Synthesis of Polyfunctional Pyridines via Copper-Catalyzed Oxidative Coupling Reactions

Article abstract of DOI:10.1021/acs.joc.6b02081

An efficient and concise approach for the synthesis of polysubstituted pyridines has been achieved through copper-catalyzed oxidative sp³ C-H coupling of oxime acetates with toluene derivatives. Besides, benzylamine and p-toluenesulfonylhydrazo

Full text of DOI:10.1021/acs.joc.6b02081

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Article
Synthesis of Polyfunctional Pyridines via
Copper-Catalyzed Oxidative Coupling Reactions
Yajie Fu, Panpan Wang, Xin Guo, Ping Wu, Xu Meng, and Baohua Chen
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.6b02081 • Publication Date (Web): 04 Nov 2016
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Synthesis of Polyfunctional Pyridines via Copper-Catalyzed
Oxidative Coupling Reactions
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Yajie Fua, Panpan Wanga, Xin Guoa, Ping Wua, Xu Mengb and Baohua Chena,*
a State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Gansu, and Key
Laboratory of Nonferrous
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Metal Chemistry and Resources Utilization of Gansu Province, Lanzhou 730000, People’s Republic
of China
Fax: (+86)ꢀ931ꢀ891ꢀ2582; eꢀmail: chbh@lzu.edu.cn
b State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou Research Institute of LICP,
Lanzhou Institute of Chemical Physics (LICP), Chinese Academy of Sciences, Lanzhou 730000
Abstract: An efficient and concise approach for the synthesis of
polysubstituted pyridines has been achieved through copperꢀcatalyzed
oxidative sp3 C−H coupling of oxime acetates with toluene derivatives.
Besides, benzylamine and pꢀtoluenesulfonylhydrazone were also
introduced to react with oxime acetates to enrich the diversity of this
synthetic method. These transformations provide highly flexible and
facile preparation of substituded pyridines and thus are useful in practical
synthesis.
Introduction
Functionalized pyridines have been well recognized as privileged
Nꢀheterocycles, which are found in a broad array of natural products,
medicines, and functional materials.1 In particular, they play an important
role in organic synthesis as building blocks and find use in catalysis and
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coordination chemistry.2 Thus, much effort has been devoted to efficient
syntheses of pyridine derivatives using a variety of protocols.3 Despite
efficiency and importance in chemical synthesis, many existing
transformations can sometimes face the limitation of relatively
harsh reaction conditions or the utilization of the costly starting materials.
Therefore, the development of a more concise and straightforward
procedure for acquisition of pyridine derivatives from easily available
starting materials is still highly desirable.
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Ketoximes and derivatives are meritorious synthetic building blocks4
as highly effective candidates for the Beckmann rearrangement and
Semmler−Wolff reaction.5 Oxime derivatives have emmerged as versatile
building blocks, especially for the synthesis of pyridines, thus, transition
metalꢀcatalyzed coupling reactions using oximes and their derivatives as
substrates in pyridine synthesis have gained increased attention.6
Synthetic transformations of oximes via metalꢀmediated N−O bond
cleavage have been pioneered by Narasaka.7 Later, the group of Zhu8 and
Hartwig9 have reported Pdꢀcatalyzed cyclization of ketoxime
carboxylates. Besides, Guan’s group achieved the Cuꢀcatalyzed
condensation of ketoxime acetates and aldehydes for the synthesis of
pyridines in 2011. Very recently, Feꢀcatalyzed cyclization of ketoxime
carboxylates and N,Nꢀdialkylanilines for the synthesis of polysubstituted
pyridines has also been developed by Guan’s group (scheme 1, eq 1).10
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Here we present a useful synthetic method for preparation of
polysubstituted pyridines through copperꢀcatalyzed oxidative sp3 C−H
coupling of oxime acetates with toluene derivatives. Moreover,
benzylamine and pꢀtoluenesulfonylhydrazone were also employed to
react with oxime acetates to enrich the diversity of synthetic methods for
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the synthesis of substituted pyridines (scheme 1, eq 2).
Scheme 1. Synthetic approaches to pyridines from oximes
Results and Discussion Sections
We initially investigated our reaction by employing acetophenone
oxime acetate 1a and toluene 2a as model substrates in the presence of
o
Cu(OTf)2 catalyst in toluene (2.0 mL) at 100 C for 8 h under air
atmosphere. Encouragingly, the reaction provided the product
2,4,6ꢀtriphenylpyridine 3aa in 23% yield (Table 1, entry 1). Subsequently,
various oxidants were tested to optimize the reation conditions.
Compared with O2, TBHP, MnO2, and DTBP, PhI(OAc)2 proved to be
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the optimal oxidants, affording the desired product 3aa in 76% yield
(Table 1, entries 2ꢀ6 ). Screening of other common metal catalysts, such
as CuBr, Cu(OAc)2, CuI, and FeCl3 showed that Cu(OTf)2 was the best
choice (Table1, entries 8ꢀ11). Further investigation of reaction solvents
revealed that toluene gave the best yield, while other solvents including
Dioxane, DMSO and PhCl offered lower results (Table 1, entries 12ꢀ14).
It is worth mentioning that the yield of 3aa was increased to 72% when
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temperature raised to 120 C under the condition of PhCl as solvent
(Table 1, entry 15). Besides, lower yields of desired product were
observed when the temperature was changed (Table 1, entries 16ꢀ17).
