N-heterocyclic carbene (NHC)-modulated Pd/Cu cocatalyzed three-component synthesis of 2,6-diarylquinolines

Article abstract of DOI:10.1039/c4ob00231h

Two new NHC adducts of cyclopalladated ferrocenylpyrazine complexes 1-2 have been prepared and characterized. An efficient NHC-modulated Pd/Cu cocatalyzed three-component coupling reaction for the synthesis of 2,6-diarylquinolines from aminobenzyl alcohol

Full text of DOI:10.1039/c4ob00231h

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N-heterocyclic carbene (NHC)-modulated Pd/Cu
cocatalyzed three-component synthesis of
2,6-diarylquinolines†
Cite this: Org. Biomol. Chem., 2014,
12, 3114
Chen Xu,*a,c Hong-Mei Li,b Xiao-Er Yuan,c Zhi-Qiang Xiao,c Zhi-Qiang Wang,a
Wei-Jun Fu,a Bao-Ming Ji,a Xin-Qi Hao*c and Mao-Ping Songc
Two new NHC adducts of cyclopalladated ferrocenylpyrazine complexes 1–2 have been prepared and
characterized. An efficient NHC-modulated Pd/Cu cocatalyzed three-component coupling reaction for
the synthesis of 2,6-diarylquinolines from aminobenzyl alcohols, aryl ketones, and arylboronic acids in air
is described. The reaction involves oxidation, cyclization and Suzuki reactions. The luminescence of the
resulting arylquinolines 3–30 was also investigated.
Received 29th January 2014,
Accepted 11th March 2014
DOI: 10.1039/c4ob00231h
www.rsc.org/obc
using oxidatively stable ligands. These ligands often consist of
nitrogen donors, such as amine and pyridine ligands.9,10
Introduction
The quinoline moiety plays a vital role as an intermediate for Moreover, NHC ligands have been proven to be effective in
the design of many biologically active compounds.1 Moreover, various Pd-catalyzed processes11 as well as in alcohol oxi-
quinolines also found wide utility as synthons for formation of dation.12 Considering the unique activity of NHC ligand-modu-
conjugated molecules2 or ligands for the preparation of phos- lated Pd catalysts, we were interested in developing a NHC-
phorescent complexes.3 Among several routes to quinoline syn- modulated Pd-catalyzed modified Friedländer reaction for the
thesis, the metal-catalyzed modified Friedländer reaction4 is quinoline synthesis.
one of the simplest methods, where 2-aminobenzyl alcohol,
On the other hand, multicomponent reactions (MCRs) are
which is cheaper and more stable than 2-aminobenzaldehyde, ideal synthetic tools to generate multiple molecular scaffolds
is allowed to react with carbonyl compounds to form quinoline from readily available starting materials in a single synthetic
derivatives. Several groups have reported the use of Ru,5 Ir6 operation without the need for isolation of intermediates.13
and other metal catalysts7 for the synthesis of quinolines from Very recently we have developed
a PPh3-cyclometallated
amino alcohols and ketones via oxidation and cyclization. The iridium(III) hydride/Pd(OAc)2 cocatalyzed reaction of acetyl-
first step of the reaction is metal-catalyzed oxidation of alco- ferrocene, bromoarylmethanols, and arylboronic acids under
hols. Among metal salts and complexes, those of palladium nitrogen.14 This method was successfully applied to one-pot
have been widely used in alcohol oxidation.8 This reaction tra- synthesis of 6-aryl-2-ferrocenylquinolines. However, the metals
ditionally requires catalytic Pd(II) and stoichiometric Cu salts (Ir/Pd) involved are certainly expensive; the synthesis of ferro-
under aerobic conditions. However, palladium complexes cenylquinolines was not a multicomponent reaction but a
compatible with these reaction conditions are quite limited sequential process. Therefore, the development of a more con-
because phosphines and related organic ligands often degrade venient and inexpensive catalyst system that can be used for
rapidly under oxidizing reaction conditions.9 Recently, great the quinoline synthesis is desired. As a continuation of our
progress has been made for the palladium-catalyzed oxidation interest in the synthesis and application of cyclometalated
complexes,15 we prepared new adducts of cyclopalladated
ferrocenylpyrazine complexes and described the first NHC-
aCollege of Chemistry and Chemical Engineering, Luoyang Normal University,
Luoyang, Henan 471022, China
bDepartment of Life Science, Luoyang Normal University, Luoyang, Henan 471022,
China
modulated Pd/Cu cocatalyzed three-component reaction of
aminobenzyl alcohols, aryl ketones, and arylboronic acids in
air, providing a series of luminescent arylquinolines.
cCollege of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou,
Henan 450001, China. E-mail: xubohan@163.com, xqhao@zzu.edu.cn
†Electronic supplementary information (ESI) available: 1H and 13C NMR spectra
Results and discussion
for all products. The absorption and photoluminescence spectra for 3–30. CCDC
969892–969893, 969896–969899. For ESI and crystallographic data in CIF or
other electronic format see DOI: 10.1039/c4ob00231h
The synthetic route to two new NHC adducts of cyclopalla-
dated ferrocenylpyrazine complexes 1–2 is demonstrated in
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alcohol, and phenylboronic acid in air was chosen as the
model reaction.
Table 1 provides information on the impact of a catalyst, a
base and a solvent on the efficiency of this process. In the
absence of copper salts, the desired product 3 was not
observed using 2 as a catalyst and only 4-acetylbiphenyl was
produced as a Suzuki coupling product. Then, different
copper salts and NHC adducts of palladacycle were tested
in the presence of air with K2CO3 as a base in dioxane
(entries 1–5). The results indicated that 2/Cu(OAc)2 was the
best among these tested catalysts (65%, entry 3). The effect of
bases and solvents was further investigated under the above
conditions (entries 6–14). We were delighted to find that
the use of Cs2CO3 and dioxane leads to an improvement in
performance of this MCR, and 3 was isolated in a 90% yield
(entry 8), showing that this MCR is viable. Decreasing the
Pd catalyst loading to 0.1 mol% led to a TON of 610 and a
moderate yield (entry 15).
Scheme 1 Preparation of adducts of cyclopalladated ferrocenylpyra-
zine complexes 1–2.
With the optimized conditions in hand, the scope of the
reaction was investigated with various arylboronic acids
(Table 2). Similar to the result of phenylboronic acid, a good
yield (88%) was obtained in the case of 1-naphthylboronic
acid. The electronic nature of the substituents on the arylboro-
nic acids did have an effect on the reaction. Electron-donating
substrates reacted to give the corresponding products 5–7, the
yields (89–93%) are slightly higher than the yields (76–81%) of
electron-withdrawing substrates 8–10.
In contrast to 2-arylquinolines, only one example of 2,6-di-
arylquinoline has been reported.19 To broaden the substrate
scope, we further investigated this MCR under the same reac-
tion conditions using (2-amino-5-bromophenyl)methanol
instead of 2-aminobenzyl alcohol. Gratifyingly, as depicted in
Table 3, the corresponding 6-aryl-2-phenylquinolines 11–18
were also obtained with good yields (79–94%). Moreover, aryl-
quinolines 13, 15 and 17 were confirmed by X-ray diffraction
(Fig. S2–4†).
