Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg as Novel and Recoverable Nanocatalysts

Article abstract of DOI:10.1007/s10562-018-2379-3

Abstract: Two heterogeneous catalysts, MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg, were synthesized by immobilization of Cd or Hg complexes on MCM-41 as novel, efficient, recoverable and stable nanocatalysts for Oxidation of sulfides to sulfoxides and

Full text of DOI:10.1007/s10562-018-2379-3

Catalysis Letters
https://doi.org/10.1007/s10562-018-2379-3
Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides
in the Presence of MCM-41@Tryptophan-Cd and MCM-41@
Tryptophan-Hg as Novel and Recoverable Nanocatalysts
Somayeh Molaei · Taiebeh Tamoradi · Mohammad Ghadermazi · Arash Ghorbani‑Choghamarani2
1
1
1,2
Received: 5 February 2018 / Accepted: 1 April 2018
©
Springer Science+Business Media, LLC, part of Springer Nature 2018
Abstract
Two heterogeneous catalysts, MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg, were synthesized by immobiliza-
tion of Cd or Hg complexes on MCM-41 as novel, efficient, recoverable and stable nanocatalysts for Oxidation of sulfides to
sulfoxides and oxidative coupling of thiols into their corresponding disulfides. These functionalized complexes were charac-
terized by FT-IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and N adsorption–des-
2
orption isotherms. The designed catalysts successfully oxidized a variety of sulfides and thiols with short reaction times in
high to excellent yields at room temperature and recovered for several times without significant loss of their catalytic activity.
Graphical Abstract
Synthesis of Cd and Hg tryptophan complexes immobilized on to surface of mesoporous MCM-41 under mild reaction
conditions has been presented. After characterization of these catalysts, their catalytic activity has been investigated for the
synthesis of sulfoxide and disulfides derivatives.
Keywords MCM-41 · Heterogeneous catalysts · Sulfoxide and disulfides
Extended author information available on the last page of the article
Vol.:(0
1
123456789)
3

S. Molaei et al.
1
Introduction
the immobilization of homogeneous catalysts [11–14].
mesoporous silica MCM-41 became the most attractive
member of the family M41S due to its unique properties
like high surface area, good thermal stability, low mass
density and large pore volume [15–17] and it has been
a focus for many potential applications as nanoscience
[18], catalysis [19, 20], environmental purification [21]
and drug delivery [22]. MCM-41 consists of an array
of uniform hexagonal channels of tunable size [21, 23].
Because of the nature of MCM-41 pore structure, it has
the availability of a large number of free silanol groups
[20]. Attachment of active molecules to the inner pore
surfaces can be exploited as catalyst for different types of
Catalysis plays a main role on new approaches to the
development of green chemistry principles [1]. Homoge-
neous catalysts are recommended for performing a wide
range of chemical transformations considering their per-
formance in activity and selectivity. However their separa-
tion and recovery after a reaction is a challenge. Immobi-
lizing homogeneous catalysts on supports was introduced
to overcome their separation and reuse problems. This
immobilization affords catalyst with the advantages of
both homogeneous (selectivity, tunability, and homoge-
neous sites) and heterogeneous (separation, recovery, and
reuse) catalysts [2–4]. During the recent years, immobili-
zation of homogeneous catalysts on various solid supports
has been of huge interest [5–7]. Even though, immobiliza-
tion of homogeneous catalysts usually reduces the cata-
lytic activity [8, 9]. Nanotechnology, a fast-growing area,
can overcome this drawback and act as efficient bridges
between homogeneous and heterogeneous catalysts [10].
Among various nanoparticles, mesoporous materials cover
large number of applications in heterogeneous support for
O
MCM-41@Tryptophan-M (Cat)
S
S
R1
R2
R1
R2
H O , rt
2
2
M=Cd or Hg
Scheme 2 The oxidation of sulfides into sulfoxides
Scheme 1 Synthesis of MCM-
4
1@Tryptophan-M
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
reactions. Loaded metal complexes into the channel walls
is highly desirable in the development of reusable cata-
lysts [24, 25]. Tryptophan is an amino acid present in all
natural proteins and has an indole functional group [26].
