Fabrication of magnetic amino-functionalized nanoparticles for S-arylation of heterocyclic thiols

Article abstract of DOI:10.1039/c4ra08782h

A series of uniformed mono-disperse magnetic nanoligands (MNLs) (CoFe₂O₄-NH₂ (MNL A), Fe₃O₄@Si(CH₂)₃NH₂ (MNL B), Fe₃O₄@Si(CH₂)₃

Full text of DOI:10.1039/c4ra08782h

RSC Advances
View Article Online
View Journal | View Issue
PAPER
Fabrication of magnetic amino-functionalized
nanoparticles for S-arylation of heterocyclic thiols†
Cite this: RSC Adv., 2014, 4, 48980
a
a
Yanhong Liu,abc Lincheng Zhou, Xinping Hui, Zhenwen Dong,a Hao Zhu,a
*
*
Yanming Shaoa and Yanfeng Lia
A
series of uniformed mono-disperse magnetic nanoligands (MNLs) (CoFe2O4–NH2 (MNL A),
Fe3O4@Si(CH2)3NH2 (MNL B), Fe3O4@Si(CH2)3NHC(O) (CH2)2PEI (MNL C) and Fe3O4@Si(CH2)3NHC(O)PEI
(MNL D)) were obtained by loading two ligands, an aminosilane coupling agent and PEI-600, onto
magnetic nanoparticles prepared using a solvothermal method. The catalytic applications of the
synthesized MNLs were explored for the cross-coupling reaction of heterocyclic thiols with aromatic
iodides. The reactions were carried out in the presence of CuI (5 mol%), MNL (10 mol% N) and K2CO3
(1.3 eq.) in DMF at 120 ꢀC. A variety of heterocyclic sulfides were afforded in good to excellent yields (up
to 98%) when MNL B was used. The magnetic, crystal, organic matter structure and morphology of MNL
B exhibited no obvious changes after five consecutive cycles. XPS characterization of MNL B revealed
the combination of a small amount of Cu0 nanoparticles, but this had no significant effect on catalytic
performance.
Received 17th August 2014
Accepted 19th September 2014
DOI: 10.1039/c4ra08782h
www.rsc.org/advances
CuO nanoparticles for the catalysis of C–S cross-coupling was
rst reported in 2007.15 These reactions are effective at 80 ꢀC in
Introduction
DMSO in the presence of KOH under a nitrogen atmosphere
without ligands, and CuO is found to be inferior to CuO
nanoparticles as catalysts of the C–S coupling reaction. Addi-
tionally, Schwab16 et al. reported excellent product yields under
ligand-free conditions by combining nanotechnology and ionic
Methods for the formation of C–S bonds are important tools in
synthetic chemistry, but are comparatively less well understood
than C–N or C–O bond formation.1 Couplings can be achieved
under harsh reaction conditions, such as high reaction
temperature combined with the use of toxic and high boiling
polar solvents like quinoline or HMPA. Alternatively, suldes
can be prepared by reducing aryl sulfones or aryl sulfoxides
using strong reducing agents such as LiAlH4 and DIBAL-H.2 To
overcome these difficulties, considerable attention has been
focused on the development of catalytic systems for C–S cross-
coupling.3 Organosulfur chemistry has also benetted signi-
cantly from progress associated with catalysis mediated by
transition metals, including Pd,4 Ni,5 Cu,6,7 Co,8 Fe,9 In,10 La,11
Au12 and Bi.13 The strong coordination properties of organo-
sulfur compounds are responsible for deactivation of metal
catalysts.
liquids to facilitate C–S cross-coupling using CuO nanopowder
ꢁ
as a catalyst in [bmmim]+BF4
.