Finally, this newly developed coupling protocol was applied
to the synthesis of larger conjugated 6-aryl-2-((1,1′-biaryl)-4-yl)-
quinolines via oxidation/double Suzuki coupling of arylboronic
acids, 4-bromoacetophenone, and (2-amino-5-bromophenyl)-
methanol. As shown in Table 4, the desired 2,6-diarylquino-
lines 19–25 were isolated in good yields (75–91%) by using
3 equiv. of arylboronic acids and a Pd catalyst loading of 2 mol%.
In the same manner, switching the methyl or methoxy
group from the para-position to the ortho-position on the
benzene ring does influence the yields (76 and 79%) of 26 and
27, demonstrating that steric factors have an influence on the
Suzuki reaction. This protocol was found also to proceed suc-
cessfully with pyridinylboronic acid, furnishing moderate
yields (60 and 65%) of 29 and 30. Additionally, the molecular
structure of 27 is depicted in Fig. 2. The whole molecular struc-
ture is not planar, the dihedral angle between the middle
benzene ring and the quinoline ring is 25.4°; the benzene ring
containing the methoxy group is not coplanar to the quinoline
ring and the middle benzene ring (dihedral angles are 52.3°
and 44.0°, respectively).
Fig. 1 Molecular structure of
molecules).
2 (one of the two independent
Scheme 1. The cyclopalladation reaction was carried out with
ferrocenylpyrazine and 1 equivalent of Li2PdCl4 and NaOAc in
methanol at room temperature for 24 h. The formed red solids
were collected by filtration, and can be assigned to a dimeric
complex of palladium.15a,b Because of its poor solubility in all
common organic solvents, it was not characterized and directly
subjected to bridge-splitting reaction. The complexes 1–2 are
air and moisture stable both in the solid state and in solution.
Their structures were fully characterized by NMR and MS as
well as by single crystal X-ray analysis (Fig. S1† and Fig. 1). The
Pd–Ccarb [1.991(7) and 2.010(7) Å] bond lengths of complex 2
are similar to those of the related carbene adducts
(1.991–1.998 Å),16 while they are longer than that of complex 1
[1.984(4) Å] possibly due to the steric bulk of the IPr [N,N′-
bis(2,6-diisopropylphenyl)-imidazole-2-ylidene] ligand.
The Suzuki reaction is an extremely practical method in
organic synthesis. These reactions were generally carried out
under the protection of inert gas.17 Under an ambient atmos-
phere, the NHC-modulated Pd-catalyzed Suzuki reaction and
alcohol oxidation have been relatively less reported.11b,12a Con-
sidering that palladacycles are one of the most active catalysts
for coupling reactions,18 we hypothesized that NHC adducts of
palladacycles in combination with a copper additive can co-
catalyze the one-pot oxidation/Suzuki reaction. Thus, the three-
component reaction of 4-bromoacetophenone, 2-aminobenzyl
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Table 1 Optimization of the three-component reaction conditionsa
Entry
Catalyst (mol%)
Base
Solvent
Yieldb (%)
1
2
3
4
5
6
7
8
1/CuCl2 (1/6)
2/CuCl2 (1/6)
2/Cu(OAc)2 (1/6)
2/CuCl (1/6)
2/CuI (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (1/6)
2/Cu(OAc)2 (0.1/6)
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
KOH
Na2CO3
Cs2CO3
K3PO4
KOAc
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Cs2CO3
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
Dioxane
THF
23
49
65
30
18
34
51
90
58
37
45
72
67
42
61
9
10
11
12
13
14
15
Toluene
Xylene
DMF
Dioxane
a Reaction conditions: 4-bromoacetophenone (0.5 mmol), 2-aminobenzyl alcohol (0.6 mmol), phenylboronic acid (0.75 mmol), base (1.5 mmol),
solvent (3 mL), 110 °C, 20 h. b Isolated yield.
Table 2 Three-component reaction for the synthesis of 2-(1,1’-biaryl-4-yl)quinolinesa
a Reaction conditions: 2/Cu(OAc)2 (0.005/0.03 mmol), 4-bromoacetophenone (0.5 mmol), 2-aminobenzyl alcohol (0.6 mmol), arylboronic acids
(0.75 mmol), Cs2CO3 (1.5 mmol), dioxane (3 mL), 110 °C, 20 h. b Isolated yield.
The UV-Vis absorption and photoluminescence spectra of (411–417 nm) of arylquinolines bearing a electron-donating
3–27 were recorded in CH2Cl2 at rt, and the data are shown in methoxy group 6, 13 and 22 show a red shift versus the above
ESI.† Briefly, the structures of absorption and emission arylquinolines. In strong contrast, for 8, 18 and 26 the fluo-
spectra of the 2,6-diarylquinolines are similar to those of the rescence is heavily quenched, likely by a photoinduced elec-
same substituent-containing 2-arylquinolines. These arylqui- tron transfer process with the nitro group.20
nolines show emissions ranging from the purple to the blue
In summary, we have developed a NHC-modulated Pd/Cu
region. For example, the arylquinolines containing fluorine 10, cocatalyzed three-component reaction of aminobenzyl alco-
17 and 24 exhibit major absorption and emission bands at hols, aryl ketones, and arylboronic acids in air. This protocol
263–274 nm and 385–395 nm (Fig. 3), whereas the λmax,em provides an efficient access to a variety of 2,6-diarylquinolines
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Table 3 Three-component reaction for the synthesis of 6-aryl-2-phenylquinolinesa
a Reaction conditions: 2/Cu(OAc)2 (0.005/0.03 mmol), acetophenone (0.5 mmol), (2-amino-5-bromophenyl)methanol (0.6 mmol), arylboronic
acids (0.75 mmol), Cs2CO3 (1.5 mmol), dioxane (3 mL), 110 °C, 20 h. b Isolated yield.
Table 4 Synthesis of 6-aryl-2-(1,1’-biaryl-4-yl)quinolinesa
a Reaction conditions: 2/Cu(OAc)2 (0.01/0.03 mmol), 4-bromoacetophenone (0.5 mmol), (2-amino-5-bromophenyl)methanol (0.6 mmol),
arylboronic acids (1.5 mmol), Cs2CO3 (3 mmol), dioxane (3 mL), 110 °C, 24 h. b Isolated yield.