The present study has focused on the immobilization of
tryptophan on the surface of MCM-41 as a novel amino
acid based solid support. The selective conversion of thiols
to disulfides so that no additional oxidation takes place,
is important for many chemists both from the biological
and MCM-41@Tryptophan-Hg as new, highly efficient,
reusable and highly stable catalysts for oxidative coupling
of thiols into disulfides and oxidation of sulfides to sul-
foxides under mild condition with controlled oxidation.
2 Experimental
(
as an examples the disulfide bond plays an important
2.1 Materials and Instrumentation
role to form and stabilization of the structure of peptides
and protein) and synthesis points of view (including the
use of a wide variety of disulfides as volcanizing agents
for rubbers and elastomers, which gives these materials
extraordinary elasticity) [27–30]. Likewise, sulfoxides
are beneficial synthetic intermediates in the synthesis
of chemically and biologically crucial molecules such
as therapeutic agents, pharmaceutical and fine chemical
industries [11, 31–34]. Oxidation of sulfides and thiols
is the usual route for preparation of corresponding sul-
foxides and disulfides. Although this reaction has been
studied extensively [35–40], it is necessary to introduce
procedures that are more simple, mild, efficient and espe-
cially selective without over oxidation to the correspond-
ing materials. Herein we report MCM-41@Tryptophan-Cd
Chemicals and solvents used in this work were purchased
from Merck and Sigma-Aldrich and were used without
further purification. X-ray diffraction (XRD) patterns were
recorded on a MPD diffractometer of X’pert with Cu–Kα
radiation under the conditions of 40 kV and 40 mA. SEM
images were recorded using FESEM-TESCAN MIRA3.
Fourier transforms infrared (FTIR) spectra of KBr disks
were measured on a VERTEX70 model BRUKER FT-IR
spectrophotometer. Thermogravimetric analysis (TGA)
was performed on a Shimadzu DTG-60 instrument. Induc-
tively coupled plasma optical emission spectrometry (ICP-
OES) was used to obtain the metal content of the nanocat-
alyst. The elemental analysis of the samples was done by
Energy-dispersive X-ray spectroscopy (EDAX, TSCAN).
2.2 Preparation of MCM‑41
R
MCM-41@Tryptophan-M (Cat)
H O , rt
S
R
SH
S
R
Synthesis of MCM-41mesoporous silica was carried out
by following a similar methodology according to the litera-
ture method [41] using cetyltrimethylammonium bromide
2
2
M=Cd or Hg
(
CTAB) as the structure directing agent, tetraethylortho-
silicate (TEOS) as Si source and sodium hydroxide as pH
controlling agent. A typical synthesis gel was prepared by
Scheme 3 The oxidative coupling of thiols into disulfides
Fig. 1 TGA curves of MCM-41,
MCM-41@Tryptophan-Cd and
MCM-41@Tryptophan-Hg
1
3

S. Molaei et al.
Fig. 2 FT-IR spectra of a
MCM-41, b MCM-41@
Tryptophan, c MCM-41@
Tryptophan-Cd and d MCM-41
@Tryptophan-Cd
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
adding surfactant CTAB (1 g) to a solution of deionized
water (480 mL) and NaOH (2 M, 3.5 mL) which was stirred
at 80 °C. When the solution became uniform, 5 ml of TEOS
was slowly added into the solution. The resulting solution
was stirred for 2 h at the ambient temperature. The resulting
product was filtered, washed with distilled water and dried at
6
0 °C. Finally the collected product was calcined at 550 °C
for 5 h with rate of 2 °C/min to remove the surfactant. This
mesoporous material is designated as MCM-41.
