Decatungstate-photocatalysed C(sp³)-H azidation

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Chemistry

Background:

• C-H azidation is crucial for synthesizing nitrogen-containing compounds.
• Existing methods often rely on expensive or hazardous reagents and catalysts.
• There is a need for simpler, more sustainable C-H azidation techniques.

Purpose of the Study:

• To develop a general and efficient C-H azidation reaction.
• To utilize earth-abundant and commercially available reagents.
• To explore a photocatalytic approach for C-H bond functionalization.

Main Methods:

• Photocatalysis using tetra-n-butylammonium decatungstate.
• Azide source: p-acetamidobenzenesulfonyl azide (p-ABSA).
• Application to unactivated C(sp3)-H bonds.

Main Results:

• Successful azidation of various unactivated C(sp3)-H bonds.
• Moderate to good yields achieved.
• Excellent catalyst turnover numbers demonstrated.

Conclusions:

• A simple and general C-H azidation protocol has been established.
• The method employs cost-effective and readily available materials.
• The reaction likely proceeds via a photo-hydrogen atom transfer (photo-HAT) radical mechanism.