Although these results are promising, the small size of
nanoparticles oen makes their separation and recycling diffi-
cult. In order to circumvent such problems, super-paramagnetic
nanocatalysts with high surface area,17 whose occulation and
dispersion can be controlled reversibly by application of a
magnetic eld, have been employed as a heterogeneous catalyst
for C–S cross-coupling reactions. CuFe2O4 nanopowder has
been used to catalyze aryl–sulfur bond formation between aryl
halides and thiols/disuldes.18 Also, a magnetically recoverable
heterogeneous Cu catalyst (nano-FeDOPACu) has been used to
synthesize diarylsuldes via a one-pot multicomponent reac-
tion under microwave irradiation.19 Hence, the development of
an alternative, inexpensive, air-resistant, and recyclable ligand,
for the formation of the C–S bond, is highly desirable. In
previous studies, the small molecular ligand 1,10-phenanthro-
line, had proven to be efficient in a copper(I)-catalyzed C–S
cross-coupling reaction.20 Similarly, we report in this study the
cross-coupling of heterocyclic thiols with aromatic iodides,
catalyzed by CuI and magnetic nanoligands (MNLs) modied by
the addition of an aminosilane coupling agent aminopropyl-
triethoxysilane (APTES) and polyethylene imine-600 (PEI-600)
Nanoscale catalysts offer several advantages over traditional
methodologies, including an increase in exposed active surface
area for selective binding of substrates, which makes this a
more effective process.14 Recently, nanocatalysts have been used
to form C–S bonds between aryl halides and thiols. The use of
aCollege of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou
730000, China. E-mail: zhoulc@lzu.edu.cn; huixp@lzu.edu.cn
bKey Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics,
Chinese Academy of Sciences, Lanzhou 730000, China
cUniversity of Chinese Academy of Sciences, Beijing 100049, China
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c4ra08782h
48980 | RSC Adv., 2014, 4, 48980–48985
This journal is © The Royal Society of Chemistry 2014

View Article Online
Paper
RSC Advances
(Fig. S1†). Additionally, we report a detailed characterization
(i.e., magnetic properties, crystal structure, organic structure
and morphology) of the nanocomposite, before and aer use.
Results and discussion
Characterization of magnetic nanoligands
Fe3O4 MNPs were chosen as catalyst supports based on their
high magnetic susceptibility and their capacity for surface
functionalization. The preparation of MNLs is presented in
Scheme 1. The nitrogen content values for MNLs A, B, C and D
were 0.64, 2.71, 2.28, 2.0 mmol gꢁ1, respectively. The smaller
size of the Fe3O4 NPs (8 nm) resulted in a larger surface area
with higher activity, and the nitrogen content of MNL B may
reach as much as 3.8 wt%, which is higher than the previously
reported value of 0.61%.21
Transmission electron microscope (TEM) was used to char-
acterize the morphology and crystal structure. CoFe2O4 particles
are spherical, nearly monodisperse, and have average diameters
of approximately 23 ꢂ 3 nm (Fig. 1a and b). TEM images of
Fe3O4 MNPs prepared via the thermal decomposition of
Fe(acac)3 in benzyl ether and oleylamine, clearly indicate that
the 8 nm iron oxide MNPs are rounded and monodisperse
(Fig. 1c and d). Additionally, we observed no signicant changes
in the crystalline structure, size, or morphology of the Fe3O4
MNPs aer modication (Fig. 1e and f).
Fig. 1 TEM of MNL A (a and b), Fe3O4 NP (c and d) and MNL B (e and f).
gꢁ1, respectively. The decreasing Ms values were found to
correspond with the addition of surface functionalization,
although these species could still be separated magnetically. In
the IR spectra (Fig. S4†) of the nanoparticles, the appearance of
characteristic bands conrmed the existence of the magnetic
core and provided evidence of surface amine-functionalization.
Also, the C]O peaks for MNLs C and D were observed at 1711
cmꢁ1 and 1558 cmꢁ1, respectively. It may be that the amino
group makes the electron cloud of the C]O double bond move
to the oxygen atom, resulting in a decrease in the bond force
constant.
In the XRD pattern of MNLs A, B, C and D (Fig. S2†), the half-
peak widths of the ligands remained unchanged, and the NP
sizes were consistent with the sizes observed before surface
Catalytic studies
modication. The eld dependent magnetization curves of the Experiments were performed to identify the appropriate
ligands at room temperature (Fig. S3†) illustrate the importance conditions for the coupling reaction of 5-methyl-1,3,4-
of the dispersion state of the magnetic nanoparticles. The thiadiazol-2-thiol (1a) with iodobenzene (2a) (1.2 equiv.) using
saturation magnetization (Ms) value for Fe3O4 nanoparticles was K2CO3 (1.3 equiv.) as a base and DMF as a solvent at 120 ꢀC. The
48.9 emu gꢁ1, and Ms value for MNLs A, B, C and D were found desired product 3a was obtained at 41% yield when 5 mol% CuI
to be 70.6 emu gꢁ1, 33.5 emu gꢁ1, 16.3 emu gꢁ1, and 45.3 emu was used (Table 1, entry 1), and 5% yield in the presence of 10
Scheme 1 Synthesis of MNLs A, B, C and D.