When trying to vary the amount of PhI(OAc)2, we discovered that the
reaction with two equivalents of PhI(OAc)2 afford the optimal result
(Table 1, compared with entries 6 and 18).
Table 1. Optimization of the Reaction Conditionsa
Entry
Catalyst
Oxidant
Air
Solvent
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Toluene
Yieldb (%)
23
1
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
2
O2
31
3
TBHP
55
4
MnO2
44
5
DTBP
63
6
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
76
7
Nd
21
ꢀ
8
CuBr
Cu(OAc)2
CuI
9
14
10
12
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FeCl3
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
PhI(OAc)2
Toluene
Dioxane
DMSO
PhCl
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12
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
Cu(OTf)2
27
13
Trace
59
14
15c
16d
17c
18e
PhCl
72
Toluene
Toluene
Toluene
58
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aReaction conditions: 1a (0.2 mmol), catalyst (20 mol%), oxidant (2.0 equiv), solvent (2.0 mL), 100 oC,
h. bYields of isolated products. c120 oC. d80 oC. ePhI(OAc)2 (3.0 equiv). BHP
8
=
tertꢀbutylhydroperoxide (5.0ꢀ6.0 M in decane), DTBP = diꢀtꢀbutyl peroxide, DMSO = dimethyl
sulfoxide.
With the optimized conditions in hand, the generality of oxime acetates
was first explored, and the results were summarized in Table 2. This
coupling reaction tolerated a wide range of substituents on the aromatic
ring of oxime acetates. We found that substrates with electronꢀdonating
groups on the aromatic ring produced the corresponding pyridines in
good yields (3ab-3af), including ortho- methyl, metaꢀ methyl, paraꢀ
methyl, and methoxy at the paraꢀ, metaꢀposition. In addition,
electronꢀwithdrawing groups such as paraꢀ F, Cl, Br on the aromatic ring
seemed to be compatible well under the optimal reaction conditions with
excellent yields (3ag-3ai). Disappointingly, pꢀnitroꢀsubstituted oxime
acetate was not tolerated in this transformation and did not give the
desired product 3am, which indicated that strong electronic effect
hindered this transformation. In addition, the pꢀphenylꢀsubstituted oxime
acetate, αꢀtetralone oxime acetate, benzylideneacetone oxime acetate and
2ꢀacetylnaphthalene oxime acetate also afforded the corresponding
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pyridines (3aj-3al) in moderate yields respectively. Besides, the
isobutyraldehyde oxime acetate was also investigated, but the expected
product 3an was not observed under the standard conditions.
Table 2. Synthesis of pyridines from different oxime acetatesa,b
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N
N
N
N
3ad
(65%)
3ac
(71%)
3aa
(76%)
3ab
(74%)
O
O
N
N
N
N
O
O
Cl
Cl
F
F
3ag
3ah
(72%)
3ae
(61%)
3af
(80%)
(57%)
N
N
N
N
Br
Br
3al
3aj
3ai
3ak
(38%)
(82%)
(53%)
(47%)
N
N
O2
N
NO2
3am
3an
(nd)
(nd)
aReaction conditions: 1 (0.2 mmol), catalyst Cu(OTf)2(20 mol%), PhI(OAc)2 (0.4 mmol) in toluene (2.0 mL) at
100 oC for 8 h.
bIsolated yields.
In order to acquire a variety of polyfunctional pyridines, the
compatibility of the present method was further expanded by the
utilization of a wide range of substituted toluenes (Table 3). However, it
should be noted that reaction conditions were slightly changed: PhCl was
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considered as the best reaction solvent and the optimal temperature for
the reaction was determined to be 120 °C (Table 1, entry 15). Initially,
both electronꢀrich and electronꢀdeficient benzenes proceeded successfully
to obtain the desired products in good yields (3ba-3bk). Disappointingly,
strong electronꢀdeficient group (2ꢀNO2) was found to be incompatible and
the desired product could not be produced under the certain reaction
conditions, perhaps due to the strong electronic effect (3bl).
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Table 3. Synthesis of pyridines from diverse arylmethanea,b
aReaction conditions: 1a (0.2 mmol), 2 (0.4 mmol), catalyst Cu(OTf)2(20 mol%), PhI(OAc)2 (0.4 mmol) in PhCl
(2.0 mL) at 120 oC for 8 h.
bIsolated yields.
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Based on previous studies and literature reports,10a,11,12,13,14 a plausible
reaction mechanism is proposed as shown in Scheme 2 to explain the
formation of product 3aa. Firstly, Cu(OTf)2 would be converted into Cu+
by either a reduction or disproportionation.11 Under the action of Cu+, the
NꢀO bond of the oxime acetate 1a cleavages and would afford the imine
radical A which reacts promptly with another Cu+ to give NꢀCu2+
intermediate B.12,13 Tautomerization of B would offer the intermediate C,
while toluene 2a would be easily converted to benzaldehyde D by the
oxidation with the presence of PhI(OAc)2. Next, nucleophilic addition of
C to D would afford imine intermediate E.13 In the meantime, another
oxime acetate 1a could tautomerize to the intermediate F. Subsequently,
the intermediate G would be formed by condensation reaction of E with
F.10a Then intermediate G through betaꢀelimination would afford an
azaꢀhexaꢀ1,3,5ꢀtriene intermediate H. Finally, the intermediate H
generated underwent electrocyclization to furnish the desired product
3aa.14 Meanwhile, the Cu2+ would be reduced to active Cu+, which
completed the catalytic cycle.
