The first N-sulfinyl imines in racemic form were formed by oxidation of p-toluene-sulfenyl imines with m-CPBA.   Enantiopure p-toluene-sulfinyl imines arise by the reaction of the commercially available Andersen reagent (menthyl p-toluenesulfinate) with metallo-ketimines but is limited to ketone derived N-sulfinyl imines. A more general method for the preparation of N-sulfinyl imines is the asymmetric oxidation of achiral sulfenyl imines with a chiral oxaziridine. The utility of this method is limited by the availability of the N-sulfonyloxaziridine, which is difficult to prepare. More practical is the one-pot procedure from the Andersen reagent making a variety of p-toluene-sulfinyl imines available from both aromatic and aliphatic aldehydes.
A widely used method for the asymmetric synthesis of N-sulfinyl imines is the condensation of enantiopure primary sulfinamides with aldehyde or ketones. A mild Lewis acid dehydrating reagents such as titanium ethoxide facilitate the condensation. Many sulfinamides are commercially available in both (R)- and (S)-forms. The two most commonly used are the Davis p-toluene-sulfinamide and the Ellman tert-butanesulfinamide