This journal is © The Royal Society of Chemistry 2014
RSC Adv., 2014, 4, 48980–48985 | 48981

View Article Online
RSC Advances
Paper
Table
1 C–S coupling of 5-methyl-1,3,4-thiadiazol-2-thiol with
Using the optimized reaction conditions, we extended the
scope of this catalytic protocol to the cross-coupling reactions of
aryl iodides with heterocyclic thiols (Table 3). The coupling of 5-
methyl-1,3,4-thiadiazol-2-thiol with aryl iodides having
iodobenzene: screening of catalysts
Table 3 C–S cross-coupling of thiols with aryl iodides catalyzed by
MNL Ba
Entry
Catalyst
Yielda (%)
1
2
3
CuI (5 mol%)
MNL A (10 mol%)
CuI (5 mol%) + MNL A (10 mol%)
41
5
83
Yieldb (%)
a
Entry
Thiol
Aryl iodide
Time (h)
Isolated yield.
1
2
3
4
5
12
18
18
14
14
94
91
88
98
94
mol% MNL A (Table 1, entry 2). The reaction gave 83% yield
catalyzed by 5 mol% CuI and 10 mol% MNL A (Table 1, entry 3).
Of the four ligands, MNL B was the most effective, due to its
ability to form a more active catalytic centre with CuI (Table 2,
entries 1–4). MNL A, obtained though one-step synthesis,
exhibited the lowest nitrogen content. In comparison to the
aliphatic amine of MNL B, the nitrogen content of MNLs C and
D included amides, and these ligands showed weak coordina-
tion with CuI. So, the catalytic activity of MNLs C and D was
relatively low. Aer investigating the reaction in different
solvents (Table 2, entries 5–7), we found that the reaction
catalyzed by MNL B failed to yield the desired product in THF or
toluene. However, a moderate yield was obtained for MNL B in
DMSO. In addition, for various bases (e.g., Cs2CO3, NaOAc, KOH
and Na3PO4), the product 3a was obtained in 75–92% yield
(Table 2, entries 8–11). Thus, the optimized reaction conditions
included CuI (5 mol%), K2CO3 (1.3 equiv.) and MNL B
6
14
18
18
18
18
88
94
91
88
98
7
8
9
ꢀ
10
(10 mol%) in DMF at 120 C for 12 h.
11
12
13
18
14
12
94
88
94
Table 2 Optimization of reaction conditionsa
Entry
MNL
Base
Solvent
Temp. (ꢀC)
Yieldb(%)
14
15
12
20
91
88
1
2
3
4
5
6
7
8
A
B
C
D
B
B
B
B
B
B
B
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
K2CO3
Cs2CO3
NaOAc
KOH
DMF
DMF
DMF
DMF
Toluene
THF
DMSO
DMF
DMF
DMF
DMF
120
120
120
120
110
66
120
120
120
120
120
83
94
87
79
NR
NR
77
75
92
89
84
16
17
12
12
81
82
9
10
11
18
12
79
Na3PO4
a
Reaction conditions: MNL/CuI/base/5-methyl-1,3,4-thiadiazol-2-thiol/
a
iodobenzene ¼ 0.1 : 0.05 : 1.3 : 1 : 1.2 (mmol); reaction time: 12 h.
Reaction condition: MNL B/CuI/K2CO3/thiol/aryl iodide
¼
b
b
Isolated yield.
0.1 : 0.05 : 1.3 : 1 : 1.2 (mmol). Isolated yield.