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Scheme 2. Possible mechanism
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To widen the diversity of synthetic strategies to produce polysubstituted
pyridines, the building blocks including benzylamine (4a),
pꢀtoluenesulfonylhydrazone (5a) were introduced into this class of
reactions. The reaction of benzylamine (4a) and 1a was carried out in the
presence of Cu(OTf)2 (10 mol%) and xylene (2.0 mL) at 120 °C, and the
desired product 3aa was isolated in 78% yield (Scheme 3a). Besides,
pꢀtoluenesulfonylhydrazone (5a) was also compatible in the reaction to
form the desired product 3aa in 72% yield (Scheme 3b). These reactions
are fascinating, obtaining a range of polysubstituted pyridines through a
useful, efficient and simple method by using easily available starting
materials.
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Scheme 3. Alternative transformations to construct polysubstituted pyridines
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Ph
OAc
N
Cu(OTf)2 (10 mol%)
Ph
NH2
a)
2
+
Ph
xylene, 120 oC, 18 h
Ph
N
Ph
78%
9
1a
4a
3aa,
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Conclusion
In summary, we have developed a practical Cuꢀcatalyzed oxidative
coupling reaction to construct polysubstituted pyridines via oxidative
cleavage of C(sp3)ꢀH. Besides, two other alternative transformations were
also presented to enrich the diversity of synthetic methods for the
preparation of substituted pyridines. These processes afforded some new
approaches to polysubstituted pyridines with advantages including ready
availability of the starting materials, operational simplicity, cheap
catalysts and mild conditions. Further studies on reaction mechanism
details and the synthetic applications of this transformation are now under
investigation in our group.
Experimental Section
1
13
General remarks. H NMR and C NMR spectra were recorded on
300MHz and 100MHz in CDCl3. All chemical shifts are given as δ value
(ppm) with reference to tetramethylsilane (TMS) as an internal standard.
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The highꢀresolution mass spectra (HRMS) were recorded on an FTꢀICR
mass spectrometer using electrospray ionization (ESI). Products were
purified by flash chromatogrgraphy on 200ꢀ300 mesh silica gel. All
melting points were determined without correction. Unless otherwise
noted, commercially reagents were used without further purification.
General procedure for the synthesis of 3 (3aa/3ba as an example)
Synthesis of 3aa: A test tube was charged with oxime acetates (0.2
mmol), Cu(OTf)2(20mol%), PhI(OAc)2(0.4 mmol) in toluene (2.0 mL).
The mixture was stirred at 100 oC for 8 h under air atmosphere. When the
reaction was completed (monitored by TLC), the mixture was cooled to
room temperature. The mixture was diluted with water and extracted with
EtOAc (3×20 mL). The combined organic layers were dried over
anhydrous Na2SO4 and concentrated. The residue was purified by column
chromatography on silica gel (petroleum ether/EtOAc = 40:1) to yield the
isolated product 3aa.
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Synthesis of 3ba: A test tube was charged with oxime acetate (0.2 mmol),
toluene (0.4 mmol), Cu(OTf)2 (20 mol%), PhI(OAc)2 (0.4 mmol) in PhCl
o
(2.0 mL). The mixture was stirred at 120 C for 8 h under air. When the
reaction was completed (detected by TLC), the mixture was cooled to
room temperature. The mixture was diluted with water and extracted with
EtOAc (3×20 mL). The combined organic layers were dried over
anhydrous Na2SO4 and evaporation. The residue was purified by column
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chromatography on silica gel (petroleum ether/EtOAc = 40:1) to yield the
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isolated product 3ba.
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2,4,6-triphenyl-pyridine (3aa). White solid (23.3 mg, 76%); m. p.
102ꢀ104 oC (lit.15 m. p. 133ꢀ134 oC); 1H NMR (300 MHz, CDCl3) δ 8.26 –
8.15 (m, 4H), 7.88 (d, J = 1.0 Hz, 2H), 7.77 – 7.71 (m, 2H), 7.56 – 7.42
(m, 9H); 13C NMR (75 MHz, CDCl3) δ 157.5, 150.2, 139.6, 139.0, 129.1,
129.0, 128.9, 128.7, 127.2, 127.1, 117.1; HRMS (ESI) calcd for C23H18N
[M+H]+ 308.1434; found: 308.1437.
2,6-bis(4-methylphenyl)-4-phenylpyridine (3ab). White solid (24.8 mg,
o
74%); m. p. 126ꢀ128 oC (lit.16 m. p. 157.4ꢀ157.9 C);1H NMR (300 MHz,
CDCl3) δ 8.10 (d, J = 8.2 Hz, 4H), 7.83 (s, 2H), 7.73 (dd, J = 8.1, 1.4 Hz,
2H), 7.56 – 7.41 (m, 3H), 7.31 (d, J = 8.0 Hz, 4H), 2.43 (s, 6H);13C NMR
(75 MHz, CDCl3) δ 157.4, 150.0, 139.3, 138.9, 136.9, 129.4, 129.0,128.9,
127.1, 127.0, 116.5, 21.3; HRMS (ESI) calcd for C25H22N [M+H]+
336.1747; found: 336.1749.
