Bifunctional Squaramide-Catalyzed Oxidative Kinetic Resolution: Simultaneous Access to Axially Chiral Thioether and...

Area of Science:

• Organic Chemistry
• Asymmetric Catalysis
• Stereoselective Synthesis

Background:

• Axially chiral thioethers and sulfoxides are crucial in asymmetric transformations.
• Limited methods exist for synthesizing diverse chiral thioethers and sulfoxides.
• These compounds are valuable as ligands and organocatalysts.

Purpose of the Study:

• To develop an efficient method for synthesizing diverse axially chiral thioethers and sulfoxides.
• To establish an oxidative kinetic resolution of sulfides using a chiral catalyst.
• To explore the application of this method to benzothiophene-based sulfides.

Main Methods:

• Oxidative kinetic resolution of sulfides using cumene hydroperoxide.
• Employing a chiral bifunctional squaramide as the catalyst.
• Investigating the mechanism through hydrogen bonding interactions.

Main Results:

• Successful synthesis of various axially chiral thioethers and sulfoxides.
• Achieved excellent diastereo- and enantioselectivities.
• Demonstrated applicability to benzothiophene-based sulfides.

Conclusions:

• The developed catalytic system provides efficient access to valuable chiral sulfur compounds.
• The method broadens the scope of asymmetric synthesis of thioethers and sulfoxides.
• Hydrogen bonding interactions are key to the catalyst's efficacy.