Subscribe to RSS
DOI: 10.1055/s-0030-1258482
A Photoirradiative Phase-Vanishing Method: Efficient Generation of HBr from Alkanes and Molecular Bromine and Its Use for Subsequent Radical Addition to Terminal Alkenes
Publication History
Publication Date:
09 July 2010 (online)
Abstract
A triphasic phase-vanishing (PV) system comprised of an alkane, perfluorohexanes, and bromine was successfully combined by photoirradiation to efficiently generate hydrogen bromide, which underwent radical addition with 1-alkenes in the hydrocarbon layer to afford terminal bromides in high yields.
Key words
fluorous solvent - phase-vanishing - photoirradiation - bromination - hydrogen bromide
- Supporting Information for this article is available online:
- Supporting Information
- 1 For a general review on fluorous
chemistry, see:
Handbook of Fluorous
Chemistry
Gladysz JA.Curran DP.Horváth IT. Wiley-VCH; Weinheim: 2004. - For reviews on fluorous solvents, see:
-
2a
Ryu I.Matsubara H.Emnet C.Gladysz JA.Takeuchi S.Nakamura Y.Curran DP. In Green Reaction Media in Organic SynthesisMikami K. Blackwell Publishing; Oxford: 2005. p.59 -
2b
Matsubara H.Ryu I. In Green Separation Processes: Fundamentals and ApplicationsAfonso CAM.Crespo JG. Wiley-VCH; Weinheim: 2005. p.219 - 3
Matsubara H.Yasuda S.Sugiyama H.Ryu I.Fujii Y.Kita K. Tetrahedron 2002, 58: 4071 - 4
Matsubara H.Maeda L.Ryu I. Chem. Lett. 2005, 34: 1548 - 5
Matsubara H.Maeda L.Sugiyama H.Ryu I. Synthesis 2007, 2901 - For reviews on the ‘Phase-Vanishing’ method, see:
-
6a
Ryu I.Matsubara H.Nakamura H.Curran DP. Chem. Rec. 2008, 8: 351 -
6b
Iskra J. Lett. Org. Chem. 2006, 3: 170 - 7
Ryu I.Matsubara H.Yasuda S.Nakamura H.Curran DP. J. Am. Chem. Soc. 2002, 124: 12946 -
8a
Nakamura H.Usui T.Kuroda H.Ryu I.Matsubara H.Yasuda S.Curran DP. Org. Lett. 2003, 5: 1167 -
8b
Matsubara H.Yasuda S.Ryu I. Synlett 2003, 247 -
8c
Rahman MT.Kamata N.Matsubara H.Ryu I. Synlett 2005, 2664 -
8d
Matsubara H.Tsukida M.Yasuda S.Ryu I. J. Fluorine Chem. 2008, 129: 951 -
9a
Jana NK.Verkade JG. Org. Lett. 2003, 5: 3787 -
9b
Iskra J.Stavber S.Zupan M. Chem. Commun. 2003, 2496 -
9c
Curran DP.Werner S. Org. Lett. 2004, 6: 1021 -
9d
Podgoršek A.Stavber S.Zupan M.Iskra J. Eur. J. Org. Chem. 2006, 483 -
9e
Windmon N.Dragojlovic V. Tetrahedron Lett. 2008, 49: 6543 -
9f
Windmon N.Dragojlovic V. Beilstein J. Org. Chem. 2008, 4: 29 -
9g
Ma K.Li S.Weiss RG. Org. Lett. 2008, 10: 4155 -
9h
van Zee NJ.Dragojlovic V. Org. Lett. 2009, 11: 3190 -
9i
Pels K.Dragojlovic V. Beilstein J. Org. Chem. 2009, 5: 75 -
11a
Brown HC.Lane CF. J. Am. Chem. Soc. 1970, 92: 7212 -
11b
Brown HC.Lane CF. Tetrahedron 1988, 44: 2763 -
11c
Falorni M.Lardicci L.Giacomelli G. J. Org. Chem. 1986, 51: 5291 -
11d
Brown HC.Lane CF. J. Am. Chem. Soc. 1970, 92: 6660 -
11e
Brown HC.Lane CF.
