Synthesis of aryl substituted quinones as β-secretase inhibitors: Ligand-free direct arylation of quinones with aryl halides

Article abstract of DOI:10.1134/S1070363214080295

The simple ligand-free direct arylation of quinones with aryl halides applying Pd(OAc)₂as a catalyst in accordance with Heck reaction was studied. This reaction provided a simple and efficient synthetic approach to efficient inhibitors of β-secretase aryl-substituted quinones.

Full text of DOI:10.1134/S1070363214080295

ISSN 1070-3632, Russian Journal of General Chemistry, 2014, Vol. 84, No. 8, pp. 1615–1621. © Pleiades Publishing, Ltd., 2014.
Synthesis of Aryl Substituted Quinones
as β-Secretase Inhibitors: Ligand-Free Direct Arylation
of Quinones with Aryl Halides1
Dawei Wang, Bingyang Ge, Shuyan Yang, Hongyan Miao, and Yuqiang Ding
The Key Laboratory of Food Colloids and Biotechnology, Ministry of Education,
School of Chemical and Material Engineering, Jiangnan University, Wuxi 214122,
Jiangsu Province, China
e-mail: wangdw@jiangnan.edu.cn; yding@jiangnan.edu.cn
Received June 17, 2014
Abstract—The simple ligand-free direct arylation of quinones with aryl halides applying Pd(OAc)2 as a
catalyst in accordance with Heck reaction was studied. This reaction provided a simple and efficient synthetic
approach to efficient inhibitors of β-secretase aryl-substituted quinones.
Keywords: ligand-free, quinones, inhibitors, arylation, Heck reaction
DOI: 10.1134/S1070363214080295
INTRODUCTION
synthesis [33–34]. Surprisingly, there were no
publications on the synthesis of aryl substituted
quinones based on Heck reaction though that involved
aryl halides. The latter are much more cost efficient
than corresponding aryl boronic acids. The The direct
arylation of quinones involving aryl halides and
catalysis by Pd(OAc)2 in accordance with Heck
reaction is presented in the current paper.
Aryl substituted quinones and naphthoquinones are
important building blocks and efficient precursors of
numerous biologically active natural compounds and
pharmaceuticals [1–7]. Due to their unique structure,
aryl substituted quinones exhibit various important
biological activities [8–11], such as antibiotic,
antiviral, antitumor, antimalaria, antidiabetic, and
anticancer. Aryl substituted quinones are efficiant
inhibitors of β-secretase (BACE1) [12–14]. Bermejo-
Bescós and coworkers [15] reported the reaction of
several arylquinones and their derivatives with the
amyloidogenic compounds. However, synthesis of aryl
substituted quinones by cross-coupling of quinones
with naphthoquinones was highly limited as well as
methods of synthesis of aryl substituted quinones and
naphthoquinones [16–24]. Diazonium derivatives [25]
and boronic acids are examples are typical examples of
starting materials [26–32]. In 2009 Molina et al. [26]
described the coupling reaction of quinones with
arylboronic acids that was leading to aryl quinones.
Several more studies were also devoted to such kind of
processes (Scheme 1) [26–32].
RESULTS AND DISSCUSION
Based on our earlier data [35–39], we had selected
the common Pd(OAc)2 as a catalyst of the reaction of
quinone with iodobenzene. The targeted product was
separated with 36% yield (Table 1, entry 1). Based on
Scheme 1. The direct arylation of quinones with aryl iodide
Previous work
O
O
O
Pd, Fe
+
ArBH(OH)2
Ar
O
O
This work
O
O
Over recent decades, palladium-catalyzed Heck
reaction or cross coupling reactions of aryl halides
with nucleophiles were successfully used in organic
R
Pd
+
I
Ar
1 The text was submitted by the authors in English.
O
1615

1616
DAWEI WANG et al.
Influence of bases on the process conditions was
Table 1. Reaction conditionsa
studied. The results have proven Cs2CO3 as the most
efficient one in this reaction.
O
O
Pd(OAc)2
base, solvent
+
PhI
Upon establishing the optimum conditions, namely
Pd(OAc)2 (5%), Cs2CO3 as the base in DCE media, the
progress of Pd-catalyzed direct arylation of quinones
was studied (Table 2). In most cases the corresponding
aryl substituted quinones were separated with good to
excellent yields. Application of meta-substituted
iodobenzene resulted in moderate yield of the product
(Table 2, entry 8).
