A New Hybrid Phosphine Ligand for Palladium-Catalyzed Amination of Aryl Halides
COMMUNICATIONS
sure. The concentrate was purified by recrystallization from
MeOH (1000 mL) to give the title compound as a white
solid; yield: 218 g (77%). H NMR (300 MHz, CDCl3): d=
discussion. We also thank Mr. Y. Yaguchi, Mr. T. Kobayashi
and Mr. A. Kawaraya for their excellent analytical support.
1
1.57 (s, 3H), 1.67 (d, J=6.7 Hz, 1H), 1.87 (d, J=6.7 Hz,
1H), 7.12–7.32 (m, 6H), 7.42 (br d, J=6.9, Hz, 2H), 7.50
(dt, J=7.2 Hz, 2H); 13C NMR (75 MHz, CDCl3): d=27.0,
28.3, 42.5, 48.6, 126.6, 126.7, 128.1, 128.6, 129.1, 129.8, 142.2,
142.9.
References
[1] a) J. F. Hartwig, Angew. Chem. Int. Ed. 1998, 37, 2047;
b) B. H. Yang, S. L. Buchwald, J. Organomet. Chem.
1999, 576, 125.
Procedure for the Preparation of 6
[2] a) J. F. Hartwig, in: Handbook ofOrganopalladium
Chemistry for Organic Synthesis, (Ed.: E. Negishi),
Wiley-Interscience, New York, 2002, p 1051; b) L.
Jiang, S. L. Buchwald, in: Metal-Catalyzed Cross-Cou-
pling Reactions, 2nd edn., (Eds.: A. de Meijere, F. Die-
derich), Wiley-VCH, Weinheim, Germany, 2004, p 699.
[3] a) M. Nishiyama, T. Yamamoto, Y. Koie, Tetrahedron.
Lett. 1998, 39, 617; b) T. Yamamoto, M. Nishiyama, Y.
Koie, Tetrahedron. Lett. 1998, 39, 2367; c) L. L. Hill,
L. R. Moore, R. Huang, R. Craciun, A. J. Vincent,
D. A. Dixon, J. Chou, C. J. Woltermann, K. H. Shaugh-
nessy, J. Org. Chem. 2006, 71, 5117.
[4] a) D. Zim, S. L. Buchwald, Org. Lett. 2003, 5, 2413;
b) E. R. Strieter, D. G. Blackmond, S. L. Buchwald, J.
Am. Chem. Soc. 2003, 125, 13978; c) J. P. Wolfe, S. L.
Buchwald, Angew. Chem. Int. Ed. 1999, 38, 2413; d) X.
Huang, K. W. Anderson, D. Zim, L. Jiang, A. Klapars,
S. L. Buchwald, J. Am. Chem. Soc. 2003, 125, 6653.
[5] a) K. Suzuki, Y. Hori, T. Nishikawa, T. Kobayashi, Adv.
Synth. Catal. 2007, 349, 2089; b) K. Suzuki, A. Fon-
taine, Y. Hori, T. Kobayashi, Synlett 2007, 3206.
[6] a) N. Kataoka, Q. Shelby, J. P. Stambluli, J. F. Hartwig,
J. Org. Chem. 2002, 67, 5553; b) M. W. Hooper, M. Ut-
sunomiya, J. F. Hartwig, J. Org. Chem. 2003, 68, 2861.
[7] a) A. Zapf, M. Beller, Chem. Com. 2005, 431; b) F. Ra-
taboul, A. Zapf, R. Jackstell, S. Harkal, T. Riermeier,
A. Monsse, U. Dingerdissen, M. Beller, Chem. Eur. J.
2004, 10, 2983; c) M. Beller, T. H. Riemeier, C.-P. Rei-
singer, W. A. Herrman, Tetrahedron Lett. 1997, 38,
2073.
[8] a) M. S. Viciu, R. A. Kelly III, E. D. Stevens, F. Naud,
M. Studer, S. P. Nolan, Org. Lett. 2003, 5, 1479; b) M. S.
Viciu, R. M. Kissling, E. D. Stevens, S. P. Nolan, Org.
Lett. 2002, 4, 2229; c) G. Y. Li, G. Zheng, A. F. Noonan,
J. Org. Chem. 2001, 66, 8677; d) X. Bei, A. S. Guram,
H. W. Turner, Tetrahedron Lett. 1999, 40, 1237; e) S. Ur-
gaonkar, J. G. Verkade, J. Org. Chem. 2004, 69, 9135.
[9] For other coupling reactions using phosphine ligands,
see: a) A. F. Littke, G. C. Fu, Angew. Chem. Int. Ed.
