[106-51-4]  · C6H4O2  · 1,4-Benzoquinone  · (MW 108.10)

(useful as an oxidizing1 or dehydrogenation agent;2 can function as a dienophile3 in the Diels-Alder reaction or as a dipolarophile to prepare 5-hydroxyindole derivatives4)

Alternate Name: p-benzoquinone.

Physical Data: mp 115.7 °C; d 1.318 g cm-3.

Solubility: slightly sol water; sol alcohol, ether, hot petroleum ether, and aqueous base.

Form Supplied in: yellowish powder; widely available.

Handling, Storage, and Precautions: the solid has an irritating odor and can cause conjunctivitis, corneal ulceration, and dermatitis. In severe cases, there can be necrotic changes in the skin. Use in a fume hood.

As Oxidizing or Dehydrogenation Agent.

The ease of reduction of 1,4-benzoquinone to hydroquinone by various compounds renders it useful as an oxidizing or dehydrogenation agent.2,5 The literature shows that 1,4-benzoquinone prefers to oxidize conjugated primary allylic alcohols over other alcohols (eq 1).6 Kulkarni has demonstrated the selective oxidation of cinnamyl alcohols to cinnamaldehydes in the presence of secondary or benzylic alcohols. Primary alcohols have been oxidized to the corresponding aldehydes by using 1,4-benzoquinone as the hydrogen acceptor and hydrous zirconium(IV) oxide7 as a catalyst (eqs 2 and 3).1

Nitrogenous compounds can be oxidized by 1,4-benzoquinone in refluxing benzene.8,9 Aurich reported the conversion of hydroxyamine (1) to nitrone (2) through the reaction with 1,4-benzoquinone (eq 4).9 Wiberg used 1,4-benzoquinone to transform tetrazene (3) into molecular nitrogen (eq 5).10 Rossazza reported the oxidation of leurosine at the carbon a to nitrogen (eq 6).11

In the oxidation of alkenes with palladium(II) acetate, 1,4-benzoquinone serves as a cooxidant to reoxidize palladium(0) to palladium(II).12,13 Davidson reported the oxidation of alkene (4) to a vinyl acetate with 0.1 equiv of palladium acetate and 1 equiv of 1,4-benzoquinone (eq 7).14

Backvall reported that the reaction of 1,3-cyclohexadiene with Palladium(II) Acetate and 1,4-benzoquinone gave 1,4-diacetoxy-2-cyclohexene in high yield. The stereochemistry of the products was influenced by additives. In the presence of lithium acetate, the major trans-diacetate was obtained in 90% yield.15 Without the addition of lithium acetate, a 1:1 mixture of trans and cis isomers was produced. However, the cis-diacetate was the major (>93%) product when both lithium acetate and lithium chloride were added (eq 8).15 When the reaction was carried out in acetic acid containing trifluoroacetic acid and lithium trifluoroacetate, the trans isomer of 1-acetoxy-4-trifluoroacetoxy-2-cyclohexene was the major product in 67% yield (eq 9).16 Similar oxidative 1,4-additions of other dienes, such as 1,3-butadiene, also can be accomplished in a regio- and stereoselective fashion (eq 10).17 However, 1,4-benzoquinone has a high tendency to undergo Diels-Alder reactions when used as a cooxidant for Pd(OAc)2 in such reactions. Many reactions of this type use only catalytic amounts of 1,4-benzoquinone and stoichiometric amounts of external oxidants, such as Ce(SO4)2, Tl(OAc)3, and MnO2.18

The combination of 1,4-benzoquinone and a catalytic amount of palladium acetate can transform silyl enol ethers into conjugated enones.19 This reaction is not only regiospecific (eq 11) but also stereospecific to give the more stable trans acyclic enone (eq 12).

Antonsson used Manganese Dioxide as the oxidant and 0.05 equiv of palladium acetate and 0.20 equiv of 1,4-benzoquinone as catalyst for oxidative ring closure of 1,5-hexadienes to give cyclopentane derivatives in good yield (eq 13).20 With 1,4-benzoquinone and 10 mol % of Palladium(II) Chloride, a homoallylic alcohol underwent oxidative ring closure to give a g-butyrolactol (eq 14).21

The combination of palladium acetate and 1,4-benzoquinone was used in the ring opening of an a,b-epoxysilane to give 19% of oct-2-enal in the presence of oxygen gas (eq 15).22 Similar reagents are effective in the oxidative coupling of carbon monoxide in methanol to give methyl oxalate (eq 16).12

As Dienophile.

1,4-Benzoquinone is an excellent dienophile in the Diels-Alder reaction toward electron rich dienes.23,24 The bicyclic cycloadducts of these reactions are frequently used as the starting materials for the synthesis of natural products. A typical example is demonstrated by Mehta in a total synthesis of capnellene, in which 1,4-benzoquinone is allowed to react with 1-methyl-1,3-cyclopentadiene to give compound (5) (eq 17).25 The cycloaddition of 1,4-benzoquinone and another activated diene is shown in eq 18.26

Asymmetric Diels-Alder reactions of 1,4-benzoquinone have been reported. Several examples are shown in eqs 19-21.3,27,28

Under high pressure, even electron deficient dienes react with 1,4-benzoquinone. Dauben reported the asymmetric cycloaddition of a chiral dienic ester and 1,4-benzoquinone to produce chiral adducts with moderate enantioselectivity (eq 22).29

Preparation of 5-Hydroxyindoles.

