Sulfenamides, rearrangements with

The reaction of the thiolated PVC with Chloramine T carried out and the structure ( ) of the resultant polymer was examined (1 ). In the case of phenyl-thioether, the sulfilimine structure (2) was mainly produced accompanied with, in part, the sulfenamide structure (8,) binded to the main chain with N atom, the case of allyl thioether derivative containing C=C moiety in the pendent group, the sulfilimine (9) formed rearranged exclusively in Claisen type to the sulfenamide structure (10) connected to the main chain with S atom. 

Fig. 3.9 The acid-catalyzed rearrangement of the substituted benzimidazole pantoprazole (prodrug) to the cyclic sulfenamide (active principle) and its reaction with thiols.

Allylic sulfenamides 2 are formed by [2,3] sigmatropic rearrangement of intermediate allylic sulfur derivatives 3 with a S-N double bond generated by the following methods ... 

Weinreb and coworkers have examined some reactions of dihydrothiazine imines and have developed a new approach to vicinal diamines using these intermediates. Their method is outlined in Scheme 18. Cycloaddition of ( -2,4-hexadiene with the tosyl bis-imine gives a 1.1 1 mixture of epimeric dihydrothiazine imines (140) and (144). Subsequent transformations of these adducts took two different courses. In one, adduct (140) could be opened to allylic sulfilimine (141) which underwent a stereoselective 2,3-sigmatiopic rearrangement to sulfenamide (142) (cf. equation 54). Desulfurization of (142) yielded E)-threo vicinal sulfonamide (143). Adduct (144), which presumably exists in conformation... 

This transformation presumably proceeds with initial formation of allylic sulfilimine 55, which rearranges via an envelope-like transition state to sulfenamide 56 (cf. Scheme 1-XIU). Interestingly, NMR analysis showed that this [2,3]-sigmatropic rearrangement lies totally on the side of this sulfenamide, unlike the allylic suUbxide-sulfenate ester system, which lies predominantly to the side of the sulfoxide. Similarly, C-3 epimeric dihydrothiazine imine 58 can be converted by an identical pathway to E-erythrp vicinal diamine 59 in an efficient and totally stereoselective manner [Eq. (28)]. 

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