Superacid-Mediated Functionalization of Hydroxylated Cucurbit[n]urils.

Area of Science:

• Supramolecular Chemistry
• Materials Science
• Bioconjugation Chemistry

Background:

• Cucurbit[n]urils (CB[n]) are macrocyclic hosts with unique host-guest properties.
• Functionalization of CB[n] is crucial for expanding their applications.
• Existing methods for CB[n] functionalization have limitations.

Purpose of the Study:

• To develop a facile method for transforming hydroxylated CB[n] into diverse functional derivatives.
• To create novel CB[n]-conjugated biomaterials for advanced applications.
• To demonstrate the utility of these new materials in selective protein detection.

Main Methods:

• Nucleophilic substitution of hydroxyl groups on CB[n] with nitriles and alcohols under superacidic conditions.
• Generation of superelectrophilic carbocations on the CB framework.
• Amide coupling of monocarboxylated CB[7] with horseradish peroxidase (HRP).

Main Results:

• Efficient synthesis of various functionality-conjugated CB[n] derivatives.
• Successful preparation of a CB[7]-HRP conjugate.
• Demonstrated selective protein detection using the CB[7]-HRP conjugate and adamantylammonium (AdA) guest.
• Highlighting the potential of bioorthogonal host-guest interactions.

Conclusions:

• A versatile and efficient method for CB[n] functionalization has been established.
• Novel CB[n]-conjugated functional biomaterials can be readily prepared.
• These materials show promise for selective biomolecular detection and other bioapplications.