A general route for synthesis of N-aryl phenoxazines via copper(i)-catalyzed N-, N-, and O-arylations of 2-aminophenols

Article abstract of DOI:10.1039/c4ra09593f

A novel copper(i)-catalyzed tandem reaction of N- and O-arylations of 2-[N-(2-chlorophenyl)amino]phenols was developed, by which a series of structurally novel N-aryl phenoxazines were synthesized efficiently. This success owes much to the discovery of hi

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ARTICDLOI:E10.10T39/YC4RPA095E93F
A General Route for Synthesis of N-Aryl Phenoxazines via Copper(I)-
Catalyzed N-, N-, and O-Arylations of 2-Aminophenols
Nan Liu,a Bo Wang,a Wenwen Chen,a Chulong Liu,a Xinyan Wang,*a and Yuefei Hu*a
Received (in XXX, XXX) Xth XXXXXXXXX 20XX, Accepted Xth XXXXXXXXX 20XX
5
DOI: 10.1039/b000000x
A novel copper(I)-catalyzed tandem reaction of N- and O-arylations of 2-[N-(2-chlorophenyl)amino]-
phenols was developed, by which a series of structurally novel N-aryl phenoxazines were synthesized
efficiently. This success owes much to the discovery of highly efficient homogeneous copper(I)-catalyzed
intramolecular O-arylation of chlorobenzenes under ligand-free-like conditions. Since 2-[N-(2-chloro-
10 phenyl)amino]phenols were prepared also by copper(I)-catalyzed N-arylation of 2-aminophenols, thus a
general route for efficient synthesis of N-aryl phenoxazines was established via copper(I)-catalyzed N-,
N-, and O-arylations of 2-aminophenols in two steps.
40 in which the toxic nitrobenzene was used as a solvent for
producing high temperature.4 Thus, it is necessary to develop a
mild method for an efficient preparation of 2 to easily achieve the
molecular diversity.
As shown in Scheme 1, we report herein a novel Cu(I)-
45 catalyzed tandem reaction for N- and O-arylations of 2-[N-(2-
Introduction
The structural unit of phenoxazine (1) has been well recognized
15 as an electron-donor in numerous organic compounds used in the
developments of dye-sensitized solar cells, laser dyes, fluorescent
stains and OLEDs. When its N-atom bears an electron-accepting
group, a donor-acceptor structure is formed to serve as a dipolar
push–pull fluorophore or chromophore. Usually, the aryl groups
20 are employed for such purpose and therefore N-aryl phenoxazine
(2) has been gaining increasing importance.1,2 As shown in Figure
1, an OLED using 2PXZ-OXD as a green emitter was reported
recently to exhibit the highest EQE among TADF-based OLEDs
to date.1a
halophenyl)amino]phenols (5), by which
a series of the
derivatives of 2 were prepared efficiently in one-flask. Since the
precursor 5 was prepared also by Cu(I)-catalyzed N-arylation of
2-aminophenols (4), this work in fact presents a general route for
50 efficient synthesis of 2 by Cu(I)-catalyzed N-, N-, and O-
arylations of 2-aminophenols (4) in two steps.
NH2
i. Cu(I)-catalyzed intermolecular N-arylation
ii. Cu(I)-catalyzed intermolecular N-arylation
iii. Cu(I)-catalyzed intramolecular O-arylation
OH
R
R
N
4
O
O
i, by reference
N
N
Ar
N
Ar
N
O
X
H
N
X
O
N
N
ii
iii
1. R = H, Phenoxazine
2. R = Ar, N-Aryl phenoxazine
2PXZ-OXD
25
OH
5
O
2
OH
6
R
R
R
Figure 1. Structures of phenoxazine and N-aryl phenoxazines.
This work
Cu(I)-catalyzed tandem N- and O-arylations
Investigation showed that the construction of the skeleton of
phenoxazine (1) at laboratory-scale remains a challenging task to
date.3 Only a few protocols were reported for the synthesis of N-
Scheme 1. A general route for efficient synthesis of 2.
30 aryl phenoxazines (2) in literature, such as Pd-,1 Cu-,2,4 or base-
catalyzed5 N-arylations, as well as the photocyclizations of
azides.6 Despite the rapid development of Cu(I)-catalyzed N- and
O-arylations in the past decade,7 none of them dealt specifically
with the synthesis of N-aryl phenoxazines (2). As a result,
35 although there are three C(Ar)–N bonds and two C(Ar)–O bonds in
the molecule of 2, only the C(Ar)–N bond on C10 is usually
constructed by Cu(I)-catalyzed N-arylation2 between phenoxazine
(1) and halobenzenes (3). Even worse, the most often used
procedure for this N-arylation was established as early as in 1957,
Results and Discussion
55 Due to the steric hindrance, Cu(I)-catalyzed N-arylation of
diarylamine is much more difficult than that of monoarylamine.
Thus, the synthesis of triarylamines usually required refluxing the
mixture of the reactants, catalyst and/or ligand in high boiling
solvent (toluene, NMP or DMF) in the presence of a strong base
60 (KOtBu, NaOtBu or LiNH2).8 However, when 2-aminophenols (4)
were used as the substrates, their N-arylations could proceed with
weak bases under ligand-free conditions.9 As shown in Scheme 2,
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RSC Advances
Page 2 of 8
by using different ratios of 2-aminophenol (4a) and iodobenzene
(3a), the desired diarylamine 7 or triarylamine 8 was synthesized
in high yields. It has been confirmed that the compounds 4a and 7
not only were reactants, intermediates, or products, but also
served as ligands. Therefore, the ligand-free conditions for these
N-arylations can be considered as ligand-free-like conditions. So
far, only the derivatives of 8 bearing two identical aryl groups
were prepared by this method.
View Article Online
DOI: 10.1039/C4RA09593F
5
PhI (3a), CuI (0.1 eq.)
NHPh
K3PO4 (2 eq.), dioxane, 110 oC, 24h
Figure 2. The structure of 2a.
4a:3a = 3:1 (by mole), 92%
OH
NH2
OH
7
8
35
To further understand the results in Scheme 4, the pre-made
compounds 6a and 6b were tested as starting materials. As shown
in Scheme 5, both of them carried out Cu(I)-catalyzed O-
arylations smoothly to give 2a in 95% yields. Thus, two
PhI (3a), CuI (0.2 eq.)
