Isoindolinones via Copper-Catalyzed Intramolecular Benzylic C-H Sulfamidation

Area of Science:

• Organic Chemistry
• Catalysis
• Synthetic Methodology

Background:

• Isoindolinones are important heterocyclic scaffolds found in various biologically active molecules.
• Efficient synthetic routes to substituted isoindolinones are crucial for medicinal chemistry and drug discovery.
• Copper-catalyzed reactions offer versatile pathways for C-H functionalization and heterocycle synthesis.

Purpose of the Study:

• To develop a novel copper-catalyzed intramolecular sulfamidation reaction for synthesizing N-arylsulfonyl-1-arylisoindolinones.
• To establish a method for the subsequent deprotection of N-arylsulfonyl-1-arylisoindolinones to access free 1-arylisoindolinones.
• To investigate the reaction mechanism, including identifying the rate-determining step.

Main Methods:

• Copper-catalyzed intramolecular C-H amidation of 2-benzyl-N-tosylbenzamides and related substrates.
• Use of samarium iodide for N-deprotection of the synthesized N-arylsulfonyl-1-arylisoindolinones.
• Preliminary mechanistic studies, including kinetic analysis, to probe the reaction pathway.

Main Results:

• Successful synthesis of N-arylsulfonyl-1-arylisoindolinones via copper-catalyzed intramolecular sulfamidation.
• Efficient generation of free 1-arylisoindolinones through samarium iodide-mediated N-deprotection.
• Mechanistic studies suggest that the rate-determining step involves slow oxidation of a copper π-arene intermediate, not C-H bond cleavage.

Conclusions:

• A novel and efficient copper-catalyzed method for constructing the 1-arylisoindolinone core has been developed.
• The methodology provides access to valuable 1-arylisoindolinones through a two-step sequence.
• The mechanistic insights advance the understanding of copper-catalyzed C-H functionalization reactions.