48982 | RSC Adv., 2014, 4, 48980–48985
This journal is © The Royal Society of Chemistry 2014

View Article Online
Paper
RSC Advances
electron-donating groups resulted in a slightly low yields (Table in Fig. S8†. The N 1s signal of freshly synthesized MNL B was
3, entries 2–3), however, high yields were obtained in the pres- observed at 398.3 eV which corresponding to the binding energy
ence of electron-withdrawing groups (Table 3, entries 4 and 5). (Eb) of aliphatic amine (N–C, N–H) (Fig. S8c†). Aer the 5th run,
For 5-aryl-1,3,4-thiadiazol-2-thiol, both electron-donating and this value increased approximately 1.3 eV due to the coordina-
electron-withdrawing groups led to high yields (Table 3, entries tion interaction between copper and the nitrogen atom. The
6–12). When 4,5-diphenyl-4H-1,2,4-triazol-3-thiol, 4,6-di- peaks for Cu 2p 1/2 (951.7 eV) and Cu 2p 3/2 (932.4 eV)
methylpyrimidine-2-thiol and 5-(o-tolyl)-1,3,4-oxadiazol-2-thiol (Fig. S8f†) were close to the standard data of Cu0, which was
were treated with iodobenzene, the desired products were produced by reduction of Cu(I). The existence of Cu 2p was
afforded at 94, 91 and 88% yield, respectively (Table 3, entries consisted with an increase of N 1s binding energy, which was
13–15). Furthermore, thiophenols were investigated for this consisted with the formation of Cu0 nanoparticles. This was
reaction. As expected, the coupling reactions of thiophenols slightly reduced the catalytic performance of the material as the
with 5-methyl-1,3,4-thiadiazol-2-thiol proceeded in good yields nitrogen ligands, even though the Cu0 nanoparticles could
(Table 3, entries 16–18). The results demonstrated that the catalyze the C–S bond formation.19
catalytic activity of magnetic nano-ligands was slightly lower
than that resulting from the 1,10-phenanthroline catalyst,20
although these novel catalysts exhibited good reusability.
Conclusions
Four uniformed monodisperse magnetic nano-ligands
CoFe2O4–NH2 (MNL A), Fe3O4@Si(CH2)3NH2 (MNL B),
Recovery and reusability of MNL B
Fe3O4@Si(CH2)3NHC(O) (CH2)2PEI (MNL C), Fe3O4@Si(CH2)3-
The reusability of MNL B was also examined (Table 4). MNL B
NHC(O)PEI (MNL D) were obtained through simple procedures
was magnetically separated from the mixture aer completion
of the reaction, washed with deionized (DI) water, ethanol, ethyl
acetate by sonication, and dried at 40 C in vacuum for direct
use in additional catalytic reactions. The results showed that
MNL B could be reused at least ve times without major loss of
activity.
and used as ligands with CuI for C–S bond coupling reactions.
MNL B was found to be tolerant to the cross-coupling reaction
of heterocyclic thiols with aryl iodides having different func-
tional groups, and a variety of heterocyclic suldes were
obtained in good to excellent yields (up to 98%). The magnetic
nature of these ligands allowed for easy and rapid separation of
the heterogeneous ligands from the reaction mixture. MNL B
continued to exhibit good catalytic activity aer ve consecutive
ꢀ
To further study the changes of MNL B activity, the
morphology and structures of both the freshly synthesized MNL
B and MNL B aer the 5th run were evaluated. The powder X-ray
cycles.
diffraction analysis, the typical hysteresis loops at room
temperature (300 K) and peaks in the IR spectra (Fig. S5†)
indicated that the material exhibited good stability under the
described reaction conditions. The TEM analysis revealed
degradation of both the morphology and the dispersity of the
MNL B aer the initial successful catalytic cycles (Fig. S6†). We
Experimental section
General procedure for copper-catalyzed cross-coupling
reaction of heterocyclic thiols 1 with aryl iodides 2
Aryl iodides 2 (0.24 mmol) were added to a solution of CuI (0.01
mmol, 1.9 mg), a magnetic nanoligand (0.02 mmol N, 9 mg),
heterocyclic thiols 1 (0.2 mmol), and K2CO3 (0.26 mmol, 90 mg)
in DMF (1.0 mL). The reaction mixture was heated at 120 ꢀC for
12 h under a nitrogen atmosphere. Aer cooling to room
temperature, ethyl acetate (4 mL) and H2O (4 mL) were added,
and the organic phase was separated. The aqueous phase was
extracted with ethyl acetate (3 ꢃ 4 mL). The combined organic
phases were washed with saturated brine and dried over anhy-
drous Na2SO4. The organic solvent was then concentrated in
vacuum to yield the crude products, which was puried by silica
gel column chromatography using petroleum ether/ethyl
acetate.
could conclude that the small change resulting from coordi-
nation interaction between the ligand and copper during the
reaction did not signicantly alter catalytic performance.
