Cage-to-Cage Cascade Transformations

A series of Pd2L4-type binuclear self-assembled coordination cages (1-4), where L stands for a nonchelating bidentate ligand, were prepared. The strategies adopted for the synthesis of the cages were: combination of Pd-II with 1)a selected ligand or 2)subcomponents of the ligand. Highly efficient cage-to-cage transformation reactions are demonstrated by suitable covalent modification (from 1 to 2 or 3 or 4) or ligand-exchange reactions (from 1 to 2 or 3 or 4; from 2 to 3 or 4). Thus, new cascade transformations (from 1 to 2 to 3; from 1 to 2 to 4) are achieved beautifully.