Ph
O
O
IIIa
I
IIa
Entry
1
Base
Sovlent
Yieldb, %
36
Na2CO3
CH2Cl2
2
3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
Na2CO3
NaHCO3
KOH
Toluene
Benzene
DMF
THF
<5
<5
21
18
14
56
41
16
52
81
53
47
Synthesis of naphthoquinones under the optimum
conditions was studied. In general, the reaction could
proceed with moderate to good yield. It is noteworthy
that 1-(2-chloroetoxy)-4-iodobenzene was also
introduced in this reaction (Table 3, entry 9).
4
5
6
Dioxane
DCE
7
8
DCE
This method of Pd-catalyzed direct arylation of
quinones with aryl halides provided an efficient route
to synthesis of the inhibitors of β-secretase (BACE1)
based on cost efficient quinones. For example, 2-
phenylnaphthalene-1,4-dione (Va) was synthesized
according to this method with the yield 82% (Table 3,
entry 1). 2-(4-Hydroxyphenyl)naphthalene-1,4-dione
(VI) was synthesized by the following deprotection
reaction (Scheme 2) [41].
9
DCE
10
11
12
13
t-BuOK
Cs2CO3
K2CO3
DCE
DCE
DCE
t-BuONa
DCE
a
Conditions: I (0.5 mmol, 1.0 equiv.), IIa (1.5 equiv.), Pd(OAc)2
(5 mol %), base (1.5 equiv.), 2 mL solvent, 24 h, reflux. b Yields
base on I.
EXPERIMENTAL
General procedure. 1,4-Quinone, 1,4-naphtho-
quinone, palladium acetate and other chemicals were
obtained from commercial resources and used without
the resulting data, activity of various solvents was
evaluated (Table 1, entries 1–7). Superiority of 1,2-
dichloroethane over other solvents was established.
Scheme 2. Synthesis of BACE1 inhibitors B
O
O
Pd(OAc)2
+
I
OMe
Cs2CO3, DCE
O
O
OMe
IV
II
Vc (92%)
O
BBr3, CH2Cl2
−78°C−RT
O
OH
VI (81%)
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

SYNTHESIS OF ARYL SUBSTITUTED QUINONES
Table 2. Substrate expansion of quinonesa
1617
O
O
R
Pd(OAc)2
+ I
Cs2CO3, DCE
Ar
O
O
I
II
III
Entry Compound
Product
Yieldb, % Entry Compound
Product
Yieldb, %
1
81 (IIIa)
5
6
82 (IIIe)
O
I
O
I
O
O
t-Bu
O
t-Bu
2
83 (IIIb)
83 (IIIf)
I
I
O
O
OEt
CH3
O
O
OEt
CH3
3
O
94 (IIIc)
91 (IIId)
7
8
65 (IIIg)
53 (IIIh)
I
I
OCH3
OCH3
O
O
O
OCH3
CH3
4
O
I
I
H3C
O
Ph
O
Ph
CH3
a Conditions: I (0.5 mmol, 1.0 equiv.), II (1.5 equiv.), Pd(OAc)2 (5%), Cs2CO3 (1.5 equiv.), 2mL DCE, 24 h, reflux. b Yields base on I.
further purification. All solvents were dried, purified
and freshly distilled under nitrogen. The products were
isolated by column chromatography on silica gel (200–
300 mesh or 100–200 mesh) using petroleum ether
(60–90°C) and ethyl acetate as the eluent. The yields
presented herein are based on the results of column
chromatography. Reaction progress and product mix-
III 400 spectrometer in CDCl3 using tetramethylsilane
(TMS) as the reference.
General procedure for synthesis of IIIa from qui-
none and iodobenzene. A mixture of 1,4-quinone (I)
(54.0 mg, 0.50 mmol), iodobenzene (IIa) (153.0 mg,
0.75 mmol), Pd(OAc)2 (5.6 mg, 5 mol%), and Cs2CO3
(244.4 mg, 1.5 equiv.), in DCE (2.0 mL) was stirred at
90°C for 24 h. Upon completion, the solvent was eva-
1
tures were routinely monitored by TLC on SiO2. H
NMR spectra were recorded with a Bruker AVANCE
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

1618
DAWEI WANG et al.