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Fig. 2 Molecular structure of 27. H atoms are omitted for clarity.
t
and BuOK (2.5 mmol) under nitrogen. Dry THF was added by
a cannula and stirred at room temperature for 3 hours. The
product was separated by passing through a short silica gel
column with CH2Cl2 as an eluent, the second band was col-
lected and afforded 1–2. (1). Yield 593.3 mg, 91%; 1H NMR
(400 MHz, CDCl3): δ 8.99 (d, 1H), 8.38 (s, 1H), 8.27–8.32 (m,
3H), 7.76 (d, J = 8.2 Hz, 2H), 7.38–7.46 (m, 4H), 7.13 (d, J = 8.1
Hz, 2H), 4.49 (s, 1H), 4.19 (s, 1H), 3.45 (s, 5H), 3.41 (s, 1H),
2.37 (s, 3H), 2.27 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 169.9,
161.6, 143.3, 140.5, 139.9, 138.7, 138.3, 138.1, 130.3, 129.7,
125.7, 125.2, 123.4, 122.8, 95.6, 85.1, 73.9, 70.2, 69.5, 63.0,
21.4; MS (EI, 70 eV) m/z = 617.1 (M − Cl)+; elemental analysis
calcd (%) for C31H27ClFeN4Pd: C 56.99, H 4.17, N 8.58. Found:
C 57.05, H 4.02, N 8.77; (2). Yield 697.1 mg, 88%; 1H NMR
(400 MHz, CDCl3): δ 9.05 (s, 1H), 8.34 (s, 1H), 8.11 (d, 1H),
7.46–7.50 (m, 3H), 7.30–7.35 (m, 3H), 7.19–7.21 (m, 3H), 7.05
(d, 1H), 4.55 (s, 1H), 4.32 (s, 1H), 3.92 (s, 1H), 3.39 (s, 5H),
3.12–3.27 (m, 2H), 2.88–2.94 (m, 2H), 1.53–1.62 (m, 9H), 1.42
(d, 3H), 1.12–1.22 (m, 3H), 0.98 (d, 3H), 0.86 (d, 3H); 13C NMR
(100 MHz, CDCl3): δ 173.8, 161.4, 148.1, 147.1, 145.5, 144.7,
143.6, 140.3, 139.1, 136.6, 136.3, 130.4, 130.1, 125.5, 125.1,
124.9, 124.7, 124.5, 123.3, 96.8, 84.9, 70.5, 69.6, 62.9, 29.8,
29.2, 29.1, 28.6, 28.0, 27.4, 25.6, 25.2, 23.8, 23.5, 23.4, 21.8; MS
(EI, 70 eV) m/z = 757.2 (M − Cl)+; elemental analysis calcd (%)
for C41H47ClFeN4Pd: C 62.05, H 5.97, N 7.06. Found: C 62.11,
H 5.79, N 7.13.
Fig. 3 Normalized absorption and emission of 10, 17 and 24, emission
of 6, 13 and 22 (absorption spectra are omitted for clarity) in CH2Cl2
at rt.
via oxidation, cyclization and Suzuki reaction. Future work will
report on the photoactive complexes of these arylquinolines.
Experimental section
General methods
1H and 13C NMR spectra were recorded on a spectrometer in
CDCl3 at 400 and 100 MHz, respectively, with TMS as an
internal standard. MS experiments were performed with EI
General procedure for synthesis of 2-(1,1′-biaryl-4-yl)quinolines
3–10
source. All new compounds were further characterized by A 10 mL round-bottom flask was charged with the prescribed
elemental analysis. The absorption and photoluminescence amount of catalyst, 4-bromoacetophenone (0.5 mmol), 2-ami-
spectra were recorded on a UV-Vis and a fluorescence spectro- nobenzyl alcohol (0.6 mmol), arylboronic acids (0.75 mmol),
photometer in CH2Cl2 at rt, respectively. Solvents were dried the selected base (1.5 mmol) and solvent (3 mL). The reaction
and freshly distilled prior to use. All other chemicals were mixture was then placed in an oil bath and heated at 110 °C
commercially available except for ferrocenylpyrazine which was for 20 h, then cooled and quenched with water. The organic
prepared according to the published procedures.21 Com- layer was separated and the aqueous layer was extracted with
pounds 3,22 5 (spectra not provided),23 and 1119 are known ethyl acetate, then the combined organic layers were washed
compounds, while other compounds are new compounds.
with water, dried over MgSO4, filtered, and the solvent was
removed on a rotary evaporator. The resulting residue was puri-
fied by flash chromatography on silica gel using CH2Cl2–
Preparation of complexes 1–2
A mixture of ferrocenylpyrazine (1 mmol), Li2PdCl4 (1.1 mmol) petroleum ether (1/1) as an eluent. The third band was
and NaOAc (1 mmol) in 20 mL of dry methanol was stirred for collected and afforded the solids 3–10.
24 h at room temperature. The red solids (yield: 91%) were
2-(1′-Naphthyl-1-phenyl-4-yl)quinoline (4). Yield 109.7 mg,
collected by filtration and washed several times with metha- 88%; 1H NMR (400 MHz, CDCl3): δ 8.23–8.30 (m, 4H),
nol. A Schlenk tube was charged with the above red solids 7.82–8.03 (m, 5H), 7.73–7.80 (m, 1H), 7.67 (d, J = 8.3 Hz, 2H),
(0.5 mmol), the corresponding imidazolium salts (1.25 mmol) 7.42–7.55 (m, 5H); 13C NMR (100 MHz, CDCl3): δ 157.2, 148.4,
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141.9, 139.8, 138.7, 136.9, 131.6, 130.7, 129.8, 128.4, 127.9, 127.3, 126.4, 126.0, 125.9, 119.0, 118.8, 115.9, 115.7; MS (EI,
127.6, 127.3, 127.0, 126.4, 126.2, 126.0, 125.9, 125.5, 119.1; MS 70 eV) m/z = 300.1 (M + H)+; elemental analysis calcd (%) for
(EI, 70 eV) m/z = 332.1 (M + H)+; elemental analysis calcd (%) C21H14FN: C 84.26, H 4.71, N 4.68. Found: C 84.21, H 4.64,
for C25H17N: C 90.60, H 5.17, N 4.23. Found: C 90.69, H 5.06, N 4.86.
N 4.28.
General procedure for synthesis of 6-aryl-2-phenylquinolines
11–18
2-(4′-Methylbiphenyl-4-yl)quinoline (5). Yield 119.2 mg,
1
92%; H NMR (400 MHz, CDCl3): δ 8.20–8.24 (m, 4H), 7.90 (d,
J = 4.6 Hz, 1H), 7.84 (d, J = 4.6 Hz, 1H), 7.73–7.75 (m, 3H), A 10 mL round-bottom flask was charged with 2/Cu(OAc)2
7.51–7.57 (m, 3H), 7.28 (d, J = 7.9 Hz, 2H), 2.41 (s, 3H); 13C (0.005/0.03 mmol), acetophenone (0.5 mmol), (2-amino-5-
NMR (100 MHz, CDCl3): δ 157.0, 148.3, 142.0, 138.3, 137.7, bromophenyl)methanol (0.6 mmol), arylboronic acids
137.5, 136.8, 129.7, 129.6, 128.0, 127.5, 127.4, 127.2, 127.0, (0.75 mmol), Cs2CO3 (1.5 mmol) and dioxane (3 mL). The reac-
126.3, 119.0, 21.2; MS (EI, 70 eV) m/z = 296.1 (M + H)+; elemen- tion mixture was then placed in an oil bath and heated at
tal analysis calcd (%) for C22H17N: C 89.46, H 5.80, N 4.74. 110 °C for 20 h. After removal of the solvent, the resulting
Found: C 89.52, H 5.89, N 4.57.
residue was purified by flash chromatography on silica gel
2-(4′-Methoxybiphenyl-4-yl)quinoline (6). Yield 149.7 mg, using CH2Cl2–petroleum ether (1/1) as an eluent. The third
93%; 1H NMR (400 MHz, CDCl3): δ 8.24 (d, J = 8.4 Hz, 3H), band was collected and afforded the solids 11–18.
