Inchemistry, asulfilimine (orsulfimide) is a type ofchemical compound containing asulfur-to-nitrogen bond which is often represented as adouble bond (S=N). In fact, a double bond violates theoctet rule, and the bond may be considered asingle bond with aformal charge of +1 on the sulfur and a formal charge of −1 on the nitrogen. Theparent compound is sulfilimineH2S=NH, which is mainly of theoretical interest.
Examples includeS,S-diphenylsulfilimine[2] and sulfoximines [Category] such as methylphenylsulfoximine:[3]
Methyl-phenylsulfoximine, a sulfur(VI) compound (left), andS,S-diphenylsulfilimine, a sulfur(IV) compound (right)
In the case of a sulfoximine, the bonds can be considered single bonds, with formal charges of −1 on both the oxygen and the nitrogen, and a formal charge of +2 on the sulfur.
Most sulfilimines areN-substituted with electron-withdrawing groups. These compounds are typically prepared by oxidation of thioethers with electrophilic amine reagents, such aschloramine-T in the presence of a base:[4]
R2S + ClNHTs → R2S=NTs + HCl
An alternative route involves reactions of electrophilic sulfur compounds with amines. The imidosulfonium reagents provide a source of "Me2S2+", which are attacked by amines.
In general, aliphatic sulfilimines are not stable above −30 °C (−22 °F).[5]
KMnO4 can oxidize sulfilimines to sulfoximines, but the latter are more generally produced from addition ofazides tosulfoxides.[5]
Sulfilimine bonds stabilizecollagen IV strands found in theextracellular matrix[6] and arose at least 500 mya.[7] These bonds covalently connecthydroxylysine andmethionine residues of adjacent polypeptide strands to form a larger collagen trimer.
^Elsegood, Mark R. J.; Holmes, Kathryn E.; Kelly, Paul F.; Parr, Jonathan; Stonehouse, Julia M. (2002). "The preparation and structure of novel sulfimide systems; X-ray crystal structures of 1,4-(PHS{NH})2C6H4 (And dihydrate), 1,2-(PHS{NH})(PHS)C6H4·H2O and of [Ph2SNH] and its hydrate".New Journal of Chemistry.26 (2):202–206.doi:10.1039/b103502a.
^Gilchrist, Thomas L.; Moody, Christopher J. (1977). "The chemistry of sulfilimines".Chemical Reviews.77 (3):409–435.doi:10.1021/cr60307a005.
^abRoesky, H. W. (1971). "The Sulfur–Nitrogen Bond". In Senning, Alexander (ed.).Sulfur in Organic and Inorganic Chemistry. Vol. 1. New York: Marcel Dekker. pp. 27–28,30–31.ISBN0-8247-1615-9.LCCN70-154612.