Cs2CO3 (3 eq.), DMF, 110 oC, 24 h
4a:3a = 1:3 (by mole), 87%
NPh2
OH
4a
conclusions were drawn: first, the compound
6 was the
PhI (3a)
10 Scheme 2. Ligand-free-like N-arylations of 4a.
PhI (3a)
40 intermediate for the tandem reaction; secondly, the problem that
5a gave the lower yield of 2a in the tandem reaction occurred in
the conversion of 5a into 6a, in which the highly reactive
bromide group may carry out an undesired N-arylation between
two molecules of 5a, besides the desired N-arylation between 5a
45 and 3a.
7
When we repeated the procedure for the synthesis of 8 starting
from 4a, we found that the yield of the intermediate 7 remained
in less than 3% during the entire process. It was clearly revealed
that the conversion of 4a into 7 was the rate-determining step and
15 the conversion of 7 into 8 was a fast process. As shown in
Scheme 3, this hypothesis was proved by using the pre-made 7 as
a substrate to give 8 in 88% yield within 4 h.
X
CuI (0.1 eq.), Cs2CO3 (2 eq.)
DMF, 110 oC, 12 h
N
N
6a, X = Br, 95%
6b, X = Cl, 95%
PhI (3a, 2 eq.), CuI (0.1 eq.)
Cs2CO3 (2 eq.), DMF, 110 oC, 4 h
OH
O
NHPh
OH
NPh2
OH
6
2a
88%
Scheme 5. Cu(I)-catalyzed intramolecular O-arylations of 6a and 6b.
8
7
It was well known that Cu(I)-catalyzed O-arylation of chloro-
benzenes was the most difficult task compared with that of
50 bromo- and iodobenzenes. Only a few successful procedures
were reported in literature, such as by using heterogeneous nano-
catalysts10a-c or large amounts of ligands (0.2-0.8 equiv).10d-e To
the best of our knowledge, the conversion of 6b into 2a is the first
example of highly efficient homogeneous Cu(I)-catalyzed O-
55 arylation of chlorobenzene under the ligand-free-like conditions.
This work is so important because the O-arylation by using
chloroaromatics as arylating reagents to replace bromo- or
iodoaromatics in the synthesis of aryl ethers has been identified to
be one of “dream reactions” by the ACS-GCI Pharmaceutical
60 Roundtable in 2005.11
Scheme 3. A fast conversion of 7 into 8.
20
This result also strongly indicated that the unsymmetric
triphenylamine 2-[N-(2-halophenyl)-N-phenylamino]phenol (6)
may be synthesized easily via Cu(I)-catalyzed N-arylation
between iodobenzene (3a) and 2-[N-(2-halophenyl)amino]phenol
(5). Thus, we may expect that N-phenyl phenoxazine (2a) is
25 synthesized via Cu(I)-catalyzed intramolecular O-arylation of 6.
To our surprise, a novel tandem reaction for N- and O-arylations
of 5 occurred to yield 2a directly instead of the excepted 6 when
the mixture of 3a and 5 was treated with CuI (Scheme 4). As
shown in Figure 2, the structure of 2a was confirmed by single
30 crystal X-ray diffraction analysis.
Therefore, we were encouraged to study the O-arylation of
chlorobenzene further. As shown in Scheme 6, no intermolecular
O-arylation product 9 was obtained at all from the substrate 8 and
65 chlorobenzene under ligand-free-like conditions. Very low yields
of 9 were obtained with the ligands L1-L5 (the most efficient
ligands reported in literature).10d-e,12 In a recent reference, the
synthesis of xanthones by using Cu(I)-catalyzed intramolecular
O-arylation of chlorobenzenes was reported to fail,13 even though
70 the corresponding bromo- and iodobenzenes worked well.
Therefore, we strongly believed that the highly efficient
formation of 2a from 6b may depend on the structural nature of
6b rather than the differences between the intermolecular and
intramolecular O-arylations.
X
PhI (3a, 2 eq.), CuI (0.2 eq.), Cs2CO3
H
N
N
(3 eq.), DMF, 110 oC, 12 h
5a, X = Br, 55%
5b, X = Cl, 86%
O
OH
5
2a
Intermolecular
N-arylation
Intramolecular
O-arylation
X
N
OH
6
Scheme 4. The tandem reaction for N- and O-arylations of 5.
2
| Journal Name, [year], [vol], 00–00
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RSC Advances
Ph
N
PhCl (2 eq.), CuI (0.1 eq.)
Cs2CO3 (2 eq.), DMF, 110 oC, 12 h
and 0.05 equiv, respectively, in n-butylnitrile (entry 3). But, all
NPh2
OPh
other solvents gave relatively lower yields of 2a (entries 6-13).
View Article Online
25 Although CuI, CuCl, and CuCN (entrieDs O3I,: 1104.10a3n9d/C41R5A)09g5a9v3eF
Ligand-free, 0%
With ligand L1-L5 (0.1 eq.), 0-13%
OH
comparable yields of 2a, we preferred to choose CuI for its
chemical stability and easy performance.
8
9
But
But
OH
O
N
EtO
HO
Then, the effects of reaction time and bases were tested. As
shown in Table 2, the yield of 2a was increased by increasing the
30 reaction time (entries 1-3). Both Cs2CO3 (entry 1) and K3PO4
(entry 4) were suitable bases for this reaction, but all others were
inactive (entries 5-8). Finally, the entry 3 was assigned as our
standard conditions.
O
O
O
O
O
N.HCl
OH OH
L4[11b]
L1[10d]
L2[10e]
L3[11a]
L5[11c]
Scheme 6. Cu(I)-catalyzed intermolecular O-arylations of 8 and PhCl.
Table 2. Effects of reaction time and basesa
As shown in Scheme 7, when 5b was treated with CuI in the
absence of PhI (3a), it was recovered in 93% yield without any
intramolecular O-arylated product phenoxazine (1). Thus, we
hypothesized that the Cu(I)-catalyzed O-arylations of 5b, 6b and
8 may be mainly controlled by the electronic effect rather than by
the steric effect. Those phenomena may arise from the fact that
5b, 6b and 8 are also redox-active ligands, which may have
PhI (3a, 1.1 eq.), CuI (0.05 eq.)
