Ruthenium-catalyzed one-pot aromatic secondary amine formation from nitroarenes and alcohols

Article abstract of DOI:10.1002/asia.201000945

Beg, steal, or borrow: The synthesis of aromatic secondary amines has been developed using commercially available [Ru(acac)₃]/dppe as the catalyst. Chlorobenzene solvent gave high selectivity, with only trace amounts of imine and tertiary amine observed.

Full text of DOI:10.1002/asia.201000945

COMMUNICATION
DOI: 10.1002/asia.201000945
Ruthenium-Catalyzed One-Pot Aromatic Secondary Amine Formation from
Nitroarenes and Alcohols
[
a]
Yong Liu, Wen Chen, Chao Feng, and Guojun Deng*
Nitrogen-containing compounds are of great importance
as building blocks for agrochemicals, dyes, pharmaceuticals,
[1]
and ligands. Much effort has been made on the develop-
[2]
ment of methods for the synthesis of CÀN bonds. Secon-
dary amines are extremely important pharmacophores in
numerous biologically active compounds owing to their in-
teresting physiological activities. A number of catalytic and
[3]
non-catalytic procedures, such as 1) direct alkylation of
[4]
Scheme 1. Borrowing-hydrogen methodology in the alkylation of amines
with alcohols.
amines with alkyl and aryl halides, 2) reductive amination
[5]
of ketones and aldehydes, 3) hydroamination of unsaturat-
[6]
ed hydrocarbons with amines, and 4) direct CÀH amina-
[7]
tion, have been developed for the synthesis of secondary
amines in the past few decades. However, the overalkylation
of amines, a commonly encountered problem with these ap-
proaches, has limited their application for the synthesis of
[11]
the seminal work reported by Grigg et al. and Watanable
[12]
et al.,
great progress has been made in the transition-
metal-catalyzed direct alkylation of amines with alcohols.
The borrowing-hydrogen methodology has been widely used
[8]
secondary amines.
[13]
Recently, there has been significant interest in the transi-
tion-metal-catalyzed N-alkylation of amines using alcohols
as the alkylation reagent. Alcohols are readily available, in-
expensive, and non-toxic. Most alcohols are poor electro-
philes and are not suitable as direct alkylating agents for
amines. However, alcohols can be readily activated by oxi-
dation to afford aldehydes or ketones and used as direct al-
in the synthesis of secondary amines as well as the synthe-
sis of primary amines, tertiary amines, and N-alkylated sul-
[14]
fonamides in high yields under mild conditions.
Nitroarenes are stable and readily available compounds
[15]
and can be reduced to amines using hydrogen. However,
the selective reduction of nitro groups is still a challenging
[16]
problem. The direct amination of nitroarenes with alco-
hols is rare compared with the great breakthroughs being
made in the alkylation of amines with alcohols. Recently, we
developed the one-pot formation of tertiary amines from ni-
[9]
kylating agents. In the typical amination of an alcohol with
an amine, the alcohol can be activated by the transfer of hy-
drogen atom onto a metal catalyst, thereby generating an al-
dehyde, followed by in situ imine formation. Subsequent re-
duction of the imine by the return of the hydrogen atom af-
fords a secondary amine. The overall process is termed as
[17]
troarenes and alcohols using a ruthenium catalyst. At the
same time, Mata and co-workers reported an imine forma-
tion from nitroarenes and alcohols catalyzed by an iridium/
[18]
“
borrowing hydrogen” (Williams and co-workers, Scheme 1)
palladium complex. In those reactions, the nitroarenes are
reduced to their corresponding primary amines in situ using
the hydrogen generated from alcohol oxidation. This
method affords a concise route for CÀN bond formation.
[10]
or “hydrogen autotransfer” (Yus and co-workers). Since
[
a] Y. Liu, W. Chen, C. Feng, Prof. Dr. G. Deng
Key Laboratory for Environmental Friendly Chemistry and Applica-
tion of Ministry of Education
During our investigation of the reaction conditions, we ob-
served a small amount of secondary amine in the reaction
mixture. Therefore, we thought it might be possible to gen-
erate secondary amines selectively after screening the reac-
tion conditions. Herein, we report the ruthenium-catalyzed
formation of secondary amines from nitroarenes and alco-
hols using the borrowing hydrogen methodology.
