1-Nitro-2-phenylthioethylene1

[101933-27-1]  · C8H7NO2S  · 1-Nitro-2-phenylthioethylene  · (MW 181.23)

(Michael acceptor for the preparation of nitro enamines,3,4 a-nitro aldehyde acetals,5 and indolizines;6 dienophile in the Diels-Alder reaction3,7)

Alternate Name: 1-phenylthio-2-nitroethylene.

Solubility: sol EtOH, acetone, THF, Et2O, CHCl3, CH2Cl2.

Analysis of Reagent Purity: NMR d 6.66 (d, J = 12 Hz, 1H), 7.24-7.56 (m, 5H), 8.18 (d, J = 12 Hz, 1H).

Preparative Method: from 2-nitroethanol2 by the sequence shown in eq 1,3 which can be extended into a general synthesis of b-phenylthio nitroalkenes.3

Michael Acceptor.

Electron-deficient alkenes substituted with nitro and phenylthio groups are useful reagents for the preparation of 1-nitroalkenes via the addition-elimination sequence. The reaction with various amines affords a general method for the synthesis of nitro enamines (eq 2).3,4 However, the reaction with alkoxides does not give 1-alkoxynitroethylenes, but gives 2,2-dialkoxynitroethanes; this affords a useful method for the synthesis of a-nitro aldehyde acetals (eq 3).5

This reagent reacts with the pyridinium salts in the presence of Triethylamine to give the indolizine (eq 4)6 via the azomethine ylide.

Dienophile.

Although this reagent undergoes the Diels-Alder reaction with reactive dienes (eq 5),3 its reactivity is low compared to that of the corresponding sulfoxide and sulfone.

Oxidation of this reagent with m-Chloroperbenzoic Acid gives 1-phenylsulfinyl-2-nitroethylene, which is an excellent dienophile and acts as a nitroacetylene equivalent in the Diels-Alder reaction (eq 6).7

Related Reagents.

1-Nitro-2-phenylsulfonylethylene.


1. (a) Ono, N.; Kaji, A. S 1986, 693. (b) Ono, N. Nitro Compounds: Recent Advances in Synthesis and Chemistry; Feuer, H.; Nielsen, A. T., Eds; VCH: New York, 1990; p 1.
2. Noland, W. E. OSC 1973, 5, 833.
3. Ono, N.; Kamimura, A.; Kaji, A. JOC 1986, 51, 2139.
4. Kamimura, A.; Ono, N. S 1988, 921.
5. Kamimura, A.; Nagashima, T. S 1990, 694.
6. Tominaga, Y.; Ichihara, Y.; Hosomi, A. H 1988, 27, 2345.
7. (a) Ono, N.; Kamimura, A.; Kaji, A. JOC 1988, 53, 251. (b) Jung, M. E.; Grove, D. CC 1987, 753.

Noboru Ono

Ehime University, Matsuyama, Japan



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