Oligopyridones: preparation and their folding behavior in polar aprotic solvents

The oligomerization of 5-bromo-2-hydroxypyridine through a CuI catalyzed one-pot condensation tactics was developed. A series of oligopyridones, from dipyridione to penta-pyridone, were therefore synthesized via the CuI-promoted C–N coupling reactions. The oligopyridones favor to have folded conformations in polar aprotic solvents. These were confirmed by using 1H NMR, NOESY, and 1D-NOE experiments.