Synlett 2006(2): 251-254  
DOI: 10.1055/s-2005-923585
LETTER
© Georg Thieme Verlag Stuttgart · New York

Electrochemical Generation and Catalytic Use of Selenium Electrophiles

Osamu Niyomura, Matthew Cox, Thomas Wirth*
Cardiff University, School of Chemistry, Park Place, Cardiff CF10 3AT, UK
Fax: +44(29)20876968; e-Mail: wirth@cf.ac.uk;
Further Information

Publication History

Received 7 November 2005
Publication Date:
23 December 2005 (online)

Abstract

The generation and use of selenium electrophiles in ­catalytic, electrochemically driven selenenylation-elimination sequences is described.

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Typical Experimental Procedure.
The alkene (0.1 mmol) was dissolved in MeOH (7 mL) and tetraethylammonium bromide (0.1 mmol), diselenide (0.01 mmol) and H2SO4 (1 µL) were added. The electrodes were inserted into the reaction mixture and constant current of 3 mA applied. After 6 h, electrolysis was stopped and the MeOH removed in vacuo. The mixture was dissolved in Et2O, washed with NaHCO3 solution and H2O before drying over MgSO4. The products were purified by preparative TLC or column chromatography.

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Spectroscopic data for 7a: 1H NMR (400 MHz, CDCl3): δ = 3.12 (s, 6 H), 3.65 (s, 3 H), 6.24 (d, J = 15.7 Hz, 1 H), 6.73 (d, J = 15.7 Hz, 1 H), 7.20-7.28 (m, 3 H), 7.38-7.40 (m, 2 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 49.7, 51.7, 100.9, 122.0, 126.9, 128.31, 128.33, 139.0, 147.8, 166.7 ppm. IR (NaCl): ν = 2950, 2832, 1727, 1659, 1449, 1436, 1304, 1276, 1192, 1167, 1072, 1046, 988, 700 cm-1. HRMS: m/z calcd for C13H16O4: 259.0941; found: 259.0941.

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Spectroscopic data for 3d: 1H NMR (400 MHz, CDCl3): δ = 1.07 (d, J = 6.1 Hz, 3 H), 1.13 (d, J = 6.1 Hz, 3 H), 3.57 (sept, J = 6.1 Hz, 1 H), 3.64 (s, 3 H), 4.95 (dd, J = 5.4, 1.4 Hz, 1 H), 6.02 (dd, J = 15.6, 1.4 Hz, 1 H), 6.91 (dd, J = 15.6, 5.4 Hz, 1 H), 7.19-7.30 (m, 5 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 21.8, 22.6, 51.6, 69.5, 77.8, 120.1, 127.3, 128.0, 128.7, 140.0, 148.8, 166.9 ppm. IR (NaCl): ν = 2971, 1725, 1659, 1453, 1435, 1298, 1272, 1167, 1120, 978, 699 cm-1. HRMS: m/z calcd for C14H18O3: 252.1594; found: 252.1593.

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Spectroscopic data for 3e: 1H NMR (400 MHz, CDCl3): δ = 2.06 (s, 3 H), 3.67 (s, 3 H), 5.97 (dd, J = 15.7, 1.5 Hz, 1 H), 6.32 (dd, J = 5.0, 1.5 Hz, 1 H), 6.95 (dd, J = 15.7, 5.0 Hz, 1 H), 7.27-7.31 (m, 5 H). 13C NMR (100 MHz, CDCl3): δ = 21.1, 51.8, 74.2, 121.2, 127.4, 128.83, 128.86, 137.1, 144.9, 166.4, 169.7. IR (NaCl): ν = 2952, 2918, 2849, 1738, 1727, 1662, 1436, 1372, 1310, 1279, 1228, 1197, 1171, 1069, 1022, 980, 699 cm-1. HRMS: m/z calcd for C13H14O4: 252.1230; found: 252.1229.

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Spectroscopic data for 7b: 1H NMR (400 MHz, CDCl3): δ = 3.11 (s, 6 H), 5.85 (d, J = 16.2 Hz, 1 H), 6.43 (d, J = 16.2 Hz, 1 H), 7.25-7.38 (m, 5 H) ppm. 13C NMR (100 MHz, CDCl3): δ = 49.8, 100.2, 101.4, 116.8, 126.9, 128.6, 128.8, 137.8, 154.0 ppm. IR (NaCl): ν = 2916, 2848, 2228, 1732, 1450, 1261, 1226, 1191, 1159, 1071, 1047, 972, 774, 746, 702 cm-1. HRMS: m/z calcd for C12H13NO2: 221.1285; found: 221.1283.