Copper-catalyzed direct oxidation and N-arylation of benzylamines with diaryliodonium salts

Article abstract of DOI:10.1007/s11426-014-5140-9

An efficient approach for the synthesis of N-arylated amides was developed via copper(II) triflate-catalyzed direct oxidation of (aryl)methylamines to primary arylamides by air and subsequent N-arylation by diaryliodonium salts. Various substituted benzylamines could be applied in the reaction, providing a series of N-arylated amides in moderate to good yields. This method showed convenient, practical, and environment friendly advantages.

Full text of DOI:10.1007/s11426-014-5140-9

SCIENCE CHINA
Chemistry
August 2014 Vol.57 No.8: 1–6
doi: 10.1007/s11426-014-5140-9
• ARTICLES •
· SPECIAL ISSUE · In Honor of the 80th Birthday of Professor QIAN Changtao
doi: 10.1007/s11426-014-5140-9
Copper-catalyzed direct oxidation and N-arylation of
benzylamines with diaryliodonium salts
LIU Xin, MAO Dan, WU ShengYing, YU JianJun, HONG Gang,
ZHAO Qiao & WANG LiMin*
Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology,
Shanghai 200237, China
Received March 3, 2014; accepted March 21, 2014
An efficient approach for the synthesis of N-arylated amides was developed via copper(II) triflate-catalyzed direct oxidation of
(aryl)methylamines to primary arylamides by air and subsequent N-arylation by diaryliodonium salts. Various substituted ben-
zylamines could be applied in the reaction, providing a series of N-arylated amides in moderate to good yields. This method
showed convenient, practical, and environment friendly advantages.
copper(II) triflate, diaryliodonium salts, N-arylated amides, oxidation
Kaneda et al. [9d] reported the successful Ru oxidants-
1 Introduction
catalyzed oxygenation of primary amines to primary amides,
respectively. Fu et al. [10] demonstrated the copper-catalyzed
aerobic oxidative synthesis of primary amides from (ar-
yl)methylamines. Zhong et al. [11] reported the successful
Cu-catalyzed oxygenation of primary amines to N-arylated
amides with the aid of O2. Xiang et al. [12] developed a
copper-catalyzed amination of aryl halides with nitriles.
Recently, diaryliodonium salts have been widely used as a
supplement for aryl halides, especially used as electrophilic
arylating agents in various reactions, such as nucleophilic
substitution reactions with nitrogen nucleophiles, carbon nu-
cleophiles, and others, as well as Cu- and Pd-catalyzed cou-
pling reactions, and trapping reactions (in which they are
used as benzyne precursors) [13–16]. Our group [17] have
also been interested in the use of diaryliodonium salts in or-
ganic synthesis. However, the application of diaryliodonium
salts for the synthesis of N-arylated amides has not been re-
ported yet. Herein, we report the synthesis of N-arylated am-
ides through the Cu(OTf)2-catalyzed oxidation and arylation
reaction of benzylamines with diaryliodonium salts, which is
efficient, convenient, practical, and environmentally friendly.
N-arylamides are important compounds, which are widely
employed in the fields of pharmaceutical chemistry and ma-
terials science [1]. Therefore, the synthesis of N-arylamides is
one of the most exciting topics in practical organic synthesis,
and several strategies for their synthesis have been developed
[1–4]. Traditionally, one of the most common methods for
the synthesis of N-arylamides is Goldberg reaction (cop-
per-catalyzed N-arylation of amides) [2]. However, it is usu-
ally carried out under harsh conditions, which limits its broad
application in organic synthesis. In recent decades, the ligand
assisted metal-catalyzed amidation of aryl halides has arou-
sed great interest among organic chemists as a practical and
efficient method for the construction of C–N bonds [3, 4].
The use of this strategy in Goldberg reaction greatly simpli-
fies the synthesis of N-arylamides [5]. For example, the Cu-
or Pd-catalyzed N-arylations of amides have been demon-
strated by Buchwald et al. [6], Hartwig et al. [7] and Ma et al.
