The first two steps in an oxidation reaction involving N-tert-butylbenzenesulfinimidoyl chloride are similar to a nucleophilic acyl substitution reaction. A nucleophile, such as an alkoxide (1), attacks the S=N bond in 2. The resulting intermediate (3) collapses and ejects chloride ion, which is a good leaving group. The resulting sulfimide has two resonance forms - 4a and 4b. Because of this, the nitrogen is basic, and via a five-membered ring transition state, it can abstract the hydrogen adjacent to the oxygen. This forms a new C=O bond and ejects a neutral sulfenamide (5), giving ketone 6 as the product. N-tert-Butylbenzenesulfinimidoyl chloride reacts with enolates, amides, and primary alkoxides by the same general mechanism.
The Swern oxidation, which converts primary and secondary alcohols to aldehydes and ketones, respectively, also uses a sulfur-containing compound (DMSO) as the oxidant and proceeds by a similar mechanism. In the Swern oxidation, elimination also occurs via a five-membered ring transition state, but the basic species is a sulfur ylide instead of a negatively charged nitrogen. Several other oxidation reactions also make use of DMSO as the oxidant and pass through a similar transition state (see #See also).