5
Base (3 eq.), n-PrCN, 115 oC, time
5b
2a
0-98%
35
Entry
Time (h)
Base
Cs2CO3
Cs2CO3
Cs2CO3
K3PO4
K2CO3
Na2CO3
NEt3
2a (%)b
1
2
3
4
5
6
7
8
6
67
96
98
94
45
0
10 different abilities to store and release electrons during the
catalytic reactions,14 but how remains unknown.
12
24
12
12
12
12
12
Cl
CuI (0.1 eq.), Cs2CO3
H
N
H
N
(2 eq.), DMF, 110 oC, 12 h
0
0
X
pyridine
O
OH
aThe mixture of 5b (1 mmol), 3a, CuI and a base in n-PrCN (2 mL) in a
5b
1
Schlenk tube was heated under N2. bIsolated yields were obtained.
Scheme 7. Cu(I)-catalyzed intramolecular O-arylations of 5b.
To generalize this novel method, the substrate scope was tested.
Next, the reaction solvents and copper-resources were screened
15 by using the conversion of 5b into 2a as a model reaction. As
shown in Table 1, the best result was still obtained when the
amounts of PhI (3a) and CuI were reduced as low as 1.1 equiv
40 As shown in Scheme 8, all desired products 2a-2x were obtained
in good to excellent yields and some of them (2a, 2d, 2e, and 2i)
were obtained in almost quantitative yields. However, the
iodobenzenes substituted by -Br, -NO2 and -CN could not give
the satisfactory yields of products (2j-2l and 2q-2r) under the
45 standard conditions. It may be caused by the fact that 4-bromo-
iodobenzene has two reaction sites and both of them could carry
out the Cu(I)-catalyzed N-arylations. The -NO2 or –CN
substituted iodobenzenes may have high reactivity to carry out
both Cu(I)-catalyzed N- and O-arylations simultaneously with the
50 substrates. But, these problems could be solved easily by heating
Table 1. Effects of the copper resources on the cycloadditiona
PhI (3a, 1.1 eq.), [Cu]
Cs2CO3 (3 eq.), solvent, 115 oC, 12 h
5b
2a
0-96%
Entry
1
2
3
4
[Cu]-resource (eq.)
Solvent
n-PrCN
n-PrCN
n-PrCN
n-PrCN
n-PrCN
DMF
2a (%)b
96
96
96
90
6
86
o
CuI (0.2)
CuI (0.1)
CuI (0.05)
CuI (0.04)
CuI (0.00)
the reaction mixture at 65 C for the first 6 h to finish the N-
o
arylation and then at 115 C for another 18 h to finish the O-
arylation. Unfortunately, dissatisfactory yields of 2a (34%), 2d
(23%), and 2q (70%) were obtained when bromobenzene, 2-
55 bromo-toluene, and 2-bromo-nitrobenzene were used as the N-
arylating reagents.
5
6
CuI (0.05)
7
CuI (0.05)
PhMe
83
8
9
CuI (0.05)
CuI (0.05)
CuI (0.05)
CuI (0.05)
CuI (0.05)
CuI (0.05)
1,4-dioxane
(CH2OH)2
(CH2Cl)2
MeCN
THF
MeOH
n-PrCN
n-PrCN
n-PrCN
n-PrCN
n-PrCN
n-PrCN
n-PrCN
52
49
20
12
10
trace
95
92
82
75
73
63
31
10
11
12
13
14
15
16
17
18
19
20
Conclusions
A novel Cu(I)-catalyzed tandem reaction for N- and O-arylations
60 of 2-[N-(2-chlorophenyl)amino]phenols was developed, by which
a series of N-phenyl phenoxazines were prepared efficiently in
“one-pot”. This work not only provides a general route for
efficient synthesis of N-phenyl phenoxazines from the
commercially available 2-aminophenols in two steps, but also
65 presents an interesting example to construct the complicated
molecules entirely by Cu(I)-catalyzed arylations from the simple
starting materials.
CuCl (0.05)
CuCN (0.05)
Cu(OAc)2.H2O (0.05)
Cu2O (0.05)
CuBr (0.05)
Cu(CO2)2.4H2O (0.05)
CuF2.H2O (0.05)
20 aThe mixture of 5b (1 mmol), 3a, [Cu] and Cs2CO3 in solvent (2 mL) in a
Schlenk tube was heated under N2. bIsolated yields were obtained.
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 3

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Page 4 of 8
Ar
N
Cl
The suspension of 2-[N-(2-chlorophenyl)amino]phenol (5b, 220
H
N
ArI (3, 1.1 eq.), CuI (0.05 eq.), Cs2CO3
(3 eq.), n-PrCN, 115 oC, 24 h
62-98%
20 mg, 1 mmol), CuI (9.5 mg, 0.05 mmol) and Cs2CO3 (977 mg, 3
View Article Online
mmol) in n-PrCN (2 mL) in a Schlenk tubeDwOaI:s1d0e.1g0a3s9s/eCd4.RTA0h9e5n93F
O
OH
R
R
iodobenzene (3a, 224 mg, 1.1 mmol) was added by a syringe.
2a-x
5b-e
o
After the resultant mixture was stirred at 115 C for 24 h under
Me
N2, the solid was filtered off. Then the solvent was evaporated on
Me
25
a rotavapor and the residue was purified by a column
Me
chromatography [silica gel, 1% EtOAc in petroleum ether (60–90
oC)] to give 255 mg (98%) of 2a as white crystals, mp 140–141
oC (lit.4 138–139 oC); 1H NMR 7.60-7.56 (m, 2H), 7.48-7.44 (m,
1H), 7.33 (d, J = 5.8, 2H), 6.68-6.55 (m, 6H), 5.89 (d, J = 5.8, 2H)
N
N
N
O
N
O
O
O
2a (98%)a
2b (92%)
2c (95%)
2d (98%)
OMe
OH
F
30 ppm; 13C NMR 143.9 (2C), 138.9, 134.4, 131.0 (2C), 130.8
(2C), 128.4 (2C), 123.2 (2C), 121.2 (2C), 115.4 (2C), 113.2 (2C)
OH
N
N
N
N
ppm.
The similar procedure was used for the preparation of products
O
O
O
O
2e (98%)
2f (74%)
2g (70%)
2h (91%)
2b-2x.