Table 3. Substrate expansion of naphthoquinonesa
O
O
O
R
Pd(OAc)2
I
+
Cs2CO3, DCE
Ar
O
V
IV
II
Entry Compound
Product
O
Yieldb, % Entry Compound
Product
O
Yieldb, %
1
82 (Va)
86 (Vb)
7
8
85 (Vg)
I
I
O
O
O
Et
Et
O
2
3
81 (Vh)
I
I
CH3
O
O
O
CH3
CH3
CH3
92 (Vc)
9
76 (Vi)
O
O
I
I
O
OCH2CH2Cl
I
OCH3
I
OCH3
OHCH2CCl
O
O
4
5
82 (Vd)
80 (Ve)
10
11
88 (Vj)
85 (Vk)
CH3
CH3
O
O
O
Ph
I
Ph
I
O
OCH3
OCH3
t-Bu
O
O
t-Bu
O
I
6
90 (Vf)
O
OEt
OEt
a
Conditions: IV (0.5 mmol, 1.0 equiv.), II (1.5 equiv.), Pd(OAc)2 (5%), Cs2CO3 (1.5 equiv.), 2 mL DCE, 24 h, reflux. b Isolated yields
based on IV.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

SYNTHESIS OF ARYL SUBSTITUTED QUINONES
1619
porated. The residue was purified by column chro-
matography on silica gel (ethyl acetate/petroleum ether =
1 : 10, v : v) to give the corresponding product IIIa.
2-Phenyl[1,4]naphthoquinone (Va). Faint yellow
solid (82%). H NMR (400 MHz, CDCl3), δ, ppm:
8.22–8.17 m (1H), 8.16–8.10 m (1H), 7.82–7.74 m
(2H), 7.61–7.56 m (2H), 7.51–7.46 m (3H), 7.09 s
(1H).
1
General method of synthesis of the compounds
VI. The compound Vc (0.1 mmol) was dissolved in
dry CH2Cl2 (2.0 mL), cooled to –78°C and 0.32 mL of
BBr3 (1.0 M in CH2Cl2) was added drop wise upon
stirring. The cooling bath was removed and following
reaction mixture stirring for ca 8 h heated it up to room
temperature. The reaction was terminated by slow
addition of water. The layers were separated, the
organic phase washed with H2O, and the combined
aqueous layers evaporated to dryness. The residue was
separated in RP-18 column (MeOH : H2O = 35 : 65) to
give brown-violet solids VI.
2-p-Tolyl-[1,4]naphthoquinone (Vb). Faint yellow
1
solid (86%). H NMR (400 MHz, CDCl3), δ, ppm:
8.19 m (1H), 8.12 m (1H), 7.80–7.75 m (2H), 7.49 d
(J = 8.1 Hz, 2H), 7.29 d (J = 8.0 Hz, 2H), 7.07 s (1H),
2.42 s (3H).
2-(4-Methoxyphenyl)[1,4]naphthoquinone (Vc).
Faint yellow solid (92%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 8.17 m (1H), 8.10 m (1H), 7.79–7.72
m (2H), 7.58 d (J = 8.5 Hz, 2H), 7.04 s (1H), 6.99 d
(J = 8.6 Hz, 2H), 3.87 s (3H).
2-Phenyl[1,4]benzoquinone (IIIa). Faint yellow
solid (81%). H NMR (400 MHz, CDCl3), δ, ppm:
7.52–7.42 m (5H), 6.84–6.90 m (3H).
2-o-Tolyl[1,4]naphthoquinone (Vd). Faint yellow
solid (82%). H NMR (400 MHz, CDCl3), δ, ppm:
8.20–8.11 m (2H), 7.81–7.76 m (2H), 7.36 t (J =
7.4 Hz, 1H), 7.30–7.25 m (2H), 7.17 d (J = 7.5 Hz,
1H), 6.93 s (1H), 2.23 s (3H).
1
1
2-p-Tolyl-[1,4]benzoquinone (IIIb). Faint yellow
1
solid (83%). H NMR (400 MHz, CDCl3), δ, ppm:
7.39 d (J = 8.2 Hz, 2H), 7.26 d (J = 8.0 Hz, 2H), 6.88–
6.77 m (3H), 2.40 s (3H).
2-(4-tert-Butylphenyl)[1,4]naphthoquinone (Ve).
Faint yellow solid (80%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 8.19 m (1H), 8.12 m (1H), 7.77 m
(2H), 7.52 d.d (J = 17.4, 8.4 Hz, 4H), 7.08 s (1H), 1.36
s (9H).
