Guest-Induced Selective Functionalization of Polyaza[n]paracyclophanes

The Determination of Protonation Constants of Peptidomimetic Cyclophanes in Binary Methanol-Water Mixtures

The protonation constants of new group of peptidomimetic cyclophanes with valine or phenylalanine moieties incorporated into the macrocyclic skeleton as well as their linear analogues were determined by potentiometric measurements in solutions of methanol-water mixtures at 25°C and constant ionic strength. The influence of cavity size, location of protonation sites, and attached substituents of the macrocyclic ligands on the protonation constants were discussed on the basis of potentiometric measurement as well as H(1)-NMR results.

Silver complexes of peptidomimetic polyazapyridinophanes. The influence of the bonding cavity size and the nature of side chains

Several peptidomimetic macrocycles containing a pyridine spacer and ring sizes ranging from 15 to 17 have been efficiently synthesized starting from valine and phenylalanine. The complexes formed have been investigated by potentiometry and NMR. Log K values show that phenylalanine derivatives are consistently more stable than valine derivatives , whilst macrocycles with ring sizes of 16 members are the most appropriate for the complexation. The NMR data, in combination with molecular modeling, allow rationalization of the structure of the complexes formed and the participation of the aromatic rings from the side chain of phenylalanine in pi-Ag+ interactions to be discarded.

Synthesis of polyazamacrocyclic compounds via modified Richman-Atkins cyclization of beta-trimethylsilylethanesulfonamides

The Richman-Atkins cyclization remains one of the most widely used methods for the preparation of macrocyclic polyamines. The use of beta-trimethylsilylethanesulfonamides (SES-sulfonamides) for the preparation of polyazamacrocyclic compounds is described. This expands existing Richman-Atkins sulfonamide macrocyclization methodology, and it successfully enables preparation of labile polyaza[n](1,4)naphthalenophanes and polyaza[n](9,10)anthracenophanes, not previously available in appreciable quantities.