Difluorocarbene/H₂O Serving as a CO₂ Equivalent for Insertion into Oxiranes

Area of Science:

• Organic Chemistry
• Synthetic Chemistry

Background:

• Oxirane ring-opening reactions are fundamental in organic synthesis.
• Developing efficient and selective methods for functionalizing oxiranes remains an active area of research.
• Cyclic carbonates are valuable synthetic intermediates and possess diverse applications.

Purpose of the Study:

• To develop a novel difluorocarbene-enabled protocol for regioselective C(sp3)-O bond cleavage of oxiranes.
• To establish an efficient and practical method for synthesizing cyclic carbonates under mild conditions.
• To introduce a metal-free system for difluorocarbene generation using a CO2 equivalent.

Main Methods:

• Utilized difluorocarbene generated from ethyl bromodifluoroacetate (BrCF2CO2Et) and water.
• Employed a metal-free reaction system.
• Investigated the regioselective cleavage of C(sp3)-O bonds in various oxiranes.

Main Results:

• Achieved efficient and regioselective C(sp3)-O bond cleavage of oxiranes.
• Successfully synthesized a range of cyclic carbonates under mild reaction conditions.
• Demonstrated the generation of difluorocarbene using BrCF2CO2Et/H2O as a CO2 surrogate.

Conclusions:

• The developed protocol offers a practical and efficient route to cyclic carbonates from oxiranes.
• The metal-free difluorocarbene generation system provides a sustainable alternative for synthetic transformations.
• This methodology expands the synthetic utility of oxiranes and difluorocarbene chemistry.