Improved Synthesis of Larger Resorcinarenes

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Macrocyclic Chemistry

Background:

• Resorcinarene macrocycles are versatile molecular hosts.
• Synthesis of larger macrocycles presents challenges.
• Understanding macrocycle conformation and packing is crucial.

Purpose of the Study:

• To synthesize larger resorcinarene macrocycles, specifically [5](OMe) and [6](OMe).
• To investigate the demethylation of these macrocycles to obtain free hydroxyl groups.
• To elucidate the solid-state structure, conformation, and packing of the synthesized macrocycles.

Main Methods:

• Lewis acid-catalyzed condensation of 1,3-dimethoxy-2-methylbenzene with paraformaldehyde.
• Demethylation of methoxy-resorcinarenes using Boron tribromide (BBr3).
• X-ray crystallography for structural analysis.

Main Results:

• Successful synthesis of [5](OMe) and [6](OMe) resorcinarene macrocycles.
• Quantitative demethylation achieved, yielding macrocycles with free OH groups.
• X-ray studies revealed specific intermolecular interactions (C-H···O, C-H···π, π···π) governing solid-state conformation and packing.

Conclusions:

• The study demonstrates a viable route to larger resorcinarene macrocycles.
• Intermolecular interactions play a critical role in the solid-state organization of these macrocycles.
• The synthesized macrocycles are potential building blocks for advanced supramolecular assemblies.