Modular synthesis of functionalized bis-bispidine tetraazamacrocycles.

An effective synthesis is reported for the construction of highly rigid and preorganized bis-bispidine tetraazamacrocycles bearing either identical or different functionalities. Using essential building blocks derived from N-Boc-N'-allylbispidinone, the modular approach facilitates independent incorporation of the functional groups to the macrocyclic framework as well as selective derivatization of one functionality in the presence of another.