addition of benzyl alcohol onto heteroarenium saltsunder basic conditions was studied. Fine-tuning of the nature of the arenium and substituents allowed the discovery of a range of pyrimidinium substrates that can undergo C6-selective alcohol addition. Crossover experiments were also performed to confirm the addition-elimination equilibriumunder basic conditions.
Pyridine N-oxide derivatives are capable of formation of stable [2]pseudorotaxanes with diamide-based macrocycles in solution and in the solid state, and their dethreading/rethreading movements can be easily controlled by acid–base stimuli.