8.21 (d, J = 8.4 Hz, 1H), 7.93 (d, J = 8.6 Hz, 1H), 7.83 (d, J =
6-(4-Methylphenyl)-2-phenylquinoline (12). Yield 137.2 mg,
8.0 Hz, 1H), 7.73 (m, 3H), 7.62 (m, 2H), 7.55 (m, 1H), 7.02 (d, 93%; 1H NMR (400 MHz, CDCl3): δ 8.16–8.24 (m, 4H), 7.98 (m,
J = 8.8 Hz, 2H), 3.88 (s, 3H); 13C NMR (100 MHz, CDCl3): 2H), 7.88 (d, J = 8.6 Hz, 1H), 7.64 (d, J = 8.1 Hz, 2H), 7.46–7.55
δ 159.4, 148.4, 141.7, 136.8, 133.1, 129.7, 129.6, 128.2, 127.9, (m, 3H), 7.31 (d, J = 8.0 Hz, 2H), 2.43 (s, 3H); 13C NMR
127.5, 127.1, 126.2, 118.9, 114.3, 55.4; MS (EI, 70 eV) m/z = (100 MHz, CDCl3): δ 157.2, 147.6, 139.7, 138.9, 138.3, 137.6,
312.1 (M + H)+; elemental analysis calcd (%) for C22H17NO: 137.5, 136.9, 136.8, 136.7, 130.1, 129.7, 129.5, 129.4, 129.3,
C 84.86, H 5.50, N 4.50. Found: C 84.80, H 5.43, N 4.64.
128.9, 127.6, 127.2, 126.8, 124.8, 119.4, 21.2; MS (EI, 70 eV) m/z
2-(3′-Methoxybiphenyl-4-yl)quinoline (7). Yield 138.5 mg, = 296.1 (M + H)+; elemental analysis calcd (%) for C22H17N:
1
89%; H NMR (400 MHz, CDCl3): δ 8.17–8.25 (m, 4H), 7.89 (d, C 89.46, H 5.80, N 4.74. Found: C 89.55, H 5.72, N 4.67.
J = 8.6 Hz, 1H), 7.81 (d, J = 8.1 Hz, 1H), 7.70–7.76 (m, 3H),
6-(4-Methoxyphenyl)-2-phenylquinoline (13). Yield 146.2 mg,
1
7.51–7.53 (m, 1H), 7.36–7.40 (m, 1H), 7.20–7.27 (m, 2H), 94%; H NMR (400 MHz, CDCl3): δ 8.17–8.26 (m, 4H), 7.97 (t,
6.91–6.94 (m, 1H), 3.87 (s, 3H); 13C NMR (100 MHz, CDCl3): 2H), 7.90 (d, J = 8.6 Hz, 1H), 7.69 (d, J = 8.6 Hz, 2H), 7.47–7.54
δ 160.0, 156.9, 148.4, 142.1, 141.9, 138.7, 136.9, 129.9, 129.8, (m, 3H), 7.04 (d, J = 8.8 Hz, 2H), 3.89 (s, 3H); 13C NMR
129.7, 128.0, 127.6, 127.5, 127.3, 126.4, 119.7, 118.9, 113.0, (100 MHz, CDCl3): δ 159.5, 147.4, 138.6, 136.8, 132.9, 130.1,
112.9, 55.4; MS (EI, 70 eV) m/z = 312.1 (M + H)+; elemental 129.3, 129.2, 128.9, 128.4, 127.5, 127.4, 124.3, 119.3, 114.4,
analysis calcd (%) for C22H17NO: C 84.86, H 5.50, N 4.50. 55.4; MS (EI, 70 eV) m/z = 312.1 (M + H)+; elemental analysis
Found: C 84.77, H 5.45, N 4.61.
calcd (%) for C22H17NO: C 84.86, H 5.50, N 4.50. Found:
2-(3′-Nitrobiphenyl-4-yl)quinoline (8). Yield 130.5 mg, 80%; C 84.74, H 5.42, N 4.67.
1H NMR (400 MHz, CDCl3): δ 8.51 (s, 1H), 8.19–8.24 (m, 5H),
6-(3-Methoxyphenyl)-2-phenylquinoline (14). Yield 140.0 mg,
7.92–8.00 (m, 2H), 7.54–7.86 (m, 6H); 13C NMR (100 MHz, 90%; 1H NMR (400 MHz, CDCl3): δ 8.16–8.23 (m, 4H),
CDCl3): δ 156.4, 148.8, 148.3, 142.3, 139.8, 139.4, 137.0, 133.1, 7.96–7.98 (m, 2H), 7.87 (d, J = 8.4 Hz, 1H), 7.42–7.55 (m, 3H),
129.9, 129.8, 128.3, 127.6, 127.5, 127.3, 126.6, 122.3, 121.9, 7.38–7.40 (m, 1H), 7.32 (m, 1H), 7.25 (m, 1H), 6.93 (m, 1H),
118.9; MS (EI, 70 eV) m/z = 327.1 (M + H)+; elemental analysis 3.89 (s, 3H); 13C NMR (100 MHz, CDCl3): δ 160.1, 157.3, 147.7,
calcd (%) for C21H14N2O2: C 77.29, H 4.32, N 8.58. Found: 141.9, 139.6, 138.8, 136.9, 130.1, 129.9, 129.3, 128.9, 127.5,
C 77.22, H 4.27, N 8.66.
127.3, 125.2, 119.9, 119.4, 113.1, 113.0, 55.3; MS (EI, 70 eV) m/z
2-(4′-Acetylbiphenyl-4-yl)quinoline (9). Yield 126.5 mg, 78%; = 312.1 (M + H)+; elemental analysis calcd (%) for C22H17NO:
1H NMR (400 MHz, CDCl3): δ 8.18–8.30 (m, 3H), 8.05 (m, 3H), C 84.86, H 5.50, N 4.50. Found: C 84.95, H 5.44, N 4.58.