College of Chemistry, Xiangtan University
Xiangtan, 411105 (China)
Fax : (+86)731-58292251
E-mail: gjdeng@xtu.edu.cn
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201000945.
1142
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Asian J. 2011, 6, 1142 – 1146

Initially, the reaction between commercially available and
inexpensive nitrobenzene (1a) and benzyl alcohol (2a) was
dimethylformamide, albeit with lower selectivities (Table 1,
entries 14 and 15). Dimethyl sulfoxide was not a suitable
solvent for this reaction (Table 1, entry 16). The yield was
improved to 94% by using chlorobenzene as a co-solvent
(Table 1, entry 17). Interestingly, imine 4a was formed in
57% yield when the amount of benzyl alcohol was reduced
to 2 equivalents (Table 1, entry 18).
chosen as a model using a RuCl catalyst. When nitroben-
3
zene was reacted with excess benzyl alcohol in the absence
of ligand, no desired product was formed, as determined by
[19]
1
GC-MS and H NMR methods (Table 1, entry 1). Subse-
With the optimized conditions in hand, the direct amina-
tion of nitroarenes with benzyl alcohol was performed and
the results are summarized in Table 2. The reactions with ni-
troarenes bearing eletron-donating (Table 2, entries 2 and 3)
and electron-withdrawing substituents on the aromatic ring
[
a]
Table 1. Screening for the optimal conditions.
[
b]
Entry Catalyst
Ligand Additive Solvent
Yield
4a
(
Table 2, entries 4 and 5) gave the desired products in good
3
a
5a
yields. Lower yield was obtained when 1-bromo-4-nitroben-
zene (1 f) was used, and the desired product was achieved in
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
[RuCl
3
2
]·3H
(PPh
2
O
) ]
3 3
n.d. n.d.
n.d. n.d.
n.d. n.d.
24 n.d.
n.d. n.d.
n.d.
21
37
42
4
3
3
2
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
[RuCl
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
6
2% yield (Table 2, entry 6). The reaction yield decreased
[Ru(CO)(H)Cl
[Ru(CO)(H) (PPh
[{Ru(p-cymene)Cl
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
(PPh
3
)
]
]
3
]
dramatically when para-nitroacetophenone was used as a
substrate (Table 2, entry 7). Nitroarenes bearing an ester
2
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
3
)
3
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
2
}
2
PPh
PPh
dppp
dppb
dppf
3
3
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
[Ru
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
(acac)
3
3
3
3
3
3
3
3
3
3
3
3
3
]
]
]
]
]
]
]
]
]
]
]
]
]
56
47
45
1
2
7
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
[
a]
Table 2. Reaction of benzyl alcohol with various nitroarenes.
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
51 10
51 23
[
b]
0
1
2
3
4
5
6
7
8
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
binap
dppe
Entry
Nitroarene
Product
Yield
87
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
61
78
85
1
1
1
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
dppe NaHCO
3
1
1a
1b
3a
3b
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
dppe KHCO
dppe KHCO
dppe KHCO
dppe KHCO
dppe KHCO
dppe KHCO
3
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
3
3
3
3
3
p-xylene 40 35
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
DMF 80
DMSO
PhCl 94
9
2
1
2
3
4
5
6
85
81
71
87
62
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
3
ACHTUNGTRENNUNG
[
c]
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
PhCl 19 57
1c
1d
1e
1f
3c
3d
3e
3f
[
(
a] Conditions: 1a (0.2 mmol), 2a (1.5 mmol), catalyst (0.01 mmol), ligand
0.015 mmol), additive (0.2 mmol), solvent (0.15 mL), 1508C, 16 h under
argon unless otherwise noted. [b] GC yield based on 1a. n.d.=not detected
(
below 1% yield). [c] 2 equiv of 2a was used.
