Titanium Dinitrogen Complex Catalyzed Hydrophosphination Leveraging the N₂-Unit Electron Reservoir.

Area of Science:

• Inorganic Chemistry
• Organometallic Chemistry
• Catalysis

Background:

• Metal dinitrogen complexes are key in mimicking the Haber-Bosch process for ammonia synthesis.
• Current applications focus on N2 functionalization to form N-X bonds via stoichiometric reactions.
• Discovering alternative catalytic roles for these complexes is a significant research goal.

Purpose of the Study:

• To explore novel catalytic applications of metal dinitrogen complexes beyond N2 functionalization.
• To demonstrate the potential of titanium dinitrogen complexes in organic transformations.
• To introduce and validate the N2-unit electron reservoir (NER) concept.

Main Methods:

• Utilized a titanium dinitrogen complex as a precatalyst for alkene hydrophosphination.
• Conducted mechanistic studies involving diphenylphosphine and ¹⁵N NMR spectroscopy.
• Investigated substrate compatibility and determined turnover numbers.

Main Results:

• The titanium dinitrogen complex effectively catalyzed alkene hydrophosphination with broad substrate compatibility.
• A high turnover number of 743 was achieved.
• Mechanistic studies revealed the N2-unit's replacement by diphenylphosphine, generating a catalytically active Ti^II species and releasing N₂.

Conclusions:

• Metal dinitrogen complexes can serve as precatalysts in organic transformations, offering an alternative to traditional N2 functionalization.
• The N2-unit electron reservoir (NER) concept provides a new strategy for generating low-valent metal species for catalysis.
• This work expands the utility of dinitrogen complexes in catalysis and reaction development.