Cl
Br
NO2
CN
35
10-(2-Methylphenyl)-phenoxazine (2b). White solid, mp 171–
173 C; IR 1633, 1485, 1334, 1269 cm-1; H NMR (DMSO-d6)
7.56-7.53 (m, 1H), 7.48-7.46 (m, 2H), 7.34-7.31 (m, 1H), 6.75-
6.62 (m, 6H), 5.71-5.68 (m, 2H), 2.14 (s, 3H) ppm; 13C NMR
40 (DMSO-d6) 143.9 (2C), 138.9, 136.8, 133.4, 132.2 (2C), 131.0,
128.9 (2C), 128.6 (2C), 123.4 (2C), 121.1, 115.4, 112.6 (2C),
17.6 ppm; HRMS (ESI-TOF) (m/z): Calcd for C19H15NO, [M]+
273.1148; found 273.1150.
o
1
N
N
O
N
O
N
O
O
2i (97%)
2j (81%)b
2k (91%)b
2l (86%)b
Me
OMe
Cl
Me
N
Me
N
Me
N
Me
N
O
O
O
O
2m (92%)
2n (90%)
2o (93%)
2p (90%)
45
10-(3-Methylphenyl)-phenoxazine (2c). White solid, mp 123–
125 C; IR1636, 1485, 1335, 1269 cm-1; H NMR (DMSO-d6)
7.58-7.52 (m, 1H), 7.35 (d, J = 7.5, 1H), 7.21-7.17 (m, 2H),
6.74-6.63 (m, 6H), 5.86-5.83 (m, 2H), 2.39 (s, 3H) ppm; 13C
NMR (DMSO-d6) 143.9 (2C), 141.2, 138.8, 134.4 (2C), 131.1,
o
1
NO2
CN
Me
Me
Me
Me
N
Me
N
N
Cl
N
O
O
O
O
50 130.7, 129.2, 127.6, 123.1 (2C), 121.1 (2C), 115.3 (2C), 113.2
(2C), 21.3 ppm; HRMS (ESI-TOF) (m/z): Calcd for C19H15NO,
[M]+ 273.1148; found 273.1145.
2r (62%)b
2s (81%)
2t (89%)
2q (86%)b
N
S
N
N
N
N
N
N
10-(4-Methylphenyl)-phenoxazine (2d). White solid, mp 124–
55 126 oC; IR2606, 1644, 1484, 1332, 1266 cm-1; 1H NMR
(DMSO-d6) 7.44 (d, J = 7.9, 2H), 7.24 (d, J = 7.9, 2H), 6.71-
6.58 (m, 6H), 5.83-5.80 (m, 2H), 2.39 (s, 3H) ppm; 13C NMR
(DMSO-d6) 143.1 (2C), 138.3, 135.6, 134.1 (2C), 131.9 (2C),
130.1 (2C), 123.7 (2C), 121.4 (2C), 115.2 (2C), 113.1 (2C), 20.8
60 ppm; HRMS (ESI-TOF) (m/z): Calcd for C19H15NO, [M]+
273.1148; found 273.1148.
O
O
O
O
2u (89%)c
2v (86%)c
2w (88%)
2x (83%)c
a Isolated yields were obtained for all products.
b The reaction proceeded at 65 oC for 6 h firstly and then at 115 oC for another 18 h.
c 0.1 Equiv of CuI was used.
Scheme 8. Substrate Scope of the Tandem Reaction
Experimental
5
General information
10-(4-Methoxyphenyl)-phenoxazine (2e). White solid, mp 170–
171 oC; IR3062, 1590, 1486, 1335, 1243 cm-1; 1H NMR
All melting points were determined on a Yanaco melting point
apparatus and were uncorrected. IR spectra were recorded as KBr 65 (DMSO-d6) 7.30 (d, J = 8.6, 2H), 7.18 (d, J = 8.9, 2H), 6.72-
6.61 (m, 6H), 5.86-5.82 (m, 2H), 3.83 (s, 3H) ppm; 13C NMR
(DMSO-d6) 159.0, 143.1 (2C), 134.3 (2C), 131.5 (2C), 130.5,
123.7 (2C), 121.2 (2C), 116.5 (2C), 115.2 (2C), 113.1 (2C), 55.4
ppm; HRMS (ESI-TOF) (m/z): Calcd for C19H15NO2, [M]+
1
pellets on a Nicolet FT-IR 5DX spectrometer. All spectra of H
NMR (300 MHz) and 13C NMR (75 MHz) were recorded on a
10 JEOL JNM-ECA 300 spectrometer in CDCl3 (otherwise as
indicated). TMS was used as an internal reference and J values
are given in Hz. HRMS were obtained on a Bruker microTOF-Q 70 289.1097; found 289.1093.
II spectrometer. The substituted 2-[N-(2-chlorophenyl)amino]-
phenols 5b (R = H), 5c (R = 4-Me), 5d (R = 3-Me) and 5e (R = 4-
15 Cl) were prepared by the reported procedure9b (See Supporting
Information).
10-(2-Hydroxyphenyl)-phenoxazine (2f). White solid, mp 152–
153 oC; IR3446, 1590, 1488, 1327, 1272 cm-1; 1H NMR
(DMSO-d6) 9.79 (s, 1H), 7.33-7.27 (m, 1H), 7.18 (d, J = 7.9,
75 1H), 7.06 (d, J = 8.3, 1H), 6.99-6.93 (m, 1H), 6.68-6.54 (m, 6H),
A Typical Procedure for the Preparation of 10-Phenyl-
phenoxazine (2a).
o
5.79-5.74 (m, 2H) ppm; 13C NMR (DMSO-d6, 125 MHz, 70 C)
4
| Journal Name, [year], [vol], 00–00
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RSC Advances
155.8, 144.0 (2C), 134.2 (2C), 132.1, 130.6, 124.7, 124.0 (2C),
(DMSO-d6) 7.71-7.39 (m, 5H), 6.71-6.46 (m, 5H), 5.82-5.80 (m,
121.5 (2C), 121.3, 118.5. 115.5 (2C), 113.4 (2C) ppm; HRMS 60 1H), 5.65 (s, 1H), 1.96 (s, 3H) ppm; 13C NMR (DMSO-d6)
View Article Online
(ESI-TOF) (m/z): Calcd for C18H13NO2, [M]+ 275.0941; found
275.0945.
