Triphenylstannane1

Ph3SnH

[892-20-6]  · C18H16Sn  · Triphenylstannane  · (MW 351.05)

(generation of carbon radicals from selenides,2 halides,3 sulfides,4 and alkynes;5 radical deoxygenation;6 reduction of a,b-unsaturated aldehydes and ketones;7 hydrostannylation of alkynes5,8 and alkenes;9 reversible addition of stannyl radicals to double bonds;10 formation of metal triphenylstannates;11 reduction of aldehydes and ketones;12 desulfonation of b-keto phenyl sulfones;13 hole-transfer-promoted hydrogenation14)

Alternate Names: triphenyltin hydride; triphenylstannyl hydride.

Physical Data: white needles, mp 26-28 °C;15,16 bp 156-158 °C/0.15 mmHg;15 d25 1.3771 g cm-3.17

Solubility: sol many common organic solvents; usually used in benzene or toluene.

Form Supplied in: commercially available as a colorless liquid that solidifies in a refrigerator.

Analysis of Reagent Purity: titration of the derived triphenyltin chloride has been used.18,19 Reactions of Ph3SnH can be followed by monitoring the 1840 cm-1 IR absorption.1h

Preparative Methods: reduction of Chlorotriphenylstannane with Lithium Aluminum Hydride in ether,12,16,20 or with Sodium Borohydride in glyme;15 reduction of bis(triphenyltin) oxide with polymethylhydrosiloxane;21 reduction of triphenyltin methoxide with diborane;22 protonation of Ph3SnLi.17,23 The reagent has also been generated in situ from Ph3SnCl and Sodium Cyanoborohydride in t-butyl alcohol.24

Handling, Storage, and Precautions: Ph3SnH can be stored for several months, and is easily repurified by Kugelrohr distillation (oil-pump vacuum) before use.25 Organotin hydrides decompose slowly at rt and are best stored at 0 °C or below.

Decomposition is catalyzed by air, silicone grease, metallic surfaces, amines and, in the case of triphenyltin hydride, by light.1h,15,16 Manipulations of the compound are usually best done in an inert atmosphere and using thoroughly clean apparatus (KOH-MeOH is better than chromic acid for cleaning in this case26). Methods have been reported for removing tin species from reactions involving stannanes, but these appear to have been described explicitly only for Tri-n-butylstannane.6,27-30 Provided that skin contact and inhalation are avoided, Ph3SnH does not present an unusual hazard.15

General.

Many processes with Ph3SnH can be done also with Bu3SnH, and vice versa; however, direct comparison of the two reagents has rarely been reported.

Formation of Carbon Radicals from Phenyl Selenides.

Many phenyl selenides have been converted into carbon radicals that have then undergone intramolecular cyclization (eq 1),31 radical ring opening (eq 2),32 or reduction (eq 3).2 Tellurides (eq 4) and telluride dichlorides are also reduced to the corresponding hydrocarbon.2,33

Radical Deoxygenation.

Ph3SnH has occasionally been used for Barton deoxygenation.6,34 In the example of eq 5, better results are obtained with Bu3SnH than with Ph3SnH.6 Alcohols and carbonyl compounds (ketones or aldehydes) have been deoxygenated by conversion into the corresponding phenyl selenides or selenoacetals, respectively, followed by treatment with Ph3SnH (eq 6).2

Formation of Carbon Radicals from Halides.

The triphenylstannyl radical, generated thermally3,35-37 or electrochemically,38 can be used for dehalogenation, the radical intermediate being captured by hydrogen transfer (eqs 7-9)9,35,36 or by an intramolecular process (eqs 10-13).38-41 In the last example (eq 13), Ph3SnH gave better results than Bu3SnH.41

Desulfurization and Disulfide Cleavage.