2
.3 Preparation of MCM‑41@Tryptophan‑M (Cd
and Hg)
Grafting of the ligand (Tryptophan) to MCM-41 was per-
formed by stirring of MCM-41(1 g) with tryptophan (1.5 g)
in deionized water (50 mL) at 50 °C for 48 h under reflux
condition. The resulting white solid was filtered, washed
with deionized water and dried at 50 °C. Finally MCM-4@
Tryptophan-Cd or Hg was prepared by stirring the above
mentioned solid (1 g) with Cd(NO ) ·4H O or Hg(NO )
Fig. 3 Nitrogen adsorption–desorption isotherms of MCM-41,
MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg
Table 1 Texture parameters obtained from nitrogen adsorption stud-
ies
3
2
2
3 2
2
3
(2.5 mmol), in ethanol under reflux condition for 16 h. Even-
tually, the resulting solid was filtered, washed with ethanol
and dried at 50 °C (Scheme 1).
Volume sample
SBET (m /g) Pore diameter
Pore (cm /g)
by BJH method
(
nm)
MCM-41
MCM-41@Trypto-
phan-Cd
987.5
294.1
3.6
2.1
1.2852
0.4369
2
.4 General Procedure for the Oxidation of Sulfides
to Sulfoxide
MCM-41@Trypto-
141.2
1.8
0.3732
phan-Hg
A mixture of sulfide (1 mmol), H O (0.5 mL) and MCM-
2
2
4
1@Tryptophan-M (Cd or Hg) (0.005 g) was stirred under
Fig. 4 XRD patterns of
the MCM-41, MCM-41@
Tryptophan-Cd and MCM-41@
Tryptophan-Hg
1
3

S. Molaei et al.
neat conditions at room temperature for appropriate time and
the progress of the reaction was monitored by TLC. After
completion of the reaction, the catalyst was separated by
filtration and washed with ethyl acetate. Finally, ethyl acetate
was evaporated, and then pure product with excellent yield
was obtained by crystallization from ethanol (Scheme 2).
After completion of the reaction, the catalyst was removed
by filtration and the mixture was washed with ethyl acetate.
The product was extracted with ethyl acetate. After the evap-
oration of ethyl acetate, the pure product was obtained by
crystallization from ethanol (Scheme 3).
2
.5 General Procedure for the Oxidation of Thiols
3 Results and Discussion
to Disulfides
3
.1 Catalyst Synthesis and Characterization
General experimental procedure for the oxidative coupling
of thiols is as following: MCM-41@Tryptophan-M (Cd or
Hg) (0.005) was added to a mixture of thiol (1 mmol) and
H O (0.5 mL) in ethanol (3 mL). Then the mixture was
Here-in, we report the synthesis and characterization of
MCM-41@Tryptophan-M (Cd and Hg) for the first time.
Also we studied their applications as novel heterogene-
ous and recoverable catalysts in the synthesis of sulfoxides
and disulfides from sulfides and thiols respectively. Both
2
2
magnetically stirred for the appropriate time at room tem-
perature. The progress of reaction was monitored by TLC.
Fig. 5 EDS pattern of a MCM-41@Tryptophan-Cd, b recovered MCM-41@Tryptophan-Cd, c MCM-41@Tryptophan-Hg and d recovered
MCM-41@Tryptophan-Hg
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
processes were carried out at room temperature. The MCM-
1@Tryptophan-M were prepared using reaction of the
mass loss for MCM-41@Tryptophan-Cd and 42% for MCM-
4
41@Tryptophan-Hg between 200 and 500 °C are assigned
to the thermal decomposition of tryptophan ligands grafting
to the MCM-41. Based on these results, the well grafting
Cd-tryptophan and Hg-tryptophan into MCM-41 channels
is verified.
immobilized tryptophan on MCM-41 with Cd or Hg(NO ) .
3
2
Tryptophan complexes supported on nanoporous MCM-41
have been characterized by a variety of techniques.