144.0, 141.7, 139.0, 134.4, 133.9, 132.6,D1O31I:.100(.120C39),/C143R0A.809(259C3)F,
128.4, 123.0, 121.3, 121.1, 115.3, 115.0, 113.9, 113.2, 20.8 ppm;
HRMS (ESI-TOF) (m/z): Calcd for C19H15NO, [M]+ 273.1148;
found 273.1147.
5
10-(4-Hydroxyphenyl)-phenoxazine (2g). White solid, mp 181–
183 oC; IR3459, 1631, 1484, 1332, 1265 cm-1; 1H NMR
(DMSO-d6) 9.85 (s, 0.94H), 7.18 (d, J = 8.6, 2H), 7.02 (d, J =
65
2-Methyl-10-(4-methylphenyl)-phenoxazine (2n). White solid,
8.6, 2H), 6.73-6.62 (m, 6H), 5.92-5.88 (m, 2H) ppm; 13C NMR
mp 71–73 oC; IR1629, 1585, 1488, 1331, 1266 cm-1; H NMR
1
o
10 (DMSO-d6, 125 MHz, 70 C) 158.0, 143.9 (2C), 135.1 (2C),
(DMSO-d6) 7.47 (d, J = 7.9, 2H), 7.26 (d, J = 8.6, 2H), 6.72-
6.60 (m, 4H), 6.46 (d, J = 7.9, 1H), 5.83-5.80 (m, 1H), 5.66 (s,
131.8 (2C), 129.8, 124.1 (2C), 121.6 (2C), 118.3 (2C), 115.6 (2C),
113.7 (2C) ppm; HRMS (ESI-TOF) (m/z): Calcd for C18H13NO2, 70 1H), 2.42 (s, 3H), 1.96 (s, 3H) ppm; 13C NMR (DMSO-d6)
[M]+ 275.0941; found 275.0940.
144.0, 141.7, 138.3, 136.2, 134.5, 134.0, 132.6, 131.6 (2C),
130.4, 122.9 (2C), 121.2, 121.0, 115.2, 115.0, 113.9, 113.2, 21.2,
20.8 ppm; HRMS (ESI-TOF) (m/z): Calcd for C20H17NO, [M]+
287.1305; found 287.1312.
15
10-(4-Fluorophenyl)-phenoxazine (2h). White solid, mp 118–
o
1
120 C; IR1631, 1484, 1324, 1266 cm-1; H NMR (DMSO-d6)
7.51-7.39 (m, 4H), 6.73-6.59 (m, 6H), 5.83-5.78 (m, 2H) ppm;
13C NMR (DMSO-d6) 162.1 (d, J = 246.7), 143.9 (2C), 134.8,
134.3 (2C), 132.7 (d, J = 8.6, 2C), 123.2 (2C), 121.4 (2C), 118.1
75
2-Methyl-10-(4-methoxyphenyl)-phenoxazine (2o). White solid,
mp 102–103 oC; IR1604, 1505, 1488, 1331, 1245 cm-1; 1H
NMR (DMSO-d6) 7.26 (d, J = 8.6, 2H), 7.15 (d, J = 8.9, 2H),
6.65-6.55 (m, 4H), 6.41 (d, J = 7.9, 1H), 5.80-5.77 (m, 1H), 5.63
20 (d, J = 22.2, 2C), 115.5 (2C), 113.1 (2C) ppm; HRMS (ESI-TOF)
(m/z): Calcd for C18H12FNO, [M]+ 277.0897; found 277.0894.
80 (s, 1H), 3.81 (s, 3H), 1.93 (s, 3H) ppm; 13C NMR (DMSO-d6)
159.3, 144.1, 141.8, 134.7, 134.3, 132.7, 131.8 (2C), 131.4,
123.0, 121.2, 121.0, 116.2 (2C), 115.2, 115.0, 113.9, 113.2, 55.5,
20.8 ppm; HRMS (ESI-TOF) (m/z): Calcd for C20H17NO2, [M]+
303.1254; found 303.1245.
10-(4-Chlorophenyl)-phenoxazine (2i). White solid, mp 178–
180 C; IR1628, 1485, 1335, 1274 cm-1; H NMR (DMSO-d6)
25 7.71 (d, J = 8.6, 2H), 7.45 (d, J = 8.6, 2H), 6.74-6.61 (m, 6H),
5.86-5.83 (m, 2H) ppm; 13C NMR (DMSO-d6) 143.1 (2C),
137.3, 133.6 (2C), 133.3, 132.6 (2C), 131.5 (2C), 123.8 (2C),
121.7 (2C), 115.4 (2C), 113.2 (2C) ppm; HRMS (ESI-TOF) (m/z):
Calcd for C18H12ClNO, [M]+ 293.0602; found 293.0601.
30
o
1
85
2-Methyl-10-(4-chlorophenyl)-phenoxazine (2p). White solid,
o
mp 106–108 C; IR 1628, 1488, 1331, 1272 cm-1; 1H NMR
7.57 (d, J = 8.6, 2H), 7.28 (d, J = 8.6, 1H), 6.70-6.43 (m, 6H),
10-(4-Bromophenyl)-phenoxazine (2j). White solid, mp 184–
5.88 (d, J = 7.9, 1H), 5.70 (s, 1H), 2.02 (s, 3H) ppm; 13C NMR
185 C (lit.[4] 200–202 C); IR3031, 1629, 1484, 1332, 1266 90 144.0, 141.7, 137.6, 134.2, 134.0, 133.6, 132.8, 132.4 (2C),
o
o
cm-1; H NMR (DMSO-d6) 7.84 (d, J = 8.3, 2H), 7.54 (d, J =
8.6, 2H), 6.75-6.62 (m, 6H), 5.87-5.84 (m, 2H) ppm; 13C NMR
35 (DMSO-d6) 143.1 (2C), 137.7, 134.5 (2C), 133.6 (2C), 133.0
(2C), 123.8 (2C), 121.9, 121.7 (2C), 115.4 (2C), 113.2 (2C) ppm;
HRMS (ESI-TOF) (m/z): Calcd for C18H12BrNO, [M]+ 337.0097;
found 337.0093.