2,6-bis(3-methylphenyl)-4-phenylpyridine (3ac). White solid (23.8 mg,
o
71%); m. p . 127ꢀ129 C; 1H NMR (300 MHz, CDCl3) δ 8.10 (d, J = 8.2
Hz, 4H), 7.85 – 7.81 (m, 2H), 7.73 (dd, J = 8.1, 1.4 Hz, 2H), 7.56 – 7.42
13
(m, 3H), 7.31 (d, J = 8.0 Hz, 4H), 2.43 (s, 6H); C NMR (75 MHz,
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CDCl3) δ 157.6, 150.1, 139.5, 138.3, 129.8, 129.1, 128.6, 127.9, 127.2,
124.3, 117.2, 21.6; HRMS (ESI) calcd for C25H22N [M+H]+ 336.1747;
found: 336.1748.
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2,6-bis(2-methylphenyl)-4-phenylpyridine (3ad). White solid (21.7 mg,
o
65%); m. p. 129ꢀ131 oC(lit.21 m. p. 129ꢀ130 C); 1H NMR (300 MHz,
CDCl3) δ 7.72 (dd, J = 7.4, 0.9 Hz, 2H), 7.59 (d, J = 0.7 Hz, 2H), 7.50
(ddd, J = 7.8, 5.6, 2.9 Hz, 4H), 7.37 – 7.23 (m, 7H), 2.48 (s, 6H); 13C
NMR (75 MHz, CDCl3) δ 160.1, 148.8, 140.7, 138.5, 135.9, 130.7, 129.8,
129.1, 129.0, 128.2, 127.1, 125.8, 120.1, 20.6; HRMS (ESI) calcd for
C25H22N [M+H]+ 336.1747; found: 336.1749.
2,6-bis(4-methoxylphenyl)-4-phenylpyridine (3ae). White solid (22.4
o
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mg, 61%); m. p. 98ꢀ100 oC (lit.19 m. p. 98ꢀ99 C) ; H NMR (300 MHz,
CDCl3) δ 8.16 (d, J = 8.9 Hz, 4H), 7.80 – 7.69 (m, 4H), 7.49 (dt, J = 8.5,
13
6.9 Hz, 3H), 7.03 (d, J = 8.9 Hz, 4H), 3.87 (s, 6H); C NMR (75 MHz,
CDCl3) δ 160.4, 156.9, 149.9, 139.3, 132.3, 129.0, 128.8, 128.3, 127.1,
115.7, 114.0, 55.4; HRMS (ESI) calcd for C25H22NO2 [M+H]+ 368.1645;
found: 368.1648.
2,6-bis(3-methoxylphenyl)-4-phenylpyridine (3af). Colorless liquid
1
(20.9 mg, 57%); H NMR (300 MHz, CDCl3) δ 7.88 (s, 2H), 7.82 – 7.78
(m, 2H), 7.77 – 7.71 (m, 4H), 7.55 – 7.50 (m, 2H), 7.48 – 7.38 (m, 3H),
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7.00 (dd, J = 7.9, 2.3 Hz, 2H), 3.92 (s, 6H); 13C NMR (75 MHz, CDCl3) δ
160.0, 157.2, 150.2, 141.1, 139.0, 129.7, 129.2, 129.1, 127.2, 119.6, 117.5,
114.8, 112.7, 55.4; HRMS (ESI) calcd for C25H22NO2 [M+H]+ 368.1645;
found: 368.1648.
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2,6-bis(4-fluorophenyl)-4-phenylpyridine (3ag). White solid (27.2 mg,
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80%); m. p. 150ꢀ152 oC; H NMR (300 MHz, CDCl3) δ 8.21 – 8.11 (m,
4H), 7.80 (d, J = 1.1 Hz, 2H), 7.75 – 7.67 (m, 2H), 7.58 – 7.41 (m, 3H),
7.25 – 7.11 (m, 4H); 13C NMR (75 MHz, CDCl3) δ 163.6 (d, JCF = 247.5
Hz), 156.4, 150.4, 138.8, 135.5 (d, JCF =3.0 Hz), 129.1, 129.1, 128.9 (d,
JCF = 8.3 Hz), 127.1, 116.7, 115.6 (d, JCF = 21.8 Hz);19F NMR (282 MHz,
CDCl3) δ ꢀ113.68; HRMS (ESI) calcd for C23H16F2N [M+H]+ 344.1246;
found: 344.1249.
2,6-bis(4-chlorophenyl)-4-phenylpyridine (3ah). White solid (27.1 mg,
o
o
72%); m. p. 162ꢀ164 C (lit.19 m. p. 126ꢀ127 C); 1H NMR (300 MHz,
CDCl3) δ 8.15 – 8.09 (m, 4H), 7.83 (s, 2H), 7.71 (dd, J = 7.7, 1.5 Hz, 2H),
13
7.54 – 7.44 (m, 7H); C NMR (75 MHz, CDCl3) δ 156.3, 150.5, 138.6,
137.7, 135.3, 129.2, 128.9, 128.7, 128.3, 127.1, 117.1; HRMS (ESI) calcd
for C23H16Cl2N [M+H]+ 376.0655; found: 376.0658.
