Synlett 2003(6): 0829-0832
DOI: 10.1055/s-2003-38749
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

Copper-Catalyzed Synthesis of Diaryl Selenide from Aryl Iodide and Diphenyl Diselenide Using Magnesium Metal

Nobukazu Taniguchi*, Tetsuo Onami
Department of Chemistry, Fukushima Medical University, Fukushima, 960-1295, Japan
Fax: +81(24)5483836; e-Mail: taniguti@fmu.ac.jp;
Further Information

Publication History

Received 19 February 2003
Publication Date:
17 April 2003 (online)

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Abstract

Various unsymmetrical diaryl selenides can be synthesized from aryl iodides and diphenyl diselenide by an addition of magnesium metal in the presence of a copper catalyst. This method can exploit efficiently two phenylselenide-molecules generated from diphenyl diselenide under neutral conditions.

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In the experiment of entry 1 in Tables [1] , 97% 2-iodotoluene and 89% diphenyl diselenide were recovered; no other products were obtained at all.

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The magnesium metal could not reduce diphenyl diselenide under our conditions. In entry 2 in Tables [1] , 97% 2-iodotoluene and 96% diphenyl diselenide were recovered.

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The reaction between CuI and (PhSe)2 produced a green precipitate. The structure of this compound is now under investigation.

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Cu(I)SePh could be prepared by refluxing Cu2O and PhSeH in EtOH for 24 h.

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A typical procedure is given for the reaction of 2-iodotoluene with diphenyl diselenide giving phenyl 2-tolyl selenide (entry 1 in Table [2] ): To a mixture of Cu2O (2.1 mg, 0.015 mmol), magnesium(powder) (14.6 mg, 0.6 mmol), 2,2′-bipyridyl(bpy) (4.6 mg, 0.03 mmol) and DMF (0.5 mL) were added 2-iodotoluene (65.4 mg, 0.3 mmol) and diphenyl diselenide (46.8 mg, 0.15 mmol), and the mixture was stirred at 110 °C for 30 h. After evaporation of the solvent, the residue was dissolved in Et2O. The solution was washed with H2O and sat. NaCl and dried over anhyd MgSO4. Chromatography on silica gel(hexane) gave phenyl 2-tolyl selenide (78.1 mg, 92%). 1H NMR (270 MHz, CDCl3): δ = 2.39 (s, 3 H), 7.06 (t, J = 7.0 Hz, 1 H), 7.15-7.41 (m, 7 H), 7.56-7.62 (m, 1 H). 13C NMR (67.5 MHz): δ = 22.3, 126.7, 127.1, 127.7, 127.8, 129.1, 129.3, 130.2, 131.5, 132.7, 133.6. 77Se (51 MHz): δ = 479.7. 4-Bromophenyl phenyl selenide: 1H NMR (270 MHz, CDCl3): δ = 7.26-7.31 (m, 5 H), 7.35-7.38 (m, 2 H), 7.45-7.48 (m, 2 H). 13C NMR (67.5 MHz): δ = 121.4, 127.7, 129.4, 130.3, 132.3, 133.2, 133.3, 134.2. 77Se (51 MHz): δ = 432.0. Anal. Calcd for C12H9SeBr: C, 46.19; H, 2.91. Found: C, 46.39; H, 3.05. Phenyl 4-trifluoromethylphenyl selenide: 1H NMR (270 MHz, CDCl3): δ = 7.24-7.37 (m, 3 H), 7.40-7.47 (m, 4 H), 7.55-7.58 (m, 2 H). 13C NMR (67.5 MHz): δ = 125.8, 125.8, 125.9, 126.0, 128.5, 128.7, 129.7, 131.0, 134.8. 77Se (51 MHz): δ = 443.1. Anal. Calcd for C13H9F3Se: C, 51.84; H, 3.01. Found: C, 51.69; H, 3.14.