[8], respectively. Tang et al. [9a], Mizuno et al. [9b, 9c] and
*Corresponding author (email: wanglimin@ecust.edu.cn)
© Science China Press and Springer-Verlag Berlin Heidelberg 2014
chem.scichina.com link.springer.com

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Liu X, et al. Sci China Chem August (2014) Vol.57 No.8
Next, diphenyliodonium salts (2a), bearing different
2 Experimental
counter anions (Table 2, entries 1, 2) were studied. Among
all the tested reagents, diphenyliodonium triflate furnished
the desired product 3a in best yield (91%, Table 2, entry 4),
whereas tetrafluoroborate, bromide only gave the by-prod-
uct N-benzylidene-1-phenylmethylamine (Table 2, entries 1,
2). Then, a series of ligands, including 1,10-phenanthroline
(L1), L-proline (L2), ethylenediamine (L3), 2,2′-dipyridyl
(L4) and N,N′-dimethylethylenediamine (DMEDA, L5)
were evaluated for the reaction (Table 2, entries 4–8). It was
observed that the ligands significantly affected the yields
and 1,10-phenanthroline (L1) gave the best result. Then,
K2CO3 was replaced by different bases, such as Cs2CO3,
K3PO4, KOH, Et3N and so on. The results indicated that
K2CO3 was the best base for this reaction (Table 2, entries
9–16). Without K2CO3, N-phenylbenz- amide (3a) was not
detected (Table 2, entry 17). Finally, we investigated the
influence of catalyst-ligand ratio and two substrates’ ratio.
We find that the reaction gave best results when
Cu(OTf)2/1,10-phenanthroline = 10%:20% and benzyla-
mine/diphenyliodonium salts = 0.6:0.2 (mmol/mmol). The
details are shown in the Supporting Information online.
With the optimal reaction conditions in hand, the elec-
tronic and steric effects of substituted benzylamines and
diaryliodonium salts were investigated (Table 3). Initially, a
set of benzylamine derivatives (1a–i) were examined by
reacting with diphenyliodonium triflate (2a) (Table 3, en-
tries 1–9). The result showed that the reaction was sensitive
to the electronic effects on the aromatic ring of the benzyl-
amines. For example, benzylamines bearing electron-with-
drawing groups, such as Cl, F, 3,4-F,F and CF3 (Table 3,
entries 2–4, 9) showed slightly higher reactivity than those
with electron-donating groups, like methyl and methoxy
moieties (Table 3, entries 7, 8). When the substrate scope was
2.1 Materials and methods
All reagents were used as received from commercial
sources, unless otherwise specified, or prepared as de-
scribed in the literature. All reagents were weighed and
handled in air. DMF and DMSO were distilled under re-
duced pressure from CaH2. Toluene and 1,4-dioxane were
distilled from sodium and benzophenone immediately be-
fore use.
1H NMR and 13C NMR spectra were respectively rec-
orded at 400 and 100 MHz, using tetramethylsilane as an
internal reference. Chemical shifts () and coupling con-
stants (J) were expressed in parts per million and hertz, re-
spectively.
2.2 General procedure for the Cu(OTf)2-catalyzed di-
rect oxidation and N-arylation of benzylamines with
diaryliodonium salts
Diaryliodonium salt (0.20 mmol), Cu(OTf)2 (10 mol%),
K2CO3 (2.5 equiv.), 1,10-phenanthroline (20 mol%), ben-
zylamine (0.60 mmol) and DMSO (2 mL) were added to a
Schlenck tube with a magnetic stir bar in the air atmosphere.
Then the Schlenck tube was sealed and stirred in an oil bath
(150 °C) for 24 h. After the reaction was complete, the reac-
tion mixture was cooled to room temperature, diluted with
CH2Cl2, and washed with brine. The combined organic ex-
tracts were dried over Na2SO4, concentrated under vacuum,
and the resulting residue was purified by silica gel column
chromatography to afford the desired product. The charac-
terizations of compounds 3ao were listed in the Supporting
Information online.