The TGA curves of the MCM-41, MCM-41@Tryp-
tophan-Cd and MCM-41@Tryptophan-Hg indicates the
weight loss of the organic material as they decompose upon
heating (Fig. 1). The weight loss (< 200) in the samples
attributed to removal of physically and chemically adsorbed
surface hydroxyl groups and organic solvents [42]. The 32%
Figure 2 shows FT-IR spectra for MCM-41, MCM-41@
Tryptophan, MCM-41@Tryptophan-Cd and MCM-41@
Tryptophan-Hg. Curve a, in Fig. 2, is FT-IR spectrum for
−
1
the MCM-41. It shows three peaks at 809 and 1086 cm
corresponding to the symmetric and asymmetric Si–O–Si
Fig. 6 SEM images of a MCM-41@Tryptophan-Cd, b recovered MCM-41@Tryptophan-Cd, c MCM-41@Tryptophan-Hg and d recovered
MCM-41@Tryptophan-Hg
1
3

S. Molaei et al.
vibration respectively and at 461 cm−1 due to the Si–O bend-
ing vibration. For the silanol (O–H), which are attached
to the MCM-41 framework, stretching vibration bands
(DBJH), the Brunauer–Emmett–Teller surface area (SBET)
and the Total pore volumes (V ) of the samples are sum-
total
marized in Table 1. Reduction of Physical parameters of
nitrogen isotherms was observed with functionalization of
the mesoporous material. These results confirm that metals
tryptophan complexes were bonded on the MCM-41.
The low-angle XRD patterns of MCM-41, MCM-41@
Tryptophan-Cd and MCM-41@Tryptophan-Hg are shown
in Fig. 4. The XRD pattern of MCM-41 shows a typical
three-peak pattern with very strong reflection at 2θ=2.51°
for d100 and two other weaker reflections at 2θ=4.30° and
4.91° for d110 and d200, respectively, that can be indexed
to well-ordered one-dimensional hexagonal mesoporous
structure of mesoporous MCM-41 [43]. Upon post grafting
of M-tryptophan into MCM-41, decreased intensity of the
(100) diffraction peak and the disappearance of the (110)
and (100) peaks are observed, indicating that the mesostruc-
ture ordering was decreased due to successful dispersion of
Cd and Hg complexs into the pore channels of MCM-41
[25]. Also, the position of d100 reflection in the samples
was retained and the patterns were similar, which means
that the MCM-41 structure remained unchanged after the
functionalization steps.
−
1
appeared at 3420 cm . In the spectrum of the MCM-41@
Tryptophan, the presence of anchored tryptophan to the solid
surface was confirmed by aliphatic C–H stretching vibra-
−1
tions appeared at about 2926 cm and C–N stretching vibra-
−
1
tion at 1630 cm . The FT-IR spectrum of Cd and Hg onto
−
1
MCM-41@Tryptophan show bands at 1090 and 1089 cm
corresponding to the asymmetric Si–O–Si vibration, 803 and
−
1
8
4
05 cm attributed to the symmetric Si–O–Si vibration,
−
1
66 and 464 cm assignable to the Si–O bending vibra-
tion. These phenomena indicate that the MCM-41 structure
remained unchanged after immobilization of metals com-
−
1
plexes on the MCM-41. The band near 1385 cm of the
MCM-41@Tryptophan is attributed to ν(NH ) bending; this
2
band is shifted to lower wavenumber in the spectrum of the
MCM-41@Tryptophan-Cd and MCM-41 @Tryptophan-Hg
due to the coordination of the amino group nitrogen atom
to the metal ion [4].
