Helical Chirality Induces a Substrate-Selectivity Switch in Carbohydrates Recognitions.

Area of Science:

• Supramolecular Chemistry
• Organic Synthesis
• Chiroptical Spectroscopy

Background:

• Hemicryptophane cages are versatile molecular receptors.
• Chirality plays a crucial role in molecular recognition.
• Cyclotriveratrylene (CTV) units offer tunable electronic properties.

Purpose of the Study:

• To synthesize a novel chiral hemicryptophane cage incorporating an electron-rich CTV unit and amine functionalities.
• To investigate the enantioselective recognition of carbohydrates by the synthesized cage.
• To explore the impact of CTV chirality on guest binding preferences.

Main Methods:

• Synthesis of a new chiral hemicryptophane cage.
• Chiral High-Performance Liquid Chromatography (HPLC) for enantiomeric resolution.
• Electronic Circular Dichroism (ECD) spectroscopy for absolute configuration assignment.
• Binding studies to determine host-guest interactions and selectivities.

Main Results:

• Successful synthesis and resolution of the racemic hemicryptophane.
• Demonstration of remarkable enantioselectivities and good binding constants for carbohydrate recognition.
• Observation of a significant shift in binding preference (glucose vs. mannose derivatives) upon altering the CTV unit's chirality (M to P).

Conclusions:

• The new chiral hemicryptophane cage is an effective receptor for carbohydrates.
• The cage's enantioselectivity and binding affinity are superior to other known hemicryptophanes.
• Chirality of the cyclotriveratrylene unit is a key factor in tuning the recognition of specific sugar derivatives.