Table 1 Optimization of the reaction conditions a)
3 Results and discussion
Initially, benzylamine (1a) and diphenyliodonium triflate
(2a) were chosen as the model substrates to optimize the
reaction conditions in terms of catalysts, bases, solvents,
and reaction temperatures under air (Table 1). To our de-
light, while using 10 mol% CuI as the catalyst, 2.5 equiv.
K2CO3 as base and DMSO as solvent at 120 °C for 24 h,
N-phenylbenzamide (3a) was obtained in 20% yield (Table
1, entry 1). When the temperature was increased to 140 or
150 °C, the desired arylated product 3a was observed in
43% and 73% yields (Table 1, entries 1–3). Other copper
catalysts were tried (Table 1, entries 4–9), and Cu(OTf)2
showed the best activity (Table 1, entry 9). The by-product
N-benzylidene-1-phenyl-methylamine was mainly generat-
ed when DMF or 1,4-dioxane was used as solvent (Table 1,
entries 10–12). When the reaction was carried in excessive
neat 1a, the desired arylated product 3a was isolated in 61%
yield (Table 1, entry 13).
T (°C)
Entry
[Cu] (mol%)
CuI (10)
CuI (10)
CuI (10)
CuBr (10)
Solvent
Yield b) (%)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
DMSO
120
140
150
150
150
150
150
150
150
150
150
150
150
150
20
43
73
44
40
29
25
65
91
CuCl (10)
Cu(OAc)2·H2O(10)
CuCl2·2H2O (10)
CuSO4 (10)
Cu(OTf)2 (10)
Cu(OTf)2 (10)
Cu(OTf)2 (10)
Cu(OTf)2 (10)
Cu(OTf)2 (10)

DMF
trace
32
toluene
1,4-dioxane
benzylamine
DMSO
n.d.c)
61
0
a) Reaction conditions: 1a (0.60 mmol), 2a (0.20 mmol), Cu salts (10
mol%), K2CO3 (2.5 equiv.), 1,10-phenanthroline (20 mol%), DMSO (2
mL), 24 h; b) isolated yields; c) no detection.

Liu X, et al. Sci China Chem January (2014) Vol.57 No.1
3
Table 2 Optimization of Cu-catalyzed N-arylation of benzylamine (1a)
and diphenyliodonium triflate (2a) a)
extended to 3- or 2-fluorobenzylamine, the corresponding
products were obtained in lower yields (Table 3, entries 5, 6).
Subsequently, various substituted diaryliodonium salts
were employed in this reaction. As shown in Table 3, dia-
ryliodonium salts with halogen substituents gave higher
yields than their mesityl equivalents (Table 3, entries
10–16). However, it is worth mentioning that the unsym-
metrical salt 2h selectively transferred the phenyl group to
the benzylamine in moderate yield (Table 3, entry 16).
A possible catalytic mechanism for this transformation is
illustrated in Scheme 1. Initially, copper-catalyzed aerobic
oxidation of benzylamine (1) provides the corresponding
imine (I), which reacts with H2O to give II. Further oxida-
tion of II affords primary arylamide B [18], which is ex-
posed to the copper catalyst A to generate the metallic in-
termediate C. Diaryliodonium salt 2 undergoes an oxidative
addition to intermediate C to form the metallic intermediate
D, which then produces the final product 3 through a reduc-
tive elimination reaction and releases the catalyst A to com-
plete the catalytic cycle.
Yield b) (%)
X
Entry
Ligand
L1
L1

Base
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
Cs2CO3
K3PO4
KOH
Ag2CO3
Et3N
t-BuOK
Na2CO3
NaHCO3

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
BF4
Br
trace
n.d.
