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Form Supplied in: colorless, stable crystalline solid; 0.5 M solution in THF or hexanes.
Handling, Storage, and Precautions: the crystalline 9-BBN-H dimer can be handled in the atmosphere for brief periods without significant decomposition. However, the reagent should be stored under an inert atmosphere, preferably below 0 °C. Under these conditions the reagent is indefinitely stable. In solution, 9-BBN is more susceptible both to hydrolysis and oxidation, and contact with the open atmosphere should be rigorously avoided. Many 9-BBN derivatives are pyrophoric and/or susceptible to hydrolysis so that individuals planning to use 9-BBN-H dimer should thoroughly familiarize themselves with the special techniques required for the safe handling of such reagents prior to their use.1b The reagent should be used in a well-ventilated hood.
Hydroborations of more substituted alkenes such as a-pinene8 or 2,3-dimethyl-2-butene4b with 9-BBN-H are slower (k2 is rate-limiting) and require heating at reflux temperature in THF for 2 and 8 h, respectively, for complete reaction to occur. However, the enantioselective reducing agent8a Alpine-borane® (see B-3-Pinanyl-9-borabicyclo[3.3.1]nonane) is formed quantitatively as a single enantiomer, the process taking place with complete Markovnikov regiochemistry, exclusively through syn addition from the least hindered face of the alkene (eq 3).
Medium-ring boracycles are efficiently prepared by the dihydroboration of a,o-dienes with 9-BBN-H followed by exchange with borane.11 In this process 9-BBN-H is particularly useful because it not only fixes the key 1,5-diboryl relationship, but also the 9-BBN ligands do not participate in the exchange process (eq 7).
Organometallic reagents can provide very useful entries to many B-substituted 9-BBN derivatives. These are particularly important for organoboranes which cannot be prepared by hydroboration.5 Both B-alkoxy and B-halo derivatives serve as useful precursors to B-alkyl, -allyl, -aryl, -vinyl or -alkynyl-9-BBN derivatives (eqs 11-16). B-Halo-9-BBN derivatives are effectively vinylated with organotin reagents.18 However, B-MeO-9-BBN is superior to its B-halo counterparts for secondary and tertiary alkyllithium reagents where the latter undergo some reduction to 9-BBN-H through b-hydride transfer from the organolithium.
Functional Group Conversions with 9-BBN-H.
As noted earlier, B-substituted-9-BBN derivatives are available from a variety of sources and organoboranes serve as a versatile entry to other functionalities. Their oxidative conversion to alcohols with alkaline Hydrogen Peroxide or Sodium Perborate31 is quantitative and occurs with complete retention of configuration, making the process highly useful.1 The 9-BBN moiety is oxidized to cis-1,5-cyclooctanediol (eq 21), a compound which can be removed from less polar products through extraction with water, selective crystallization, or by chromatography.1 The monooxidation of 9-BBN derivatives with anhydrous Trimethylamine N-Oxide (TMANO) produces 9-oxa-10-borabicyclo[3.3.2]decanes (eq 22),14 many of which are air-stable and undergo useful coupling reactions.
Carbon-Carbon Bond Formation via 9-BBN Derivatives.
Base-induced eliminations of g-haloalkyl-9-BBN derivatives give cycloalkanes (C3 to C6)1b with inversion of configuration at both carbon centers.1,39 1,1-Diboryl adducts from the dihydroboration of 1-alkynes with 9-BBN-H serve as useful precursors to B-cyclopropyl-9-BBN derivatives by a similar process (eq 28).
As a useful alternative to carbonylation, the Brown dichloromethyl methyl ether (DCME) process has been effectively used for the synthesis of 9-alkylbicyclo[3.3.1]nonan-9-ols.42 The ketone bicyclo[3.3.1]nonan-9-one (eq 29)42b has also been prepared from a hindered B-aryloxy-9-BBN derivative, with simple B-alkoxy-9-BBN derivatives failing to undergo this process. However, most borinate esters are smoothly converted to ketones through this process, including germa- and silaborinanes (eq 30).11e,f In these cases, 9-BBN-H provides the essential 1,5-diboryl relationship which allows the formation of borinane by the exchange reaction described earlier.
Allylboration with 9-BBN derivatives (see B-Allyl-9-borabicyclo[3.3.1]nonane) is an efficient process, resulting in the smooth formation of homoallylic alcohols (eq 31).43 Alkynylboranes also undergo 1,2-addition to both aldehydes and ketones.44 As with other reactions producing B-alkoxy-9-BBN byproducts, the conversion of these to alcohols with Ethanolamine also results in the formation of an alkane-insoluble 9-BBN complex which is conveniently removed, thereby greatly simplifying the workup procedure.