2,6-bis(4-bromophenyl)-4-phenylpyridine (3ai). White solid (38.1 mg,
o
o
82%); m. p. 164ꢀ166 C (lit.19 m. p. 101ꢀ102 C); 1H NMR (300 MHz,
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CDCl3) δ 8.05 (dd, J = 8.6, 2.1 Hz, 4H), 7.84 (s, 2H), 7.70 (d, J = 1.1 Hz,
13
2H), 7.62 (dd, J = 8.6, 2.1 Hz, 3H), 7.51 (dd, J = 8.4, 6.6 Hz, 4H); C
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NMR (75 MHz, CDCl3) δ 156.2, 150.4, 138.5, 138.0, 131.7, 129.1, 128.5,
127.0, 123.5, 117.0; HRMS (ESI) calcd for C23H16Br2N [M+H]+
463.9644; found: 463.9646.
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2,6-di-4-biphenylyl-4-phenylpyridine (3aj). White solid (24.3 mg, 53%);
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m. p. 191ꢀ193 C (lit.22 m. p. 192ꢀ193 C); 1H NMR (300 MHz, CDCl3) δ
8.38 – 8.27 (m, 4H), 7.98 – 7.93 (m, 2H), 7.83 – 7.74 (m, 6H), 7.71 (d, J
= 7.7 Hz, 5H), 7.54 – 7.45 (m, 6H), 7.40 (s, 2H); 13C NMR (75 MHz,
CDCl3) δ 157.1, 141.8, 140.6, 138.4, 129.7, 129.1, 129.0, 128.8, 127.5,
127.4, 127.2, 127.1, 117.0; HRMS (ESI) calcd for C35H26N [M+H]+
460.2060; found: 460.2063.
2,6-di-2-naphthalenyl-4-phenylpyridine (3ak). White solid (19.2 mg,
o
1
72%); m. p. 156ꢀ157 C; H NMR (300 MHz, CDCl3) δ 8.69 (s, 2H),
8.42 (dd, J = 8.6, 1.7 Hz, 2H), 8.08 – 7.98 (m, 6H), 7.92 – 7.88 (m, 2H),
13
7.83 (dd, J = 8.2, 1.3 Hz, 2H), 7.54 (dq, J = 6.8, 4.3 Hz, 7H); C NMR
(75 MHz, CDCl3) δ 157.4, 150.2, 138.9, 136.8, 133.7, 133.5, 129.1, 129.0,
128.7, 128.3, 127.7, 127.2, 126.4, 126.2, 124.9, 117.4; HRMS (ESI) calcd
for C31H22N [M+H]+408.1747; found: 408.1749.
5,6,8,9-Tetrahydro-7-phenyldibenz[c,h]acridine (3al). White solid
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(13.8 mg, 38%); m. p. 169ꢀ171 oC (lit.20 m. p. 164ꢀ165oC); 1H NMR (300
MHz, CDCl3) δ 8.58 (d, J = 7.7 Hz, 2H), 7.49 (t, J = 7.3 Hz, 2H), 7.45 –
7.36 (m, 3H), 7.30 (t, J = 7.3 Hz, 2H), 7.21 (t, J = 8.8 Hz, 4H), 2.90 –
2.74 (m, 4H), 2.64 (dd, J = 8.7, 5.8 Hz, 4H); 13C NMR (75 MHz, CDCl3)
δ 150.2, 147.6, 138.1, 138.0, 135.5, 131.1, 128.8, 128.8, 128.8, 127.8,
127.6, 127.2, 125.5, 28.3, 26.0; HRMS (ESI) calcd for C27H22N [M+H]+
360.1747; found: 360.1749.
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4-(4-methylphenyl)-2,6-diphenylpyridine (3ba): White solid (23.7 mg,
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o
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74%); m. p. 117ꢀ119 C (lit.18 m. p. 123ꢀ124 C); H NMR (300 MHz,
CDCl3) δ 8.20 (d, J = 7.0 Hz, 4H), 7.87 (s, 2H), 7.65 (d, J = 8.2 Hz, 2H),
7.55 – 7.43 (m, 6H), 7.33 (d, J = 7.8 Hz, 2H), 2.44 (s, 3H); 13C NMR (75
MHz, CDCl3) δ 157.4, 150.0, 139.6, 139.1, 136.1, 129.8, 129.0, 128.7,
127.1, 127.0, 116.9, 21.3; HRMS (ESI) calcd for C24H20N [M+H]+
322.1590; found: 322.1593.
4-(3-methylphenyl)-2,6-diphenylpyridine (3bb). White solid (22.4 mg,
o
1
70%); m. p.112ꢀ114 C; H NMR (300 MHz, CDCl3) δ 8.23 – 8.18 (m,
4H), 7.88 (d, J = 0.9 Hz, 2H), 7.52 (dd, J = 12.8, 6.5 Hz, 6H), 7.44 (dd, J
= 10.9, 4.2 Hz, 3H), 7.28 (d, J = 7.4 Hz, 1H), 2.47 (s, 3H); 13C NMR (75
MHz, CDCl3) δ 157.4, 150.3, 139.6, 139.0, 138.8, 129.7, 129.0, 128.7,
127.9, 127.1, 124.3, 117.1, 21.5; HRMS (ESI) calcd for C24H20N [M+H]+
322.1590; found: 322.1592.