40
91
55
12
75
83
48
78
15
n.d.
10
45
25
10
n.d.
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
OTf
L1
L2
L3
L4
L5
L1
L1
L1
L1
L1
L1
L1
L1
L1
4 Conclusions
In summary, we have developed a new, simple and practical
copper-catalyzed domino method for the synthesis of N-
arylamides using diaryliodonium salts as the electrophilic
coupling partners. The protocol uses cheap and readily
available Cu(OTf)2 as the catalyst, (aryl)methylamines as
a) Reaction conditions: 1a (0.60 mmol), 2a (0.20 mmol), Cu(OTf)2 (10
mol%), base (2.5 equiv.), ligand (20 mol%) , DMSO (2 mL), 150 °C, 24 h;
b) isolated yields.
Table 3 Copper-catalyzed amination of different benzylamine with diaryliodonium salts a)
Entry
1
2
3
4
5
6
7
8
R1
H
Cl
F
F
H
R2
H
H
H
F
R3
H
H
H
H
F
H
H
H
H
H
H
H
H
H
H
H
Ar1
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ar2
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Product
3a
3b
3c
3d
3e
3f
3g
3h
3i
3j
3k
3l
Yield b) (%)
91
80
85
93
60
75
70
72
89
84
81
86
70
67
45
70
H
F
H
CH3
OCH3
CF3
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
H
9
Ph
Ph
10
11
12
13
14
15
16
4-BrC6H4
4-ClC6H4
4-FC6H4
4-OCH3C6H4
4-CH3C6H4
mesityl
phenylethynyl
4-BrC6H4
4-ClC6H4
4-FC6H4
4-OCH3C6H4
4-CH3C6H4
mesityl
Ph
3m
3n
3o
3a
a) Reaction conditions: 1 (0.60 mmol), 2 (0.20 mmol), Cu(OTf)2 (10 mol%), K2CO3 (2.5 equiv.), 1,10-phenanthroline (20 mol%), DMSO (2 mL), air,
150 °C , 24 h; b) isolated yields.

4
Liu X, et al. Sci China Chem August (2014) Vol.57 No.8
Scheme 1 Proposed catalytic mechanism for this transformation.
2002, 43: 1101–1104
the starting materials, and economical and environmentally
friendly air as the oxidant. The corresponding N-arylamides
were afforded in moderate to good yields. The overall pro-
cess is easy to handle without the need of an inert atmos-
phere. Efforts to explore the detailed mechanism are un-
derway in our laboratory.
3
4
a) Jiang YW, Ma DW. Copper-catalyzed ligand promoted
Ullmann-type coupling reactions. In: Bullock RM, Ed. Catalysis
without Precious Metals. Weinheim: Wiley Blackwell, 2010; b)
Wang Y, Zeng J, Cui X. Recent progress in copper-catalyzed C–N
coupling reactions. Chin J Org Chem, 2010, 30: 181–199 (in Chi-
nese)
a) Guram AS, Buchwald SL. Palladium-catalyzed aromatic amina-
tions with in situ generated aminostannanes. J. Am Chem Soc, 1994,
116: 7901–7902; b) Paul F, Patt J, Hartwig JF. Palladium-catalyzed
formation of carbon-nitrogen bonds. Reaction intermediates and cat-
alyst improvements in the hetero cross-coupling of aryl halides and
tin amides. J Am Chem Soc, 1994, 116: 5969–5970; c) Lindley J.