The N adsorption–desorption isotherms results of MCM-
2
4
1, MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-
Hg are shown in Fig. 3. As shown, the BET surface area
decreased with the anchored of tryptophan complex on the
MCM-41 sample, which are in agreement with the XRD
result. The Barret–Joyner–Halenda average pore diameter
The metal content of MCM-41@Tryptophan-M was
determined using EDS. The EDS patterns of MCM-41@
Tryptophan-M and recovered MCM-41@Tryptophan-M
Table 2 Optimization of the reaction conditions for the oxidation of methylphenyl sulfide as model compound
O
S
M@Tryptophan-MCM-41
S
H O , rt
2
2
M=Cd or
Hg
Entry
Solvent
MCM-41@Tryptophan-M H O (mL)
Time (min)
Cd
Yield (%)a
Cd
2
2
(
mg)
Cd
Hg
Hg
30
30
35
Hg
1
2
3
4
5
6
7
Solvent free
Solvent free
Solvent free
Solvent free
ETOH
Ethyl acetate
Acetonitrile
3
5
7
5
5
5
5
3
5
7
5
5
5
5
0.5
0.5
0.5
0.4
0.5
0.5
0.5
35
35
30
91
94
95
90
87
80
75
94
95
95
93
87
85
85
50
45
120
150
200
110
145
190
aIsolated yields
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
Table 3 Oxidation of sulfides into sulfoxides in the presence of MCM-41@Tryptophan-M (mg) at room temperature
Entry
Sulfide
Product
Time (min)
Yield %
Cd Hg
Cd Hg
O
S
S
1
35
30
94
95
O
S
O
O
O
O
2
2
3
2
2
99
98
99
99
S
OH
OH
HO
HO
O
O
O
O
O
S
3
S
OH
HO
OH
HO
O
S
S
H C
CH2
4
5
6
7
8
9
2
H C
2
CH2
2
1
6
90
91
93
94
95
94
91
95
O
S
S
7
O
S
S
OH
OH
2
2
95
O
S
2
5
5
1
5
93
91
93
S
OH
OH
O
S
S
O
S
3
S
O
S
S
1
0
10
7
89
91
1
3

S. Molaei et al.
Table 4 Optimization of the reaction conditions for the oxidation of 2-mercaptobenzoic acid as model compound
COOH
COOH
COOH
M@Tryptophan-MCM-41
S
S
SH
H O , rt
2
2
M=Cd or
Hg
Entry
Solvent
MCM-41@Tryptophan-M H O (mL)
Time (min)
Cd
Yield (%)a
2
2
(
mg)
Cd
Hg
Hg
Cd
Hg
1
2
3
4
5
6
7
ETOH
ETOH
ETOH
ETOH
Solvent free
Ethyl acetate
Acetonitrile
3
5
7
5
5
5
5
3
5
7
5
5
5
5
0.5
0.5
0.5
0.4
0.5
0.5
0.5
25
5
10
7
25
40
100
15
5
5
91
96
96
91
76
86
88
91
96
97
91
86
83
84
7
10
85
190
aIsolated yields
catalysts are shown in Fig. 5. As shown in Fig. 5a, b EDS
spectrum of MCM-41@Tryptophan-Cd and MCM-41@
Tryptophan-Cd in the eighth recovery, shows the presence
of O, Si, C, N and Cd species in the catalyst. Also Fig. 5c,
d shows the presence of O, Si, C, N and Hg species in the
MCM-41@Tryptophan-Hg and MCM-41@Tryptophan-
Hg in the eighth recovery. To investigate the amount of Cd
and Hg in unreacted MCM-41@Tryptophan-M ICP-OES
(Scheme 2). To optimize reaction conditions, we evaluated
the influence of different solvents, amount of catalysts and
amount of H O on oxidation of methyl phenyl sulfide as a
2
2
model reaction (Table 1). Initially, the influence of different
solvents, and then the effect of catalysts amount, and subse-
quently, effect of amount of H O on the oxidation of methyl
2
2
phenyl sulfide were investigated. As shown in Table 1, the
best results were obtained with 0.005 g of catalysts in sol-
vent free condition and 0.5 ml H O at room temperature for
(
inductively coupled plasma optical emission spectrom-
2
2
etry) analysis was performed and they found to be 0.20 and
two catalysts. (Table 2, entry 2). After the optimization of
the reaction condition several sulfides with different func-
tional groups in optimal conditions, have been converted to
their corresponding sulfoxides (Table 3).