7.93 (d, J = 8.6 Hz, 1H), 7.70–7.85 (m, 6H), 7.55 (t, 1H), 2.65
6-(1-Naphthyl)-2-phenylquinolines (15). Yield 144.1 mg,
(s, 3H); 13C NMR (100 MHz, CDCl3): δ 197.8, 156.6, 148.4, 87%; 1H NMR (400 MHz, CDCl3): δ 8.20–8.29 (m, 4H),
145.1, 144.4, 140.6, 139.5, 136.9, 136.6, 136.1, 129.8, 129.7, 7.88–7.96 (m, 6H), 7.45–7.58 (m, 7H); 13C NMR (100 MHz,
129.0, 128.1, 127.7, 127.5, 127.4, 127.3, 127.2, 126.5, 118.9, CDCl3): δ 157.5, 147.6, 139.7, 139.5, 138.8, 136.9, 136.5, 133.8,
26.7; MS (EI, 70 eV) m/z = 324.1 (M + H)+; elemental analysis 132.3, 131.6, 129.4, 129.3, 128.9, 128.8, 128.4, 128.2, 128.0,
calcd (%) for C23H17NO: C 85.42, H 5.30, N 4.33. Found: 127.6, 127.3, 127.1, 126.3, 125.9, 125.8, 125.4, 119.4; MS (EI,
C 85.49, H 5.25, N 4.26.
70 eV) m/z = 332.1 (M + H)+; elemental analysis calcd (%)
2-(4′-Fluorobiphenyl-4-yl)quinoline (10). Yield 121.2 mg, for C25H17N: C 90.60, H 5.17, N 4.23. Found: C 90.71, H 5.08,
81%; 1H NMR (400 MHz, CDCl3): δ 8.17–8.25 (m, 4H), N 4.34.
7.50–7.90 (m, 8H), 7.24–7.31 (m, 1H), 7.12–7.17 (m, 1H); 13C
NMR (100 MHz, CDCl3): δ 157.2, 156.8, 148.4, 143.1, 141.5, 81%; H NMR (400 MHz, CDCl3): δ 8.27 (m, 2H), 8.19 (m, 2H),
141.1, 138.6, 136.9, 136.7, 136.6, 135.5, 131.6, 130.5, 130.0, 8.02–8.10 (m, 5H), 7.93 (d, J = 8.6 Hz, 1H), 7.83 (d, J = 8.4 Hz,
129.8, 129.7, 128.8, 128.7, 128.0, 127.7, 127.6, 127.5, 127.4, 2H), 7.21 (d, J = 8.4 Hz, 2H), 2.65 (s, 3H); 13C NMR (100 MHz,
6-(4-Acetylphenyl)-2-phenylquinoline (16). Yield 130.9 mg,
1
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CDCl3): δ 197.8, 157.8, 148.0, 144.9, 144.3, 139.4, 137.6, 137.1, (m, 5H), 7.98 (s, 1H), 7.91 (d, J = 8.8 Hz, 2H), 7.74 (d, J = 8.4
136.6, 136.1, 130.5, 129.6, 129.1, 129.0, 128.9, 127.6, 127.5, Hz, 3H), 7.52–7.59 (m, 4H), 7.28 (d, J = 8.0 Hz, 2H), 2.41 (s,
127.4, 127.3, 125.8, 119.6, 26.8; MS (EI, 70 eV) m/z = 324.1 6H); 13C NMR (100 MHz, CDCl3): δ 160.0, 148.4, 142.0, 138.3,
(M + H)+; elemental analysis calcd (%) for C23H17NO: C 85.42, 137.7, 137.6, 137.5, 136.9, 136.8, 130.1, 129.7, 129.6, 129.3,
H 5.30, N 4.33. Found: C 85.48, H 5.26, N 4.24.
128.9, 127.9, 127.6, 127.5, 127.4, 127.2, 127.0, 126.3, 124.8,
6-(4-Fluorophenyl)-2-phenylquinoline (17). Yield 125.6 mg, 119.4, 118.9, 21.2; MS (EI, 70 eV) m/z = 386.2 (M + H)+; elemen-
84%; 1H NMR (400 MHz, CDCl3): δ 8.16–8.21 (m, 4H), tal analysis calcd (%) for C29H23N: C 90.35, H 6.01, N 3.63.
7.88–7.94 (m, 3H), 7.66–7.70 (m, 2H), 7.47–7.55 (m, 3H), Found: C 90.46, H 5.92, N 3.55.
7.16–7.20 (m, 2H); 13C NMR (100 MHz, CDCl3): δ 163.9, 161.5,
2-(4′-Methoxybiphenyl-4-yl)-6-(4-methoxyphenyl)quinoline
1
157.4, 147.6, 139.6, 138.0, 136.9, 136.6, 136.5, 130.3, 129.4, (22). Yield 189.8 mg, 91%; H NMR (400 MHz, CDCl3): δ 8.23
129.2, 129.1, 129.0, 128.9, 127.6, 127.4, 125.0, 119.5, 116.0, (d, J = 8.4 Hz, 5H), 7.92 (d, J = 8.6 Hz, 2H), 7.73 (m, 2H), 7.63
115.8; MS (EI, 70 eV) m/z = 300.1 (M + H)+; elemental analysis (d, J = 8.8 Hz, 3H), 7.53–7.55 (m, 2H), 7.02 (d, J = 8.8 Hz, 3H),
calcd (%) for C21H14FN: C 84.26, H 4.71, N 4.68. Found: 3.87 (s, 6H); 13C NMR (100 MHz, CDCl3): δ 159.4, 157.0, 148.4,
C 84.32, H 4.61, N 4.77.
141.7, 137.9, 136.8, 133.1, 129.7, 129.6, 128.2, 127.9, 127.5,
6-(3-Nitrophenyl)-2-phenylquinoline (18). Yield 133.7 mg, 127.2, 127.1, 126.3, 118.9, 114.3, 55.4; MS (EI, 70 eV) m/z =
1
82%; H NMR (400 MHz, CDCl3): δ 8.49 (t, 1H), 8.30 (m, 1H), 418.2 (M + H)+; elemental analysis calcd (%) for C29H23NO2:
8.16–8.23 (m, 2H), 7.96 (d, J = 8.0 Hz, 1H), 7.82–7.84 (m, 2H), C 83.43, H 5.55, N 3.35. Found: C 83.32, H 5.61, N 3.48.
7.67–7.75 (m, 3H), 7.44–7.55 (m, 4H); 13C NMR (100 MHz,
2-(4′-Acetylbiphenyl-4-yl)-6-(4-acetylphenyl)quinoline
(23).
1
CDCl3): δ 157.4, 148.3, 140.3, 139.7, 136.8, 133.1, 130.3, 129.8, Yield 165.5 mg, 75%; H NMR (400 MHz, CDCl3): δ 8.25–8.31
129.7, 129.3, 128.9, 127.6, 127.5, 127.2, 126.3, 123.3, 122.1, (m, 2H), 8.19 (d, J = 7.6 Hz, 1H), 8.05–8.09 (m, 5H), 7.94 (d, J =
119.1; MS (EI, 70 eV) m/z = 327.1 (M + H)+; elemental analysis 8.6 Hz, 1H), 7.71–7.82 (m, 7H), 7.55 (m, 1H), 2.66 (s, 6H);
calcd (%) for C21H14N2O2: C 77.29, H 4.32, N 8.58. Found: 13C NMR (100 MHz, CDCl3): δ 197.7, 169.0, 166.5, 156.6, 148.2,
C 77.21, H 4.24, N 8.69.
