Abstract
An optically-active amidine and an achiral carboxylic acid with a m-terphenyl ligand bearing two olefin units at the both ends were prepared. When mixed in organic solvents, they quantitatively formed a supramolecular duplex, or precatenane, through salt bridge formation. The precatenane was subjected to ring-closing metathesis, and the corresponding [2]catenane was obtained in 68% yield after chromatographic purification. Moreover, we confirmed by CD and 1H NMR that the formation and dissociation of the salt bridge between the two macrocyclic components could be completely controlled by the addition of an acid or a base.
