Amides Enable Room-Temperature CO₂ Conversion: Simple Organic Molecules Challenging Metal Catalysts

Area of Science:

• Sustainable Chemistry
• Organocatalysis
• Carbon Dioxide Utilization

Background:

• Efficient conversion of carbon dioxide (CO2) into valuable chemicals is crucial for sustainable chemistry.
• Developing ambient condition catalysts, particularly organocatalysts, is highly desirable to replace precious or pollutive metal catalysts.
• Direct C(sp)-H carboxylation with CO2 offers a promising route for chemical synthesis.

Purpose of the Study:

• To discover and develop a new class of organocatalysts for direct C(sp)-H carboxylation using CO2.
• To achieve this transformation under ambient conditions, specifically at room temperature.
• To demonstrate the potential of simple amide molecules as efficient bifunctional catalysts.

Main Methods:

• Utilized amide molecules, specifically N-methylacetamide and valerolactam, as organocatalysts.
• Investigated the direct C(sp)-H carboxylation of aromatic alkynes with CO2.
• Employed Cs2CO3 as an optimal base to promote the catalytic reaction.

Main Results:

• Amide-based organocatalysts efficiently promoted the conversion of aromatic alkynes to propiolic acids.
• The reaction proceeded effectively at room temperature, a significant advancement over existing methods.
• The catalysts demonstrated high activity, comparable to transition metal catalysts, owing to the bifunctional activation of CO2 and C(sp)-H bonds by the amide group.
• Successful C-C coupling was achieved, leading to the formation of propiolic acids.

Conclusions:

• Amide molecules serve as effective bifunctional organocatalysts for direct C(sp)-H carboxylation with CO2.
• This method enables CO2 conversion into valuable chemicals like propiolic acids under mild, room-temperature conditions.
• The findings highlight the potential of simple organic molecules in catalysis and offer new avenues for sustainable chemistry research.