Table 3 Hydrodehalogenation of acidic substrates and heteroarenes
Scheme 3 Isolated yields for reductive debromination of alkyl bromides.
highly chemoselective reactions in the vicinity of halide, ester,
nitrile, thioalkyl and vinyl substituents. The practical and
rapid methodology may suggest further applications to the
selective dehalogenation of complex molecules and scavenging
of environmentally noxious halo aromatics.
Entry
Substrate
Product
Yield (%)
1
2
R = OH
R = NH2
72a
62a
Notes and references
3
4
87a
77b
1 M. Hudlicky, in Comprehensive Organic Chemistry, ed. B. M. Trost
and I. Fleming, Pergamon Press, Oxford, 1991, vol. 8, pp. 895.
2 Selected examples: (a) The Merck Index, Merck & Co, Rahway,
11th edn, 1989, p. 317; (b) A. Dobbs, J. Org. Chem., 2001, 66, 638;
(c) B. Liegault, I. Petrov, S. I. Gorelsky and K. Fagnou, J. Org.
´
Chem., 2010, 75, 1047; (d) N. Masuda, S. Tanba and A. Mori,
Org. Lett., 2009, 11, 2297; (e) D. Zhao, W. Wang, F. Yang, J. Lan,
L. Yang, G. Gao and J. You, Angew. Chem., Int. Ed., 2009, 48,
3296.
3 T. Schach, T Papenfuhs, EP 0667337 A1, 1995.
4 (a) J. Frimmel and M. Zdrazil, J. Chem. Technol. Biotechnol., 1995,
63, 17; (b) J. He, K. M. Ritalahti, K.-L. Yang, S. S. Koenigsberg
and F. E. Loffler, Nature, 2003, 424, 62.
¨
5 (a) F. Alonso, I. P. Beletskaya and M. Yus, Chem. Rev., 2002, 102,
4009. Biological dehalogenations are largely limited to alkyl
5
6
7
72
82c
78d
halides:
; (b) C. Seignez, A. Vuillenium, N. Adler and
P. Peringer, J. Hazard. Mater., 2001, 84, 265; (c) W. W. Mohn
and J. M. Tiedje, Microbiol. Rev., 1992, 56, 482.
6 Selected examples: (a) Y. Monguchi, A. Kume, K. Hattori,
T. Maegawa and H. Sajiki, Tetrahedron, 2006, 62, 7926;
(b) P. P. Cellier, J.-F. Spindler, M. Taillefer and H.-J. Cristau,
Tetrahedron Lett., 2003, 44, 7191; (c) M. S. Viciu, G. A. Grasa and
S. P. Nolan, Organometallics, 2001, 20, 3607; (d) T. V. RajanBabu,
in Encyclopedia of Reagents for Organic Synthesis, ed.
L. A. Paquette, Wiley, New York, 1995, vol. 7, pp. 5016;
(e) B. W. Knettle and R. A. Flowers, Org. Lett., 2001, 3, 2321;
(f) Y. Moglie, F. Alonso, C. Vitale, M. Yus and G. Radivoy, Appl.
Catal., A, 2006, 313, 94; (g) F. Alonso, G. Radivoy and M. Yus,
Tetrahedron, 1999, 55, 4441; (h) B. H. Lipshutz, T. Tomioka and
K. Sato, Synlett, 2001, 970; (i) C. Desmarets, S. Kuhl, R. Schneider
and Y. Fort, Organometallics, 2002, 21, 1554; (j) N. Hashimoto,
T. Hara, S. Shimazu, Y. Takahashi, T. Mitsudome, T. Mizugaki,
K. Jitsukawa and K. Kaneda, Chem. Lett., 2010, 49;
(k) V. Dichiarante, M. Fagnoni and A. Albini, Green Chem.,
2009, 11, 942; (l) S. Adimurthya and G. Ramachandraiah,
Tetrahedron Lett., 2004, 45, 5251.
8
54e
4 h. 1 mol% Fe(acac)3, 1.5 equiv. t-BuMgCl. 20 1C. GC yield.13
NMR yield.
a
b
c
d
e
7 (a) W. M. Czaplik, M. Mayer and A. Jacobi von Wangelin, Angew.
Chem., Int. Ed., 2009, 48, 607; (b) W. M. Czaplik, M. Mayer and
A. Jacobi von Wangelin, Synlett, 2009, 2931; (c) M. Mayer,
W. M. Czaplik and A. Jacobi von Wangelin, Synlett, 2009, 2919;
(d) W. M. Czaplik, J.-M. Neudorfl and A. Jacobi von Wangelin,
¨
Green Chem., 2007, 5, 1163; (e) W. M. Czaplik, M. Mayer,
S. Grupe and A. Jacobi von Wangelin, Pure Appl. Chem., 2010,
82, 1545.
8 (a) E. B. Bauer, Curr. Org. Chem., 2008, 12, 1341; (b) S. Enthaler,
K. Junge and M. Beller, Angew. Chem., Int. Ed., 2008, 47, 3317.
9 (a) W. M. Czaplik, M. Mayer, J. Cvengros and A. Jacobi von
Wangelin, ChemSusChem, 2009, 2, 396; (b) B. D. Sherry and
A. Furstner, Acc. Chem. Res., 2008, 41, 1500.
¨
10 (a) B. Bogdanovic and M. Schwickardi, Angew. Chem., Int. Ed.,
´
Scheme 2 Mechanistic rationale. a: 1.5 equiv. Mg, 1.2 equiv. LiCl,
0.01 mol% Dibal-H, THF, 0 1C, 3 h; b: 1, 5 mol% Fe(acac)3, THF,
0 1C, 1 h.
2000, 39, 4610; (b) K. Jonas, L. Schieferstein, C. Kruger and
¨
Y.-H. Tsay, Angew. Chem., Int. Ed. Engl., 1979, 18, 550.
11 H. Guo, K. Kanno and T. Takahashi, Chem. Lett., 2004, 1356.
12 H. Kryk, G. Hessel and W. Schmitt, Org. Process Res. Dev., 2007,
11, 1135.
13 (a) S. Goto, J. Velder, S. El Sheikh, Y. Sakamoto, M. Mitani,
S. Elmas, A. Adler, A. Becker, J.-M. Neudorfl, J. Lex and
¨
H.-G. Schmalz, Synlett, 2008, 1361; (b) S. Liebehentschel,
J. Cvengros and A. Jacobi von Wangelin, Synlett, 2007, 2574.
14 A. Furstner, R. Martin, H. Krause, G. Seidel, R. Goddard and
¨
In summary, we have developed a highly practical iron-
catalyzed hydrodehalogenation of aryl and heteroaryl halides.
Commercial t-BuMgCl (from Chemetall) serves as a hydride
source via an iron-centered b-hydride elimination. The mild
reaction conditions (THF, 0 1C, 90 min) tolerate various
functional groups, electron-deficient heteroarenes and allow
C. W. Lehmann, J. Am. Chem. Soc., 2008, 130, 8773.
c
6352 Chem. Commun., 2010, 46, 6350–6352
This journal is The Royal Society of Chemistry 2010