quently, various ruthenium salts were tested in this reaction
under an argon atmosphere. No desired product was ob-
served when [RuCl AHCTUNTGRENNUN(G PPh ) ], [Ru(CO)(H)Cl AHCNUTRGTENNNUG( PPh ) ], and
2 3 3 3 3
[
{Ru ACHTUNGTRENNUNG( p-cymene)Cl } ] were used as the catalyst, and the ter-
2 2
tiary amine was formed as the major product (Table 1, en-
tries 2, 3 and 5). The desired secondary amine was achieved
[
c]
7
8
1g
1h
3g
3h
31
60
in 24% yield when [Ru(CO)(H)2
catalyst (Table 1, entry 4). Secondary amine was obtained in
moderate yield with good selectivity when [Ru(acac) ]/PPh
was used as the catalyst (Table 1, entry 6). Other ligands
were tested for this reaction in the presence of [Ru(acac) ],
ACHTUNGTNERNUNG( PPh ) ] was used as the
3 3
AHCTUNGTRENNUNG
3
3
[
[
c]
AHCTUNGTRENNUNG
3
with dppp [1,3-bis(diphenylphosphino)propane], dppb [1,4-
bis(diphenylphosphino)butane], dppf [1,1’-bis(diphenylphos-
phino)ferrocene], and binap [(1,2-bis(diphenylphosphino)-
d]
9
1
1
1i
1j
3i
3j
47
65
78
1
,1’-binaphthyl)] all efficiently catalyzing the reaction, and
giving the desired product in moderate yields (Table 1, en-
tries 7–10). Dppe [1,2-bis(diphenylphosphino)ethane]
[
d]
0
1
showed the best yield among the phosphine ligands tested,
and only trace amount of imine and tertiary amine were ob-
served. The yields could be further improved by using
NaHCO and KHCO as additives (Table 1, entries 12 and
1k
3k
[
a] Conditions: 1 (0.2 mmol), 2a (1.5 mmol), dppe (0.015 mmol), [Ru-
(acac) (0.01 mmol), 1508C, KHCO (0.2 mmol), chlorobenzene
0.15 mL), 16 h in argon unless otherwise noted. [b] Yield of isolated
product, based on nitroarenes. [c] No KHCO , 48 h. [d] 48 h.
3
3
A
H
U
G
R
N
U
G
3
]
3
13). The effect of solvents on this reaction was investigated.
(
The reaction proceeded efficiently in para-xylene and N,N-
3
Chem. Asian J. 2011, 6, 1142 – 1146
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemasianj.org
1143

G. Deng et al.
COMMUNICATION
group at the para position reacted with benzyl alcohol to
give the corresponding product in good yield (Table 2,
entry 8). The position of substituents on the phenyl ring of
nitroarenes slightly affected the reaction yield. Moderate to
good yields were achieved when 1-methyl-2-nitrobenzene, 1-
nitronaphthalene, and 1-chloro-3-nitrobenzene were used
amines, secondary amines, and imines were also synthesized
selectively from nitrobenzene and benzyl alcohol under vari-
ous reaction conditions (Scheme 2).
(
Table 2, entries 9–11).
The scope of the reaction of various alcohols with nitro-
benzene is presented in Table 3. A series of functional
groups including methyl, methoxy, chloro, bromo, and tri-
[
a]
Table 3. Reaction of nitrobenzene with various alcohols.
[
b]
Entry
Nitroarene
Product
Yield
89
1
2b
2c
2d
3l
3m
3n
2
3
73
42
Scheme 2. N-alkylation of nitrobenzene with benzyl alcohol in various
conditions.
4
5
6
2e
2f
2g
3o
3p
3q
90
56
56
A tentative reaction mechanism to rationalize this trans-
formation is illustrated in Scheme 3. First, the alcohol is oxi-
dized into the aldehyde and transfers hydrogen to the ruthe-
nium catalyst to give a ruthenium-hydride complex. This
ruthenium hydride reduces the nitro group to an amine
group. An imine intermediate is formed from the amine and
the aldehyde which is reduced to the final product using the
borrowed hydrogen.
7
2h
3r
68
8
9
2i
2j
3s
3t
72
85
1
0
1
2k
2l
3u
3v
83
65
1
[
a] Conditions: 1a (0.2 mmol), 2 (1.5 mmol), dppe (0.015 mmol), [Ru-
(acac) (0.01 mmol), KHCO (0.2 mmol), chlorobenzene (0.15 mL),
508C, 16 h in argon unless otherwise noted. [b] Yield of isolated prod-
uct, based on 1a.
A
C
H
T
U
N
G
T
R
E
N
N
U
N
G
3
]
3
1
fluoromethyl groups were tolerated under the optimal reac-
tion conditions, and the desired products were obtained in
good to excellent yields (Table 3, entries 1–5). The position
of substituents had significant impact on the reaction. A
moderate yield was obtained when 3-methylbenzyl alcohol
Scheme 3. A tentative mechanism for the direct alkylation of nitroar-
enes.