While catechol- and disiamylborane derivatives were originally employed in the Pd-catalyzed cross coupling of organoboranes to unsaturated organic halides under basic conditions (Suzuki-Miyaura coupling), 9-BBN has recently found an important place in this process. Initially, B-(primary alkyl)-9-BBNs, with added bases (NaOH, TlOH, NaOMe, or K3PO4), were found to undergo efficient coupling with iodobenzene using Dichloro[1,1�-bis(diphenylphosphino)ferrocene]palladium(II) as the catalyst.54 However, while secondary alkylboranes may require this catalyst, Tetrakis(triphenylphosphine)palladium(0) is perfectly satisfactory for the coupling of n- or i-alkyl-9-BBN derivatives to unsaturated bromides, iodides, or triflates under basic conditions (eqs 42-45).
1. (a) Pelter, A.; Smith, K.; Brown, H. C. Borane Reagents; Academic: London, 1988. (b) Brown, H. C.; Midland, M. M.; Levy, A. B.; Kramer, G. W. Organic Synthesis via Boranes; Wiley: New York, 1975. (c) Brown, H. C.; Lane, C. F. H 1977, 7, 453. (d) Zaidlewicz, M. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Vol. 7 p 199. (e) Negishi, E.-I. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Vol 7, p 255. (f) Köster, R.; Yalpani, M. PAC 1991, 63, 387.
2. Köster, R. AG 1960, 72, 626.
3. (a) Knights, E. F.; Brown, H. C. JACS 1968, 90, 5281. (b) Soderquist, J. A.; Brown, H. C. JOC 1981, 46, 4599. (c) Soderquist, J. A.; Negron, A. OS 1991, 70, 169. (d) Brauer, D. J.; Kruger, C. Acta Crystallogr. B, 1973, 29, 1684.
4. (a) Scouten, C. G.; Brown, H. C. JOC 1973, 38, 4092. (b) Brown, H. C.; Knights, E. F. Scouten, C. G. JACS 1974, 96, 7765. (c) Brown, H. C.; Liotta, R.; Scouten, C. G. JACS 1976, 98, 5297. (d) Liotta, R.; Brown, H. C. JOC 1977, 42, 2836. (e) Brener, L.; Brown, H. C. JOC 1977, 42, 2702. (f) Brown, H. C.; Liotta, R.; Brener, L. JACS 1977, 99, 3427. (g) Brown, H. C.; Liotta, R.; Kramer, G. W. JOC 1978, 43, 1058. (h) Soderquist, J. A.; Hassner, A. JOM 1978, 156, C12. (i) Brown, H. C.; Liotta, R.; Kramer, G. W. JACS 1979, 101, 2966. (j) Brown, H. C.; Vara Prasad J. V. N.; Zee, S.-H. JOC 1985, 50, 1582. (k) Brown, H. C.; Vara Prasad J. V. N. JOC 1985, 50, 3002. (l) Brown, H. C.; Ramachandran, P. V.; Vara Prasad J. V. N. JOC 1985, 50, 5583. (m) Soderquist, J. A.; Anderson, C. L. TL 1986, 27, 3961. (n) Fleming, I. PAC 1988, 60, 71.
5. (a) Brown, H. C.; Rogi&cacute;, M. M. JACS 1969, 91, 4304. (b) Kramer, G. W.; Brown, H. C. JOM 1974, 73, 1. (c) ibid., JOM 1977, 132, 9. (d) Soderquist, J. A.; Brown, H. C. JOC 1980, 45, 3571. (e) Soderquist, J. A.; Rivera, I.; Negron, A. JOC 1989, 54, 4051.
6. (a) Soderquist, J. A.; Colberg, J. C.; Del Valle, L. JACS 1989, 111, 4873. See also: (b) Negishi, E.-I. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Vol 7, p 265.
7. (a) Brown, H. C.; Scouten, C. G.; Wang, K. K. JOC 1979, 44, 2589. (b) Brown, H. C.; Wang, K. K.; Scouten, C. G. PNA 1980, 77, 698. (c) Wang, K. K.; Brown, H. C. JOC 1980, 45, 5303. (d) Nelson, D. J.; Cooper, P. J. TL 1986, 27, 4693. (e) Brown, H. C.; Chandrasekharan, J.; Nelson, D. J. JACS 1984, 106, 3768. (f) Chandrasekharan, J.; Brown, H. C. JOC 1985, 50, 518.