The XPS technique had been employed to characterize the
surface chemical composition of nanoligands. The XPS spectra
of freshly synthesized MNL B and MNL B aer the 5th run
(Fig. S7†) indicated no obvious differences. The high-resolution
spectra of Fe 2p, C 1s, N 1s, Si 2p, O 1s and Cu 2p were showed
Table 4 Recycling experiments of MNL B in the C–S bond coupling
reactiona
Recyclability experiments
Recycling reactions were performed using MNL B. Aer
completion of the reaction, MNL B was recovered magnetically
and the reaction solution was decanted. MNL B was washed
with DI water (2 ꢃ 5 mL), ethanol (2 ꢃ 5 mL), ethyl acetate (2 ꢃ
5 mL), dried at 40 ꢀC under vacuum and reused for the next run.
Recycle reactions were performed as described above.
Run
1
2
3
4
5
Yieldb (%)
94
94
90
90
89
a
Reaction conditions: MNL B/CuI/K2CO3/5-methyl-1,3,4-thiadiazol-2-
thiol/iodobenzene ¼ 0.1 : 0.05 : 1.3 : 1 : 1.2 (mmol). b Isolated yield.
This journal is © The Royal Society of Chemistry 2014
RSC Adv., 2014, 4, 48980–48985 | 48983

View Article Online
RSC Advances
Paper
A. C. Massabni, Catal. Lett., 2006, 109, 171; (m) Z. Jiang,
J. She and X. Lin, Adv. Synth. Catal., 2009, 351, 2558; (n)
C. F. Fu, Y. H. Liu, S. M. Peng and S. T. Liu, Tetrahedron,
2010, 66, 2119; (o) Y. Hirai and Y. Uozumi, Chem. Lett.,
2011, 40, 934; (p) N. Iranpoor, H. Firouzabadi and
A. Rostami, Appl. Organomet. Chem., 2013, 27, 501.
Acknowledgements
We are grateful for the nancial support of the National Natural
Science Foundation of China (21172099 and 21372106).
Notes and references
5 (a) N. Taniguchi, J. Org. Chem., 2004, 69, 6904; (b) Y. Zhang,
K. N. Ngeow and J. Y. Ying, Org. Lett., 2007, 9, 3495; (c)
A. Saxena, A. Kumar and S. Mozumdar, Appl. Catal., A,
2007, 317, 210; (d) S. Jammi, P. Barua, L. Rout, P. Saha and
T. Punniyamurthy, Tetrahedron Lett., 2008, 49, 1484; (e)
Y. Q. Cao, Z. Zhang, Y. X. Guo and G. Q. Wu, Synth.
Commun., 2008, 38, 1325; (f) P. Guan, C. S. Cao, Y. Liu,
Y. F. Li, P. He, Q. Chen, G. Liu and Y. H. Shi, Tetrahedron
Lett., 2012, 53, 5987; (g) K. Okamoto, J. B. Housekeeper and
C. K. Luscombe, Appl. Organomet. Chem., 2013, 27, 639.
6 (a) C. Palomo, M. Oiarbide, R. Lopez and E. Gomez-Bengoa,
Tetrahedron Lett., 2000, 41, 1283; (b) C. G. Bates,
R. K. Gujadhur and D. Venkataraman, Org. Lett., 2002, 4,
2803; (c) S. V. Ley and A. W. Thomas, Angew. Chem., Int.
Ed., 2003, 42, 5400; (d) Y. J. Wu and H. He, Synlett, 2003,
1789; (e) K. Kauz, U. Schlotz and D. Ganzer, Synlett, 2003,
2428; (f) W. Deng, Y. Zou, Y. F. Wang, L. Liu and
Q. X. Guo, Synlett, 2004, 1254; (g) I. P. Beletskaya and
A. V. Cheprakov, Coord. Chem. Rev., 2004, 248, 2337; (h)
G. Zeni, Tetrahedron Lett., 2005, 46, 2647; (i) Y. J. Chen and
H. H. Chen, Org. Lett., 2006, 8, 5609; (j) D. Zhu, L. Xu,
F. Wu and B. Wan, Tetrahedron Lett., 2006, 47, 5781; (k)
A. K. Verma, J. Singh and R. Chaudhary, Tetrahedron Lett.,
2007, 48, 7199; (l) X. Lv and W. Bao, J. Org. Chem., 2007,
72, 3863; (m) B. C. Ranu, A. Saha and R. Jana, Adv. Synth.