(
2g) was used whereas only trace amounts of desired prod-
uct were formed when 2-methylbenzyl alcohol was used
Table 3, entry 6). 2-Pyridinemethanol (2i) reacted smoothly
In summary, we have developed the selective ruthenium-
catalyzed synthesis of secondary amines using nitroarenes
and primary alcohols as starting materials. The ruthenium
catalyst and additive played a key role in this reaction.
Excess alcohol was necessary to afford satisfactory reaction
yields. Alcohol oxidation, nitro reduction, and imine reduc-
tion were performed in a cascade sequence. The reaction
proceeded well for a range of different substrates. Lowering
(
with nitrobenzene and gave the desired secondary amine in
good yield (Table 3, entry 8). To our delight, besides benzyl
alcohol and its derivatives, simple aliphatic alcohols also re-
acted with nitrobenzene to give the desired products in
good to excellent yields (Table 3, entries 9–11). Tertiary
1144
www.chemasianj.org
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Asian J. 2011, 6, 1142 – 1146

Ruthenium-Catalyzed One-Pot Aromatic Secondary Amine Formation from Nitroarenes and Alcohols
the amount of alcohol to two equivalents afforded the imine
as the major product in moderate yield. Further investiga-
tion, including optimization of the imine formation, reaction
scope, mechanism, and further applications of this CÀN
selected examples, see: a) A. F. Abdel-Magid, K. G. Carson, B. D.
Harris, C. A. Maryanoff, R. D. Shah, J. Org. Chem. 1996, 61, 3849;
b) T. Mizuta, S. Sakaguchi, Y. Ishii, J. Org. Chem. 2005, 70, 2195;
c) O. Y. Lee, K. L. Law, D. Yang, Org. Lett. 2009, 11, 3302.
6] a) J. Seayad, A. Tillack, C. G. Hartung, M. Beller, Adv. Synth. Catal.
2002, 344, 795; b) M. Beller, C. Breindl, M. Eichberger, C. G. Har-
tung, J. Seayad, O. Thiel, A. Tillack, H. Trauthwein, Synlett 2002,
[
bond formation are underway in our laboratory.
1
579; c) M. Utsunomiya, R. Kuwano, M. Kawatsura, J. F. Hartwig, J.
Am. Chem. Soc. 2003, 125, 5608; d) J. Ryu, G. Y. Li, T. J. Marks, J.
Am. Chem. Soc. 2003, 125, 12584; e) J. F. Hartwig, Pure Appl.
Chem. 2004, 76, 507; f) M. Utsunomiya, J. F. Hartwig, J. Am. Chem.
Soc. 2004, 126, 2702; g) K. C. Hultzsch, D. V. Gribkov, F. Hample, J.
Organomet. Chem. 2005, 690, 4441; h) A. M. Johns, M. Mtsunomiya,
C. D. Incarvito, J. F. Hartwig, J. Am. Chem. Soc. 2006, 128, 1828;
i) A. Leyva, A. Corma, Adv. Synth. Catal. 2009, 351, 2876; j) P.
Roesky, Angew. Chem. 2009, 121, 4988; Angew. Chem. Int. Ed. 2009,
Experimental Section
Representative Experimental Procedure (3a)
A reaction vessel was charged with [Ru
6.1 mg, 0.015 mmol), and KHCO (20 mg, 0.2 mmol) and purged with
argon three times. Nitrobenzene (1a, 24.6 mg, 0.2 mmol), benzyl alcohol
2a, 0.15 mL, 1.5 mmol), and chlorobenzene (0.15 mL) were added by sy-
3
ACHTUNGTRENNUNG( acac) ] (4 mg, 0.01 mmol), dppe
(
3
(
ringe. The resulting solution was stirred at 1508C for 16 h. After cooling
to room temperature, the volatile compounds were removed under
vacuum and the residue was purified by column chromatography on neu-
4
8, 4892; k) K. Hesp. M. Stradiotto, ChemCatChem 2010, 2, 1192.
[
7] For reviews on C-H amination, see: a) F. Collet, R. Dodd, P.
