Transfer Hydrogenation Catalyzed by a Bifunctional Cobalt-Based Supramolecular Complex Offering Hydrogen Bonding...

Area of Science:

• Supramolecular Chemistry
• Catalysis
• Materials Science

Background:

• Cobalt-containing supramolecular complexes offer potential for catalytic applications.
• Dual-functional catalysts can enhance reaction efficiency and selectivity.
• Heterogeneous catalysis provides advantages in separation and reusability.

Purpose of the Study:

• To synthesize and characterize a cobalt-containing supramolecular complex (Co-L) with dual Lewis acidic-basic and Brønsted acidic sites.
• To investigate the catalytic activity of Co-L in base-free transfer hydrogenation of carbonyl and imine compounds.
• To elucidate the synergistic mechanism involving dual functionalities in the catalytic process.

Main Methods:

• Synthesis and characterization of the cobalt supramolecular complex (Co-L).
• Heterogeneous catalytic transfer hydrogenation reactions using isopropanol as a hydrogen donor.
• Mechanistic studies involving spectral analysis and molecular docking.

Main Results:

• Co-L demonstrated high catalytic activity and exclusive selectivity for the base-free transfer hydrogenation of diverse aldehydes, ketones, and imines.
• Effective transformation of biomass-derived (furfural, levulinic acid, 5-methylfurfural) and pharmaceutical substrates (cinnamaldehyde, estrone) was achieved.
• Mechanistic studies revealed synergistic catalysis between Lewis acid-base sites (Co2+/OH-) and Brønsted acid sites (-COOH).

Conclusions:

• The Co-L complex is an efficient heterogeneous catalyst for base-free transfer hydrogenation.
• The dual functionalities of Co-L are crucial for its remarkable catalytic performance.
• This study highlights the potential of supramolecular complexes in green chemistry and catalysis.