Exploring Triel Bonding to Halogens for More Potent σ-Holes

Area of Science:

• Focuses on supramolecular chemistry and physical organic chemistry.
• Investigates noncovalent interactions, specifically halogen bonding and triel bonding.

Background:

• Noncovalent interactions are fundamental to molecular structure and reactivity.
• Halogen bonding is a significant noncovalent interaction with growing research interest.
• Strategies to enhance and control halogen bonding are actively sought.

Purpose of the Study:

• To explore the use of neutral and cationic boron centers to enhance halogen bonding.
• To investigate the mechanism of electron donation from halogen atoms to boron centers.
• To demonstrate the catalytic potential of enhanced halogen bonding in imine reduction.

Main Methods:

• Employed computational studies to model triel bond donor-acceptor X → B interactions.
• Utilized experimental studies to validate computational findings and assess catalytic activity.
• Focused on naphthyl scaffolds to achieve peri-proximity for enhanced interactions.

Main Results:

• Demonstrated that triel bond interactions (X → B, where X = Cl, Br, I) enhance halogen bonding.
• Quantified the enhancement in halogen bonding ability by over 7 kcal/mol.
• Showcased the application of this enhanced halogen bonding in catalyzing imine reduction.

Conclusions:

• Neutral and cationic boron centers significantly enhance halogen bonding through X → B interactions.
• The peri-proximity on a naphthyl scaffold facilitates electron donation, strengthening the interaction.
• This study advances fundamental understanding in organoboron chemistry and halogen bonding, with practical catalytic applications.