−
1
0
.85 mmol g respectively.
The morphological of the catalysts was investigated using
SEM technique. Figure 6 shows the SEM photographs of
MCM-41@Tryptophan-M catalysts and recovered MCM-
In second part of our study, we evaluated the catalytic
activity of MCM-41@Tryptophan-M (Cd and Hg) in oxi-
dative coupling thiols into their corresponding disulfides
(Scheme 3). In order to optimize reaction conditions, 2-mer-
captobenzoic acid was chosen as a model and the influence
of different amounts of catalyst, H O , and the nature of
4
1@Tryptophan-M catalysts. As shown in this figure, the
nanoparticles are made up of uniform nanosized spherical
particles. Also no significant changes in the surface mor-
phology occurred after recovery.
2
2
3.2 Catalytic Studies
solvent were studied (Table 4). Table 4 indicates that 0.005 g
of catalysts and 0.5 ml H O in ethanol were the best condi-
2
2
As the first part of our program, the catalytic activity of
MCM-41@Tryptophan-M (Cd and Hg) was examined for
the oxidation of sulfides into corresponding sulfoxides
tions for oxidative coupling of thiols to disulfides at room
temperature in both catalysts. (Table 4, entry 2). Then
we investigated oxidative coupling of various thiols with
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
Table 5 Oxidative coupling of thiols into disulfides in the presence of MCM-41@Tryptophan-M (mg) at room temperature
Entry
Sulfide
Product
Time (min)
Yield %
Cd
5
Hg
Cd Hg
COOH
COOH
COOH
SH
SH
S
S
S
S
1
5
96
96
2
3
4
5
6
7
8
1
2
1
95
95
92
91
S
S
SH
1
91
91
94
90
89
N
N
S
S
S
S
S
SH
4
4
S
N
S
H
N
N
N
SH
10
10
25
10
5
94
N
H
N
N
H
OH
OH
HO
94
91
S
S
HS
Br
SH
S
S
15
Br
Br
OH
O
OH
O
S
HO
O
OH
S
2
2
98
98
O
O
SH
O
HO
HO
SH
S
S
9
1
1
1
90
90
SH
S
S
1
0
2
93
95
1
3

S. Molaei et al.
present heterogeneous systems could be applicable for the
chemo selective oxidative coupling of thiols and oxidation
of sulfides.
3.3 Reusability of the Catalyst
Finally, the reusability of the MCM-41@Tryptophan-Cd
and MCM-41@Tryptophan-Hg were evaluated for the
oxidation of 3,3′-thiodipropionic acid and oxidative cou-
pling of 4-methylthio ethanol as a model reaction under
the optimized conditions. Upon completion of the reaction,
the catalyst was recovered using simple filtration from the
reaction mixture after each cycle and washed with the
ethyl acetate, and subjected to the next run (Fig. 7).
As shown in Fig. 8, the catalysts could be reused up
to eight cycles without detectable lose of catalytic activ-
ity. The recovered catalysts were characterized by SEM
Fig. 7 Recovery of MCM-41@Tryptophan-M by simple filteration
(
Fig. 5b, d). They indicate that the morphology of the
recovered MCM-41@Tryptophan-M (Cd and Hg) catalysts
and unreacted catalysts are similar. During the catalyst
recycling, the decreased activity ascribed to the low leach-
ing of Cd and Hg from MCM-41 functionalized.
3.4 Comparison of the Catalyst
To demonstrate the merit of MCM-41@Tryptophan-M (Cd
and Hg) the catalytic data was compared with that found
in the literature, the results for the oxidation of dibenzyl
sulfide and benzyl mercaptan as representative examples.
As shown in Table 6 MCM-41@Tryptophan-M (Cd and
Hg) show a better catalytic activity in terms of the best
reaction time and high yield.
