trans-(±)-2-tert-butyl-3-phenyloxaziridine:: A unique reagent for the oxidation of thiolates into sulfenates

Aliphatic thiolates were efficiently converted into the corresponding sulfenates by smooth oxidation with trans-(+/-)-2-tert-butyl-3-phenyloxaziridine at room temperature (five examples). Subsequent electrophilic quench with benzyl bromide led to sulfoxides (S-alkylation) in good to moderate yields. Application of the protocol to an aromatic substrate was also successful. This work represents the first valuable example of the use of this poorly active oxidizing agent in synthetic organic chemistry without the need for activating conditions.