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4-(2-methylphenyl)-2,6-diphenylpyridine (3bc). White solid (20.8 mg,
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65%); m. p. 108ꢀ110 C (lit.18 m. p. 120ꢀ122 C); H NMR (300 MHz,
CDCl3) δ 8.22 – 8.14 (m, 4H), 7.67 (s, 2H), 7.54 – 7.41 (m, 6H), 7.33 (q,
J = 3.4 Hz, 4H), 2.36 (s, 3H); 13C NMR (75 MHz, CDCl3) δ 156. 8, 151.3,
139.8, 139.5, 135.1, 130.7, 129.2, 129.0, 128.7, 128.5, 128.3, 127.1,
126.1, 119.3, 20.4; HRMS (ESI) calcd for C24H20N [M+H]+ 322.1590;
found: 322.1594.
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4-(3,5-dimethylphenyl)-2,6-phenylpyridine (3bd). White solid (24.7
mg, 77%); m. p. 119ꢀ121 oC; 1H NMR (300 MHz, CDCl3) δ 8.22 – 8.18
(m, 5H), 7.87 (s, 2H), 7.50 (d, J = 7.8 Hz, 6H), 7.35 (s, 2H), 2.43 (s, 6H);
13C NMR (75 MHz, CDCl3) δ 157.3, 150.4, 139.6, 139.0, 138.7, 130.6,
128.9, 128.6, 127.1, 125.0, 117.1, 21.4; HRMS (ESI) calcd for C25H22N
[M+H]+ 336.1747; found: 336.1749.
4-(4-methoxyphenyl)-2,6-diphenylpyridine (3be). White solid (22.8 mg,
o
o
68%); m. p. 100ꢀ102 C (lit.15 m. p. 99ꢀ100 C); 1H NMR (300 MHz,
CDCl3) δ 8.41 – 7.97 (m, 4H), 7.87 (d, J = 9.6 Hz, 2H), 7.80 – 7.68 (m,
2H), 7.57 – 7.21 (m, 8H), 2.42 (d, J = 14.3 Hz, 6H); 13C NMR (75 MHz,
CDCl3) δ 160.5, 157.5, 149.7, 139.8, 131.4, 129.0, 128.7, 128.4, 127.2,
116.7, 114.6, 55.5; HRMS (ESI) calcd for C24H20NO [M+H]+ 338.1540;
found: 338.1543.
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4-(4-fluorophenyl)-2,6-diphenylpyridine (3bf). White solid (25.3 mg,
78%); m. p. 138ꢀ140 oC (lit.16 m. p. 203.4ꢀ204.6 oC); 1H NMR (300 MHz,
CDCl3) δ 8.30 – 8.14 (m, 4H), 7.86 (d, J = 17.2 Hz, 2H), 7.78 – 7.68 (m,
2H), 7.48 (dd, J = 14.6, 7.5 Hz, 6H), 7.34 – 7.09 (m, 2H); 13C NMR (75
MHz, CDCl3) δ 163.4 (d, JCF = 246.0 Hz), 157.6, 149.1, 139.4, 135.1 (d,
JCF = 3.0 Hz), 129.1, 129.0 (d, JCF = 5.3 Hz), 128.7, 127.1, 116.9, 116.1
(d, JCF = 21.0 Hz);19F NMR (282 MHz, CDCl3) δ ꢀ113.52; HRMS (ESI)
calcd for C23H17FN [M+H]+ 326.1340; found: 326.1342.
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4-(4-chlorophenyl)-2,6-diphenylpyridine (3bg). White solid (24.2 mg,
71%); m. p. 130ꢀ132 oC (lit.16 m. p. 125.9ꢀ127.5 oC); 1H NMR (300 MHz,
CDCl3) δ 8.25 – 8.13 (m, 4H), 7.83 (s, 2H), 7.67 (d, J = 8.5 Hz, 2H), 7.55
– 7.39 (m, 8H); 13C NMR (75 MHz, CDCl3) δ 157.6, 148.9, 139.4, 137.5,
135.2, 129.3, 129.1, 128.7, 128.4, 127.1, 116.8; HRMS (ESI) calcd for
C23H17ClN [M+H]+ 342.1044; found: 342.1047.
4-(4-bromophenyl)-2,6-diphenylpyridine (3bh). White solid (27.8 mg,
o
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72%); m. p. 132ꢀ134 C (lit.19 m. p. 166ꢀ167 C); 1H NMR (300 MHz,
CDCl3) δ 8.22 – 8.16 (m, 4H), 7.83 (s, 2H), 7.66 – 7.60 (m, 3H), 7.55 –
13
7.44 (m, 7H); C NMR (75 MHz, CDCl3) δ 157.9, 149.2, 139.6, 138.2,
132.5, 129.4, 129.0, 127.4, 123.6, 117.0; HRMS (ESI) calcd for
C23H17BrN [M+H]+ 386.0539; found: 386.0542.