4
Conclusion
Fig. 8 Reusability of MCM-41@Tryptophan-M (a) Cd and (b) Hg
catalysts for oxidation of 3,3′-thiodipropionic acid and (c) Cd and (d)
Hg oxidative coupling of 4-methylthio ethanol
We successfully immobilized Tryptophan-Cd and Trypto-
phan-Hg onto functionalized mesoporous MCM-41. The
MCM-41@Tryptophan-M catalysts were characterized by
FT-IR, XRD, TGA, BET, SEM, EDX and ICP-OES tech-
niques. These catalysts catalyzed oxidation of sulfides to
sulfoxides and thiols to disulfides in the presence of H O .
optimal conditions (Table 5). As shown in Tables 3 and 5,
thiols and sulfide were successfully converted to the corre-
sponding material, and all products were obtained in high to
excellent yields in the short reaction time. There is no over
oxidation to sulfone (for oxidation of sulfides) or sulfoxide
2
2
The main findings of this work are simple work-up, short
reaction times, and high yields of products. The catalysts
are selective and they can easily separated using a simple
filtration without any loss of their catalytic activity.
(
for the oxidative coupling of thiols) was observed; so the
1
3

Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of…
Table 6 Comparison results
Entry Substrate
Reagent
Time (min) Yield (%) Ref.
of prepared catalysts for the
oxidation of dibenzyl sulfide
and benzyl mercaptan with
previously reported procedure
1
2
3
4
5
6
7
8
9
1
1
1
1
1
1
1
1
1
1
1
Dibenzyl sulfide
MCM-41
60
60
7
20
10
91
94
99
97
96
97
96
96
23
13
91
92
98
95
96
99
90
91
This work
This work
This work
This work
[44]
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
Dibenzyl sulfide
MCM-41@Tryptophan
MCM-41@Tryptophan-Cd
MCM-41@Tryptophan-Hg
Zr(IV)/isatin-MCM-48
Ni-salen-MCM-41
6
30
145
137
120
20
15
60
60
2
[11]
[11]
[40]
[35]
Cd-salen-MCM-41
Fe O /salen of Cu(II)
3
4
Fe O @SiO @DOPisatin-Ni
3
4
2
0
1
2
3
4
1
2
3
4
5
6
Fe O @SiO @DOPisatin-Cu
[35]
3
4
2
Benzyl mercaptan MCM-41
This work
This work
This work
This work
[41]
[39]
[45]
[28]
[46]
[27]
Benzyl mercaptan MCM-41@Tryptophan
Benzyl mercaptan MCM-41@Tryptophan-Cd
Benzyl mercaptan MCM-41@Tryptophan-Hg
Benzyl mercaptan VO@MCM-41-Cys
Benzyl mercaptan Ni-SMTU@boehmite
Benzyl mercaptan Fe O -Adenine-Zn
Benzyl mercaptan M-salen-MNPs (M: Cr, Zn, Cd, Co, Ni)
Benzyl mercaptan DSA@MNPs
Benzyl mercaptan Cu-Schiff base@MCM-41
1
60
225
90
60
60
60
3
4
Acknowledgements We gratefully acknowledge the support of this
16. Yang P, Gai S, Lin J (2012) Chem Soc Rev 41:3679–3698
17. Nikoorazm M, Ghorbani-Choghamarani A, Ghorbani F, Mahdavi
H, Karamshahi Z (2014) J Porous Mat 22:261–267
work by University of Kurdistan and University of Ilam.
1
8. Torney F, Trewyn BG, Lin VS, Wang K (2007) Nat Nanotechnol
2
:295–300
References
1
2
9. Martín-Aranda RM, Čejka J (2009) Top Catal 53:141–153
0. Hajjami M, Ghorbani F, Bakhti F (2014) Appl Catal A
470:303–310
1
2
.
.