8. (a) Midland, M. M. CR 1989, 89, 1553. (b) Brown, H. C.; Ramachandran, P. V. PAC 1991, 63, 307; ibid., ACR 1992, 25, 16. (c) Srebnik, M.; Ramachandran, P. V. Aldrichim. Acta 1987, 20, 9. (d) Brown, H. C.; Srebnik, M.; Ramachandran, P. V. JOC 1989, 54, 1577.
9. Liu, C.; Wang, K. K. JOC 1986, 51, 4733.
10. (a) Evans, D. A.; Fu, G. C.; Hoveyda, A. H. JACS 1988, 110, 6917. (b) Burgess, K.; van der Donk, W. A.; Jarstfer, M. B.; Ohlmeyer, M. JACS 1991, 113, 6139.
11. (a) Negishi, E.-I.; Burke, P. L.; Brown, H. C. JACS 1972, 94, 7431. (b) Burke, P. L.; Negishi, E.-I.; Brown, H. C. JACS 1973, 95, 3654. (c) Brown, H. C.; Pai, G. G. H 1982, 17, 77. (d) ibid., JOM 1983, 250, 13. (e) Soderquist, J. A.; Shiau, F.-Y.; Lemesh, R. A. JOC 1984, 49, 2565. (f) Soderquist, J. A.; Negron, A. JOC 1989, 54, 2462. However, for the unusual behavior of the 9-BBN systems with alkynyltins, see: (g) Bihlmayer, C.; Kerschl, S.; Wrackmeyer, B. ZN(B) 1987, 42, 715. (h) Wrackmeyer, B.; Abu-Orabi, S. T. CB 1987, 120, 1603. (i) Bihlmayer, C.; Abu-Orabi, S. T.; Wrackmeyer, B. JOM 1987, 322, 25.
12. Colberg, J. C.; Rane, A.; Vaquer, J.; Soderquist, J. A. JACS 1993, 115, 6065.
13. (a) Brown, H. C., Scouten, C. G.; Liotta, R. JACS 1979, 101, 96. (b) Wang, K. K.; Scouten, C. G.; Brown, H. C., JACS 1982, 104, 531. (c) Blue, C. D.; Nelson, D. J. JOC 1983, 48, 4538.
14. Soderquist, J. A.; Najafi, M. R. JOC 1986, 51, 1330.
15. Nelson, D. J.; Blue, C. D.; Brown, H. C. JACS 1982, 104, 4913.
16. Hara, S.; Dojo, H.; Takinami, S.; Suzuki, A. TL 1983, 24, 731.
17. Brown, C. A.; Coleman, R. A. JOC 1979, 44, 2328.
18. Singleton, D. A.; Martinez, J. P. JACS 1990, 112, 7423.
19. Brown, H. C.; Bhat, N. G.; Rajagopalan, S. OM 1986, 5, 816.
20. Campbell, Jr., J. B.; Molander, G. A. JOM 1978, 156, 71.
21. Soderquist, J. A.; Rivera, I. TL 1989, 30, 3919.
22. Soderquist, J. A.; Negron, A. JOC 1987, 52, 3441.
23. (a) Bhatt, M. V. JOM 1978, 156, 221. See also: (b) Köster, R.; Grassberger, M. A. LA 1968, 719, 169. (c) Brown, H. C.; Kulkarni, S. U. JOC 1979, 44, 281. (d) ibid., JOC 1979, 44, 2422.
24. (a) Inoue, T.; Uchimaru, T.; Mukaiyama, T. CL 1977, 153. (b) Inoue, T.; Mukaiyama, T. BCJ 1980, 53, 174. (c) Masamune, S.; Choi, W.; Kerdesky, F. A. J.; Imperiali, B. JACS 1981, 103, 1566. (d) Masamune, S.; Choi, W.; Peterson, S. S.; Sita, L. R. AG(E) 1985, 24, 1.
25. Cha, J. S.; Kim, J. E.; Oh, S. Y.; Kim, J. D. TL 1987, 28, 4575.
26. (a) Brown, H. C.; Kulkarni, S. U. IC 1977, 16, 3090. (b) ibid., JOC 1977, 42, 4169. (c) Brown, H. C.; Soderquist, J. A. JOC 1980, 45, 846. (d) Brown, H. C.; Singaram, B.; Mathew, C. P. JOC 1981, 46, 2712. (e) Brown, H. C.; Mathew, C. P.; Pyun, C.; Son, J. C.; Yoon, Y. M. JOC 1984, 49, 3091. (f) Soderquist, J. A.; Rivera, I. TL 1988, 29, 3195. (g) Hubbard, J. L. TL 1988, 29, 3197.
