[77933-53-0]  · C4H6N4O4Pd  · Bis(acetonitrile)dinitropalladium(II)  · (MW 280.54)

(reagent capable of catalyzing the oxidation of alkenes to ketones2,3 and the nitration of alkenes3)

Physical Data: yellow solid.

Solubility: sol acetone, dichloromethane, acetonitrile; sparingly sol toluene.

Analysis of Reagent Purity: 1H NMR (acetone-d6): 2.16 ppm (s).3

Preparative Method: prepared from the reaction of Pd(MeCN)2Cl2 (formed from the reaction of Palladium(II) Chloride and Acetonitrile) with 2 equiv of Silver(I) Nitrite in acetonitrile. Removal of silver chloride by filtration after 1 h and evaporation of the solvent gives the complex as a yellow solid in quantitative yield.3

Handling, Storage, and Precautions: darkening of the complex occurs on extended drying under vacuum or upon recrystallization from acetonitrile and toluene. The complex should be stored under an inert atmosphere. Palladium compounds are reported to be slightly toxic and acetonitrile is highly flammable and lachrymatory.

Oxidation and Nitration of Alkenes.

Bis(acetonitrile)dinitropalladium(II) has been shown to be effective for the catalytic oxidation of alkenes to ketones2,3 or for the nitration of alkenes.3 Which of the possible products is obtained is primarily dependent on the choice of solvent.2 If the reaction is carried out in acetone, formation of the ketone is favored, but if toluene is used the nitration product predominates (eq 1).

The reaction in toluene, however, takes over a week to go to completion because of the sparing solubility of the palladium complex. A more recent study has shown that the same yields and selectivity can be obtained in 5 h by carrying out the reaction in refluxing dichloromethane.3 It should be noted that nitration with this complex is limited to terminal alkenes. Internal (such as cis-2-butene) and cyclic (such as cyclohexene) alkenes react with the complex to give primarily oxidized products.

1. (a) Beck, I. E.; Gusevskaya, E. V.; Likholobov, V. A.; Ermakov, Y. I. React. Kinet. Catal. Lett. 1987, 33, 209. (b) Beck, I. E.; Gusevskaya, E. V.; Stepanov, A. G.; Likholobov, V. A.; Nekipelov, V. M.; Yermakov, Y. I.; Zamaraev, K. I. J. Mol. Catal. 1989, 50, 167.
2. Andrews, M. A.; Kelly, K. P. JACS 1981, 103, 2894.
3. Andrews, M. A.; Chang, T. C. T.; Cheng, C. W. F.; Kapustay, L. V.; Kelly, K. P.; Zweifel, M. J. OM 1984, 3, 1479.

Kevin J. Smith

The Ohio State University, Columbus, OH, USA

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