144.4, 136.6, 129.8, 129.7, 129.0, 128.1, 127.7, 127.5, 127.4,
127.2, 126.5, 118.9, 26.8; MS (EI, 70 eV) m/z = 442.2 (M + H)+;
elemental analysis calcd (%) for C31H23NO2: C 84.33, H 5.25,
N 3.17. Found: C 84.44, H 5.32, N 3.05.
General procedure for synthesis of 6-aryl-2-(1,1′-biaryl-4-yl)-
quinolines 19–30
A 10 mL round-bottom flask was charged with 2/Cu(OAc)2
2-(4′-Fluorobiphenyl-4-yl)-6-(4-fluorophenyl)quinoline (24).
1
(0.01/0.03 mmol), 4-bromoacetophenone (0.5 mmol), Yield 157.2 mg, 80%; H NMR (400 MHz, CDCl3): δ 8.18–8.23
(2-amino-5-bromophenyl)methanol (0.6 mmol), arylboronic (m, 4H), 7.91–7.96 (m, 2H), 7.84 (d, J = 8.2 Hz, 1H), 7.68–7.76
acids (1.5 mmol), Cs2CO3 (3.0 mmol) and dioxane (3 mL). The (m, 3H), 7.62–7.65 (m, 2H), 7.48–7.56 (m, 2H), 7.15–7.22 (m,
reaction mixture was then placed in an oil bath and heated at 3H); 13C NMR (100 MHz, CDCl3): δ 156.9, 148.5, 141.2, 138.7,
110 °C for 24 h. After removal of the solvent, the resulting 138.2, 137.0, 136.9, 130.5, 129.9, 129.8, 129.2, 129.1, 129.0,
residue was purified by flash chromatography on silica gel 128.9, 128.8, 128.2, 127.7, 127.6, 127.5, 126.5, 125.2, 119.6,
using CH2Cl2–petroleum ether (1/1) as an eluent. The third 118.9, 116.1, 116.0, 115.9, 115.8; MS (EI, 70 eV) m/z = 394.1
band was collected and afforded the solids 19–30.
(M + H)+; elemental analysis calcd (%) for C27H17F2N: C 82.43,
2-(Biaryl-4-yl)-6-phenylquinoline (19). Yield 151.8 mg, 85%; H 4.36, N 3.56. Found: C 82.27, H 4.26, N 3.75.
1H NMR (400 MHz, CDCl3): δ 8.17–8.26 (m, 5H), 8.00 (t, 1H),
2-(3′-Methoxybiphenyl-4-yl)-6-(3-methoxyphenyl)quinoline
7.90–7.93 (m, 1H), 7.83 (d, J = 8.6 Hz, 1H), 7.67–7.77 (m, 5H), (25). Yield 185.7 mg, 89%; 1H NMR (400 MHz, CDCl3):
7.46–7.53 (m, 5H), 7.39 (t, 1H); 13C NMR (100 MHz, CDCl3): δ 8.22–8.27 (m, 4H), 7.98 (m, 2H), 7.93 (d, J = 8.6 Hz, 1H), 7.76
δ 157.3, 148.4, 142.1, 140.6, 140.4, 139.7, 139.0, 138.6, 137.0, (d, J = 8.4 Hz, 2H), 7.37–7.44 (m, 2H), 7.32 (d, J = 8.0 Hz, 1H),
136.8, 130.2, 129.7, 129.4, 129.0, 128.9, 128.0, 127.7, 127.6, 7.21–7.28 (m, 3H), 6.92–6.97 (m, 2H), 3.90 (s, 3H), 3.89 (s, 3H);
127.5, 127.4, 127.3, 127.2, 126.3, 125.2, 119.4; MS (EI, 70 eV) 13C NMR (100 MHz, CDCl3): δ 160.1, 160.0, 156.8, 147.8, 142.1,
m/z = 358.2 (M + H)+; elemental analysis calcd (%) for 141.9, 141.8, 138.8, 138.6, 137.0, 130.1, 130.0, 129.9, 129.4,
C27H19N: C 90.72, H 5.36, N 3.92. Found: C 90.78, H 5.25, 127.9, 127.6, 127.3, 125.2, 119.9, 119.7, 119.2, 113.1, 113.0,
N 3.97.
112.9, 55.4, 55.3; MS (EI, 70 eV) m/z = 418.2 (M + H)+; elemen-
2-(1′-Naphthyl-1-phenyl-4-yl)-6-(1-naphthyl)quinoline (20). Yield tal analysis calcd (%) for C29H23NO2: C 83.43, H 5.55, N 3.35.
198.9 mg, 87%; 1H NMR (400 MHz, CDCl3): δ 8.31–8.38 (m, Found: C 83.61, H 5.43, N 3.46.
4H), 7.95–8.05 (m, 9H), 7.72 (d, J = 7.8 Hz, 2H), 7.49–7.61 (m,
2-(3′-Nitrobiphenyl-4-yl)-6-(3-nitrophenyl)quinoline (26).
8H); 13C NMR (100 MHz, CDCl3): δ 147.7, 141.9, 138.9, 138.7, Yield 174.4 mg, 78%. 1H NMR (400 MHz, CDCl3): δ 8.54 (m,
137.0, 133.9, 132.4, 131.6, 130.7, 129.5, 128.5, 128.4, 128.3, 1H), 8.50 (m, 1H), 8.18–8.33 (m, 5H), 8.07–8.09 (m, 1H),
128.1, 127.9, 127.6, 127.4, 127.2, 126.9, 126.4, 126.2, 126.0, 7.93–8.01 (m, 3H), 7.86 (d, J = 8.2 Hz, 1H), 7.58–7.81 (m, 4H),
125.9, 125.5, 119.5; MS (EI, 70 eV) m/z = 458.2 (M + H)+; 7.54–7.58 (m, 1H). 13C NMR (100 MHz, CDCl3): δ 189.5, 156.3,
elemental analysis calcd (%) for C35H23N: C 91.87, H 5.07, 148.8, 148.3, 142.3, 140.3, 139.8, 139.4, 137.1, 136.9, 133.2,
N 3.06. Found: C 91.96, H 5.01, N 3.13.
133.1, 133.0, 129.8, 128.9, 128.3, 127.6, 127.5, 126.5, 123.3,
2-(4′-Methylbiphenyl-4-yl)-6-(4-methylphenyl)quinoline (21). 122.9, 122.3, 122.2, 122.1, 121.9, 119.8, 118.8; MS (EI, 70 eV)
1
Yield 169.5 mg, 88%; H NMR (400 MHz, CDCl3): δ 8.21–8.25 m/z = 448.1 (M + H)+; elemental analysis calcd (%) for
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C27H17N3O4: C 72.48, H 3.83, N 9.39. Found: C 72.63, H 3.70,
N 9.28.