27. (a) Brown, H. C.; Krishnamurthy, S. T 1979, 35, 567. (b) Brown, H. C.; Park, W. S.; Cho, B. T. JOC 1986, 51, 1934. (c) Brown, H. C.; Cho, B. T.; Park, W. S. JOC 1988, 53, 1231. (d) Narasimhan, S. IJC(B) 1986, 25B, 847 (e) Cha, J. S.; Yoon, M. S.; Kim, Y. S.; Lee, K. W. TL 1988, 29, 1069. (f) Soderquist, J. A.; Rivera, I. TL 1988, 29, 3195. (g) Cha, J. S.; Lee, K. W.; Yoon, M. S.; Lee, J. C.; Yoon, N. M. H 1988, 27, 1713. (h) Hutchins, R. O.; Abdel-Magid, A.; Stercho, Y. P.; Wambsgams, A. JOC 1987, 52, 702.
28. Toi, H.; Yamamoto, Y.; Sonoda, A.; Murahashi, S.-I. T 1981, 37, 2261.
29. (a) Kramer, G. W.; Brown, H. C. JOM 1975, 90, Cl. (b) ibid., JACS, 1976, 98, 1964. (c) ibid., JOC 1977, 42, 2832.
30. (a) Krishnamurthy, S.; Brown, H. C. JOC 1975, 40, 1864 (b) ibid., JOC 1977, 42, 1197. (c) Molin, H.; Pring, B. G. TL 1985, 26, 677.
31. Kabalka, G. A.; Shoup, T. M.; Goudgaon, N. M. JOC 1989, 54, 5930.
32. Negishi, E.-I. In Comprehensive Organometallic Chemistry; Wilkinson, G.; Stone, F. G. A.; Abel, E. W., Eds.; Pergamon: Oxford, 1982; Vol 7, p 337.
33. (a) Lane, C. L.; Brown, H. C. JOM 1971, 26, C51. (b) Brown, H. C.; DeLue, N. R. JACS 1974, 96, 311.
34. (a) Yamamoto, Y.; Brown, H. C. CC 1973, 801. (b) ibid., JOC 1974, 39, 861.
35. Brown, H. C.; DeLue, N. R.; Kabalka, G. W.; Hedgecock, Jr., H. C. JACS 1976, 98, 1290.
36. Lane, C. L., PhD Thesis, Purdue University, 1972.
37. (a) Brown, H. C.; Midland, M. M.; Levy, A. B.; Suzuki, A.; Sano, S.; Itoh, M. T 1987, 43, 4079. (b) Brown, H. C.; Salunkhe, A. M.; Singaram, B. JOC 1991, 56, 1170. (c) For related behavior with a-diazo ketones, see: Hooz, J.; Gunn, D. M. TL 1969, 3455.
38. (a) Brown, H. C.; Rogi&cacute;, M. M. JACS 1969, 91, 2146. (b) Brown, H. C.; Rogi&cacute;, M. M.; Nambu, H.; Rathke, M. W. JACS 1969, 91, 2147. (c) Brown, H. C.; Rogi&cacute;, M. M.; Rathke, M. W.; Kabalka, G. W. JACS 1969, 91, 2150.
39. (a) Brown, H. C.; Rhodes, S. P. JACS 1969, 91, 2149. (b) ibid., JACS 1969, 91, 4306.
40. Brown, H. C.; Knights, E. F. JACS 1968, 90, 5283.
41. (a) Brown, H. C.; Hubbard, J. L.; Smith, K. S 1979, 701. (b) Hubbard, J. L.; Smith, K. JOM 1984, 276, C41. (c) Kabalka, G. W.; Delgado, M. C.; Kunda, U. S.; Kunda, S. A. JOC 1984, 49, 174.
42. (a) Carlson, B. A.; Katz, J.-J.; Brown, H. C. JOC 1973, 38, 3968. (b) Carlson, B. A.; Brown, H. C. OSC 1988, 6, 137.
43. (a) Kramer, G. W.; Brown, H. C. JOC 1977, 42, 2292. (b) Yamamoto, Y.; Yatagai, H.; Maruyama, K. JACS 1981, 103, 3229.
