Efficient Kinetic-Resolution Copolymerization of Epoxides and CO₂ Achieved via Computation-Guided Catalyst Design.

Area of Science:

• Polymer Chemistry
• Asymmetric Catalysis
• Organometallic Chemistry

Background:

• Enantioselective resolution copolymerization of racemic epoxides and CO2 is key for isotactic polycarbonates.
• Existing catalytic systems lack both high chemo- and stereoselectivity.
• Understanding catalyst behavior is crucial for designing improved systems.

Purpose of the Study:

• To understand factors governing activity, chemoselectivity, and stereoselectivity in chiral bimetallic cobalt complexes.
• To computationally design and experimentally synthesize a highly selective catalyst.
• To establish a theoretical framework for designing chiral catalysts in asymmetric polymerization.

Main Methods:

• Computation-guided strategy to analyze chiral bimetallic cobalt complexes.
• Computational fine-tuning of bimetallic synergy.
• Experimental synthesis and testing of a designed catalyst.

Main Results:

• Identified key factors for catalyst activity, chemoselectivity, and stereoselectivity.
• Developed a privileged chiral bimetallic catalyst with 6,6-ditriflate substituents.
• Achieved unprecedented enantioselectivity (s-factor > 300) and high chemoselectivity (>95% carbonate units).

Conclusions:

• The designed catalyst enables efficient enantioselective resolution copolymerization of various racemic epoxides with CO2.
• Computational design significantly improved catalyst performance.
• This work provides a roadmap for developing advanced chiral catalysts for asymmetric polymerization.