2,4-Dinitrobenzenesulfenyl Chloride

[528-76-7]  · C6H3ClN2O4S  · 2,4-Dinitrobenzenesulfenyl Chloride  · (MW 234.63)

(sulfenylation agent used in electrophilic additions,1,2 diene synthesis,12 protection of nucleosides,13 and preparation of propargyl alcohol synthons for use in cycloaddition chemistry15)

Alternate Name: 2,4-dinitrophenylsulfenyl chloride.

Physical Data: mp 94-97 °C.

Solubility: sol most common organic solvents.

Form Supplied in: commercially available as a solid (96% pure).

Handling, Storage, and Precautions: corrosive; lachrymator. This reagent should be handled in a fume hood.

Electrophilic Additions.

The most common use of 2,4-dinitrobenzenesulfenyl chloride is in electrophilic additions. The reagent reacts with a variety of nucleophiles by displacement of the chlorine atom (eq 1).1 The electrophilic addition of this reagent to alkenes (eq 2),2 alkynes,3 and allenes4 has been extensively studied. The addition occurs in a trans stereospecific fashion. Additives to the reaction, such as Lithium Perchlorate and Formic Acid, reportedly increase the electrophilicity of the reagent.5,6 Mechanistic aspects, along with stereo- and regioselectivity, have been reported.2b,7-11

Diene Synthesis.

The 1,4-dehydration of allylic alcohols using 2,4-dinitrobenzenesulfenyl chloride and Triethylamine provides 1,3-dienes in good yields (eq 3).12 The reaction involves a 2,3-sigmatropic rearrangement of the sulfenate ester, followed by a thermal syn elimination. Selenenate esters can also be converted to the 1,3-dienes, but the conditions are more severe and the reaction is less general than with this reagent.

Protection of Nucleosides.

The 2,4-dinitrobenzenesulfenyl group serves as a protecting group for both the hydroxy functionalities and the base in nucleosides (eq 4).13,14 Dinitrobenzenesulfenic esters are stable to pyridine solutions of Acetic Anhydride or p-Toluenesulfonyl Chloride. 1,3-Dicyclohexylcarbodiimide conditions for forming oligonucleosides also do not affect this protecting group. Deprotection is readily accomplished with nucleophilic reagents such as Sodium Thiosulfate, Thiophenol, or Potassium Cyanide.

Propargyl Alcohol Synthons in Cycloadditions.

Allenic sulfoxides can serve as propargyl alcohol equivalents in 1,3-dipolar cycloaddition reactions.15 Treatment of propargyl alcohol with 2,4-dinitrobenzenesulfenyl chloride and triethylamine gives the transient sulfenate ester that spontaneously rearranges to the allenic sulfoxide. The (2,4-dinitrophenyl)sulfinyl-substituted allene reacts smoothly with a variety of nitrones. The initially formed cycloadduct undergoes a 2,3-sigmatropic rearrangement to produce sulfenate esters of isoxazolidines (eq 5).

1. Kharasch, N.; Potempa, S. J.; Wehrmeister, H. L. CRV 1946, 39, 269.
2. (a) Kharasch, N.; Wehrmeister, H. L.; Tigerman, H. JACS 1947, 69, 1612. (b) Kharasch, N.; Buess, C. M. JACS 1949, 71, 2724.
3. Kharasch, N.; Assony, S. J. JACS 1953, 75, 1081.
4. Jacobs, T. L.; Macomber, R.; Zunker, D. JACS 1967, 89, 7001.
5. (a) Zefirov, N. S.; Sadovaja, N. K.; Maggerramov, A. M.; Bodrikov, I. V.; Kasrtashov, V. R. T 1975, 31, 2948. (b) Smit, W. A.; Zefirov, N. S.; Bodrikov, I. V.; Krimer, M. Z. ACR 1979, 12, 282. (c) Zefirov, N. S.; Sadovaya, N. K.; Novgorodtseva, L. A.; Bodrikov, I. V. T 1978, 34, 1373.
6. Kanska, M.; Fry, A. TL 1986, 27, 5063.
7. Cram, D. J. JACS 1949, 71, 3883.
8. Schmid, G. H.; Csizmadia, V. M. CJC 1966, 44, 1338.
9. Mueller, W. H.; Butler, P. E. JACS 1966, 88, 2866.
10. Bodrikov, I. V.; Borisov, A. V.; Smit, W. A.; Lutsenko, A. I. TL 1984, 25, 4983.
11. Okuyama, T.; Izawa, K.; Fueno, T. JOC 1974, 39, 351.
12. Reich, H. J.; Wollowitz, S. JACS 1982, 104, 7051.
13. Letsinger, R. L.; Fontaine, J.; Mahadevan, V.; Schexnayder, D. A.; Leone, R. E. JOC 1964, 29, 2615.
14. (a) Welch, C. J.; Bazin, H.; Heikkilä, J.; Chattopadhyaya, J. ACS 1985, B39, 203. (b) Bazin, H.; Heikkilä, J.; Chattopadhyaya, J. ACS 1985, B39, 391.
15. Padwa, A.; Bullock, W. H.; Norman, B. H.; Perumattam, J. JOC 1991, 56, 4252.

Judi A. McKinney

Tularik Inc., South San Francisco, CA, USA

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