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4-(2-chlorophenyl)-2,6-diphenylpyridine (3bi). White solid (20.5 mg,
o
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60%); m. p. 108ꢀ110 C (lit.18 m. p. 113ꢀ114 C); 1H NMR (300 MHz,
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CDCl3) δ 8.24 – 8.15 (m, 4H), 7.77 (d, J = 2.1 Hz, 2H), 7.55 – 7.36 (m,
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10H); C NMR (75 MHz, CDCl3) δ 156.9, 148.5, 139.4, 138.5, 132.3,
131.0, 130.4, 129.8, 129.1, 128.8, 128.7, 127.5, 127.2, 127.1, 119.4;
HRMS (ESI) calcd for C23H17ClN [M+H]+ 342.1044; found: 342.1046.
4-(3-chlorophenyl)-2,6-diphenylpyridine (3bj). White solid (21.2 mg,
62%); m. p. 117ꢀ119 C; 1H NMR (300 MHz, CDCl3) δ 8.28 – 8.12 (m,
o
4H), 7.86 (d, J = 14.8 Hz, 2H), 7.63 – 7.42 (m, 9H); 13C NMR (75 MHz,
CDCl3) δ 157.7, 148.8, 140.9, 139.3, 135.1, 130.4, 129.2, 129.0, 129.0,
128.7, 127.3, 127.1, 125.4, 116.9; HRMS (ESI) calcd for C23H17ClN
[M+H]+ 342.1044; found: 342.1048.
4-(2,4-dichlorophenyl)-2,6-diphenylpyridine (3bk). Colorless liquid
(24.1 mg, 64%); 1H NMR (300 MHz, CDCl3) δ 8.30 – 8.08 (m, 4H), 7.80
– 7.67 (m, 2H), 7.57 – 7.35 (m, 9H); 13C NMR (75 MHz, CDCl3) δ 157.0,
147.5, 139.2, 137.0, 135.0, 133.1, 131.6, 130.1, 129.2, 128.7, 127.5,
127.2, 127.1, 119.2; HRMS (ESI) calcd for C23H16Cl2N [M+H]+ 376.0655;
found: 376.0658.
Supporting Information
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Copies of H and C NMR spectra for all reaction products. The
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materials are available free of charge on the ACS Publications website.
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Corresponding Author:
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*Fax: (+86)ꢀ931ꢀ891ꢀ2582. Eꢀmail: chbh@lzu.edu.cn
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References
(1) (a) Taylor, R. D.; MacCoss, M.; Lawson, A. D. G. J. Med. Chem. 2014, 57, 5845−5859;
(b) Byrne, J. P.; Kitchen, J. A.; Gunnlaugsson, T. Chem. Soc. Rev. 2014, 43, 5302−5325;
(c) Desimoni, G.; Faita, G.; Quadrelli, P. Chem. Rev. 2014, 114, 6081−6129; (d) Carey, J.
S.; Laffan, D.; Thomson, C.; Williams, M. T. Org. Biomol. Chem. 2006, 4, 2337−2347; (e)
Roughley, S. D.; Jordan, A. M. J. Med. Chem. 2011, 54, 3451−3479; (f) Sasabe, H.; Kido,
J. Chem. Mater. 2011, 23, 621−630.
(2) (a) Sebren, L. J.; Devery, J. J., 3rd; Stephenson, C. R. ACS catalysis 2014, 4, 703ꢀ716; (b)
Gibson, V. C.; Redshaw, C.; Solan, G. A. Chem. Rev. 2007, 107, 1745−1776; (c) Hostyn,
S.; Van Baelen, G.; Lemiere, G. L. F.; Maes, B. U. W. Adv. Synth. Catal. 2008, 350,
2653−2660; (d) Yadav, A. K.; Verbeeck, S.; Hostyn, S.; Franck, P.; Sergeyev, S.; Maes, B.
U. Org. Lett. 2013, 15, 1060−1063.
(3) (a) Chen, M. Z.; Micalizio, G. C. J. Am. Chem. Soc. 2012, 134, 1352−1356; (b) Lei, C.ꢀH.;
Wang, D.ꢀX.; Zhao, L.; Zhu, J.; Wang, M.ꢀX. J. Am. Chem. Soc. 2013, 135, 4708−4711; (c)
Yoshida, M.; Mizuguchi, T.; Namba, K. Angew. Chem. Int. Ed. 2014, 53, 14550−14554;
(d) Jiang, Y.; Park, C.ꢀM.; Loh, T.ꢀP. Org. Lett. 2014, 16, 3432−3435; (e) Zhao, M. N.;
Ren, Z. H.; Yu, L.; Wang, Y. Y.; Guan, Z. H. Org. Lett. 2016, 18, 1194−1197; (f) Huang,
H.; Cai, J.; Tang, L.; Wang, Z.; Li, F.; Deng, G. J. J. Org. Chem. 2016, 81, 1499−1505; (g)
Donohoe, T. J.; Bower, J. F.; Baker, D. B.; Basutto, J. A.; Chan, L. K.; Gallagher, P. Chem.
Commun. 2011, 47, 10611−10613; (h) Ren, Z.ꢀH.; Zhang, Z.ꢀY.; Yang, B.ꢀQ.; Wang,
Y.ꢀY.; Guan, Z.ꢀH. Org. Lett. 2011, 13, 5394−5397; (i) Ohashi, M.; Takeda, I.; Ikawa, M.;
Ogoshi, S. J. Am. Chem. Soc. 2011, 133, 18018−18021.
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(4) (a) Sukhorukov, A. Y.; Ioffe, S. L. Chem. Rev. 2011, 111, 5004−5041; (b) Narasaka, K.