Copper assisted nucleophilic substitution of aryl halogen. Tetrahe-
dron, 1984, 40: 1433–1456; d) Yin J, Buchwald SL. Palladium-
catalyzed intermolecular coupling of aryl halides and amides. Org
Lett, 2000, 2: 1101–1104; e) Yin J, Buchwald SL. Pd-catalyzed in-
termolecular amidation of aryl halides: the discovery that xantphos
can be trans-chelating in a palladium complex. J Am Chem Soc, 2002,
124: 6043–6048
a) Klapars A, Antilla JC, Huang X, Buchwald SL. A general and ef-
ficient copper catalyst for the amidation of aryl halides and the
N-arylation of nitrogen heterocycles. J Am Chem Soc, 2001, 123:
7727–7729; b) Klapars A, Huang X, Buchwald SL. A general and
efficient copper catalyst for the amidation of aryl halides. J Am Chem
Soc, 2002, 124: 7421–7428; c) Crawford KR, Padwa A. Copper-
catalyzed amidations of bromo substituted furans and thiophenes.
Tetrahedron Lett, 2002, 43: 7365–7368; d) Mallesham B, Rajesh BM,
Reddy PR, Srinivas D, Trehan S. Highly efficient CuI-catalyzed
coupling of aryl bromides with oxazolidinones using buchwald’s
protocol: a short route to linezolid and toloxatone. Org Lett, 2003, 5:
963–965; e) Deng W, Wang YF, Zou Y, Liu L, Guo QX. Amino
acid-mediated Goldberg reactions between amides and iodides.
Tetrahedron Lett, 2004, 45: 2311–2315; f) Hosseinzadeh R,
Tajbakhsh M, Mohadjerani M, Mehdinejad H. Copper-catalyzed
amidation of aryl iodides using KF/Al2O3: an improved protocol.
Synlett, 2004: 1517–1520; g) Strieter ER, Blackmond DG, Buchwald
SL. The role of chelating diamine ligands in the Goldberg reaction: a
kinetic study on the copper-catalyzed amidation of aryl iodides. J Am
Chem Soc, 2005, 127: 4120–4121; h) Zheng N, Buchwald SL.
Copper-catalyzed regiospecific synthesis of N-alkylbenzimidazoles.
Org Lett, 2007, 9: 4749–4751; i) Altman RA, Hyde AM, Huang X,
This work was financially supported by the National Nature Science
Foundation of China (21272069, 20672035) and the Fundamental Re-
search Funds for the Central Universities and Key Laboratory of Or-
ganofluorine Chemistry, Shanghai Institute of Organic Chemistry, Chinese
Academy of Sciences.
1
a) Valeur E, Bradley M. Amide bond formation: beyond the myth of
coupling reagents. Chem Soc Rev, 2009, 38: 606–631; b) Allen CL,
Williams JMJ. Amide bond formation: beyond the myth of coupling
reagents. Metal-catalysed approaches to amide bond formation. Chem
Soc Rev, 2011, 40: 3405–3415; c) Zhang DW, Zhao X, Hou JL, Li
ZT. Aromatic amide foldamers: structures, properties, and functions.
Chem Rev, 2012, 112: 5271–5316; d) Garcia-Alvarez R, Crochet P,
Cadierno V. Metal-catalyzed amide bond forming reactions in an
environmentally friendly aqueous medium: nitrile hydrations and
beyond. Green Chem, 2013, 15: 46–66; e) Alécio AC, Bolzani VS,
Young MCM, Kato MJ, Furlan M. Antifungal amide from leaves of
piper hispidum. J Nat Prod, 1998, 61: 637–639; f) Onnis V, Cocco
MT, Fadda R, Congiu C. Synthesis and evaluation of anticancer ac-
tivity of 2-arylamino-6-trifluoromethyl-3-(hydrazonoca-rbonyl) pyri-
dines. Bioorgan Med Chem, 2009, 17: 6158–6165
5
2
a) Goldberg I. Ueber phenylirungen bei gegenwart von kupfer als
katalysator. Ber Dtsch Chem Ges, 1906, 39: 1691–1692; b) Freeman
HS, Butler JR, Freedman LD. Acetyldiarylamines by arylation of ac-
etanilides. Some applications and limitations. J Org Chem, 1978, 43:
4975–4977; c) Ito A, Saito T, Tanaka K, Yamabe T. Synthesis of oligo
(m-aniline). Tetrahedron Lett, 1995, 36: 8809–8812; d) Sugahara M,
Ukita T.
