IV-Sulfonyloxaziridines

The transition state for oxygen transfer from iV-sulfonyloxaziridines to alkenes was studied by Anderson eta/, using the endocyclic restriction test <19990L1415>. In this study, molecules containing both the oxaziridine and alkene functionalities were prepared, and the ability of each system to intramolecularly transfer oxygen was evaluated. The results are consistent with a transition state in which N-0 bond cleavage is more advanced than C-O bond cleavage. 

Scheme 12.19 gives some examples of enolate oxidation using iV-sulfonyloxaziridines. 

The novel highly optically active polysulfoxides (111) and (112) (276) with chiral sulfonyl groups in the main chain were prepared by asymmetric oxidation of corresponding polysulfides by using chiral A/-sulfonyloxaziridine. The polysulfoxide with the enantiomeric excess (ee) of up to 91% was obtained in good chemoselectivity when the reaction was carried out with one equivalent of (—)-iV-sulfonyloxaziridine (113) in chloroform at room temperature followed by reflux. 

The tartrate (or TADDOL) derived approach to catalyst design has also been applied to the enantioselective a-hydroxylation of p-ketoesters. In this case, an enantiospecihc titanium(IV) complex combines with a sulfonyloxaziridine as the... 

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