4H-Pyran and Pyrylium Hemispherands: Partly Preorganized Ionophores with Reactive Molecular Cavities

Article abstract of DOI:10.1021/jo00237a027

The synthesis and reactivity of a 2,6-diaryl-substituted pyrylium cation incorporated in an 18-membered macrocycle (3a,b) has been studied.Hemispherands with a central pyridine (4a,b) and with alkyl- or phenyl-substituted pyridinium ions (5a,b) were obtai