Lewis Base-Enhanced C-H Bond Functionalization Mediated by a Diiron Imido Complex

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Chemistry

Background:

• Metal-ligand multiply bonded (MLMB) complexes offer unique reactivity.
• Controlling nuclearity is crucial for selective catalytic pathways.
• C-H bond functionalization remains a significant challenge in synthetic chemistry.

Purpose of the Study:

• To investigate how ligand design influences the nuclearity and reactivity of diiron complexes.
• To develop an exclusively bimetallic reaction pathway for C-H bond functionalization.
• To explore the catalytic potential of diiron imido complexes in C-H activation.

Main Methods:

• Synthesis of diiron alkoxide, imido, and amide complexes.
• Treatment of diiron alkoxide with an azide to form imido species.
• Isolation and characterization of various diiron complexes.
• Catalytic testing for C-H bond functionalization reactions, including toluene amination.

Main Results:

• A diiron imido complex capable of hydrogen atom abstraction (HAA) was synthesized.
• Various diiron complexes with bridging amide and terminal alkoxide ligands were isolated.
• An asymmetric pyridine-bound diiron imido complex showed competence in toluene amination.
• Mechanistic studies indicated that bimetallic bridging imido complexes are the active intermediates.

Conclusions:

• Ligand design can control the nuclearity and reactivity of MLMB complexes.
• Diiron imido complexes provide a viable platform for bimetallic C-H functionalization.
• Lewis base coordination enhances C-H functionalization efficiency in these systems.