Multicomponent Assembly of High-Component Covalent Organic Cages

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Materials Science

Background:

• Multicomponent reactions (MCRs) are efficient for synthesizing complex molecules in one pot.
• Covalent organic cages (COCs) offer tunable structures for various applications.
• The application of MCRs in constructing COCs remains underdeveloped.

Purpose of the Study:

• To develop a multicomponent reaction strategy for fabricating novel covalent organic cages.
• To explore the synthesis of high-component covalent organic cages with unique topologies.
• To demonstrate the functionalization of these cages for specific properties.

Main Methods:

• Utilized a Schiff-base reaction (C═N bonds) combined with dative B←N and B─O bond formation.
• Employed bowl-shaped tetraformylcalix[4]resorcinarene, amino-substituted phenylboronic acid, and alcohol synthons.
• Characterized the resulting [6+24+24] MCOCs using single crystal X-ray crystallography.

Main Results:

• Successfully synthesized coronavirus-shaped multicomponent covalent organic cages (MCOCs) with a [6+24+24] assembly.
• Achieved MCOCs with up to 54 components, the highest reported for covalent organic cages.
• Demonstrated the ability to create MCOCs of varying sizes and topologies by altering building blocks.
• Showcased functionalization via one-pot reactions and post-synthetic modification.

Conclusions:

• Multicomponent reactions are a powerful tool for constructing complex, high-component covalent organic cages.
• The reported MCOCs possess large cavities and tunable windows, suitable for diverse applications.
• This MCR approach offers a versatile platform for designing functional organic cages with tailored properties.