Catal., 2007, 349, 2690; (n) H. Zhang, W. Cao and D. Ma,
Synth. Commun., 2007, 37, 25; (o) H.-J. Xu, X.-y. Zhao, Y. Fu
and Y.-S. Feng, Synlett, 2008, 3063; (p) P. Buranaprasertsuk,
J. W. W. Chang, W. Chavasiri and P. W. H. Chan,
Tetrahedron Lett., 2008, 49, 2023; (q) H. J. Xu, X. Y. Zhao,
J. Deng, Y. Fuand and Y. S. Feng, Tetrahedron Lett., 2009,
50, 434; (r) S. Murru, H. Ghosh, S. K. Sahoo and
B. K. Patel, Org. Lett., 2009, 11, 4254; (s) Y. Feng, X. Zhao,
J. Wang, F. Zheng and H. Xu, Chin. J. Chem., 2009, 27,
2423; (t) N. R. Jogdand, B. B. Shingate and M. S. Shingare,
Tetrahedron Lett., 2009, 50, 6092; (u) Y. Feng, H. Wang,
F. Sun, Y. Li, X. Fu and K. Jin, Tetrahedron, 2009, 65, 9737;
(v) D. J. C. Prasad, A. B. Naidu and G. Sekar, Tetrahedron
Lett., 2009, 50, 1411; (w) P.-F. Larsson, A. Correa, M. Carril,
P.-O. Norrby and C. Bolm, Angew. Chem., Int. Ed., 2009, 48,
5691; (x) S. Jammi, S. Sakthivel, L. Rout, T. Mukherjee,
S. Mandal, R. Mitra, P. Saha and T. Punniyamurthy, J. Org.
Chem., 2009, 74, 1971; (y) N. Jung and S. Brase, J. Comb.
Chem., 2009, 11, 47; (z) X. Ku, H. Huang, H. L. Jiang and
H. Liu, J. Comb. Chem., 2009, 11, 338.
1 T. Kondo and T. Mitsudo, Chem. Rev., 2000, 100, 3205.
2 (a) T. Yamamoto and Y. Sekine, Can. J. Chem., 1984, 62, 1544;
(b) J. Lindley, Tetrahedron, 1984, 40, 1433; (c)
R. J. S. Hickman, B. J. Christie, R. W. Guy and T. White,
Aust. J. Chem., 1985, 38, 899; (d) A. V. Bierbeek and
M. Gingras, Tetrahedron Lett., 1998, 39, 6283.
3 (a) H. J. Cristau, B. Chabaud, A. Chene and H. Christol,
Synthesis, 1981, 11, 892; (b) K. Takagi, Chem. Lett., 1987, 16,
2221; (c) G. Mann, D. Baranano, J. F. Hartwig,
A. L. Rheingold and I. A. Guzei, J. Am. Chem. Soc., 1998,
120, 9205; (d) C. Millois and P. Diaz, Org. Lett., 2000, 2,
1705; (e) P. S. Herradura, K. A. Pendola and R. K. Guy, Org.
Lett., 2000, 2, 2019; (f) C. Savarin, J. Srogl and
L. S. Liebeskind, Org. Lett., 2002, 4, 4309; (g)
F. Y. Kwongand and S. L. Buchwald, Org. Lett., 2002, 4,
3517; (h) C. G. Bates, P. Saejueng, M. Q. Doherty and
D. Venkataraman, Org. Lett., 2004, 6, 5005; (i) M. Carril,
´
R. SanMartin, E. Domınguez and I. Tellitu, Chem.–Eur. J.,
2007, 13, 5100; (j) E. Sperotto, G. P. M. van Klink, J. G. de
Vries and G. van Koten, J. Org. Chem., 2008, 73, 5625; (k)