2-(4-Methoxyphenyl)[1,4]benzoquinone (IIIc).
Faint yellow solid (94%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 7.48 d (J = 8.8 Hz, 2H), 6.97 d (J =
8.8 Hz, 2H), 6.88–6.77 m (3H), 3.86 s (3H).
2-(4-Ethoxyphenyl)[1,4]naphthoquinone (Vf).
Faint yellow solid (90%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 8.17 m (1H), 8.14–8.08 m (1H), 7.80–
7.73 m (2H), 7.57 d (J = 8.9 Hz, 2H), 7.05 s (1H), 6.98
d (J = 8.8 Hz, 2H), 4.10 q (J = 7.0 Hz, 2H), 1.45 t (J =
7.0 Hz, 3H).
2-Biphenyl-4-yl[1,4]benzoquinone (IIId). Faint
1
yellow solid (91%). H NMR (400 MHz, CDCl3), δ,
ppm: 7.77–7.59 m (6H), 7.50 t (J = 7.5 Hz, 2H), 7.41 t
(J = 7.5 Hz, 1H), 7.03–6.85 m (3H).
2-(4-tert-Butyl-phenyl)[1,4]benzoquinone (IIIe).
Faint yellow solid (82%).1H NMR (400 MHz, CDCl3),
δ, ppm: 7.47 d (J = 8.5 Hz, 2H), 7.42 d (J = 8.5Hz,
2H), 6.87–6.79 m (3H), 1.34 s (9H).
2-(4-Ethylphenyl)[1,4]naphthoquinone (Vg).
1
Yellow solid (85%). H NMR (400 MHz, CDCl3), δ,
ppm: 8.19 m (1H), 8.12 m (1H), 7.80–7.75 m (2H),
7.52 d (J = 8.1 Hz, 2H), 7.31 d (J = 8.1 Hz, 2H), 7.07 s
(1H), 2.72 q (J = 7.6 Hz, 2H), 1.28 t (J = 7.6 Hz, 3H).
2-(4-Ethoxy-phenyl)-[1,4]benzoquinone (IIIf).
Faint yellow solid (83%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 7.53 d (J = 8.6 Hz, 1H), 7.47 d (J =
8.7 Hz, 1H), 7.36 s (1H), 7.13 m (1H), 6.97–6.77 m
(3H), 4.09 q (J = 6.9 Hz, 2H), 1.44 t (J = 7.0 Hz, 1H).
2-m-Tolyl[1,4]naphthoquinone (Vh). Faint yellow
1
solid (81%). H NMR (400 MHz, CDCl3) δ 8.17–8.18
m (1H), 8.10–8.12 m (1H), 7.76–7.78 m (2H), 7.29–
7.37 m (4H), 7.06 s (1H), 2.42 s (3H).
2-(2-Methoxyphenyl)[1,4]benzoquinone (IIIg).
Faint yellow solid (65%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 7.42 m (1H), 7.16 d.d (J = 7.5,
1.6 Hz, 1H), 7.02 t (J = 7.5 Hz, 1H), 6.97 d (J =
8.3 Hz, 1H), 6.87–6.79 m (3H), 3.78 s (3H).
2-[4-(2-Chloroethyl)phenyl][1,4]naphthoqui-
none (Vi). Faint yellow solid (76%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 8.20–8.15 m (1H), 8.11 m (1H), 7.80–
7.74 m (2H), 7.58 d (J = 8.5 Hz, 2H), 7.05 s (1H), 7.01
d (J = 8.5 Hz, 2H), 4.30 t (J = 5.8 Hz, 2H), 3.85 t (J =
5.8 Hz, 2H). 13C NMR (101 MHz, CDCl3), δ, ppm:
185.17 s, 184.73 s, 147.28 s, 133.97 s, 133.80 s,
2-m-Tolyl-[1,4]benzoquinone (IIIh). Faint yellow
1
solid (53%). H NMR (400 MHz, CDCl3), δ, ppm:
7.35–7.24 m (4H), 6.88–6.80 m (3H), 2.40 s (3H).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

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DAWEI WANG et al.
7. Liu, J.-K., Chem. Rev., 2006, vol. 106, p. 2209.
132.55 s, 132.14 s, 131.18 s, 127.04 s, 126.41 s,
125.93 s, 114.72 s, 68.07 s, 41.70 s. Calculated, %: C
72.85; H 4.42; Cl 11.95; O 10.78. C18H13ClO2. Found,
%: C 72.79; H 4.40; Cl 11.99; O 10.82.
