Base-catalyzed inversion of chiral sulfur centers. A computational study

Area of Science:

• Computational chemistry
• Organic chemistry
• Stereochemistry

Background:

• Chiral sulfoxides are important synthetic targets.
• Understanding racemization mechanisms is crucial for asymmetric synthesis.
• Pyramidal inversion in sulfur compounds is a key stereochemical process.

Purpose of the Study:

• To investigate the pyramidal inversion of chiral sulfoxides SO(X)(Me) using computational methods.
• To explore the potential of tertiary amines in catalyzing the racemization of these compounds.
• To propose a dynamic kinetic resolution mechanism for chiral sulfoxide synthesis.

Main Methods:

• Density Functional Theory (DFT) calculations using the Becke3LYP method.
• Theoretical modeling of pyramidal inversion in SO(X)(Me) where X = Cl, OMe, p-MePh.
• Analysis of base-catalyzed racemization pathways.

Main Results:

• The study confirms that tertiary amines, such as trimethylamine (NMe3), can catalyze the racemization of SO(Cl)(Me).
• Computational results indicate a feasible pathway for base-catalyzed inversion.
• The specific substituent X influences the inversion barrier and catalytic effect.

Conclusions:

• Base-catalyzed racemization of SO(Cl)(Me) by tertiary amines is theoretically supported.
• This process presents a viable dynamic kinetic resolution strategy for the asymmetric synthesis of chiral sulfoxides.
• The findings contribute to the development of efficient methods for producing enantiomerically pure sulfoxides.