Synlett 2005(3): 526-528  
DOI: 10.1055/s-2005-862360
LETTER
© Georg Thieme Verlag Stuttgart · New York

Regioselective Hydrochalcogenation Reaction of 1,2-Allenyl Phosphine Oxides: A Novel Synthesis of b-Organochalcogenyl Allyl Phosphine Oxides

Zhimeng Wua, Xian Huang*a,b
a Department of Chemistry, Zhejiang University (Xixi Campus), Hangzhou 310028, P. R. China
b State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, P. R. China
Fax: +86(571)88807077; e-Mail: huangx@mail.hz.zj.cn;
Further Information

Publication History

Received 15 November 2004
Publication Date:
04 February 2005 (online)

Abstract

Organyl thiolate, selenolate or tellurolate anions reacted with allenyl phosphine oxides to give b-(organochalcogenyl)allyl phosphine oxides in good yields. The reaction was regioselective, giving exclusively one isomer in all cases studied. The palladium-catalyzed cross-coupling of compound 3d with terminal alkynes to give β-alkynyl allyl phosphine oxide underwent efficiently in ­moderate yields.

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Preparation of β-Organochalcogenyl Allyl Phosphine Oxides 3. General Procedure. Allenyl diphenyl phosphine oxides (0.5 mmol) in 2 mL THF was added dropwise to a solution of RYNa, prepared in situ by reduction of (RY)2 (0.25 mmol) with NaBH4 (0.6 mmol) in 2 mL EtOH at r.t. under nitrogen. After the reaction was complete (5 min), the reaction was diluted with sat. brine (10 mL) and extracted with EtOAc (3 ¥ 15 mL). The organic layer was dried over anhyd MgSO4. After filtration and removal of the solvent in vacuo, the residue was purified via chromatography on silica gel with n-hexane-EtOAc (1:1) as the eluent to give the product 3.
Selected spectral data for 3o: mp 106-108 °C. 1H NMR (400 MHz, CDCl3): d = 7.75-7.71 (m, 4 H), 7.74-7.25 (m, 6 H), 3.57 (d, 2 H, J = 13.8 Hz), 2.41 (t, 2 H, J = 7.4 Hz), 1.91 (d, 3 H, J = 5.3 Hz), 1.63 (d, 3 H, J = 3.5 Hz), 1.41-1.36 (m, 2 H), 1.25-1.18 (m, 2 H), 0.77 (t, 3 H, J = 7.4 Hz). 13C NMR (100 MHz, CDCl3): d = 143.48 (d, J = 9.8 Hz), 133.09 (d, J = 96.9 Hz), 131.71 (d, J = 2.7 Hz), 128.38 (d, J = 11.3 Hz), 112.67 (d, J = 11.6 Hz), 39.64 (d, J = 67.4 Hz), 32.21, 26.90, 26.11 (d, J = 2.9 Hz), 22.97, 21.63 (d, J = 2.7 Hz), 13.66. IR (KBr): 3054, 1595, 1493, 1452, 1436, 1187, 1120, 744, 718, 695 cm-1. MS (EI): m/z (%) = 406, 349, 269, 201, 183, 155, 125, 107, 95, 83, 77, 67, 51, 41. Anal. Calcd for C21H27OPSe: C, 62.22; H, 6.71. Found: C, 61.95, H, 6.59.

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Preparation of β-Alkynyl Allyl Phosphine Oxides 4. General Procedure.
The mixture of 3d (1 mmol), terminal acetylene (2.0 mmol), PdCl2 (10 mol%), CuI (10 mol%) and Et3N (1.0 mmol) in 2 mL MeOH was stirred at r.t. for about 24 h under N2. After the reaction completed, the reaction was diluted with sat. brine (10 mL) and extracted with EtOAc (3 ¥ 15 mL). The organic layer was dried over anhyd MgSO4. After filtration and removal of the solvent in vacuo, the residue was purified via chromatography on silica gel with n-hexane-EtOAc (1:1) as the eluent to give the products 4.
Selected data of compound 4b: oil. 1H NMR (400 MHz, CDCl3): d = 7.83-7.78 (m, 4 H), 7.49-7.29 (m, 6 H), 3.28 (d, J = 14.4 Hz, 2 H), 2.00 (t, J = 6.3 Hz, 2 H), 1.87 (d, J = 5.08 Hz, 3 H), 1.65 (d, J = 3.5 Hz, 3 H), 1.29 (m, 4 H), 0.85 (q, J = 6.3 Hz, 3 H). 13C NMR (100 MHz, CDCl3): d = 143.87 (d, J = 9.3 Hz), 133.07 (d, J = 97 Hz), 131.53 (d, J = 2.7 Hz), 131.37 (d, J = 9.1 Hz), 128.16 (d, J = 11.7 Hz), 107.77 (d, J = 9.4 Hz), 93.77 (d, J = 1.6 Hz), 81.06, 35.33 (d, J = 68.3 Hz), 30.81, 23.73 (d, J = 2.7 Hz), 21.93, 20.58 (d, J = 2.7 Hz), 18.98, 13.59. IR (KBr): 2254, 1605, 1402, 1195 cm-1. MS (EI): m/z (%) = 351, 308, 202, 155, 83, 77, 47, 41. Anal. Calcd for C23H27OP: C, 78.83; H, 7.77. Found: C, 78.76, H, 7.82.