Ph3SnH has occasionally been used for desulfurization,4,42 the process being facilitated in the example shown in eq 14 by the presence of an a-heteroatom.4 Disulfides can also be cleaved (initially to thiyl radicals).38,43

Cyclization of Acetylenic Alkenes.5,24,44

Acetylenic alkenes undergo cyclization on treatment with Ph3SnH under radical conditions (eqs 15 and 16).5,24 In the example of eq 15, and in related processes, lower yields were obtained with Bu3SnH.24

Reduction of a,b-Unsaturated Aldehydes and Ketones.7,45 -52

Double and (apparently) triple bonds conjugated with the carbonyl group in a,b-unsaturated aldehydes and ketones are reduced by Ph3SnH in a radical process (eqs 17 and 18).7

Hydrostannylation of Alkynes and Alkenes.

Allenes (eq 19)53,54 and alkynes (eqs 20 and 21)8,55 are hydrostannylated in the presence of a palladium catalyst. Use of Ph3SnH rather than Bu3SnH gives a higher proportion of the (Z)-isomer in (eq 19).54

Alkynes5,56-58 (eq 22)5 and alkenes9,59,60 (eqs 23 and 24)9,59 are also hydrostannylated under radical conditions.

In contrast to a,b-unsaturated aldehydes and ketones (which are usually46 reduced to the saturated carbonyl compounds), a,b-unsaturated esters61 are generally62,63 hydrostannylated7,57,63-65 under mild radical conditions (eq 25). In the example of eq 25, Bu3SnH reacted sluggishly and the process was incomplete.7 The hydrostannylation can be highly stereoselective (eq 26).66

Reversible Addition of Triphenylstannyl Radicals to Double Bonds.

The process summarized in eq 27 was slightly more stereoselective with Ph3SnH than with Bu3SnH, but the proportion of the enone was higher.10 Ring expansion of the type shown in eq 28 sometimes proceeded more efficiently with Ph3SnH than with Bu3SnH.67

Preparation of Metal Triphenylstannates.

Ph3SnK is easily prepared from Ph3SnH and Potassium Hydride,68 Ph3SnNa from the stannane and Sodium Hydride,69 Ph3SnLi from the stannane and Lithium Diisopropylamide,11 and (Ph3Sn)2Zn.TMEDA from the stannane and Diethylzinc in the presence of N,N,N,N-Tetramethylethylenediamine.70

Reduction of Ketones and Aldehydes to Alcohols.12,71-74

Reduction of ketones and aldehydes with Ph3SnH has been reported (eq 29).12,71,72

When a ketone is treated with an acid chloride in the presence of Ph3SnH, reductive acylation of the ketone occurs (eq 30).75

Desulfonylation of b-Keto Phenyl Sulfones.13

Although Bu3SnH is usually used for desulfonylation of b-keto phenyl sulfones, Ph3SnH gave a better yield in the case shown in eq 31.

Hole-Transfer-Promoted Hydrogenation.

Ph3SnH can be used as a source of hydrogen to saturate double bonds in a process mediated by triarylamminium ions (eq 32).14


