ENANTIOSELECTIVE SYNTHESIS OF CHIRAL SULFOXIDES USING PENTANIDIUM CATALYSTS

Abstract

Molecules containing chiral sulfinyl groups are frequently used as chiral auxiliaries, ligands and intermediates in asymmetric organic synthesis. In particular, the chiral sulfinyl group also presents in some biologically active compounds, for example the marketed drug Esomeprazole, and even nature products. A series of approaches have been developed to achieve the optically active sulfoxides and also make it possible for large-scale asymmetric syntheses in either stoichiometric or catalytic mode. Currently, two main strategies exist. One is the nucleophilic substitution by organometallic reagents in which the sulfur is the electrophilic center, whereas the other is the oxidation of prochiral sulfides in which the sulfur is of nucleophilic character. In this thesis, the deployment of a novel sulfenate species as the nucleophile in the synthesis of enantioenriched sulfoxides was studied using a catalytic amount of halogenated pentanidium catalysts. Good results were obtained and preliminary mechanistic study was conducted.