Regioselective N-Functionalization of Tetraazacycloalkanes
摘要:
Bisaminal type compounds obtained by condensation of pyruvic aldehyde with the suitable open-chain tetraamine followed by cyclization with either dibromoethane or dibromopropane can be regioselectively quaternized by a wide range of alkylating agents. Removal of the bisaminal bridge yields the monosubstituted tetraazamacrocycle or bismacrocycle. Further functionalization allows the preparation of bifunctional ligands or trisubstituted macrocycles. The structure of six compounds was solved by X-ray diffraction, and the unexpected results are rationalized according to the molecular modeling calculations.
What is described are macrocyclic compounds formed by reaction of a cyclic compound, which contains an amine, with an epoxide. The macrocyclic compound has the following structure:
When substituents R and R′ that are hydrophobic substituents, the macrocyclic compound functions as a lipid and is compatible with lipid systems, including liposomes and lipid particles. When present in certain lipid systems, the macrocyclic compound enhances the ability of the lipid system to facilitate delivery of therapeutic molecules to target cells in a mammalian subject.