1. Reviews: (a) Omae, I. JOM Libr. 1989. (b) MOC 1978, 13/6. (c) Pereyre, M.; Quintard, J.-P.; Rahm, A. Tin in Organic Synthesis; Butterworths: London, 1987. (d) Kupchik, E. J. In Organotin Compounds; Sawyer, A. K., Ed.; Dekker: New York, 1971; Vol. 1, Chapter 2. (e) Kuivila, H. G. S 1970, 499. (f) Kuivila, H. G. ACR 1968, 1, 299. (g) Ingham, R. K.; Rosenberg, S. D.; Gilman, H. CRV 1960, 60, 459. (h) Kuivila, H. G. Adv. Organomet. Chem. 1964, 1, 47.
2. Clive, D. L. J.; Chittattu, G. J.; Farina, V.; Kiel, W. A.; Menchen, S. M.; Russell, C. G.; Singh, A.; Wong, C. K.; Curtis, N. J. JACS 1980, 102, 4438.
3. Kuivila, H. G.; Menapace, L. W. JOC 1963, 28, 2165.
4. Nicolaou, K. C.; McGarry, D. G.; Somers, P. K.; Veale, C. A.; Furst, G. T. JACS 1987, 109, 2504.
5. Nozaki, K.; Oshima, K.; Utimoto, K. T 1989, 45, 923.
6. Barton, D. H. R.; Motherwell, W. B.; Stange, A. S 1981, 743.
7. Nozaki, K.; Oshima, K.; Utimoto, K. BCJ 1991, 64, 2585.
8. Ichinose, Y.; Oda, H.; Oshima, K.; Utimoto, K. BCJ 1987, 60, 3468.
9. Nakamura, E.; Machii, D.; Inubushi, T. JACS 1989, 111, 6849.
10. Kim, S.; Koh, J. S. TL 1992, 33, 7391.
11. Reimann, W.; Kuivila, H. G.; Farah, D.; Apoussidis, T. OM 1987, 6, 557. Cf. Still, W. C. JACS 1978, 100, 1481.
12. Kuivila, H. G.; Beumel, Jr., O. F. JACS 1961, 83, 1246.
13. Smith, A. B., III; Hale, K. J.; McCauley, J. P., Jr. TL 1989, 30, 5579.
14. Mirafzal, G. A.; Bauld, N. L. JACS 1992, 114, 5457.
15. Birnbaum, E. R.; Javora, P. H. Inorg. Synth. 1970, 12, 45.
16. van der Kerk, G. J. M.; Noltes, J. G.; Luitjen, J. G. A. J. Appl. Chem. 1957, 7, 366.
17. Tamborski, C.; Ford, F. E.; Soloski, E. J. JOC 1963, 28, 181.
18. Lorenz, D. H.; Becker, E. I. JOC 1962, 27, 3370.
19. Lorenz, D. H.; Shapiro, P.; Stern, A.; Becker, E. I. JOC 1963, 28, 2332.
20. Hoyte, R. M.; Denney, D. B. JOC 1974, 39, 2607.
21. Hayashi, K.; Iyoda, J.; Shiihara, I. JOM 1967, 10, 81.
22. Amberger, E.; Kula, M.-R. CB 1963, 96, 2560.
23. Allen, C. M. J. Chem. Educ. 1970, 47, 479.
24. Lee, E.; Ko, S. B.; Jung, K. W.; Chang, M. H. TL 1989, 30, 827.
25. Standard practice in this laboratory.
26. Klingler, R. J.; Mochida, K.; Kochi, J. K. JACS 1979, 101, 6626.
27. Leibner, J. E.; Jacobus, J. JOC 1979, 44, 449.
28. Tanner, D. D.; Blackburn, E. V.; Diaz, G. E. JACS 1981, 103, 1557.
29. Berge, J. M.; Roberts, S. M. S 1979, 471.
30. Macmullin, E. C.; Peach, M. E. JOM 1973, 52, 355.
31. Clive, D. L. J.; Boivin, T. L. B.; Angoh, A. G. JOC 1987, 52, 4943.
32. Clive, D. L. J.; Daigneault, S. JOC 1991, 56, 3801.
33. Bergman, J.; Engman, L. JACS 1981, 103, 5196.
34. Cf. Clive, D. L. J.; Beaulieu, P. L.; Set, L. JOC 1984, 49, 1313.