J. Chem. Soc. D: Chem. Commun. 1971, 521 -
11f
Lane CF.Brown HC. J. Organomet. Chem. 1971, 26: C51 -
11g
Tufariello JJ.Hovey MM. J. Chem. Soc. D: Chem. Commun. 1970, 372 -
11h
Kabalka GW.Sastry KAR.Hsu HC.Hylarides MD. J. Org. Chem. 1981, 46: 3113 -
11i
Maruoka K.Sano H.Shinoda K.Nakai S.Yamamoto H. J. Am. Chem. Soc. 1986, 108: 6036 -
11j
Tufariello JJ.Hovey MM. J. Am. Chem. Soc. 1970, 92: 3221 -
12a
Tamao K.Yoshida J.Takahashi M.Yamamoto H.Kakui T.Matsumoto H.Kurita A.Kumada M. J. Am. Chem. Soc. 1978, 100: 290 -
12b
Tamao K.Yoshida J.Yamamoto H.Kakui T.Matsumoto H.Takahashi M.Kurita A.Murata M.Kumada M. Organometallics 1982, 1: 355 -
13a
Hart DW.Schwartz J. J. Am. Chem. Soc. 1974, 96: 8115 -
13b
Tolstikov GA.Miftakhov MS.Valeev FA. Izv. Akad. Nauk SSSR, Ser. Khim. 1979, 2576 -
14a
Isagaga K.Tatsumi K.Otsuji Y. Chem. Lett. 1977, 1117 -
14b
Sato F.Sato S.Kodama H.Sato M. J. Organomet. Chem. 1977, 142: 71 -
14c
Lee H.-S.Kim C.-E. J. Korean Chem. Soc. 2003, 47: 297 -
14d
Lee H.-S.Lee G.-Y. J. Korean Chem. Soc. 2005, 49: 321 -
14e
Gavrilenko VV.Kolesov VS.Zakharkin LI. Izv. Akad. Nauk SSSR, Ser. Khim. 1985, 681 - 16 For an example of the use of HBr
to prepare key substrates for sequential radical reactions, see:
Zhang W.Hua Y.Geib SJ.Hoge G.Dowd P. Tetrahedron 1994, 50: 12579
References and Notes
¹H NMR of the concentrated reaction mixture in entry 6 of Table 1 shows peaks assigned to 2-bromo-2,4,4-trimethyl-pentane as the product, suggesting that hydrogen abstraction from isooctane would occur selectively at the tertiary position of isooctane.
15The reaction without fluorous phase gave an inferior result. For example, irradiation of a mixture of bromine (1.16 mmol) and isooctane (6 mL) with a 500 W Xe lamp for 30 min, followed by addition of 1-dodecene (1 mmol) at r.t., gave 1-bromododecane in 79% yield together with unreacted 1-dodecene (11%). In this procedure, probably some HBr generated would outgas during the reaction.
17
Typical Procedure
for Photoirradiative Phase
-
Vanishing Hydrogen Bromide Addition to Alkenes (Table
2, entry 2): FC-72 (6 mL) was placed in a Pyrex test tube (13 mm
Æ × 105
mm) to which bromine (2.1 mmol, 340 mg) was added slowly using a
glass pipette. Isooctane (1.5 mL) solution of 1-dodecene (2.0 mmol,
340 mg) was then added slowly, forming three layers. The test tube
was irradiated with a 500 W Xenon lamp for 2 h. The isooctane layer
was taken up with a pipette. Then, additional hexane (4 × 4
mL) was placed on the residual FC-72 layer, followed by decanting
off. The combined organic layer was washed with aq 10% Na2S2O3 (30
mL) and sat. brine (30 mL), dried over Na2SO4,
and concentrated. Purification by a short column chromatography
on silica gel with hexane gave 1-bromo-dodecane (480 mg, 96%).