(1; R1 = Me, R2 = Me)

[22236-45-9]  · C9H13NO3S2  · S,S-Dimethyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 247.37) (2; R1 = Et, R2 = Et)

[42153-72-0]  · C11H17NO3S2  · S,S-Diethyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 275.43) (3; R1 = i-Pr, R2 = i-Pr)

[42153-73-1]  · C13H21NO3S2  · S,S-Diisopropyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 303.49) (4; R1 = Ph, R2 = Me)

[42153-74-2]  · C14H15NO3S2  · S-Methyl-S-phenyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 309.44) (5; R1 = Ph, R2 = c-C5H9)

[33332-99-9]  · C18H21NO3S2  · S-Cyclopentyl-S-phenyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 363.54) (6; R1 = Ph, R2 = Cy)

[33367-88-3]  · C19H23NO3S2  · S-Cyclohexyl-S-phenyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 377.57) (7; R1 = Ph, R2 = Bn)

[38764-59-9]  · C20H19NO3S2  · S-Benzyl-S-phenyl-N-(p-toluenesulfonyl)sulfoximine  · (MW 385.54)

(conversion of aldehydes and ketones to oxiranes,1,2 ketones or oxiranes to oxetanes,3 imines to aziridines,1,2 and electrophilic alkenes to cyclopropanes1,2)

Alternate Name: S,S-dimethyl-N-tosylsulfoximine.

Physical Data: (1) mp 167-169 °C, 170 °C (from ethanol);2,4 (2) mp 89-91 °C; (3) mp 75-77 °C; (4) mp 107-109 °C; (5) mp 143-144 °C; (6) mp 145-146 °C; (7) mp 148-149 °C.

Solubility: moderately sol EtOH, THF, DMSO.

Form Supplied in: (1) white solid; commercially available.

Preparative Methods: excess DMSO containing Copper(II) Chloride (or another copper catalyst)2,4 is treated with Chloramine-T trihydrate. (1) is obtained in 90% yield after aqueous EDTA workup and recrystallization from ethanol.

The other N-tosylsulfoximines can be prepared by the tosylation of N-H sulfoximines with p-Toluenesulfonyl Chloride in the presence of base,2 but the two most useful and general methods are the oxidation of N-tosylsulfilimines with basic Hydrogen Peroxide,5 m-Chloroperbenzoic Acid anion,6 Sodium Hypochlorite,8 or Ruthenium(VIII) Oxide/sodium metaperiodate7 and the copper powder-promoted reaction of sulfoxides with p-Toluenesulfonyl Azide.2,9

Handling, Storage, and Precautions: (1) is a highly crystalline compound with no known toxicity and unlimited shelf life.

The generation of N-p-toluenesulfonyl-sulfonimidoyl-stabilized carbanions is best accomplished by stirring a slurry of N-tosylsulfoximine, e.g. (1), and Sodium Hydride in DMSO at rt until hydrogen evolution ceases (2-4 h). THF solutions of the lithium salts of N-tosylsulfoximines can be prepared by deprotonation with n-Butyllithium. These anions, which are quite stable at room or slightly elevated temperatures, form a class of nucleophilic alkylidene transfer reagents. The mechanism of these transfer reactions is similar to that of sulfonium ylide reactions but the leaving groups are water-soluble anions rather than neutral molecules (eq 1). The nucleophilic transfer chemistry of sodium N-tosylmethanesulfonimidoylmethide (8) is similar to that of dimethylsulfoxonium methylide10 in regard to regio- and stereochemical selectivity in that the products reflect thermodynamic control.11 Anion (8) has been reported to be superior to dimethylsulfonium and dimethylsulfoxonium methylides for reactions in which enolate formation is a serious problem.12

These salts have been used to prepare oxiranes from aldehydes and ketones (eqs 2 and 3),2 cyclopropanes from enones (eq 4),2 and aziridines from imines (eq 5).2 Alkylidene groups which have been transferred using reagents in this series include methylene, ethylidene, isopropylidene, benzylidene, cyclopentylidene, and cyclohexylidene. Optically active versions of these reagents have been studied, but enantiomeric excesses of the resulting alkylidene transfer products have only been modest.2 The reaction of carbanion (8) with epoxides results in the expansion of the ring by one carbon (eq 2). This unique oxetane synthesis, which can be carried out in one step by simply treating the ketone with 3 equiv of (8), is quite general and illustrates the use of (1) as a [-CH2CH2+] synthon.3

Reagent (1) can also be converted to an ethylene transfer reagent by condensation with benzonitrile, followed by reduction of the ketosulfoximine and dehydration (eq 6). The resulting S-vinyl-N-tosylsulfoximine reacts with stabilized anions to give cyclopropanes.13 The N-tosyl group in N-tosylsulfoximines can be cleaved reductively using Sodium Anthracenide.14

Related Reagents.

N,S-Dimethyl-S-phenylsulfoximine; Dimethylsulfonium Methylide; Dimethylsulfoxonium Methylide; Diphenylsulfonium Methylide; Isopropyldiphenylsulfonium Tetrafluoroborate.

1. (a) Johnson, C. R. Aldrichim. Acta 1985, 18, 3. See also: (b) Kennewell, P. D.; Taylor, J. B. CSR 1980, 9, 477; (c) Oae, S.; Furukawa, N. In Sulfilimines and Related Derivatives; American Chemical Society: Washington, 1983.
2. Johnson, C. R.; Krichhoff, R. A.; Reischer, R. J.; Katekar, G. F. JACS 1973, 95, 4287.
3. Welch, S. C.; Rao, A. S. C. P.; Lyon, J. T.; Assercq, J.-M. JACS 1983, 105, 252.
4. (a) Carr, D.; Seden, T. P.; Turner, R. W. TL 1969, 477; (b) Heintzelman, R. W.; Swern, D. S 1976, 731.
5. Johnson, C. R.; Krichhoff, R. A. JOC 1979, 44, 2280.
6. Huang, S.-L.; Swern, D. JOC 1979, 44, 2510.
7. (a) Veale, H. S.; Levin, J.; Swern, D. TL 1978, 503. (b) Ketcha, D. M.; Swern, D. SC 1984, 14, 915.
8. Akutagawa, K.; Furukawa, N.; Oae, S. JOC 1984, 49, 2282.
9. Kwart, H.; Kahn, A. A. JACS 1967, 89, 1950.
10. Corey, E. J.; Chaykovsky, M. JACS 1965, 87, 1353.
11. Johnson, C. R.; Schroeck, C. W.; Shanklin, J. R. JACS 1973, 95, 7424.
12. Andersen, N. H.; Ladner, D. W.; Moore, A. L. SC 1978, 8, 437.
13. Johnson, C. R.; Lockard, J. P.; Kennedy, E. R. JOC 1980, 45, 264.
14. Johnson, C. R.; Lavergne, O. JOC 1989, 54, 986.

Carl R. Johnson

Wayne State University, Detroit, MI, USA

Claire Dufour & Viresh H. Rawal

The Ohio State University, Columbus, OH, USA

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