Iron-Catalyzed Intramolecular C(sp(2))-H Amination

Area of Science:

• Organometallic Chemistry
• Catalysis
• Synthetic Organic Chemistry

Background:

• Noble metal-based catalysts are commonly used for C-H amination reactions.
• These methods often require harsh conditions and exhibit limited functional group tolerance.
• Development of cost-effective and sustainable catalytic systems is crucial.

Purpose of the Study:

• To develop a novel iron-based catalyst for direct intramolecular C-H amination.
• To synthesize carbazoles and indoles efficiently under mild conditions.
• To provide a sustainable alternative to noble metal catalysis.

Main Methods:

• Utilized tetrabutylammonium iron complex, Bu4N[Fe(CO)3(NO)] (TBA[Fe]), as a nucleophilic catalyst.
• Investigated intramolecular C-H amination of α-azidobiaryls and (azidoaryl)alkenes.
• Performed reactions under mild conditions with low catalyst loadings.

Main Results:

• Successfully catalyzed the direct intramolecular C-H amination of α-azidobiaryls to form carbazoles.
• Successfully catalyzed the direct intramolecular C-H amination of (azidoaryl)alkenes to form indoles.
• Demonstrated broad functional-group tolerance and high efficiency.

Conclusions:

• The iron complex TBA[Fe] is an effective catalyst for direct C-H amination.
• This method provides a mild, efficient, and sustainable alternative to noble metal-catalyzed procedures.
• The broad functional group tolerance makes this a versatile synthetic tool.