Radical cyclizations terminated by Ir-catalyzed hydrogen atom transfer

Area of Science:

• Organic Chemistry
• Catalysis
• Reaction Mechanisms

Background:

• Radical cyclization is a powerful tool in organic synthesis.
• Hydrogen atom transfer (HAT) is crucial for many catalytic processes.
• Developing efficient and selective catalytic systems remains a key challenge.

Purpose of the Study:

• To describe a new system coupling catalytic radical cyclization and Ir-catalyzed hydrogen atom transfer (HAT).
• To identify a suitable HAT catalyst that rapidly activates H(2) without causing hydrogenation.
• To demonstrate the efficiency of Vaska's complex in this dual catalytic system.

Main Methods:

• Utilizing a system that combines radical cyclization with Ir-catalyzed HAT.
• Screening and evaluating potential HAT catalysts for H(2) activation.
• Characterizing the performance of Vaska's complex as the HAT catalyst.

Main Results:

• A successful coupling of catalytic radical cyclization and Ir-catalyzed HAT was achieved.
• Vaska's complex was identified as an efficient HAT catalyst, activating H(2) rapidly.
• The catalyst did not promote undesired hydrogenation reactions.

Conclusions:

• The described system provides an effective method for combining radical cyclization and HAT catalysis.
• Vaska's complex is a suitable catalyst for Ir-catalyzed HAT, offering rapid H(2) activation.
• This work expands the toolkit for catalytic radical reactions.