Photothermal Conversion Promotes Challenging S_NAr for Facile C─N Bond Formation

Area of Science:

• Organic Chemistry
• Synthetic Chemistry
• Photochemistry

Background:

• Nucleophilic aromatic substitution (S_NAr) is crucial for synthesizing aromatic C─N bonds.
• Existing S_NAr methods struggle with less activated electrophiles due to high activation energy barriers.

Purpose of the Study:

• To develop a photothermal approach for challenging S_NAr reactions.
• To overcome limitations in activating electrophiles for C─N bond formation.

Main Methods:

• Utilizing carbon black as an inexpensive photothermal agent with red light irradiation.
• Investigating photothermally mediated Newman Kwart Rearrangement (NKR) principles.
• Employing computational studies to analyze reaction barriers.

Main Results:

• Successful S_NAr reactions with poorly activated intermolecular substrates.
• Identified challenges with inhomogeneous photothermal heating affecting reactant colocalization.
• Developed a sequential S_NAr strategy for difficult intramolecular substitutions.

Conclusions:

• Photothermal conversion offers a novel route for difficult S_NAr reactions.
• A sequential S_NAr approach enables the synthesis of diverse fused heterocycles.