S-Phenyl-S-vinyl-N-(p-toluenesulfonyl)sulfilimine1

[56692-06-9]  · C15H15NO2S2  · S-Phenyl-S-vinyl-N-(p-toluenesulfonyl)sulfilimine  · (MW 305.45)

(vinylation;1,2 cyclopropanation;3 hetero-ring construction4)

Physical Data: mp 111-113 °C.

Solubility: insol H2O; sol EtOH, MeOH, acetone, chloroform, other common polar organic solvents.

Preparative Method: the title reagent (1) is prepared via sulfimination of 2-chloroethyl phenyl sulfide5 followed by dehydrochlorination.6 The sulfimination is carried out as follows. A solution of the sulfide (10 mmol) in CH2Cl2 (70 mL) and a solution of Chloramine-T trihydrate (11 mmol) and tetrabutylammonium chloride (0.2 mmol) in water (70 mL) are vigorously stirred at 40 °C for 4 h. The resulting S-(2-chloroethyl)-S-phenyl-N-tosylsulfilimine (2) is recrystallized from CH2Cl2-Et2O. The yield is almost quantitative (mp 101-103 °C).5 The dehydrochlorination is carried out as follows. A solution of (2) (10 mmol) in benzene (100 mL) and a solution of NaOH (10.5 mmol) and tetrabutylammonium bromide (0.05 mmol) in water (50 mL) are vigorously stirred at rt overnight. The crude product is recrystallized from CH2Cl2-Et2O. The yield of (1) is almost quantitative (mp 111-113 °C).6

Handling, Storage, and Precautions: stable and storable at rt in a sealed bottle. Use in a fume hood.

Vinylation.1,2

Sulfilimine (1) undergoes Michael-type addition with various protic nucleophiles (RZH) such as alcohols, thiols, amines, and amides. The reactions of (1) with an excess of RZH in the presence of Sodium Hydride in THF are carried out at rt for several hours to 1 day to give the corresponding adducts in high yields. The amount of NaH used depends on the basicity of attacking nucleophile. The basicity of the intermediate carbanion formed is estimated to be between those of alcohols and amines. When alcohols and thiols are used as RZH, the addition reactions proceed in the presence of catalytic amounts of NaH (eqs 1-3), while the reactions of (1) with amines require equimolar amounts of NaH. The adducts obtained decompose at higher temperature (ca. 20-30 °C) than their melting points to give vinyl compounds in almost pure form (eq 4).1

Similarly, allyl vinyl ethers2a and alkynyl vinyl ethers2b can be obtained from the addition reactions between (1) and allyl or alkynyl alcohols followed by the thermal decomposition of the adducts (eqs 5 and 6). The times required for completion of the addition reaction are about 24 h for primary alcohols in THF and for secondary and tertiary ones used as cosolvents. Under these conditions the corresponding vinyl ethers can be obtained from allyl, methallyl, crotyl, and 1-methylallyl alcohols in high overall yields (>80%). Alkynyl vinyl ethers are also formed efficiently.

Cyclopropanation.3

When the sulfilimine (1) is allowed to react with diprotic nucleophiles (RZH2) in the presence of equimolar amounts of NaH, cyclic compounds incorporating the vinyl carbons are produced. When the compounds RZH2 are active methylene compounds, cyclopropane derivatives are obtained (eq 7). The addition is carried out at rt for 24 h and then the cyclization at 35-40 °C for 4 h. In this way, the corresponding cyclopropanes are formed from dibenzoylmethane, anthrone, and fluorene in 60-77% yields.

Hetero-ring Construction.4

Amides, as diprotic nucleophiles RZH2, react with (1) in THF to give 2-substituted oxazolines (eq 8). The addition is carried out at rt for 24 h and then the cyclization at 40 °C for 5 h. The yields of 2-aryloxazolines (ca. 70%) are superior to those of the alkyl analogs.

Miscellaneous.

The reaction of (1) with Methyllithium in THF gives mainly a polymer,7 whereas the reactions with Grignard reagents (R = Ph, p-Tol, Et, i-Pr) give 2-substituted phenyl vinyl sulfides in 45-76% yields via addition and elimination of the tosylamino group (eq 9).7

Related Reagents.

S,S-Dimethyl-N-(p-toluenesulfonyl)sulfilimine; S,S-Diphenylsulfilimine; Ethyl Vinyl Ether; Phenyl Vinyl Sulfide; p-Tolyl Vinyl Sulfoxide; Vinyl Acetate.


1. Yamamoto, T.; Okawara, M. CL 1975, 581.
2. (a) Yamamoto, T.; Fujita, S.; Sugawara, K.; Watanabe, T. OPP 1995, 27, 99. (b) Yamamoto, T.; Fujita, S.; Nanayama, T.; Katagiri, S. Unpublished results.
3. Ikeda, K.; Satoh, H.; Yamamoto, T. OPP 1992, 24, 557.
4. Ikeda, K.; Honda, H.; Matsuo, T.; Yamamoto, T. OPP 1995, 27, 103.
5. Yamamoto, T.; Yoshida, D. OPP 1988, 20, 271.
6. Shimizugawa, Y.; Takahashi, T.; Ishii, M.; Yamamoto, T. OPP 1990, 22, 522.
7. Yamamoto, T.; Kakimoto, M.; Okawara, M. TL 1977, 1659.

Tamotsu Yamamoto

Kanto Gakuin University, Yokohama, Japan



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