NNB-Type Tridentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C⁻H Borylation

Area of Science:

• Organometallic Chemistry
• Catalysis
• Ligand Design

Background:

• Boryl ligands are crucial in catalysis due to their strong electron-donating capabilities.
• Aryl C-H borylation is a key transformation in organic synthesis.

Purpose of the Study:

• To design and synthesize novel NNB-type boryl anions as tridentate ligands.
• To investigate their efficacy in promoting aryl C-H borylation reactions.

Main Methods:

• Synthesis of NNB-type boryl anions.
• Catalyst preparation using [IrCl(COD)]₂ and the designed ligands.
• Testing the catalytic activity across various (hetero)arene substrates.

Main Results:

• The developed NNB-type boryl ligands effectively promote aryl C-H borylation.
• The resulting iridium catalyst exhibits high activity for a wide range of substrates.
• The catalyst demonstrates efficacy with electron-rich and sterically hindered arenes.

Conclusions:

• NNB-type boryl anions serve as effective tridentate ligands in homogeneous catalysis.
• This research introduces a valuable new ligand class for organometallic catalysis, particularly for C-H borylation.