35. Brown, H. C.; Liu, K.-T. JACS 1970, 92, 3502.
36. Miura, K.; Ichinose, Y.; Nozaki, K.; Fugami, K.; Oshima, K.; Utimoto, K. BCJ 1989, 62, 143.
37. Jensen, F. R.; Patterson, D. B. TL 1966, 3837.
38. Tanaka, H.; Suga, H.; Ogawa, H.; Abdul Hai, A. K. M.; Torii, S.; Jutland, A.; Amatore, C. TL 1992, 33, 6495.
39. Ichinose, Y.; Oshima, K.; Utimoto, K. CL 1988, 1437.
40. Hanessian, S.; Dhanoa, D. S.; Beaulieu, P. L. CJC 1987, 65, 1859.
41. Magnol, E.; Malacria, M. TL 1986, 27, 2255.
42. Baldwin, J. E.; Adlington, R. M.; Kang, T. W.; King, L. G.; Patel, V. K. H 1989, 28, 759.
43. Baldwin, J. E.; Adlington, R. M.; Kang, T. W.; Lee, E.; Schofield, C. J. CC 1987, 104.
44. Munt, S. P.; Thomas, E. J. CC 1989, 480.
45. Wolf, H. R.; Zink, M. P. HCA 1973, 56, 1062.
46. Cf. Leusink, A. J.; Noltes, J. G. TL 1966, 2221.
47. Yamasaki, M. CC 1972, 606.
48. Yoshi, E.; Koizumi, T.; Ikeshima, H.; Ozaki, K.; Hayashi, I. CPB 1975, 23, 2496.
49. Pereyre, M.; Valade, J. CR(C) 1965, 260, 581.
50. Pereyre, M.; Valade, J. BSF(2) 1967, 1928.
51. Pommerenk, U.; Sengewin, H.; Welzel, P. TL 1972, 3415.
52. Yoshi, E.; Yamasaki, M. CPB 1968, 16, 1158.
53. Ichinose, Y.; Oshima, K.; Utimoto, K. BCJ 1989, 61, 2693.
54. Koerber, K.; Gore, J.; Vatele, J.-M. TL 1991, 32, 1187.
55. Cochran, J. C.; Bronk, B. S.; Terrence, K. M.; Phillips, H. K. TL 1990, 31, 6621.
56. Delmas, M. A.; Maire, J. C.; Pinzelli, R. JOM 1969, 16, 83.
57. Leusink, A. J.; Noltes, J. G. JOM 1969, 16, 91.
58. Juenge, E. C.; Hawkes, S. J.; Snider, T. E. JOM 1973, 51, 189.
59. Ducharme, Y.; Latour, S.; Wuest, J. D. OM 1984, 3, 208.
60. Wardell, J. L.; Wigzell, J. McM. JCS(D) 1982, 2321.
61. Cf. Satoh, D.; Hashimoto, T. CPB 1976, 24, 1950.
62. Pereyre, M.; Colin, G.; Valade, J. TL 1967, 4805.
63. Pereyre, M.; Colin, G.; Valade, J. BSF(2) 1968, 3358.
64. Rahm, A.; Pereyre, M. JOM 1975, 88, 79.
65. Podestá, J. C.; Chopa, A. B.; Ayala, A. D. JOM 1981, 212, 163.
66. Ayala, A. D.; Giagante, N.; Podestá, J. C.; Neumann, W. P. JOM 1988, 340, 317.
67. Kim, S.; Lee, S. TL 1991, 32, 6575.
68. Corriu, R.; Guerin, C.; Kolani, B. Inorg. Synth. 1989, 25, 110.
69. Corriu, R. J. P.; Guerin, C. JOM 1980, 197, C19.
70. Nonaka, T.; Okuda, Y.; Matsubara, S.; Oshima, K.; Utimoto, K.; Nozaki, H. JOC 1986, 51, 4716.
71. Cf. Fung, N. Y. M.; deMayo, P.; Schauble, J. H.; Weedon, A. C. JOC 1978, 43, 3977.
72. Rahm, A.; Pereyre, M. BSB 1980, 89, 843.
73. Tanner, D. D.; Diaz, G. E.; Potter, A. JOC 1985, 50, 2149.
74. Patin, H.; Roullier, L.; Dabard, R. CR(C) 1970, 271, 1103.
75. Kaplan, L. JACS 1966, 88, 4970.

Derrick L. J. Clive

University of Alberta, Edmonton, Canada



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