Radical Addition Reactions of Diphenylphosphine Sulfide

Abstract

Radical additions of diphenylphosphine sulfide [Ph₂P(S)H] to various C=C bonds offers a general, mild and ­efficient approach to alkyl(diphenyl)phosphine sulfides.

radical reaction - phosphorus hydride - C=C bonds

References

Selected examples:

1a Trofimov BA. Gusarova NK. Malysheva SF. Ivanova NI. Sukhov BG. Belogorlova NA. Kuimov VA. Synthesis  2002,  2207 

1b Rey P. Taillades J. Rossi JC. Gros G. Tetrahedron Lett.  2003,  44:  6169 

1c Dubert O. Gautier A. Condamine E. Piettre SR. Org. Lett.  2002,  4:  359 

1d Gautier A. Garipova G. Dubert O. Oulyadi H. Piettre SR. Tetrahedron Lett.  2001,  42:  5673 

1e Sato A. Yorimitsu H. Oshima K. Angew. Chem. Int. Ed.  2005,  44:  1694 

2a Jessop CM. Parsons AF. Routledge A. Irvine D. Tetrahedron Lett.  2003,  44:  479 

2b Jessop CM. Parsons AF. Routledge A. Irvine DJ. Tetrahedron: Asymmetry  2003,  14:  2849 

3

Pantazis, D.; McGrady, J. E. unpublished results.

4a Semenzin D. Etemad-Moghadam G. Albouy D. Diallo O. Koenig M. J. Org. Chem.  1997,  62:  2414 

4b Leca D. Fensterbank L. Lacôte E. Malacria M. Chem. Soc. Rev.  2005,  34:  858 

5 Peters G. J. Am. Chem. Soc.  1960,  82:  4751 

6

Performed in a CEM Focused Microwave Synthesis System.

7

All new compounds gave consistent spectral and HRMS data.

8

Typical Procedure. To diphenylphosphine sulfide (0.327 g, 3 equiv, 1.5 mmol) in a N₂ flushed flask was added non-degassed dioxane (2 mL), followed by methyl methacrylate (0.053 mL, 0.5 mmol). Then, Et₃B (1 M solution in hexane, 0.15 mL, 0.3 equiv, 0.15 mmol) was added and the reaction was left to stir for 4 h. After this time a further portion of Et₃B (1 M solution in hexane, 0.15 mL, 0.3 equiv, 0.15 mmol) was added, and the mixture was left to stir for 16 h. The reaction mixture was then concentrated in vacuo to afford the crude product. Following column chromatography (4:1, PE-EtOAc), methyl 3-(diphenylphosphorothioyl)-2-methylpropanoate (9) was isolated as a colourless oil (0.147 g, 92%); R _f = 0.2 (4:1, PE-EtOAc). IR (thin film): ν_max = 3054 (m), 2975 (m), 2949 (m), 1731 (s, C=O), 1436 (s, P-Ph), 1309 (m), 1274 (m), 1211 (s), 1158 (s), 1102 (s), 1027 (m), 998 (m) cm^-1.
¹H NMR (400 MHz, CDCl₃): δ = 7.91-7.80 (4 H, m, 4 × CH Ar), 7.54-7.41 (6 H, m, 6 × CH Ar), 3.46 (3 H, s, O-CH ₃), 3.21-3.08 [2 H, m, P(S)CH ₂-CH], 2.52-2.41 [1 H, m, P(S)CH₂-CH], 1.18 (3 H, d, J = 7 Hz, CH₂-CH-CH ₃).
¹³C NMR (100.6 MHz, CDCl₃): δ = 175.8 (d, ³ J _C-P = 9.5 Hz, O=C-O-CH₃), 133.1 (d, ¹ J _C-P = 80.5 Hz, C _q Ar), 132.3 (d, ¹ J _C-P = 80.5 Hz, C _q Ar), 131.6 (d, ⁴ J _C-P = 3.0 Hz, CH Ar), 131.5 (d, ⁴ J _C-P = 3.0 Hz, CH, Ar), 131.3 (d, ² J _C-P = 10.5 Hz, 2 × CH Ar), 131.0 (d, ² J _C-P 10.0 Hz, 2 × CH Ar), 128.7 (d, ³ J _C-P 12.0 Hz, 2 × CH Ar), 128.5 (d, ³ J _C-P = 12.0 Hz, 2 × CH Ar), 51.9 (O-CH₃), 35.5 [d, ¹ J _C-P = 57 Hz, P(S)CH₂], 34.3 [d, ² J _C-P = 1 Hz, P(S)CH₂-CH], 19.4 (d, ³ J _C-P = 8.5 Hz, CH₂-CH-CH₃). ³¹P NMR (161.9 MHz, CDCl₃): δ = 41.3 [Ph₂ P(S)]. MS (CI, NH₃): m/z (%) = 319 (100), 218 (17). HRMS: m/z calcd for C₁₇H₁₉O₂PS: [M + H⁺] 319.0922 (0.2 ppm); found: [M + H⁺] 319.0921.

9

Deprotonation of Ph₂P(S)H and addition to electron-poor alkenes has been reported previously (see ref. 4).

For some recent examples see:

10a Daniewski AR. Garofalo LM. Kabat MM. Synth. Commun.  2002,  32:  3031 

10b Nemoto T. Ojika M. Sakagami Y. Tetrahedron Lett.  1997,  38:  5667 

10c Houille O. Schmittberger T. Uguen D. Tetrahedron Lett.  1996,  37:  625 

11a Nelson A. Warren S. J. Chem. Soc., Perkin Trans. 1  1999,  1963 

11b Wallace P. Warren S. J. Chem. Soc., Perkin Trans. 1  1988,  2971 

11c Warren S. Wyatt P. J. Chem. Soc., Perkin Trans. 1  1998,  249 

11d Buss AD. Warren S. J. Chem. Soc., Perkin Trans. 1  1985,  2307 

11e Green IR. Tocoli FE. Synth. Commun.  2002,  32:  947 

11f Horner L. Hoffmann H. Wippel HG. Klahre G. Chem. Ber.  1959,  92:  2499 

11g Horner L. Hoffmann H. Klink W. Ertel H. Toscano VG. Chem. Ber.  1962,  95:  581 

11h Lythgoe B. Moran TA. Nambudiry MEN. Ruston S. Tideswell J. Wright PW. Tetrahedron Lett.  1975,  16:  3863 

11i Lythgoe B. Moran TA. Nambudiry MEN. Tideswell J. Wright PW. J. Chem. Soc., Perkin Trans. 1  1978,  590 

Deprotonation of alkyl(diphenyl)phosphine sulfides and reaction with MeI or CO₂ has been reported. See:

12a Yoshifuji M. Ishizuka T. Choi YJ. Inamoto N. Tetrahedron Lett.  1984,  25:  553 

12b Savignac M. Cadiot P. Mathey F. Can. J. Chem.  1982,  60:  840 

13 See for example: Gilbertson SR. Chang C.-WT. J. Org. Chem.  1998,  63:  8424