Dauban, Chem. Commun. 2009, 5061; b) A. Armstrong, J. Collins,
Angew. Chem. 2010, 122, 2332; Angew. Chem. Int. Ed. 2010, 49,
À
tral alumina gel (petroleum ether) to give 3a (CAS: 103–32–2) as a color-
1
less oil, yield: 32.6 mg (87%). H NMR (400 MHz, CDCl
3
, 258C, refer-
2
282. For selected examples on direct aromatic C H amination, see:
enced to TMS): d=7.35–7.21 (m, 5H), 7.11 (d, J=7.5 Hz, 2H), 6.65 (t,
J=7.2 Hz, 1H), 6.56 (d, J=7.8 Hz, 2H), 4.31 (s, 2H), 3.93 ppm (br s,
c) W. Peter Tsang, N. Zheng, S. L. Buchwald, J. Am. Chem. Soc.
2
005, 127, 14560; d) J. Jordan-Hore, C. Johansson, M. Gulias, E.
1
3
1
1
H); C NMR (100 MHz, CDCl
3
, 258C, TMS): d=147.7, 139.2, 129.3,
Beck, M. Gaunt, J. Am. Chem. Soc. 2008, 130, 16184; e) T. Wasa,
J. Q. Yu, J. Am. Chem. Soc. 2008, 130, 14058; f) T. Mei, X. Wang, J.
Yu, J. Am. Chem. Soc. 2009, 131, 10806; g) R. Fan, W. Li, D. Pu, L.
Zhang, Org. Lett. 2009, 11, 1425; h) Y. Tan, J. F. Hartwig, J. Am.
Chem. Soc. 2010, 132, 3676; i) Q. Shuai, G. Deng, Z. Chua, D.
Bohle, C. J. Li, Adv. Synth. Catal. 2010, 352, 632; j) H. Zhao, M.
Wang, W. Su. M. Hong, Adv. Synth. Catal. 2010, 352, 1301.
8] a) R. F. Borch, H. D. Durst, J. Am. Chem. Soc. 1969, 91, 3996;
b) A. F. Abdel-Majid, K. G. Carson, B. D. Harris, C. A. Maryanoff,
R. Shath, J. Org. Chem. 1996, 61, 3849; c) M. B. Smith, J. March in
Marchꢀs Advanced Organic Chemistry, Wiley, New York, 2001,
p. 1187, and references therein.
9] a) G. Tojo, M. Fernꢂndez in Oxidation of Alcohols to Aldehydes and
Ketones, Springer, New York, USA, 2006; b) G. Dobereiner, R.
Crabtree, Chem. Rev. 2010, 110, 681.
10] For excellent recent reviews on borrowing hydrogen methodology
and hydrogen autotransfer reaction, see: a) K. I. Fujita, R. Yamagu-
chi, Synlett 2005, 4, 560; b) G. Guillena, D. Ramꢃn, M. Yus, Angew.
Chem. 2007, 119, 2410; Angew. Chem. Int. Ed. 2007, 46, 2358; c) M.
Hamid, P. Slatford, J. M. J. Williams, Adv. Synth. Catal. 2007, 349,
28.7, 127.7, 127.4, 118.1, 113.4, 48.7 ppm; MS (EI) m/z (%) 183, 106, 91-
ACHTUNGTRENNUNG( 100), 77.
Acknowledgements
[
[
This work was supported by the National Natural Science Foundation of
China (20902076), Xiangtan University “Academic Leader Program”
09QDZ12) and the “One Hundred Talent Project” of Hunan Province.
(
We thank Prof. C.-J. Li (McGill University) for helpful discussions.
Keywords: alcohols · alkylation · nitroarenes · ruthenium ·
[
secondary amines
[
1] a) J. K. Landquist in Comprehensive Heterocyclic Chemistry (Eds.:
A. R. Katritzky, C. W. Rees), Pergamon, New York, 1984; b) S.
Patai in The Chemistry of Amines, Nitroso, Nitro and Related
Groups, Wiley, Chichester, 1996; c) S. A. Lawrence in Amines: Syn-
thesis Properties and Applications, Cambridge University Press,
Cambridge, 2004.
1
555; d) T. D. Nixon, M. K. Whittlesey, J. M. J. Williams, Dalton
Trans. 2009, 5, 753; e) G. Guillena, D. J. Ramꢃn, M. Yus, Chem. Rev.
2
010, 110, 1611; f) A. Watson, J. M. J. Williams, Science 2010, 329,
6
35.
