Dual Selectivity Expressed in [2 + 2 + 1] Dynamic Clipping of Unsymmetrical [2]Catenanes

A π-templated dynamic [2 + 2 + 1] clipping protocol is established for the synthesis of [2]catenanes from two parts dialdehyde, two parts diamine, and one part tetracationic cyclophane. It is further diversified for the selective formation of an unsymmetrical [2]catenane showing great translational selectivity by employing two different dialdehydes in a one-pot reaction. The dual selectivity and the dynamic nature are verified by 1H NMR spectroscopy, X-ray single-crystal structural studies, and exchange experiments.