8. Zhang, B., Salituro, G., Szalkowski, D., Li, Z., Zhang, Y.,
Royo, I., Vitella, D., Diez, M.T., Pelaez, F., Ruby, C.,
Kendall, R.L., Mao, X., Griffin, P., Calaycay, J.,
Zierath, J.R., Heck, J.V., Smith, R.G., and Moller, D.E.,
Science, 1999, vol. 284, p. 974.
9. Coleman, R.S., Felpin, F.-X., and Chen, W., J. Org.
Chem., 2004, vol. 69, p. 7309.
10. Nikolovska-Coleska, Z., Xu, L., Hu, Z., Tomita, Y., Li, P.,
Roller, P.P., Wang, R., Fang, X., Guo, R., Zhang, M.,
Lippman, M.E., Yang, D., and Wang, S., J. Med.
Chem., 2004, vol. 47, p. 2430.
2-Biphenyl-4-yl[1,4]naphthoquinone (Vj).
1
Yellow solid (88%). H NMR (400 MHz, CDCl3), δ,
ppm: 8.24–8.19 m (1H), 8.16–8.12 m (1H), 7.81–7.78
m (2H), 7.73–7.64 m (6H), 7.48 t (J = 7.5 Hz, 2H),
7.39 t (J = 7.4 Hz, 1H), 7.14 s (1H).
2-(3-Methoxyphenyl)[1,4]naphthoquinone (Vk).
Faint yellow solid (85%). 1H NMR (400 MHz,
CDCl3), δ, ppm: 8.17–8.19 m (1H), 8.11–8.12 m (1H),
7.77–7.79 m (2H), 7.36–7.40 m (1H), 7.10–7.15 m
(1H), 7.07 s (1H), 7.01–7.03 m (2H), 3.86 s (3H).
11. Viault, G., Grée, D., Das, S., Yadav, J. S., and Grée, R.,
Eur. J. Org. Chem., 2011, vol. 7, p. 1233.
12. Hadden, M.K., Hill, S.A., Davenport, J., Matts, R.L.,
and Blagg, B.S., Bioorg. Med. Chem., 2009, vol. 37,
p. 634.
13. Citron, M., Neuroscience, 2004, vol. 5, p. 677
14. Findeis, M.A., Pharmacol. Ther., 2007, vol. 116, p. 266.
15. Ortega, A., Rincón, Á., Jiménez-Aliaga, K.L., Bermejo-
Bescós, P., Martín-Aragón, S., Molina, M.T., and
Csákÿ, A.G., Bioorg. Med. Chem. Lett., 2011, vol. 21,
p. 2183.
2-(4-Hydroxyphenyl)[1,4]naphthoquinone (VI).
1H NMR (400 MHz, CDCl3), δ, ppm: 8.12–8.07 m
(1H), 8.05–8.01 m (1H), 7.73–7.65 m (2H), 7.49–7.41
m (2H), 6.96 s (1H), 6.90–6.82 m (2H), 5.69 s (1H).
CONCLUSIONS
The ligand-free direct arylation of quinones by aryl
halides with Pd(OAc)2 as a catalyst according to Heck
was studied. The reaction products were accumulated
with moderate to good yields. This reaction provided
an easy and convenient method of synthesis of aryl-
substituted quinones. Further study of the process with
a broader range of compounds is in progress.
16. Zhang, H.-B., Liu, L., Chen, Y.-J., Wang, D., and Li, C.-J.,
Adv. Synth. Catal., 2006, vol. 348, p. 229.
17. Miyamura, H., Shiramizu, M., Matsubara, R., and
Kobayashi, S., Angew. Chem. Int. Ed., 2008, vol. 47,
p. 8093.
18. Lockner, J.W., Dixon, D.D., Risgaard, R., and Baran, P.S.,
Org. Lett., 2011, vol. 13, p. 5628.
19. Ilangovan, A., Saravanakumar, S., and Malayappasamy, S.,
ACKNOWLEDGMENTS
Org. Lett., 2013, vol. 15, p. 4968.
20. Zhang, S., Song, F., Zhao, D., and You, J. Chem.
Commun., 2013, vol. 49, p. 4558.