44. Brown, H. C.; Molander, G. A.; Singh, S. M.; Racherla, U. S. JOC 1985, 50, 1577.
45. (a) Jacob, III, P.; Brown, H. C. JOC 1977, 42, 579. (b) Soderquist, J. A.; Vaquer, J. TL 1990, 31, 4545.
46. (a) Jacob, III, P.; Brown, H. C. JACS 1976, 98, 7832. (b) Sinclair, J. A.; Molander, G. A.; Brown, H. C. JACS 1977, 99, 954.
47. Molander, G. A.; Brown, H. C. JOC 1977, 42, 3106.
48. Molander, G. A.; Zinke, P. W. OM 1986, 5, 2161.
49. (a) Sharma, S.; Oehlschlager, A. C. TL 1988, 29, 261. See also: (b) ibid., JOC 1989, 54, 5064. (c) Hutzinger, M. W.; Singer, R. D.; Oehlschlager, A. C. JACS 1990, 112, 9397.
50. (a) Singleton, D. A.; Martinez, J. P. TL 1991, 32, 7365. (b) Singleton, D. A.; Leung, S.-W. JOC 1992, 57, 4796. (c) Singleton, D. A.; Redman, A. M. TL 1994, 35, 509.
51. Andemichael, Y. W.; Huang, Y.; Wang, K. K. JOC 1993, 58, 1651.
52. (a) Evans, D. A.; Bartroli, J.; Shih, T. L. JACS 1981, 103, 2127. (b) Gage, J. R.; Evans, D. A. OS 1989, 68, 77, 83. (c) Evans, D. A.; Dow, R. L.; Shih, T. I.; Takacs, J. M.; Zahler, R. JACS 1990, 112, 5290. (d) Heathcock, C. H. Aldrichim. Acta 1990, 23, 99.
53. Shimizu, H.; Hara, S.; Suzuki, A. SC 1990, 20, 549.
54. (a) Miyaura, N.; Ishiyama, T.; Ishikawa, M.; Suzuki, A. TL 1986, 27, 6369. (b) Miyaura, N.; Ishiyama, T.; Sasaki, H.; Ishikawa, M.; Satoh, M.; Suzuki, A. JACS 1989, 111, 314.
55. (a) Hoshino, Y.; Ishiyama, T.; Miyaura, N.; Suzuki, A. TL 1988, 29, 3983. (b) Oh-e, T.; Miyaura, N.; Suzuki, A. SL 1990, 221. (c) Soderquist, J. A.; Santiago, B.; Rivera, I. TL 1990, 31, 4981. (d) Soderquist, J. A.; Santiago, B. TL 1990, 31, 5113. (e) Suzuki, A. PAC 1991, 63, 419. (f) Ishiyama, T.; Miyaura, N.; Suzuki, A. SL 1991, 687. (g) Ishiyama, T.; Miyaura, N.; Suzuki, A. OS 1992, 71, 89. (h) Miyaura, N.; Ishikawa, M.; Suzuki, A. TL 1992, 33, 2571. (i) Ishiyama, T.; Abe, S.; Miyaura, N.; Suzuki, A. CL 1992, 691. (j) Santiago, B.; Soderquist, J. A. JOC 1992, 57, 5844. (k) Rivera, I.; Colberg, J. C.; Soderquist, J. A. TL 1992, 33, 6919. (l) Nomoto, Y.; Miyaura, N.; Suzuki, A. SL 1992, 727. (m) Oh-e, T.; Miyaura, N.; Suzuki, A. JOC 1993, 58, 2201. (n) Soderquist, J. A.; Rane, A. M. TL 1993, 34, 5031. (o) Johnson, C. R.; Braun, M. P. JACS 1993, 115, 11014.
56. (a) Wakita, Y.; Yasunaga, T.; Akita, M.; Kojima, M. JOM 1986, 301, C17. (b) Ishiyama, T.; Miyaura, N.; Suzuki, A. BCJ 1991, 64, 1999. (c) ibid., TL 1991, 32, 6923. (d) Ishiyama, T.; Oh-e, T.; Miyaura, N.; Suzuki, A. TL 1992, 33, 4465.
57. (a) Soderquist, J. A.; Colberg, J. C. SL 1989, 25. (b) Soderquist, J. A.; Colberg, J. C. TL 1994, 35, 27.
58. Rivera, I.; Soderquist, J. A. TL 1991, 32, 2311.

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