[
[
11] R. Grigg, T. R. B. Mitchell, S. Sutthivaiyakit, N. Tongpenyai, J.
Chem. Soc. Chem. Commun. 1981, 611.
12] a) Y. Watanabe, Y. Tsuji, Y. Ohsugi, Tetrahedron Lett. 1981, 22,
2667; b) Y. Watanabe, Y. Tsuji, H. Ige, Y. Ohsugi, T. Ohta, J. Org.
Chem. 1984, 49, 3359; c) K. Huh, Y. Tsuji, M. Kobayashi, F. Okuda,
Y. Watanable, Chem. Lett. 1988, 449.
[
[
[
2] For selected reviews on CÀN bonds formation, see: a) T. Mꢁller, K.
Hultzsch, M. Yus, F. Foubelo, M. Tada, Chem. Rev. 2008, 108, 3795;
b) G. Evano, N. Blanchard, M. Toumi, Chem. Rev. 2008, 108, 3054;
c) F. Monnier, M. Taillefer, Angew. Chem. 2009, 121, 7088; Angew.
Chem. Int. Ed. 2009, 48, 6954.
3] For reviews on secondary amine formation, see a) R. N. Salvatore,
C. H. Yoon, K. W. Jung, Tetrahedron 2001, 57, 7785; b) J. Seayad, A.
Tillack, C. G. Hartung, M. Beller, Adv. Synth. Catal. 2002, 344, 795;
c) S. Gomez, J. A. Peters, T. Maschmeyer, Adv. Synth. Catal. 2002,
[13] One of the pioneer works of the ruthenium-catalyzed reaction of al-
cohols and amines to give secondary and tertiary amines was report-
ed by S. I. Murahashi et. al: S. I. Murahashi, K. Kondo, T. Hakata,
Tetrahedron Lett. 1982, 23, 229. For other selected examples of sec-
ondary amine formation using borrowing hydrogen methodlogy, see:
a) Y. Watanabe, Y. Morisaki, T. Kondo, T. Mitsudo, J. Org. Chem.
1996, 61, 4214; b) G. Cami-Kobeci, P. Slatford, M. K. Whittlesey,
J. M. J. Williams, Bioorg. Med. Chem. Lett. 2005, 15, 535; c) M.
Hamid, J. M. J. Williams, Chem. Commun. 2007, 725; d) D. Holl-
mann, A. Tillack, D. Michalik, R. Jackstell, M. Beller, Chem. Asian
J. 2007, 2, 403; e) S. Naskar, M. Bhattacharjee, Tetrahedron Lett.
2007, 48, 3367; f) B. Blank, M. Madalska, R. Kempe, Adv. Synth.
Catal. 2008, 350, 749; g) K. I. Fujita, Y. Enoki, R. Yamaguchi, Tetra-
hedron 2008, 64, 1943; h) R. Yamaguchi, S. Kawagoe, C. Asai, K. I.
Fujita, Org. Lett. 2008, 10, 181; i) G. Lamb, A. Watson, K. Jolley, A.
Maxwell, J. M. J. Williams, Tetrahedron Lett. 2009, 50, 3374; j) K.
3
44, 1037.
4] For reviews, see: a) J. F. Hartwig in Handbook of Organopalladium
Cheistry for Organic Synthesis (Ed.: E. Negishi), Wiley, New York,
2
002; b) L. Jiang, S. L. Buchwald in Metal-Catalyzed Cross-Coupling
Reactions, 2nd ed., Vol. 2, Wiley-VCH, Weinheim, Germany, 2004,
p. 699; c) C. Mauger, G. Mignani, Aldrichimica Acta 2006, 39, 17;
d) M. Willis, Angew. Chem. 2007, 119, 3470; Angew. Chem. Int. Ed.
007, 46, 3402; e) D. Surry, S. Buchwald, Angew. Chem. 2008, 120,
438; Angew. Chem. Int. Ed. 2008, 47, 6338; f) Y. Aubin, C. Fisch-
2
6
meister, C. Thomas, J. Renaud, Chem. Soc. Rev. 2010, 39, 4130.
