Multifold Post-Modification of Macrocycles and Cages by Isocyanate-Induced Azadefluorination Cyclisation

Area of Science:

• Supramolecular Chemistry
• Organic Chemistry
• Materials Science

Background:

• Organic macrocycles and cages are versatile supramolecular scaffolds.
• Functionalization of these structures is crucial for developing advanced materials.
• Existing methods for post-modification can be limited in scope and efficiency.

Purpose of the Study:

• To develop a novel post-modification strategy for fluorinated organic macrocycles and cages.
• To explore the mechanism and scope of the azadefluorination cyclisation (ADFC) reaction.
• To demonstrate the utility of ADFC for creating functional supramolecular materials and cross-linked membranes.

Main Methods:

• Investigation of reaction mechanism and scope using DFT calculations.
• Synthesis and characterization of modified macrocycles and cages using various aromatic isocyanates.
• Structural confirmation through single-crystal X-ray diffraction (SC-XRD) and 19F NMR spectroscopy.

Main Results:

• Successful introduction of functional groups into two- and three-dimensional supramolecular scaffolds.
• Elucidation of the azadefluorination cyclisation (ADFC) mechanism.
• Demonstration of excellent chemical stability of the modified compounds.
• Application of ADFC for late-stage functionalization and direct generation of cross-linked membranes using ditopic isocyanates.

Conclusions:

• ADFC provides a powerful and versatile method for the post-modification of organic macrocycles and cages.
• This approach expands the possibilities in multi-step supramolecular chemistry by utilizing readily available isocyanates.
• The resulting functionalized supramolecular entities exhibit high stability and can be further utilized in cross-coupling reactions or for membrane fabrication.