Pure Appl. Chem. 2002, 74, 143−149; (c) Narasaka, K.; Kitamura, M. Eur. J. Org. Chem.
2005, 4505−4519; (d) Wei, Y.; Yoshikai, N. J. Am. Chem. Soc. 2013, 135, 3756−3759; (e)
Huang, H.; Ji, X.; Tang, X.; Zhang, M.; Li, X.; Jiang, H. Org. Lett. 2013, 15, 6254−6257;
(f) Zhao, M. N.; Hui, R. R.; Ren, Z. H.; Wang, Y. Y.; Guan, Z. H. Org. Lett. 2014, 16,
3082−3085.
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(5) (a) Ramón, R. S.; Bosson, J.; DíezꢀGonzález, S.; Marion, N.; Nolan, S. P. J. Org. Chem.
2010, 75, 1197−1202; (b) Ganguly, N. C.; Mondal, P. Synthesis 2010, 3705−3709; (c)
Ramalingan, C.; Park, Y.ꢀT. J. Org. Chem. 2007, 72, 4536−4538; (d) Sukhorukov, A. Y.;
Ioffe, S. L. Chem. Rev. 2011, 111, 5004−5041.
(6) (a) Prithwiraj, D.; Nonappa; Pandurangan, K.; Maitra, U.; Wailes, S. Org. Lett. 2007, 9,
2767−2770; (b) Maimone, T. J.; Buchwald, S. L. J. Am. Chem. Soc. 2010, 132,
9990−9991.
(7) (a) Narasaka, K. Pure Appl. Chem. 2002, 74, 143−149; (b) Narasaka, K.; Kitamura, M.
Eur. J. Org. Chem. 2005, 4505−4519;
(8) Gerfaud, T.; Neuville, L.; Zhu, J. Angew. Chem. Int. Ed. 2009, 48, 572−577.
(9) Tan, Y.; Hartwig, J. F. J. Am. Chem. Soc. 2010, 132, 3676−3677.
(10) (a) Ren, Z.ꢀH.; Zhang, Z.ꢀY.; Yang, B.ꢀQ.; Wang, Y.ꢀY.; Guan, Z.ꢀH. Org. Lett. 2011, 13,
5394−5397; (b) Zhao, M. N.; Ren, Z. H.; Yu, L.; Wang, Y. Y.; Guan, Z. H. Org. Lett.
2016, 18, 1194−1197; (c) Zhao, M.ꢀN.; Hui, R.ꢀR.; Ren, Z.ꢀH.; Wang, Y.ꢀY.; Guan, Z.ꢀH.
Org. Lett. 2014, 16, 3082−3085.
(11) (a) Wang, Y.; Chen, C.; Peng, J. Angew. Chem. Int. Ed. 2013, 52, 5323−5327; (b)
Hickman, A. J.; Sanford, M. S. ACS Catal. 2011, 1, 170−174; (c) Chen, B.; Hou, X.ꢀL.; Li,
Y.ꢀX.; Wu, Y.ꢀD. J. Am. Chem. Soc. 2011, 133, 7668−7671; (d) Wagner, A. M.; Sanford,
M. S. Org. Lett. 2011, 13, 288−291; (e) Xiao, B.; Fu, Y.; Xu, J.; Gong, T.ꢀJ.; Dai, J.ꢀJ.; Yi,
J.; Liu, L. J. Am. Chem. Soc. 2010, 132, 468−469.
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Page 22 of 22
1
2
3
4
5
6
7
8
(12) (a) Trost, B. M.; Rhee, Y. H. J. Am. Chem. Soc. 2002, 124, 2528−2533; (b) Nitta, M.;
Iino, Y. Bull. Chem. Soc. Jpn. 1986, 59, 2365−2367; (c) Deeming, A. J.; Owen, D. W.;
Powell, N. I. J. Organomet. Chem. 1990, 398, 299−310.
9
(13) Takai, K.; Katsura, N.; Kunisada, Y. Chem. Commun. 2001, 1724−1725.
(14) Liu, S.; Liebeskind, L. S. J. Am. Chem. Soc. 2008, 130, 6918−6919.
(15) Alinezhad, H.; Tajbakhsh, M.; Ghobadi, N. Synth. Commun. 2015, 45, 1964.
(16) Li, J.; He, P.; Yu, C., Tetrahedron 2012, 68, 4138ꢀ4144.
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
(17) Safari, J.; Zarnegar, Z.; Borujeni, M. B. Chem. Pap. 2013, 67, 688.
(18) Adib, M.; Tahermansouri, H.; Koloogani, S. A.; Mohammadi, B.; Bijanzadeh, H. R.,
Tetrahedron Letters 2006, 47, 5957ꢀ5960.
(19) Nagarapu, L.; Aneesa; Peddiraju, R.; Apuri, S., Catalysis Communications 2007, 8,
1973ꢀ1976.
(20) Wu, P.; Cai, X.ꢀM.; Wang, Q.ꢀF.; Yan, C.ꢀG., Synthetic Communications 2011, 41,
841ꢀ850.
(21) Fang, A. G.; Mello, J. V.; Finney, N. S., Tetrahedron 2004, 60, 11075ꢀ11087.
(22) Tewari, R. S.; Dubey, A. K., Journal of Chemical & Engineering Data 1980, 25, 91ꢀ92.
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