Y. Jiang, Y. Qin, S. Xie, X. Zhang, J. Dong and D. Ma, Org.
Lett., 2009, 11, 5250; (l) S. Bhadra, B. Sreedhar and
B. Ranu, Adv. Synth. Catal., 2009, 351, 2369; (m)
C. K. Chen, Y. W. Chen, C. H. Lin, H. P. Lin and C. F. Lee,
Chem. Commun., 2010, 46, 282; (n) M. Gohain, C. Marais
and B. C. B. Bezuidenhoudt, Tetrahedron Lett., 2012, 53,
1048; (o) Z. Q. Ni, S. C. Wang, H. Mao and Y. J. Pan,
Tetrahedron Lett., 2012, 53, 3907; (p) P. Mishra,
H. K. Maurya, B. Kumar, V. K. Tandon and V. J. Ram,
Tetrahedron Lett., 2012, 53, 1056; (q) C. F. Lee, Y. C. Liu
and S. S. Badsara, Chem.–Asian J., 2014, 9, 706; (r)
M. M. Sontakke, A. A. Jichkar, M. G. Dhonde, C. S. Bhaskar
and B. N. Berad, Synth. Commun., 2014, 44, 340.
4 (a) M. J. Dickens, J. P. Gilday, T. J. Mowlem and
D. A. Widdowson, Tetrahedron, 1991, 47, 8621; (b)
T. Ishiyama, M. Mori, A. Suzuki and N. Miyaura, J.
Organomet. Chem., 1996, 525, 225; (c) N. Zheng,
J. C. McWilliams, F. J. Fleitz, J. D. Armstrong and
R. P. Volante, J. Org. Chem., 1998, 63, 9606; (d) U. Schopfer
and A. Schlapbach, Tetrahedron, 2001, 57, 3069; (e) G. Y. Li,
G. Zheng and A. F. Noonan, J. Org. Chem., 2001, 66, 8677;
(f) G. Y. Li, Angew. Chem., Int. Ed., 2001, 40, 1513; (g)
M. Murata and S. L. Buchwald, Tetrahedron, 2004, 60, 7397;
(h) T. Itoh and T. Mase, Org. Lett., 2004, 6, 4587; (i)
C. Mispelaere-Canivet, J. F. Spindler, S. Perrio and
7 (a) J. She, Z. Jiang and Y. Wang, Tetrahedron Lett., 2009, 50,
593; (b) T. Ramana, P. Saha, M. Das and T. Punniyamurthy,
Org. Lett., 2010, 12, 84; (c) M. S. Kabir, M. Lorenz,
M. L. Van Linn, O. A. Namjoshi, S. Ara and J. M. Cook, J.
Org. Chem., 2010, 75, 3626; (d) Y.-S. Feng, Y.-Y. Li, L. Tang,
W. Wu and H.-J. Xu, Tetrahedron Lett., 2010, 51, 2489; (e)
´
P. Beslin, Tetrahedron, 2005, 61, 5253; (j) M. A. Fernandez-
´
Rodrıguez, Q. Shen and J. F. Hartwig, Chem.–Eur. J., 2006,
´
´
12, 7782; (k) M. A. Fernandez-Rodrıguez, Q. Shen and
J. F. Hartwig, J. Am. Chem. Soc., 2006, 128, 2180; (l)
´
R. S. Barbieri, C. R. Bellato, A. K. C. Dias and
48984 | RSC Adv., 2014, 4, 48980–48985
This journal is © The Royal Society of Chemistry 2014

View Article Online
Paper
RSC Advances
H.-L. Kao and C.-F. Lee, Org. Lett., 2011, 13, 5204; (f)
X. Y. Zhang, X. Y. Zhang and S. R. Guo, J. Sulfur Chem.,
J. L. Petersen and X. D. Shi, Angew. Chem., Int. Ed., 2014,
53, 4657.
2011, 32, 23; (g) Q. Z. Zhou, B. Zhang, T. Q. Du, H. N. Gu, 13 P. Malik and D. Chakraborty, Appl. Organomet. Chem., 2012,
H. J. Jiang and R. N. Chen, Tetrahedron, 2012, 68, 4233; (h) 26, 557.
K. Su, Y. T. Qiu, Y. W. Yao, D. Y. Zhang and S. Jiang, 14 (a) V. Polshettiwar and R. S. Varma, Green Chem., 2010, 12,
Synlett, 2012, 2853; (i) Y. S. Feng, H. X. Qi, W. C. Wang,
Y. F. Liang and H. J. Xu, Tetrahedron Lett., 2012, 53, 2914;
(j) R. S. Xu, L. Yue and Y. J. Pan, Tetrahedron, 2012, 68,
5046; (k) J. Mondal, N. Salam and A. Bhaumik, J. Nanosci.