131.4 (2C), 132.0, 121.7, 121.5, 115.5, 115.2, 113.9, 113.2, 20.8
ppm; HRMS (ESI-TOF) (m/z): Calcd for C19H14ClNO, [M]+
307.0758; found 307.0756.
1
95
2-Methyl-10-(4-nitrophenyl)-phenoxazine (2q). Red solid, mp
184–185 C; IR 1641, 1514, 1493, 1343, 1328, 1276 cm-1; H
NMR (DMSO-d6) 8.43 (d, J = 8.9, 2H), 7.69 (d, J = 8.9, 2H),
6.78-6.63 (m. 4H), 6.53 (d, J = 7.9, 1H), 5.97 (d, J = 7.6, 1H),
5.81 (s, 1H) , 1.96 (s, 3H) ppm; 13C NMR (DMSO-d6) 146.9,
o
1
40
10-(4-Nitrophenyl)-phenoxazine (2k). Red solid, mp 191-193
oC; IR1636, 1520, 1487, 1337, 1271 cm-1; 1H NMR (DMSO-d6)
8.47 (d, J = 9.0, 2H), 7.74 (d, J = 8.9, 2H), 6.83-6.69 (m, 6H), 100 145.8, 144.4, 142.1, 133.1, 133.0, 132.6, 131.3 (2C), 126.4 (2C),
6.02 (d, J = 4.9, 2H) ppm; 13C NMR (DMSO-d6) 146.8, 145.0,
143.6 (2C), 132.9 (2C), 131.5 (2C), 126.6 (2C), 123.8 (2C), 122.4
123.1, 122.7, 122.4, 116.0, 115.7, 114.4, 113.8, 20.8 ppm; HRMS
(ESI-TOF) (m/z): Calcd for C19H14N2O3, [M]+ 318.0999; found
318.0998.
45 (2C), 115.7 (2C), 114.0 (2C) ppm; HRMS (ESI-TOF) (m/z):
Calcd for C18H12N2O3, [M]+ 304.0842; found 304.0845.
105
2-Methyl-10-(4-Cyanophenyl)-phenoxazine (2r). Yellowish
o
10-(4-Cyanophenyl)-phenoxazine (2l). Yellowish solid, mp
solid, mp 132–133 C; IR 2221, 1637, 1491, 1331, 1268 cm-1;
158–159 C; IR2226, 1633, 1596, 1488, 1333, 1273 cm-1; H
50 NMR (DMSO-d6) 8.14 (d, J = 8.6, 2H), 7.67 (d, J = 8.2, 2H),
6.79-6.68 (m, 6H), 5.92 (d, J = 7.6, 2H) ppm; 13C NMR (DMSO-
1H NMR (DMSO-d6) 8.09 (d, J = 8.2, 2H), 7.62 (d, J = 8.2, 2H),
6.73-6.60 (m, 4H), 6.48 (d, J = 7.9, 1H), 5.85 (d, J = 7.2, 1H),
5.69 (s, 1H), 1.94 (s, 3H) ppm; 13C NMR (DMSO-d6) 144.2,
o
1
d6) 143.3 (2C), 143.1, 135.5 (2C), 133.0 (2C), 131.7 (2C), 110 143.8, 141.8, 134.9 (2C), 131.2, 132.9, 132.8, 131.8 (2C), 123.1,
123.8 (2C), 122.1 (2C), 118.3, 115.6 (2C), 113.5 (2C), 111.4 ppm;
HRMS (ESI-TOF) (m/z): Calcd for C19H12N2O, [M]+ 284.0944;
55 found 284.0940.
122.4, 122.2, 118.1, 115.8, 115.6, 114.1, 113.4, 112.1, 20.8 ppm;
HRMS (ESI-TOF) (m/z): Calcd for C20H14N2O, [M]+ 298.1101;
found 298.1100.
2-Methyl-10-phenyl-10H-phenoxazine (2m). White solid, mp 115 1-Methyl-10-(4-methylphenyl)-phenoxazine (2s). White solid,
1
92–94 oC; IR1628, 1588, 1487, 1329, 1266 cm-1; 1H NMR
mp 82–84 oC; IR 1649, 1504, 1470, 1314, 1274 cm-1; H NMR
This journal is © The Royal Society of Chemistry [year]
Journal Name, [year], [vol], 00–00 | 5

RSC Advances
Page 6 of 8
products 2a-2x and CIF file for the single crystal X-ray diffraction
analysis of 2a]. See DOI: 10.1039/b000000x/
(DMSO-d6) 7.26-7.11 (m, 5H), 7.00-6.81 (m, 6H), 2.23 (s, 3H),
1.78 (s, 3H) ppm; 13C NMR (DMSO-d6) 151.2, 150.1, 146.8,
135.9, 134.4, 132.9, 132.2, 129.8 (2C), 126.2, 125.3 (2C), 124.5,
124.4, 123.3, 122.4, 116.4, 114.2, 20.8, 18.8 ppm; HRMS (ESI-
TOF) (m/z): Calcd for C20H17NO, [M]+ 287.1305; found
287.1307.
View Article Online
DOI: 10.1039/C4RA09593F
60 1 (a) J. Lee, K. Shizu, H. Tanaka, H. Nomura, T. Yasuda and C.
Adachi, J. Mater. Chem. C, 2013, 1, 4599–4604; (b) R. Menzel, S.
Kupfer, R. Mede, D. Weiß, H. Görls, H. González and R. Becker,
Eur. J. Org. Chem. 2012, 5231–5247; (c) H. Tanaka, K. Shizu, H.
Miyazaki and C. Adachi, Chem. Commun. 2012, 48, 11392–11394;
5
65
70
75
80
(d) Y. Park, B. Kim, C. Lee, A. Hyun, S. Jang, J.-H. Lee, Y.-S. Gal,
T. H. Kim, K.-S. Kim and J. Park, J. Phys. Chem. C 2011, 115,
4843–4850; (e) K. Ono, M. Joho, K. Saito, M. Tomura, Y.
Matsushita, S. Naka, H. Okada and H. Onnagawa, Eur. J. Inorg.
Chem. 2006, 3676–3683; (f) G.-S. Jiao, A. Loudet, H. B. Lee, S.
