Double N,B-Type Bidentate Boryl Ligands Enabling a Highly Active Iridium Catalyst for C-H Borylation

Area of Science:

• Organometallic Chemistry
• Catalysis
• Ligand Design

Background:

• Boryl ligands are valuable in catalysis due to their strong electron-donating capabilities.
• Developing new ligand types is crucial for advancing catalytic reactions.

Purpose of the Study:

• To design and synthesize novel double N,B-type boryl anions as bidentate ligands.
• To utilize these ligands for promoting sp(2) C-H borylation reactions.
• To establish the first example of a bidentate boryl ligand in homogeneous organometallic catalysis.

Main Methods:

• Synthesis of a symmetric pyridine-containing tetraaminodiborane(4) compound as a ligand precursor.
• In situ catalyst generation using the ligand precursor and [Ir(OMe)(COD)]2.
• Application of the catalyst in sp(2) C-H borylation of various (hetero)arene substrates.

Main Results:

• A novel bidentate boryl ligand was successfully designed and synthesized.
• The ligand facilitated the in situ generation of a highly active iridium catalyst.
• The catalyst demonstrated broad substrate scope, including electron-rich and sterically hindered (hetero)arenes.

Conclusions:

• Double N,B-type boryl anions are effective bidentate ligands for sp(2) C-H borylation.
• This work introduces the first bidentate boryl ligand for homogeneous organometallic catalysis.
• The developed catalytic system offers a versatile approach for functionalizing diverse (hetero)arenes.