1998, 37, 3387; b) A. F. Littke, G. C. Fu, J. Org. Chem.
1999, 64, 10; c) M. Feuerstein, H. Doucet, M. Santelli,
J. Org. Chem. 2001, 66, 5923; d) M. Feuerstein, H.
Doucet, M. Santelli, Tetrahedron Lett. 2001, 42, 5659;
e) G. Adjabeng, T. Brenstrum, J. Wilson, C. Frampton,
A. Robertson, J. Hillhouse, J. McNulty, A. Capretta,
Org. Lett. 2003, 5, 953.
A small amount of iodine and t-BuMgCl were added to a
solution of magnesium turnings (18.2 g, 0.754 mmol) in THF
(73 mL) at room temperature under a nitrogen atmosphere.
After stirring for 3 h, a solution of compound 7 (174 g, 0.718
mol) in THF (523 mL) was added dropwise to the premixed
solution. The reaction solution was stirred at 658C overnight
and then cooled to room temperature. The resulting solution
was added dropwise to a solution of CuI (145 g, 0.761 mol),
LiBr (68.6 g, 0.790 mol) and di-tert-butylchlorophosphine
(143 g, 0.790 mol) in THF (699 mL) at 558C. After stirring
for 6 h, hexane (900 mL) was added at 358C and the mixed
solution was cooled to 108C. A generated copper salt was
separated by filtration and dissolved with toluene. The tolu-
ene solution was washed with aqueous ammonia under air
until the color of the solution change from blue to colorless.
After washing with water, the solution was concentrated
under reduced pressure. The concentrate was purified from
methanol (930 mL) to give the title compound as a white
1
solid; yield: 162 g (64%). H NMR (500 MHz, CDCl3): d=
1.22 (d, J=13.1 Hz, 9H), 1.28–1.33 (m, 1H), 1.31 (d, J=
6.3 Hz, 9H), 1.36 (d, J=1.2 Hz, 3H), 2.27 (dd, J=5.2,
12.6 Hz, 1H), 7.06 (tt, J=1.2, 7.3 Hz, 1H), 7.13–7.20 (m,
3H), 7.28 (br t, J=7.7 Hz, 2H), 7.34 (br d, J=7.2 Hz, 2H),
7.43 (br d, J=8.3 Hz, 2H); 13C NMR (125 MHz, CDCl3):
d=24.9 (d, J=4.1 Hz), 26.6 (d, J=33.7 Hz), 28.4 (d, J=
8.4 Hz), 31.5 (d, J=13.9 Hz), 32.3 (d, J=13.6 Hz), 33.5 (d,
J=26.5 Hz), 34.8 (d, J=27.9 Hz), 40.6 (d, J=13.1 Hz),
125.5, 126.1, 127.1, 128.1, 130.3 (d, J=4.2 Hz), 131.2 (d, J=
1.6 Hz), 142.6 (d, J=6.9 Hz), 144.0; 31P NMR (202 MHz,
CDCl3): d=39.25; HR-MS (ESI): m/z=353.2403, calcd. for
C24H33P [M+H]+: 353.2398.
Typical Procedure for the Coupling Reaction of Aryl
Halides with Amines
Aryl halide (1.1 equiv.) and amine (1 equiv.) were added to
a solution of NaO-t-Bu (1.2 equiv.), [(p-allyl)PdCl]2 (0.5
mol%) and ligand 6 (2.0 mol%) in toluene (0.5M) at room
temperature under a nitrogen atmosphere. The mixture was
stirred at 100–1208C for the time specified. After cooling to
room temperature, the reaction solution was diluted with
toluene, washed with water, dried over anhydrous MgSO4
and concentrated under reduced pressure. Purification of
the concentrate by column chromatography on silica gel
and/or recrystallization gave the coupling product.
[10] Phosphine ligand 6 is commercially available from
Strem Chemicals.
[11] a) K. R. J. Thomas, J. T. Lin, Y. T. Tao, C. W. Ko, J. Am.
Chem. Soc. 2001, 123, 9404; b) K. Brunner, A. Van
Dijken, H. J. J. A. Bçrner, M. Bastiaansen, N. M. M.
Kiggen, B. M. W. Langeveld, J. Am. Chem. Soc. 2004,
126, 6035.
Acknowledgements
We are grateful to Prof. Dr. T. Nakai, Dr. T. Hagiwara, Dr.
N. Sayo and Dr. T. Saito for helpful suggestion and useful
Adv. Synth. Catal. 2008, 350, 652 – 656
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