Kalinin, L. B.-A. Johansson and K. Burgessa, Tetrahedron 2003, 59,
3109–3116.
(a) J. Sun, H. Jiang, J. Zhang, Y. Tao and R. Chen, New J. Chem.
2013, 37, 977–985; (b) K. M. Karlsson, X. Jiang, S. K. Eriksson, E.
Gabrielsson, H. Rensmo, A. Hagfeldt, and L. Sun, Chem. Eur. J.
2011, 17, 6415–6424; (c) K. Kim, S. Jeong, C. Kim, E. Kim, E.
Kwon, H. Kim, B.-D. Choi and Y. S. Han, Synth. Met. 2010, 160,
549–555; (d) Y. Zhu, A. P. Kulkarni, P.-T. Wu and S. A. Jenekhe,
Chem. Mater. 2008, 20, 4200–4211; (e) Y. Zhu, A. P. Kulkarni and
S. A. Jenekhe, Chem. Mater. 2005, 17, 5225–5227; (f) A. Higuchi
and Y. Shirota, Mol. Cryst. Liq. Cryst. 1994, 242, 127–133.
(a) I. Thome and C. Bolm, Org. Lett. 2012, 14, 1892–1895, and the
references cited therein; (b) P. Thansandote, E. Chong, K.-O.
Feldmann and M. Lautens, J. Org. Chem. 2010, 75, 3495–3498.
H. Gilman and L. Moore, J. Am. Chem. Soc. 1957, 79, 3485–3487.
2-Chloro-10-(4-methylphenyl)-phenoxazine (2t). White solid,
o
mp 105–107 C; IR 2923, 1629, 1485, 1330, 1265 cm-1; 1H
10 NMR (DMSO-d6) 7.47 (d, J = 7.9, 2H), 7.29 (d, J = 8.2, 2H),
6.74-6.61 (m, 5H), 5.84-5.81 (m, 1H), 5.70 (d, J = 2.1, 1H), 2.40
(s, 3H) ppm; 13C NMR (DMSO-d6) 143.7, 142.6, 138.8, 135.6,
135.4, 133.7, 131.9 (2C), 130.1 (2C), 128.0, 123.4, 121.6, 120.4,
116.0, 115.3, 113.5, 113.2, 21.2 ppm; HRMS (ESI-TOF) (m/z):
15 Calcd for C19H14ClNO, [M]+ 307.0758; found 307.0762.
2
10-(2-Pyridyl)-phenoxazine (2u). White solid, mp 103–104 oC;
1
IR 3061, 1587, 1489, 1329, 1274, 1043 cm-1; H NMR 8.69-
8.67 (m, 1H), 7.88-7.82 (m, 1H), 7.38-7.26 (m, 2H), 6.81-6.68 (m,
20 6H), 6.43-6.40 (m, 2H) ppm; 13C NMR 153.7, 150.5, 145.4
(2C), 139.3, 132.8 (2C), 123.2 (2C), 122.6 (2C), 122.2, 122.1,
115.9 (2C), 115.6 (2C) ppm; HRMS (ESI-TOF) (m/z): Calcd for
C17H12N2O, [M+H]+ 261.1022; found 261.1020.
3
4
85 5 A. Mori, S. Kinoshita, M. Furusyo and K. Kamikawa, Chem.
Commun. 2010, 46, 6846–6848.
o
25
10-(3-Pyridyl)-phenoxazine (2v). White solid, mp 147–149 C;
1
6
(a) L. S. Klimenko, I. A. Oskina, V. M. Vlasov, I. Y. Bagryanskaya
and Y. V. Gatilov, Russ. Chem. Bull., Int. Ed. 2007, 56, 1130–1134;
(b) L. S. Klimenko, S. Z. Kusov, V. M. Vlasov, E. N. Tchabueva
and V. V. Boldyrev, Mendeleev Commun. 2006, 16, 224–225.
For selected reviews, see: (a) J. Keilitz, H. A. Malik and M. Lautens,
Top. Heterocycl. Chem. 2013, 32, 187–224; (b) T. R. M. Rauws and
B. U. W. Maes, Chem. Soc. Rev. 2012, 41, 2463–2497; (c) C.
Fischer, B. Koenig, Beilstein J. Org. Chem. 2011, 7, 59–74; (d) E.
Sperotto, G. P. M. van Klink, G. van Koten and G. J. de Vries,
Dalton Trans. 2010, 39, 10338–10351; (e) F. Monnier and M.
Taillefer, Angew. Chem., Int. Ed. 2009, 48, 6954–6971; (f) G.
Evano, N. Blanchard and M. Toumi, Chem. Rev. 2008, 108, 3054–
3131. (g) S. V. Ley and A. W. Thomas, Angew. Chem., Int. Ed.
2003, 42, 5400–5449.
IR  3050, 1588, 1485, 1329, 1270, 1021 cm-1; H NMR 8.74
(d, J = 4.1, 1H), 8.64 (s, 1H), 7.76-7.72 (m, 1H), 7.57-7.53 (m,
1H), 6.76-6.58 (m, 6H), 5.87 (d, J = 7.6, 2H) ppm; 13C NMR
152.8, 149.5, 143.9 (2C), 139.0, 135.7, 133.8 (2C), 125.4, 123.3
90
95
7
30 (2C), 121.9 (2C), 115.7 (2C), 113.1 (2C) ppm; HRMS (ESI-TOF)
(m/z): Calcd for C17H12N2O, [M+H]+ 261.1022; found 261.1025.
10-(4-Pyridyl)-phenoxazine (2w). White solid, mp 118–120 oC;
IR  3061, 1578, 1489, 1332, 1274 cm-1; 1H NMR 8.79 (d, J =
35 4.8, 2H), 7.32 (d, J = 6.2, 2H), 6.81-6.68 (m, 6H), 6.19 (d, J = 7.6,
2H) ppm; 13C NMR (2C), 147.9, 145.1 (2C), 132.5 (2C),
123.5 (2C), 123.3 (2C), 122.8 (2C), 116.1 (2C), 114.8 (2C) ppm;
HRMS (ESI-TOF) (m/z): Calcd for C17H12N2O, [M+H]+
261.1022; found 261.1021.