The reaction of 1,4-benzoquinone with certain enamines has been used to prepare 5-hydroxyindole derivatives.4,30 The first example was reported by Nenitzescu, in which he successfully prepared ethyl 5-hydroxy-2-methylindole-3-carboxylate from 1,4-benzoquinone and ethyl 3-aminocrotonate (eq 23).4 The ease of the reaction and the availability of the reactants have made it a popular method for indole synthesis. However, the yields of this type of reaction vary over a wide range (5-90%).

As Reaction Promoter.

In the hydrogenation of nitrobenzene with platinum catalyst in DMSO, addition of 1,4-benzoquinone accelerates the reaction rate.31

1. Kuno, H.; Shibagaki, M.; Takahashi, K.; Matsushita, H. BCJ 1991, 64, 312.
2. Walker, D.; Hiebert, J. D. CRV 1967, 67, 153.
3. Tripathy, R.; Carroll, P. J.; Thornton, E. R. JACS 1990, 112, 6743.
4. Nenitzescu, C. D. Bull. Soc. Chim. Rom. 1929, 11, 37 (CA 1930, 24, 110).
5. Turner, A. B.; Ringold, H. J. JCS(C) 1967, 1720.
6. Kulkarni, M. G.; Mathew, T. S. TL 1990, 31, 4497.
7. Shibagaki, M.; Takahashi, K.; Matsushita, H. BCJ 1988, 61, 3283.
8. Fujita, S.; Sano, K. JOC 1979, 44, 2647.
9. Aurich, H. G.; Mobus, K. D. T 1989, 45, 5815.
10. Wiberg, N.; Bayer, H.; Vasisht, S. K.; Meyers, R. CB 1980, 113, 2916.
11. Goswami, A.; Schaumberg, J. P.; Duffel, M. W.; Rosazza, J. P. JOC 1987, 52, 1500.
12. Current, S. P. JOC 1983, 48, 1779.
13. Backvall, J.-E. ACR 1983, 16, 335.
14. Brown, R. G.; Chaudhari, R. V.; Davidson, J. M. JCS(D) 1977, 183.
15. Backvall, J.-E.; Nordberg, R. E. JACS 1981, 103, 4959.
16. Backvall, J.-E.; Vagberg, J.; Nordberg, R. E. TL 1984, 25, 2717.
17. (a) Bäckvall, J.-E.; Nordberg, R. E.; Nyström, J. E. TL 1982, 23, 1617. (b) Backvall, J. E.; Nyström, J.-E.; Nordberg, R. E. JACS 1985, 107, 3676.
18. Backvall, J.-E.; Bystrom, S. E.; Nordberg, R. E. JOC 1984, 49, 4619.
19. Ito, Y.; Hirao, T.; Saegusa, T. JOC 1978, 43, 1011.
20. Antonsson, T.; Heumann, A.; Moberg, C. CC 1986, 518.
21. Nokami, J.; Ogawa, H.; Miyamoto, S.; Mandai, T.; Wakabayashi, S.; Tsuji, J. TL 1988, 29, 5181.
22. Hirao, T.; Murakami, T.; Ohno, M.; Ohshiro, Y. CL 1991, 299.
23. (a) Marchand, A. P.; Allen, R. W. JOC 1974, 39, 1596. (b) Hill, R. K.; Newton, M. G.; Pantaleo, N. S.; Collins, K. M. JOC 1980, 45, 1593. (c) Jurczak, J.; Kozluk, T.; Filipek, S.; Eugster, C. H. HCA 1983, 66, 222. (d) Kozikowski, A. P.; Hiraga, K.; Springer, J. P.; Wang, B. C.; Xu, Z.-B. JACS 1984, 106, 1845. (e) Burnell, D. J.; Valenta, Z. CC 1985, 1247. (f) Pandey, B.; Zope, U. R.; Ayyangar, N. R. SC 1989, 19, 585.
24. Danishefsky, S.; Craig, T. A. T 1981, 37, 4081.
25. Mehta, G.; Reddy, D. S.; Murty, A. N. CC 1983, 824.
26. Krohn, K. TL 1980, 21, 3557.
27. Gupta, R. C.; Raynor, C. M.; Stoodley, R. J.; Slawin, A. M. Z.; Williams, D. J. JCS(P1) 1988, 1773.
28. McDougal, P. G.; Jump, J. M.; Rojas, C.; Rico, J. G. TL 1989, 30, 3897.
29. Dauben, W. G.; Bunce, R. A. TL 1982, 23, 4875.
30. Monti, S. A. JOC 1966, 31, 2669.
31. Kushch, S. D.; Izakovich, E. N.; Khidekel, M. L.; Strelets, V. V. IZV 1981, 7, 1500 (CA 1981, 95, 149 595s).

Teng-Kuei Yang & Chi-Yung Shen

National Chung-Hsing University, Taichung, Republic of China

Copyright 1995-2000 by John Wiley & Sons, Ltd. All rights reserved.