A
facile copper-catalyzed Ullmann condensation:
N-arylation of heterocyclic compounds containing an NHCO
moiety. Chem Pharm Bull, 1997, 45: 719–721; e) Lange JHM,
Hofmeyer LJF, Hout FAS, Osnabrug SJM, Verveer PC, Kruse CG,
Feenstra RW. Monopositive chlorocarbonium ions. Tetrahedron Lett,

Liu X, et al. Sci China Chem January (2014) Vol.57 No.1
5
Buchwald SL. Orthogonal Pd- and Cu-based catalyst systems for the
C- and N-arylation of oxindoles. J Am Chem Soc, 2008, 130:
9613–9620; j) Monnier F, Taillefer M. Catalytic C–C, C–N, and C–O
ullmann-type coupling reactions: copper makes a difference. Angew
Chem Int Ed, 2008, 47: 3096–3099; k) Strieter ER, Bhayana B,
Buchwald SL. Mechanistic studies on the copper-catalyzed N-
arylation of amides. J Am Chem Soc, 2009, 131: 78–88; l) Wang C,
Liu L, Wang W, Ma DS, Zhang H. Copper-catalyzed N-arylation of
amides using (S)-N-methylpyrrolidine-2-carboxylate as the ligand.
Molecules, 2010, 15: 1154–1160; m) Wang M, Yu H, You X, Wu J,
Shang Z. A general and efficient CuBr2-catalyzed N-arylation of
secondary acyclic amides. Chin J Chem, 2012, 30: 2356–2362
a) Fors BP, Dooleweerdt K, Zeng Q, Buchwald SL. An efficient sys-
tem for the Pd-catalyzed cross-coupling of amides and aryl chlorides.
Tetrahedron, 2009, 65: 6576–6583; b) Su MJ, Buchwald SL. A bulky
biaryl phosphine ligand allows for palladium-catalyzed amidation of
five-membered heterocycles as electrophiles. Angew Chem Int Ed,
2012, 51: 4710–4713; c) Ikawa T, Barder TE, Biscoe MR, Buchwald
SL. Pd-catalyzed amidations of aryl chlorides using monodentate
biaryl phosphine ligands: a kinetic, computational, and synthetic
14 a) Kalyani D, Deprez NR, Desai LV, Sanford MS. Oxidative C−H
activation/C−C bond forming reactions: synthetic scope and mecha-
nistic insights. J Am Chem Soc, 2005, 127: 7330–7331; b) Deprez NR,
Kalyani D, Krause A, Sanford MS. Room temperature palladium-
catalyzed 2-arylation of indoles. J Am Chem Soc, 2006, 128:
4972–4973; c) Phipps RJ, Grimster NP, Gaunt MJ. Cu(II)-catalyzed
direct and site-selective arylation of indoles under mild conditions. J
Am Chem Soc, 2008, 130: 8172–8174; d) Deprez NR, Sanford MS.
Synthetic and mechanistic studies of Pd-catalyzed C−H arylation
with diaryliodonium salts: evidence for a bimetallic high oxidation
state Pd intermediate. J Am Chem Soc, 2009, 131: 11234–11241; e)
Phipps RJ, Gaunt MJ. A meta-selective copper-catalyzed C–H bond
arylation. Science, 2009, 323: 1593–1597; f) Xiao B, Fu Y, Xu J,
Gong JJ, Dai JY, Liu L. Pd(II)-catalyzed C−H activation/aryl-aryl
coupling of phenol esters. J Am Chem Soc, 2010, 132: 468–469; g)
Ciana CL, Phipps RJ, Brandt JR, Meyer FM, Gaunt MJ. A highly
para-selective copper(II)-catalyzed direct arylation of aniline and
phenol derivatives. Angew Chem Int Ed, 2011, 50: 458–462; h)
Duong HA, Gilligan RE, Cooke ML, Phipps RJ, Gaunt MJ. Cop-
per(II)-catalyzed meta-selective direct arylation of -aryl carbonyl
compounds. Angew Chem Int Ed, 2011, 50: 463–466; i) Vaddula B,
Leazer J, Varma RS. Copper-catalyzed ultrasound-expedited N-
arylation of sulfoximines using diaryliodonium salts. Adv Synth Catal,
2012, 354: 986–990; j) Xu J, Zhang PB, Gao YZ, Chen YY, Tang G.
