Cyclam Functionalization through Isocyanate Insertion in Zr–N Bonds

The insertion of isocyanates in (Bn2Cyclam)­ZrX2 is regioselective; (Bn2Cyclam)­Zr­(OR)2 produces urea-like moieties by the insertion of RNCO in the Zr–Namido bonds of the cyclam ring. Depending on the bulkiness of the isocyanate R groups, O- and N-bound ureates are formed. (Bn2Cyclam)­Zr­(NHtBu)2 reacts with MesNCO at the terminal Zr–N bonds.