efficient, practical, and ligand-free palladium-catalyzed carbonylation of aryl iodides with alkenylboronic acids has been developed. A variety of chalcones and α-branched enones were isolated in satisfactory to good yields with good substrate compatibilities under an ambient pressure of CO at room temperature. Moreover, the transformation proceeds well in the presence of a substoichiometric amount of base. The merit of this strategy as a late-stage functionalization platform has been demonstrated by modifications of complex substrates derived from estrone and 3-phenyl-l-alanine.