Pd-Catalyzed Spirocyclization via C-H Activation and Benzyne Insertion

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Spirocyclic compounds are prevalent in natural products and pharmaceuticals.
• Efficient synthetic routes to spirooxindoles and spirodihydrobenzofurans are highly sought after.

Purpose of the Study:

• To develop a novel palladium-catalyzed spirocyclization reaction.
• To synthesize spirooxindoles and spirodihydrobenzofurans efficiently.
• To elucidate the reaction mechanism.

Main Methods:

• Palladium-catalyzed spirocyclization reaction.
• Mechanistic studies involving carbopalladation, C-H activation, and benzyne insertion.
• Synthesis of diverse spirooxindoles and spirodihydrobenzofurans.

Main Results:

• Successful synthesis of spirooxindoles and spirodihydrobenzofurans.
• Good to excellent yields achieved for both compound classes.
• Demonstration of reaction scalability.

Conclusions:

• A new, efficient, and scalable palladium-catalyzed spirocyclization has been established.
• The reaction mechanism involves key steps of carbopalladation, C-H activation, and benzyne insertion.
• This methodology provides valuable access to important spirocyclic scaffolds.