Shape-persistent macrocycles: structures and synthetic approaches from arylene and ethynylene building blocks

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Organic Synthesis

Background:

• Shape-persistent arylene ethynylene macrocycles are of significant interest due to their unique structures and properties.
• These macrocycles have applications in supramolecular chemistry and materials science.

Purpose of the Study:

• To review recent advancements in the synthesis of arylene ethynylene macrocycles.
• To compare cross-coupling methods with dynamic covalent chemistry for macrocycle formation.

Main Methods:

• Cross-coupling reactions, including Sonogashira and Glaser couplings.
• Dynamic covalent chemistry utilizing reversible metathesis reactions.

Main Results:

• Cross-coupling methods suffer from kinetically determined product distribution and 'overshooting' of oligomer length.
• Dynamic covalent chemistry provides a thermodynamically controlled, one-step approach to macrocycles.
• Mechanistic studies confirm the thermodynamic control in dynamic covalent synthesis.

Conclusions:

• Dynamic covalent chemistry represents a more efficient route for synthesizing arylene ethynylene macrocycles.
• Future challenges include the synthesis of site-specifically functionalized and complex 2D/3D macrocyclic structures.