21. Pirrung, M.C., Park, K., and Li, Z., Org. Lett., 2001,
We gratefully acknowledge financial support of this
research by the National Natural Science Foundation
of China (nos. 21401080, 21371080), 333 Talent
Project of Jiangsu Province (BRA2012165), the Funda-
mental Research Funds for the Central Universities
(JUDCF13016) and the Postgraduate Innovation
Project of Jiangsu Province (CXZZ13_0746).
vol. 3, p. 365.
22. Pirrung, M.C., Deng, L., Li, Z., and Park, K. J. Org.
Chem., 2002, vol. 67, p. 8374.
23. Knölker, H.-J., Fröhner, W., and Reddy, K.R.,
Synthesis, 2002, p. 557.
REFERENCES
24. Yadav, J.S., Reddy, B.V.S., and Swamy, T., Tetra-
hedron Lett., 2003, vol. 44, p. 9121.
1. Babula, P., Mikelova, R., Kizek, R., Havel, L., and
Sladky, Z., Ceska Slovens. Farm., 2006, vol. 55, p. 151.
2. Koyama, J., Recent Patents Anti-Infect. Drug. Discov.,
25. Honraedt, A., Callonnec, F.L., Grognec, E.L., Fer-
nandez, V., and Felpin, F.-X., J. Org. Chem., 2013,
vol. 78, p. 4604.
2006, vols. 1, p. 113.
3. Babula, P., Adam, V., Havel, L., and Kizek, R., Ceska
Slovens. Farm., 2007, vol. 56, p. 114.
26. Molina, M.T., Navarro, C., Moreno, A., and Csaky, A.G.,
Org. Lett., 2009, vol. 11, p. 4938.
4. Verma, R. P., Anti-Cancer Agents Med. Chem., 2006,
27. Demchuk, O.M., and Pietrusiewicz, K.M., Synlett, 2009,
vol. 6, p. 489.
vol. 7, p. 1149.
5. Bishop, K.J.M., Klajn, R., and Grzybowski, B.A.,
Angew. Chem. Int. Ed., 2006, vol. 45, p. 5348.
6. Gould, S.J., Chem. Rev., 1997, vol. 97, p. 2499.
28. Fujiwara, Y., Domingo, V., Seiple, I.B., Gianatassio, R.,
Bel, M.D., and Baran, P.S., J. Am. Chem. Soc., 2011,
vol. 133, p. 3292.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 84 No. 8 2014

SYNTHESIS OF ARYL SUBSTITUTED QUINONES
1621
29. Wang, J., Wang, S., Wang, G., Zhang, J., and Yu, X.-Q.,
36. Li, L., Wu, F., Zhang, S., Wang, D., Ding, Y., and Zhu, Z.,
Chem. Commun., 2012, vol. 48, p. 11769.
Dalton Trans., 2013, vol. 42, p. 4539.
30. Singh, P.P., Aithagani, S.K., Yadav, M., Singh, V.P.,
and Vishwakarma, R.A., J. Org. Chem., 2013, vol. 78,
p. 2639.
31. Komeyama, K., Kashihara, T., and Takaki, K., Tetra-
hedron Lett., 2013, vol. 54, p. 1084.
37. Zhang, S., and Ding, Y., Organometallics, 2011, vol. 30,
p. 633.
38. Zhang, S., Shi, L., and Ding, Y., J. Am. Chem. Soc.,
2011, vol. 133, p. 20218.
39. Yang, W., Zhang, S., Ding, Y., Shi, L., and Song, Q.,
32. Deb, A., Manna, S., Maji, A., Dutta, U., and Maiti, D.,
Chem. Commun., 2011, vol. 47, p. 5310.
Eur. J. Org. Chem., 2013, p. 5251.
33. Negishi, E., Coperet, C., Ma, S., Liou, S.-Y., and Liu, F.,
Chem. Rev., 1996, vol. 96, p. 365.
34. Beletskaya, I.P., and Cheprakov, A.V., Chem. Rev.,
40. Wang, D., Cai, R., Sharma, S., Jirak, J., Thum-
manapelli, S.K., Akhmedov, N.G., Zhang, H., Liu, X.,
Petersen, J.L., Shi, X., J. Am. Chem. Soc., 2012,
vol. 134, p. 9012.
2000, vol. 100, p. 3009.
35. Yang, W., Wang, D., Song, Q., Zhang, S., Wang, Q.,
41. Wang, D., Lu, S., and Zhou, Y., Tetrahedron Lett.,
and Ding, Y., Organometallics, 2013, vol. 32, p. 4130.
2009, vol. 50, p. 1282.
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