Zhao YF. Copper-catalyzed P-arylation via direct coupling of dia-
ryliodonium salts with phosphorus nucleophiles at room temperature.
J Org Chem, 2013, 78: 8176–8183; k) Lv TY, Wang Z, You JS, Lan
JB, Gao G. Copper-catalyzed direct aryl quaternization of N-substi-
tuted imidazoles to form imidazolium salts. J Org Chem, 2013, 78:
5723–5730; l) Sinai Á, Mészáros Á, Gáti T, Kudar V, Palló A, Novák
Z. Copper-catalyzed oxidative ring closure and carboarylation of
2-ethynylanilides. Org Lett, 2013, 15: 5654–5657; m) Cullen SC,
Shekhar S, Nere NK. Cu-catalyzed couplings of aryl iodonium salts
with sodium trifluoromethanesulfinate. J Org Chem, 2013, 78:
12194–12201; n) Wang Y, Chen C, Peng J, Li M. Copper(II)-
catalyzed three-component cascade annulation of diaryliodoniums,
nitriles, and alkynes: a regioselective synthesis of multiply substitut-
ed quinolines. Angew Chem Int Ed, 2013, 52: 5323–5327; o) Su X,
Chen C, Wang Y, Chen JJ, Lou ZB, Li M. One-pot synthesis of
quinazoline derivatives via [2+2+2] cascade annulation of diarylio-
donium salts and two nitriles. Chem Commun, 2013, 49: 6752–6754
15 Kang SK, Lee HW, Choi WK, Choi WK, Hong RK, Kim JS. Palla-
dium-catalyzed synthesis of arylamines from diphenyliodonium tet-
rafluoroborate and secondary amine. Synth Commun, 1996, 26:
4219–4224
6
investigation.
J Am Chem Soc, 2007, 129: 13001–13007; d)
Dooleweerdt K, Fors BP, Buchwald SL. Pd-catalyzed cross-coupling
reactions of amides and aryl mesylates. Org Lett, 2010, 12: 2350–
2353
Shen QL, Hartwig JF. Lewis acid acceleration of C−N bond-forming
reductive elimination from heteroarylpalladium complexes and
catalytic amidation of heteroaryl bromides. J Am Chem Soc, 2007,
129: 7734–7735
Xu LT, Jiang YW, Ma DW. Synthesis of 3-substituted and
2,3-disubstituted quinazolinones via Cu-catalyzed aryl amidation.
Org Lett, 2012, 14: 1150–1153
a) Tang R, Diamond SE, Neary N, Mares F. Homogeneous catalytic
oxidation of amines and secondary alcohols by molecular oxygen. J
Chem Soc, Chem Commun, 1978: 562–562; b) Kim JW, Yamaguchi
K, Mizuno N. Heterogeneously catalyzed efficient oxygenation of
primary amines to amides by a supported ruthenium hydroxide
catalyst. Angew Chem Int Ed, 2008, 47: 9249–9251; c) Wang Y,
Kobayashi H, Yamaguchi K, Mizuno N. Manganese oxide-catalyzed
transformation of primary amines to primary amides through the
sequence of oxidative dehydrogenation and successive hydration.
