Secondary-sphere preorganization enables nickel-catalyzed nitrile hydroboration

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Chemistry

Background:

• Nitrile hydroboration is a key transformation in organic synthesis.
• Developing efficient and mild catalytic systems remains a challenge.

Purpose of the Study:

• To develop a novel nickel-catalyzed system for nitrile hydroboration.
• To investigate the mechanism of the catalytic process.

Main Methods:

• Nickel-catalyzed reaction of nitriles with pinacolborane.
• Utilizing a tethered NHC-pyridonate ligand.
• Mechanistic studies including intermediate isolation.

Main Results:

• Efficient catalysis achieved with 5 mol% Ni loading.
• Room temperature reaction conditions with reaction times under 6 hours.
• Isolation and characterization of catalytically relevant intermediates.

Conclusions:

• The tethered NHC-pyridonate ligand plays a crucial cooperative role.
• The ligand simultaneously activates both the nitrile and the borane reagent.
• This work provides a new, efficient method for nitrile hydroboration.