[reaction: see text] Introduction of an electron-withdrawing group on the aromatic ring of N-methylacetanilide decreased the ratio of the cis conformer, and the ratio correlates well with the Hammett sigma values of the substituents. These steric properties can be applied to achieve amide conformational switching by protonation at the aromatic substituent of 4-[bis(dimethylamino)]-N-methylacetanilide or N-[p-(dimethylamino)phenyl]-N-phenylacetamide.

No abstract

Rotacatenanes were synthesized by the catalytic reaction using a macrocyclic phenanthroline-CuI complex followed by the installation of another ring by the template method. In this approach, the size of the ring component of the rotaxane turns out to be a very important factor for the synthesis of rotacatenanes.