J. A. McCammon and S. M. Cohen, J. Am. Chem. Soc., 2010,
132, 8232; (c) B. Leόn, J. C. N. Fong, K. C. Peach,
W. R. Wong, F. H. Yildiz and R. G. Linington, Org. Lett.,
2013, 15, 1234.
2 (a) S. P. Economopoulos, C. L. Chochos, V. G. Gregorlou,
J. K. Kallitsis, S. Barrau and G. Hadziioannou, Macromole-
cules, 2007, 40, 921; (b) R. S. Walters, C. M. Kraml,
N. Byrne, D. M. Ho, Q. Qin, F. J. Coughlin, S. Bernhard and
R. A. Pascal, J. Am. Chem. Soc., 2008, 130, 16435;
(c) R. Cinar, J. Nordmann, E. Dirksen and T. J. J. Müller,
Org. Biomol. Chem., 2013, 11, 2597.
3 (a) Q. Zhao, C. Y. Jiang, M. Shi, F. Y. Li, T. Yi, Y. Cao and
C. H. Huang, Organometallics, 2006, 25, 3631; (b) Z. H. Ma,
J. Q. Ding, B. H. Zhang, C. Y. Mei, Y. X. Cheng, Z. Y. Xie,
L. X. Wang, X. B. Jing and F. S. Wang, Adv. Funct. Mater.,
2010, 20, 138; (c) A. Wada, Q. S. Zhang, T. Yasuda,
I. Takasu, S. Enomoto and C. Adachi, Chem. Commun.,
2012, 5340; (d) A. Zucca, D. Cordeschi, L. Maidich,
M. I. Pilo, E. Masolo, S. Stoccoro, M. A. Cinellu and S. Galli,
Inorg. Chem., 2013, 52, 7717.
4 (a) R. Martínez, D. J. Ramόn and M. Yus, J. Org. Chem.,
2008, 73, 9778; (b) J. Marco-Contelles, E. Pérez-Mayoral,
A. Samadi, M. C. Carreiras and E. Soriano, Chem. Rev.,
2009, 109, 2652; (c) S. V. Ryabukhin, V. S. Naumchik,
A. S. Plaskon, O. O. Grygorenko and A. A. Tolmachev,
J. Org. Chem., 2011, 76, 5774.
5 (a) C. S. Cho, B. T. Kim, T. J. Kim and S. C. Shim, Chem.
Commun., 2001, 2576; (b) C. S. Cho, B. T. Kim, H. J. Choi,
T. J. Kim and S. C. Shim, Tetrahedron, 2003, 59, 7997;
(c) K. Motokura, T. Mizugaki, K. Ebitani and K. Kaneda,
Tetrahedron Lett., 2004, 45, 6029; (d) R. Martínez,
D. J. Ramón and M. Yus, Tetrahedron, 2006, 62, 8988;
(e) R. Martínez, D. J. Ramόn and M. Yus, Eur. J. Org. Chem.,
2007, 1599.
6 (a) K. Taguchi, S. Sakaguchi and Y. Ishii, Tetrahedron Lett.,
2005, 46, 4539; (b) P. J. Black, G. Cami-Kobeci,
M. G. Edwards, P. A. Slatford, M. K. Whittlesey and
J. M. J. Williams, Org. Biomol. Chem., 2006, 4, 116;
(c) T. Suzuki, Chem. Rev., 2011, 111, 1825.
7 (a) C. S. Cho, H. J. Seok and S. C. Shim, J. Heterocycl.
Chem., 2005, 42, 1219; (b) C. S. Cho, W. X. Ren and
S. C. Shim, Tetrahedron Lett., 2006, 47, 6781; (c) C. S. Cho
and W. X. Ren, J. Organomet. Chem., 2007, 692, 4182.
8 (a) R. A. Sheldon, I. W. C. E. Arends and A. Dijksman,
Catal. Today, 2000, 57, 157; (b) D. R. Jensen, J. S. Pugsley
and M. S. Sigman, J. Am. Chem. Soc., 2001, 123, 7475;
(c) A. F. Lee, J. N. Naughton, Z. Liu and K. Wilson, ACS
Catal., 2012, 2, 2235.
2-(2′-Methoxybiphenyl-4-yl)-6-(2-methoxyphenyl)quinoline
(27). Yield 164.8 mg, 79%; 1H NMR (400 MHz, CDCl3):
δ 8.18–8.26 (m, 4H), 7.92–7.95 (m, 3H), 7.71 (d, J = 8.4 Hz, 2H),
7.37–7.47 (m, 4H), 7.01–7.11 (m, 4H), 3.86 (s, 3H), 3.85 (s, 3H);
13C NMR (100 MHz, CDCl3): δ 157.1, 156.7, 156.6, 147.6, 139.6,
138.3, 136.9, 136.7, 131.9, 130.8, 130.2, 130.1, 129.1, 129.0,
128.9, 127.6, 127.2, 127.1, 121.0, 120.9, 119.1, 111.3, 55.6; MS
(EI, 70 eV) m/z = 418.2 (M + H)+; elemental analysis calcd (%)
for C29H23NO2: C 83.43, H 5.55, N 3.35. Found: C 83.26,
H 5.49, N 3.54.
2-(2′-Methylbiphenyl-4-yl)-6-(2-methylphenyl)quinoline (28).
1
Yield 146.4 mg, 76%; H NMR (400 MHz, CDCl3): δ 8.20–8.26
(m, 4H), 7.95 (d, J = 8.6 Hz, 1H), 7.72–7.77 (m, 2H), 7.48–7.52
(m, 3H), 7.29–7.32 (m, 7H), 2.35 (s, 3H), 2.34 (s, 3H); 13C NMR
(100 MHz, CDCl3): δ 157.2, 147.4, 143.1, 141.5, 141.2, 140.1,
138.3, 136.9, 135.6, 135.5, 131.6, 130.5, 130.0, 129.8, 129.3,
127.7, 127.5, 127.3, 127.2, 127.0, 126.3, 126.0, 119.3, 119.0,
20.6; MS (EI, 70 eV) m/z = 386.2 (M + H)+; elemental analysis
calcd (%) for C29H23N: C 90.35, H 6.01, N 3.63. Found: C 90.48,
H 6.13, N 3.84.
2-(4-Phenylpyridine-4-yl)-6-pyridin-4-ylquinoline (29). Yield
107.7 mg, 60%. 1H NMR (400 MHz, CDCl3): δ 8.75 (br, 7H),
8.29–8.35 (m, 1H), 8.00–8.13 (m, 1H), 7.83 (d, J = 8.4 Hz, 1H),
7.54–7.68 (m, 7H); 13C NMR (100 MHz, CDCl3): δ 150.7, 150.5,
150.4, 147.6, 145.5, 137.4, 130.8, 128.6, 128.3, 127.5, 127.4,
126.0, 121.5, 119.6; MS (EI, 70 eV) m/z = 360.1 (M + H)+;
elemental analysis calcd (%) for C25H17N3: C 83.54, H 4.77,
N 11.69. Found: C 83.65, H 4.68, N 11.74.
