Effective Coordination Promoted Carbene N─H Bond Insertion on Heterogeneous Cu Catalyst

Area of Science:

• Catalysis
• Organic Chemistry
• Materials Science

Background:

• Carbene insertion into N─H bonds is crucial in organic synthesis.
• Highly coordinative aliphatic amines pose challenges for existing catalysts.
• Development of efficient heterogeneous catalysts is needed.

Purpose of the Study:

• To design and evaluate a rationally designed copper nanowire (Cu NW) catalyst for carbene N─H bond insertion.
• To investigate the catalytic mechanism, especially with challenging aliphatic amines like monoethanolamine (MEA).

Main Methods:

• Synthesis of well-defined Cu NW heterogeneous catalysts.
• Catalytic testing of carbene insertion reactions between α-aryl diazoesters and aliphatic amines.
• Characterization using Infrared spectroscopy and theoretical studies.
• Kinetic studies and Hammett-plot analysis.

Main Results:

• Cu NW catalyst efficiently catalyzed carbene insertion with moderate to high yields.
• Strong coordination of MEA on Cu NW surface confirmed.
• Kinetic studies indicated dual Cu atom involvement in the rate-determining step.
• Hammett-plot analysis supported a concerted N─H carbene insertion mechanism.

Conclusions:

• The Cu NW catalyst exhibits exceptional performance in carbene N─H bond insertion.
• The study elucidates a dual-atom catalytic mechanism.
• Heterogeneous catalysts are significant for advancing organic transformations.