743; (b) A. M. Balu, B. Baruwati, E. Serrano, J. Cot,
J. Garcia-Martinez, R. S. Varma and R. Luque, Green Chem.,
2011, 13, 2750; (c) R. B. Nasir Baig and R. S. Varma, Green
Chem., 2012, 14, 625.
Nanotechnol., 2013, 13, 4883; (l) A. Banerjee, S. K. Santra, 15 L. Rout, T. Sen and T. Punniyamurthy, Angew. Chem., Int. Ed.,
S. K. Rout and B. K. Patel, Tetrahedron, 2013, 28, 9096; (m) 2007, 46, 5583.
S. G. Babu and R. Karvembu, Tetrahedron Lett., 2013, 54, 16 R. S. Schwab, D. Singh, E. E. Alberto, P. Piquini,
1677; (n) B. Y. Bhong, A. V. Shelke and N. N. Karade,
Tetrahedron Lett., 2013, 54, 739.
O. E. D. Rodrigues and A. L. Braga, Catal. Sci. Technol.,
2011, 1, 569.
¨
8 Y. C. Wong, T. T. Jayanth and C. H. Cheng, Org. Lett., 2006, 8, 17 (a) S. Shylesh, W. R. Thiel and V. Schunemann, Angew.
5613.
Chem., Int. Ed., 2010, 49, 3428; (b) C. W. Lim and I. S. Lee,
Nano Today, 2010, 5, 412; (c) V. Polshettiwar, R. Luque,
A. Fihri, H. Zhu, M. Bouhrara and J.-M. Basset, Chem. Rev.,
2011, 111, 3036; (d) R. B. Nasir Baig and R. S. Varma,
Chem. Commun., 2013, 49, 752.
9 (a) A. Correa, M. Carril and C. Bolm, Angew. Chem., Int. Ed.,
2008, 47, 2880; (b) A. Correa, O. G. Mancheno and C. Bolm,
Chem. Soc. Rev., 2008, 37, 1108; (c) W. Y. Wu, J. C. Wang
and F. Y. Tsai, Green Chem., 2009, 11, 326; (d) H. B. Wang,
˜
L. Wang, J. S. Shang, X. Li, H. Y. Wang, J. Gui and 18 (a) K. Swapna, S. N. Murthy, M. T. Jyothi and
A. W. Lei, Chem. Commun., 2012, 48, 76.
Y. V. D. Nageswar, Org. Biomol. Chem., 2011, 9, 5989; (b)
N. Panda, A. K. Jena and S. Mohapatra, Appl. Catal., A,
2012, 433–434, 258.
10 (a) V. P. Reddy, K. Swapna, A. V. Kumar and K. R. Rao, J. Org.
Chem., 2009, 74, 3189; (b) V. P. Reddy, A. V. Kumar,
K. Swapna and K. R. Rao, Org. Lett., 2009, 11, 1697.
11 S. N. Murthy, B. Madhav, V. P. Reddy and Y. V. D. Nageswar,
Eur. J. Org. Chem., 2009, 5902.
19 R. B. Nasir Baig and R. S. Varma, Chem. Commun., 2012, 48,
2582.
20 L.-F. Niu, Y. Cai, C. Liang, X.-P. Hui and P.-F. Xu,
Tetrahedron, 2011, 67, 2878.
12 (a) M. Jean, J. Renault, P. van de Weghe and N. Asao,
Tetrahedron Lett., 2010, 51, 378; (b) Y. M. Xi, B. L. Dong, 21 Z. C. Xu, C. M. Shen, Y. L. Hou, H. J. Gao and S. H. Sun,
E. J. McClain, Q. Y. Wang, T. L. Gregg, N. G. Akhmedov,
Chem. Mater., 2009, 21, 1778.
This journal is © The Royal Society of Chemistry 2014
RSC Adv., 2014, 4, 48980–48985 | 48985