The Corey-Kim oxidation is an organic reaction used to convert an alcohol to an aldehyde or ketone using N-chlorosuccinimide (NCS), dimethylsulfide (DMS) and triethylamine (TEA). The mechanism begins with the reaction of DMS with NCS to afford S,S-dimethylsuccinimidosulfonium chloride, also known as "Corey-Kim reagent". This electrophilic reagent is then attacked by the nucleophilic oxygen of the alcohol to form a S-O bond. The addition of TEA results in deprotonation of one of the methyl groups to form a zwitterionic species that undergoes a rearrangement reaction to release DMS gas and provide the final product.
Corey, E. J.; Kim, C. U. J. Am. Chem. Soc. 1972, 94, 7586–7587.