100
105
110
8
For selected references, see: (a) A. Tlili, F. Monnier and M. Taillefer,
Chem. Commun. 2012, 48, 6408–6410; (b) C.-K. Tseng, C.-R. Lee,
C.-C. Han and S.-G. Shyu, Chem. Eur. J. 2011, 17, 2716–2723; (c)
H. Xu and C. Wolf, Chem. Commun. 2009, 1715–1717. (d) N. S.
Nandurkar, M. J. Bhanushali, M. D. Bhor and B. M. Bhanage,
Tetrahedron Lett. 2007, 48, 6573–6576; (e) Y.-H. Liu, C. Chen and
L.-M. Yang, Tetrahedron Lett. 2006, 47, 9275–9278; (f) A. S.
Gajare, K. Toyota, M. Yoshifuji and F. Ozawab, Chem. Commun.
2004, 1994–1995; (g) N. M. Patil, A. A. Kelkar, Z. Nabi and R. V.
Chaudhari, Chem. Commun. 2003, 2460–2461; (h) A. A. Kelkar, A.
M. Patil and R. V. Chaudhari, Tetrahedron Lett. 2002, 43, 7143–
7146; (i) R. K. Gujadhur, D. Venkataraman and J. T. Kintigh,
Tetrahedron Lett. 2001, 42, 4791–4793; (j) R. K. Gujadhur, C. G.
Bates and D. Venkataraman, Org. Lett. 2001, 3, 4315–4317.
40
10-(3-Thienyl)-phenoxazine (2x). White solid, mp 123–125 oC;
IR  3095, 1531, 1481, 1321, 1268 cm-1; H NMR 7.56-7.54
1
(m, 1H), 7.35-7.34 (m, 1H), 7.02 (d, J = 4.8, 1H) 6.70-6.60 (m,
6H), 6.07-6.04 (m, 2H) ppm; 13C NMR  (2C), 136.8,
45 134.0 (2C), 127.7, 127.2, 124.7, 123.3 (2C), 121.5 (2C), 115.4
(2C), 113.3 (2C) ppm; HRMS (ESI-TOF) (m/z): Calcd for
C17H12N2O, [M]+ 265.0561; found 265.0557.
115 9 (a) Y. Li, H. Wang, L. Jiang, F. Sun, X. Fu and C. Duan, Eur. J. Org.
Chem. 2010, 6967–6973; (b) D. Maiti and S. L. Buchwald, J. Am.
Chem. Soc. 2009, 131, 17423–17429; (c) H. F. Wang, Y. M. Li, F. F.
Sun, Y. Feng, K. Jin and X. N. Wang, J. Org. Chem. 2008, 73,
8639–8642.
Acknowledgements
This work was supported by the National Natural Scientific
50 Foundation of China (No. 21372142, 21472107 and 21072112).
120 10 (a) R. Arundhathi, D. Damodara, R. R. Likhar, M. L. Kantam, P.
Saravanan, T. Magdaleno and S. H. Kwon, Adv. Synth. Catal. 2011,
353, 1591–1600. (b) B. Sreedhar, R. Arundhathi, P. L. Reddy and M.
L. Kantam, J. Org. Chem. 2009, 74, 7951–7954; (c) J. Y. Kim, J. C.
Park, A. Kim, A. Y. Kim, H. J. Lee, H. Song and K. H. Park, Eur. J.
Notes and references
a Department of Chemistry, Tsinghua University, Beijing 100084, P. R.
China. Fax: +86-10-62771149; Tel: +86-10-62795380; E-mail:
yfh@mail.tsinghua.edu.cn and wangxinyan@mail.tsinghua.edu.cn.
125
Inorg. Chem. 2009, 4219–4223; (d) Q. Zhang, D. Wang, X. Wang
and K. Ding, J. Org. Chem. 2009, 74, 7187–7190; (e) N. Xia and M.
Taillefer, Chem. Eur. J. 2008, 14, 6037–6039.
55 † Electronic
Supplementary
Information
(ESI)
available:
[Characterizations of compounds 5b-e, 1H and 13C NMR spectra for
6
| Journal Name, [year], [vol], 00–00
This journal is © The Royal Society of Chemistry [year]

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RSC Advances
11 D. J. C. Constable, P. J. Dunn, J. D. Hayler, G. R. Humphrey, H. L.
Leazer, R. J. Linderman, Jr., K. Lorenz, J. Manley, B. A. Pearlman,
A.; Wells, A. Zaks and T. Y. Zhang, Green Chem. 2007, 9, 411–420.
12 (a) X. Lv and W. Bao, J. Org. Chem. 2007, 72, 3863–3867. (b). Y.-J.
Chen and H.-H. Chen, Org. Lett. 2006, 8, 5609–5612. (c) D. Ma and
Q. Cai, Org. Lett. 2003, 5, 3799–3802.
View Article Online
DOI: 10.1039/C4RA09593F
5
13 N. Barbero, R. SanMartin and E. Dominguez, Green Chem. 2009, 11,
830–836.
14 (a) V. Lyaskovskyy and B. de Bruin, ACS Catal. 2012, 2, 270−279.
(b) W. I. Dzik, J. I. van der Vlugt, J. N. H. Reek and B. de Bruin,
Angew. Chem., Int. Ed. 2011, 50, 3356–3358, and the references
therein.
10
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View Article Online
DOI: 10.1039/C4RA09593F
Graphical Abstract
A General Route for Synthesis of N-Aryl Phenoxazines via
Copper(I)-Catalyzed N-, N-, and O-Arylations of 2-Aminophenols
Nan Liu,a Bo Wang,a Wenwen Chen,a Chulong Liu,a Xinyan Wang,*a and Yuefei Hu*a
Cu-catalyzed
intermolecular N-arylation
Cu-catalyzed
intermolecular N-arylation
Cu-catalyzed
intramolecular O-arylation
Cl
2-Cl-PhI, CuI, K3PO4
1,4-dioxane, 110 oC, 24 h
PhI, CuI, Cs2CO3
n-PrCN, 115 oC, 24 h
H
N
NH2
N
O
98%
92%
OH
OH
24 samples in 62-98%
Cu-catalyzed tandem N- and O-arylations
A novel copper(I)-catalyzed tandem reaction of N- and O-arylations was developed
and a general route for synthesis of N-aryl phenoxazines via copper-catalyzed N-, N-,
and O-arylations of 2-aminophenols was established.