5] S. Dayagi in The Chemistry of the Carbon-Nitrogen Double Bond,
[
(
Ed.: S. Patai), Interscience, London, 1970, Chap. 2, pp. 61–147. For
Chem. Asian J. 2011, 6, 1142 – 1146
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemasianj.org
1145

G. Deng et al.
COMMUNICATION
Shimizu, M. Nishimura, A. Satsuma, ChemCatChem 2009, 1, 497;
k) R. Martꢄnez, D. Ramꢃn, M. Yus, Org. Biomol. Chem. 2009, 7,
Neubert, A. Tillack, J. M. J. Williams, M. Beller, Chem. Eur. J. 2010,
16, 3590; j) K. Yamaguchi, J. He, T. Oishi, N. Mizuno, Chem. Eur. J.
2010, 16, 7199; k) D. Pingen, C. Muller, D. Vogt, Angew. Chem.
2010, 122, 8307; Angew. Chem. Int. Ed. 2010, 49, 8130; l) X. Cui, Y.
Zhang, F. Shi, Y. Deng, Chem. Eur. J. 2011, 17, 1021; m) M. W. Zhu,
K. Fujita, R. Yamaguchi, Org. Lett. 2010, 12, 1336; n) O. Saidi, A.
Blacker, G. Lamb, S. Marsden, J. Taylor, J. M. J. Williams, Org. Pro-
cess Res. Dev. 2010, 14, 1046; o) X. Cui, F. Shi, Y. Zhang, Y. Deng,
Tetrahedron Lett. 2010, 51, 2048.
2
176; l) B. Blank, S. Michlik, R. Kempe, Adv. Synth. Catal. 2009,
3
51, 2903; m) O. Saidi, A. Blacker, M. Farah, S. Marsden, J. M. J.
Williams, Chem. Commun. 2010, 46, 1541; n) A. Martꢄnez-Asencio,
D. J. Ramꢃn, M. Yus, Tetrahedron Lett. 2010, 51, 325; o) L. He, X.
Lou, J. Ni, Y. Liu, Y. Cao, K. Fan, Chem. Eur. J. 2010, 16, 13965.
14] For other CÀN bond-formation reactions using the borrowing-hy-
[
drogen methodology, see: a) M. Hamid, J. M. J. Williams, Tetrahe-
dron Lett. 2007, 48, 8263; b) C. Gunanathan, D. Milstein, Angew.
Chem. 2008, 120, 8789; Angew. Chem. Int. Ed. 2008, 47, 8661;
c) J. L. He, J. W. Kim, K. Yamaguchi, N. Mizuno, Angew. Chem.
[15] N. Ono in The Nitro Group in Organic Synthesis, Wiley-VCH, New
York, 2001.
[16] For an excellent example of highly selective nitro-hydrogenation,
see: A. Corma, P. Serna, Science 2006, 313, 332.
2
009, 121, 10072; Angew. Chem. Int. Ed. 2009, 48, 9888; d) A. Bꢅhn,
A. Tillack, S. Imm, K. Mevius, D. Michalik, D. Hollmann, L. Neu-
bert, M. Beller, ChemSusChem 2009, 2, 551; e) X. Cui, F. Shi, M.
Tse, D. Gçrdes, K. Thurow, M. Beller, Y. Deng, Adv. Synth. Catal.
[17] C. Feng, Y. Liu, S. M. Peng, Q. Shuai, G. J. Deng, C.-J. Li, Org. Lett.
2010, 12, 4888.
[18] Z. Alessandro, J. A. Mata, E. Peris, Chem. Eur. J. 2010, 16, 10502.
[19] In some cases, chlorobenzene is used as reducing reagent. No reduc-
tion was observed in the absence of alcohol in chlorobenzene under
our reaction conditions.
2
009, 351, 2949; f) F. Shi, A. Tse, X. Cui, D. Gçrdes, D. Michalik, K.
Thurow, Y. Deng, M. Beller, Angew. Chem. 2009, 121, 6026; Angew.
Chem. Int. Ed. 2009, 48, 5912; g) M. Hamid, C. Liana Allen, G.
Lamb, A. Maxwell, H. Maytum, A. Watson, J. M. J. Williams, J. Am.
Chem. Soc. 2009, 131, 1766; h) K. Fujita, A. Komatsubara, R. Yama-
guchi, Tetrahedron 2009, 65, 3624; i) S. Bahn, S. Imm, K. Mevius, L.
Received: December 31, 2010
Published online: March 4, 2011
1146
www.chemasianj.org
ꢀ 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Asian J. 2011, 6, 1142 – 1146