ORGANIC
LETTERS
2011
Vol. 13, No. 14
3750–3753
Nickel-Catalyzed Amination of Aryl
Phosphates through Cleaving Aryl
CÀO Bonds
Jin-Hua Huang†,‡ and Lian-Ming Yang*,†
Beijing National Laboratory for Molecular Sciences (BNLMS), Laboratory of
New Materials, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190,
China, and Graduate School of Chinese Academy of Sciences, Beijing 100049, China
Received May 27, 2011
ABSTRACT
The amination of triaryl phosphates was achieved using a Ni(II)À(σ-Aryl) complex/NHC catalyst system in dioxane at 110 °C in the presence of NaH
as base. Electron-neutral, -rich, and -deficient triaryl phosphates were coupled with a wider range of amine partners including cyclic and acyclic
secondary amines, aliphatic primary amines, and anilines in good to excellent yields.
Transition-metal-catalyzed amination reactions have
become a powerful tool for the formation of aromatic
CÀN bonds which are ubiquitous in pharmaceuticals,
agrochemicals, and materials.1 In these transformations,
aryl halides represent the most widely employed type of
electrophilic substrates. On the other hand, phenolic deri-
vatives as potential electrophiles have been receiving con-
siderable attention due to their ease of preparation and
handling, pronouncedstability, low toxicity, and lowcost.2
Although this is a challenging task because phenol-derived
compounds are traditionally regarded as “inert” sub-
strates, several successful examples have been achieved
in palladium-catalyzed aminations of aryl triflates3 and
sulfonates.4,5 In recent years, efforts to explore catalytic
cross-coupling reactions of these “unusual” electrophiles
have focused on nickel-based catalysts6 because nickel
systems possess the advantages of cheapness and high
reactivity toward relatively inert electrophiles without the
use of specially tailored ligands. In2000, Bolmreported the
first example of Ni(0)-catalyzed amination of tosylates
with sulfoximines.7 Subsequently, our group found that
aryl tosylates were aminated effectively with amines/ani-
lines using a Ni(II) complex as a precatalyst.8 Tobisu and
Chatani established anisoles and aryl carboxylates as
effective electrophiles in the nickel(0)-catalyzed amination.9
(4) Pd-catalyzed aminations of aryl tosylates and benzenesulfonates:
(a) Hamann, B. C.; Hartwig, J. F. J. Am. Chem. Soc. 1998, 120, 7369.
(b) Huang, X.-H.; Anderson, K. W.; Zim, D.; Jiang, L.; Klapars, A.;
Buchwald, S. L. J. Am. Chem. Soc. 2003, 125, 6653. (c) Roy, A. H.;
Hartwig, J. F. J. Am. Chem. Soc. 2003, 125, 8704. (d) Ogata, T.; Hartwig,
J. F. J. Am. Chem. Soc. 2008, 130, 13848.
(5) Pd-catalyzed aminations of aryl mesylates: (a) So, C. M.; Zhou,
Z.; Lau, C. P.; Kwong, F. Y. Angew. Chem., Int. Ed. 2008, 47, 6402.
(b) Fors, B. P.; Watson, D. A.; Biscoe, M. R.; Buchwald, S. L. J. Am.
Chem. Soc. 2008, 130, 13552.
(6) For a recent review on Ni-catalyzed cross-couplings involving
CÀO bonds, see: Rosen, B. M.; Quasdorf, K. W.; Wilson, D. A.; Zhang,
N.; Resmerita, A. M.; Garg, N. K.; Percec, V. Chem. Rev. 2011, 111,
1346.
(7) Bolm, C.; Hildebrand, J. P.; Rudolph, J. Synthesis 2000, 7, 911.
(8) Gao, C.-Y.; Yang, L.-M. J. Org. Chem. 2008, 73, 1624.
(9) (a) Shimasaki, T.; Tobisu, M.; Chatani, N. Angew. Chem., Int. Ed.
2010, 49, 2929. (b) Tobisu, M.; Shimasaki, T.; Chatani, N. Chem. Lett.
2009, 38, 710.
† Beijing National Laboratory for Molecular Sciences.
‡ Graduate School of Chinese Academy of Sciences.
(1) For selected reviews, see: (a) Hartwig, J. F. Angew. Chem., Int. Ed.
1998, 37, 2047. (b) Muci, A. R.; Buchwald, S. L. Top. Curr. Chem. 2002,
219, 131. (c) Kienle, M.; Dubbaka, S. R.; Brade, K.; Knochel, P. Eur. J.
Org. Chem. 2007, 4166. (d) Beletskaya, I. P.; Cheprakov, A. V.; Coordin.
Chem. Rev. 2004, 248, 2337. (e) Monnier, F.; Taillefer, M. Angew.
Chem., Int. Ed. 2009, 48, 6954.
(2) For a leading reference, see: Metal-Catalyzed Cross-Coupling
Reactions; Diederich, F., Stang, P. J., Eds.; Wiley-VCH: Weinheim,
Germany, 1997.
(3) Pd-catalzed aminations of aryl triflates: (a) Wolfe, J. P.; Buchwald,
S. L. J. Org. Chem. 1997, 62, 1264. (b) Louie, J.; Driver, M. S.; Hamann,
B. C.; Hartwig, J. F. J. Org. Chem. 1997, 62, 1268.
(10) Ramgren, S. D.; Silberstein, A. L.; Yang, Y.; Garg, N. K. Angew.
Chem., Int. Ed. 2011, 50, 2171.
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10.1021/ol201437g
Published on Web 06/20/2011
2011 American Chemical Society