2-(4-Phenylpyridine-3-yl)-6-pyridin-3-ylquinoline (30). Yield
116.7 mg, 65%. 1H NMR (400 MHz, CDCl3): δ 8.86 (br, 3H),
8.66 (br, 4H), 8.31–8.34 (m, 1H), 8.00–8.05 (m, 1H), 7.89 (d, J =
8.0 Hz, 3H), 7.78 (d, J = 8.4 Hz, 1H), 7.41–7.44 (m, 4H); 13C
NMR (100 MHz, CDCl3): δ 156.9, 149.3, 148.8, 148.2, 147.9,
139.1, 137.1, 135.6, 134.6, 134.3, 133.5, 131.9, 130.7, 129.0,
128.3, 127.6, 127.4, 126.8, 125.6, 123.8, 123.0, 119.5; MS (EI,
70 eV) m/z = 360.1 (M + H)+; elemental analysis calcd (%)
for C25H17N3: C 83.54, H 4.77, N 11.69. Found: C 83.61, H 4.83,
N 11.58.
Acknowledgements
This work was supported by the National Science Foundation
of China (no. 21272110, 21102135 and U1204205), the Aid
Project for the Leading Young Teachers in Henan Provincial
Institutions of Higher Education of China (2013GGJS–151) and
the Science Foundation of Henan Education Department
(14A150049).
9 B. A. Steinhoff, I. A. Guzei and S. S. Stahi, J. Am. Chem. Soc.,
2004, 126, 11268.
10 (a) T. Nishimura, T. Onoue, K. Ohe and S. Uemura, Tetra-
hedron Lett., 1998, 39, 6011; (b) T. Nishimura, T. Onoue,
K. Ohe and S. Uemura, J. Org. Chem., 1999, 64, 6750;
(c) J. A. Mueller and M. S. Sigman, J. Am. Chem. Soc., 2003,
125, 7005; (d) J. A. Mueller, A. Cowell, B. D. Chandler and
M. S. Sigman, J. Am. Chem. Soc., 2005, 127, 14817;
Notes and references
1 (a) J. P. Michael, Nat. Prod. Rep., 2008, 25, 166;
(b) M. Rouffet, C. A. F. Oliveira, Y. Udi, A. Agrawal, I. Sagi,
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Paper
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(e) T. S. Mei, E. W. Werner, A. J. Burckle and M. S. Sigman,
J. Am. Chem. Soc., 2013, 135, 6830.
11 (a) W. A. Herrmann, Angew. Chem., Int. Ed., 2002, 41, 1290;
(b) M. G. Dai, B. Liang, C. H. Wang, Z. J. You, J. Xiang,
G. B. Dong, J. H. Chen and Z. Yang, Adv. Synth. Catal.,
2004, 346, 1669; (c) S. P. Nolan, N-Heterocyclic Carbenes in
(b) C. Xu, Y. P. Zhang, Z. Q. Wang, W. J. Fu, X. Q. Hao,
Y. Xu and B. M. Ji, Chem. Commun., 2010, 6852;
(c) J. L. Niu, X. Q. Hao, J. F. Gong and M. P. Song, Dalton
Trans., 2011, 40, 5135; (d) C. Xu, Z. Q. Wang, Z. Li,
W. Z. Wang, X. Q. Hao, W. J. Fu, J. F. Gong, B. M. Ji and
M. P. Song, Organometallics, 2012, 31, 798.
Synthesis, Wiley-VCH, Weinheim, Germany, 2006; 16 (a) M. S. Viciu, R. A. Kelly III, E. D. Stevens, F. Naud,
(d) E. A. B. Kantchev, C. J. O’Brien and M. G. Organ, Angew.
Chem., Int. Ed., 2007, 46, 2768.
12 (a) D. R. Jensen, M. J. Schultz, J. A. Mueller and
M. S. Sigman, Angew. Chem., Int. Ed., 2003, 42, 3810;
(b) D. R. Jensen and M. S. Sigman, Org. Lett., 2003, 5, 63;
M. Studer and S. P. Nolan, Org. Lett., 2003, 5, 1479;
(b) E. A. B. Kantchev and J. Y. Ying, Organometallics,
2009, 28, 289; (c) C. Xu, H. M. Li, Z. Q. Wang,
W. J. Fu, Y. Q. Zhang and B. M. Ji, Aust. J. Chem., 2012, 65,
366.
(c) J. A. Mueller, C. P. Goller and M. S. Sigman, J. Am. 17 (a) N. Miyaura and A. Suzuki, Chem. Rev., 1995, 95, 2457;
Chem. Soc., 2004, 126, 9724; (d) C. N. Cornell and
M. S. Sigman, J. Am. Chem. Soc., 2005, 127, 2796;
(b) R. A. Altman and S. L. Buchwald, Nat. Protocols, 2007, 2,
3115.
(e) C. N. Cornell and M. S. Sigman, Inorg. Chem., 2007, 46, 18 J. Dupont, C. S. Consorti and J. Spencer, Chem. Rev., 2005,
1903; (f) O. Kose and S. Saito, Org. Biomol. Chem., 2010, 8, 105, 2527.
896; (g) X. L. Liu, Q. Q. Xia, Y. J. Zhang, C. Y. Chen and 19 M. Yao, H. Shibuya, T. Kato, H. Inoue and N. Yoshioka,
W. Z. Chen, J. Org. Chem., 2013, 78, 8531. Polyhedron, 2005, 24, 2828.
13 (a) Multicomponent Reactions, ed. J. Zhu and H. Bienaym, 20 (a) R. Ziessel, L. Bonardi and G. Ulrich, Dalton Trans., 2006,
Wiley-VCH, Weinheim, 2005; (b) D. J. Ramόn and M. Yus,
Angew. Chem., Int. Ed., 2005, 44, 1602; (c) A. Dömling,
Chem. Rev., 2006, 106, 17.
2913; (b) J. Massue, D. Frath, G. Ulrich, P. Retailleau and
R. Ziessel, Org. Lett., 2012, 14, 230.
21 R. Horikoshi, C. Nambu and T. Mochida, Inorg. Chem.,
2003, 42, 6868.
14 C. Xu, X. Q. Hao, Z. Q. Xiao, Z. Q. Wang, X. E. Yuan,
W. J. Fu, B. M. Ji and M. P. Song, J. Org. Chem., 2013, 78, 22 A. M. Berman, J. C. Lewis, R. G. Bergman and
8730. J. A. J. Ellman, J. Am. Chem. Soc., 2008, 130, 14926.
15 (a) C. Xu, Z. Q. Wang, W. J. Fu, X. H. Lou, Y. F. Li, F. F. Cen, 23 N. O. Buu-Hoi, N. Hoan and R. Royer, Bull. Soc. Chim. Fr.,
H. J. Ma and B. M. Ji, Organometallics, 2009, 28, 1909; 1950, 489.
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