Chem Commun, 2012, 48: 2642–2644; d) Mori K, Yamaguchi K,
Mizugaki T, Ebitani K, Kaneda K. Catalysis of a hydroxyapatite-
bound Ru complex: efficient heterogeneous oxidation of primary
amines to nitriles in thepresence of molecular oxygen. Chem
Commun, 2001: 461–462
7
8
9
10 Xu W, Jiang YY, Fu H. Copper-catalyzed aerobic oxidative synthesis
of primary amides from (aryl)methanamines. Synlett, 2012, 23:
801–804
11 Xu M, Zhang XH, Shao YL, Han JS, Zhong P. The synthesis of
N-arylated amides via copper(II) triflate-catalyzed direct oxygenation
and N-arylation of benzylamines with aryl iodides. Adv Synth Catal,
2012, 354: 2665–2670
12 Xiang SK, Zhang DX, Hu H, Shi JL, Liao LG, Feng C, Wang BQ,
Zhao KQ, Hu P, Yang H, Yu WH. Synthesis of N-arylamides by
copper-catalyzed amination of aryl halides with nitriles. Adv Synth
Catal, 2013, 355: 1495–1499
16 Kang SK, Lee SH, Lee D. Copper-catalyzed N-arylation of amines
with hypervalent iodonium salts. Synlett, 2000, 2000: 1022–1024
17 a) Guo FL; Wang LM, Wang PQ, Yu JJ, Han JW. transition-metal-
free N-arylation of carbazoles and C-arylation of tetrahydrocarba-
zoles by using diaryliodonium salts. Asian J Org Chem, 2012, 1:
218–221; b) Guo FL, Han JW, Mao S, Li J, Geng X, Yu JJ, Wang
LM. Direct C-arylation of polyfluoroarenes with diaryliodonium salts
via Pd(OAc)2-catalysis. RSC Adv, 2013, 3: 6267–6270; c) Mao S,
Guo F, Li J, Geng X, Yu JJ, Han JW, Wang LM. Copper-catalyzed
direct N-arylation of naphthalimides using diaryliodonium salts. Syn-
lett, 2013, 24: 1959–1962
13 a) Zhdankin VV, Stang PJ. Recent developments in the chemistry of
polyvalent iodine compounds. Chem Rev, 2002, 102: 2523–2584; b)
Zhdankin VV, Stang PJ. Chemistry of polyvalent iodine. Chem Rev,
2008, 108: 5299–5358; c) Merritt EA, Olofsson B. Diaryliodonium
salts: a journey from obscurity to fame. Angew Chem Int Ed, 2009,
48: 9052–9070
18 a) Xu W, Jiang YY, Fu H. Copper-catalyzed aerobic oxidative syn-
thesis of primary amides from (aryl)methanamines. Synlett, 2012, 23:
801–804; b) Wang Y, Kobayashi H, Yamaguchi K, Mizuno N. Man-
ganese oxide-catalyzed transformation of primary amines to primary
amides through the sequence of oxidative dehydrogenation and suc-
cessive hydration. Chem Commun, 2012, 48: 2642–2644

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Liu X, et al. Sci China Chem August (2014) Vol.57 No.8
LIU Xin received his BSc degree from East China University of Science and Technology in 2011.
Subsequently, he joined Professor Limin Wang’s group in the same university. His research focuses
on the transition metal catalyzed cascade reaction.
MAO Dan received her BSc degree from East China University of Science and Technology in 2010.
She is currently pursuing her PhD in Fine Chemicals in the same university under the supervision of
Professor Limin Wang. Her research interests focus on organic reactions catalyzed by rare earth
metals.
WANG LiMin is Professor at East China University of Science and Technology. He received his
PhD in Applied Chemistry from Dalian University of Technology in 1998 under the supervision of
Professor Zuwang Wu, and carried out a postdoctoral research at SIOC under the supervision of
Professor Changtao Qian. He was a visiting scientist under Professor David B. Collum at Cornell
University, NY, from 2009 to 2010. His main scientific interests include chemistry of rare earth
metals, synthetic methodology and fine chemicals.