Hutchings GJ (2009) J Mater Chem 19:1222–1235
Havasi F, Ghorbani-Choghamarani A, Nikpour F (2016)
Microporous Mesoporous Mater 224:26–35
Arai M, Zhao F (2015) Catalysts 5:868–870
Tamoradi T, Ghorbani-Choghamarani A, Ghadermazi M (2018)
Polyhedron (in Press)
21. Lv L, Wang K, Zhao XS (2007) J Colloid Interface Sci
305:218–225
3
4
.
.
22. Slowing II, Vivero-Escoto JL, Wu CW, Lin VS (2008) Adv Drug
Deliv Rev 60:1278–1288
23. Sonwane CG, Bhatia SK (2000) J Phys Chem B 104:9099–9110
24. Jain SL, Rana BS, Singh B, Sinha AK, Bhaumik A, Nandi M, Sain
B (2010) Green Chem 12:374
5
6
7
8
9
.
.
.
.
.
Sun J, Cheng W, Fan W, Wang Y, Meng Z, Zhang S (2009) Catal
Today 148:361–367
Zakharova MV, Kleitz F, Fontaine F-G (2017) ChemCatChem
25. Ghorbani-Choghamarani A, Nikpour F, Ghorbani F, Havasi F
(2015) RSC Adv 5:33212–33220
9
:1886–1890
Cánepa AL, Elías VR, Vaschetti VM, Sabre EV, Eimer GA,
Casuscelli SG (2017) Appl Catal A 545:72–78
Dehghani F, Sardarian AR, Esmaeilpour M (2013) J Organomet
Chem 743:87–96
26. Pfefferkorn ER, Eckel M, Rebhun S (1986) Mol Biochem Parasitol
20:215–224
27. Hajjami M, Rahmani S (2015) J Porous Mat 22:1265–1274
28. Ghorbani-Choghamarani A, Darvishnejad Z, Tahmasbi B (2015)
Inorganica Chim Acta 435:223–231
Havasi F, Ghorbani-Choghamarani A, Nikpour F (2015) New J
Chem 39:6504–6512
29. Zhang Z, Li W, Liu J, Chen X, Bu Y (2012) J Organomet Chem
706–707:89–98
1
1
0. Shylesh S, Schunemann V, Thiel WR (2010) Angew Chem Int
Ed Engl 49:3428–3459
30. Naga N, Moriyama K, Furukawa H (2017) J Polym Sci A
55:3749–3756
1. Nikoorazm M, Ghorbani-Choghamarani A, Mahdavi H,
Esmaeili SM (2015) Microporous Mesoporous Mater
31. Villalobos L, Ren T (2013) Inorg Chem Commun 28:52–54
32. Shiri L, Tahmasbi B (2016) Phosphorus Sulfur Silicon Relat Elem
192:53–57
2
11:174–181
1
1
1
1
2. González-Arellano C, Corma A, Iglesias M, Sánchez F (2004)
Adv Synth Catal 346:1758–1764
33. Romanelli GP, Villabrille PI, Cáceres CV, Vázquez PG, Tundo P
(2011) Catal Comm 12:726–730
3. Nikoorazm M, Ghorbani-Choghamarani A, Khanmoradi M
(
2016) Appl Organomet Chem 30:705–712
34. Jeon HB, Kim KT, Kim SH (2014) Tetrahedron Lett
55:3905–3908
4. Tamoradi T, Ghadermazi M, Ghorbani-Choghamarani A (2018)
Catal Lett (in Press)
35. Hajjami M, Sharifirad F, Gholamian F (2017) Appl Organomet
Chem 31:e3844
5. Williams CD, Travis KP, Burton NA, Harding JH (2016)
Microporous Mesoporous Mater 228:215–223
36. Firouzabadi H, Iranpoor N, Pourali A-R (2004) Synlett 0347–0349
1
3

S. Molaei et al.
3
3
7. Raber E, McGuire R (2002) J Hazard Mater 93:339–352
42. Nikoorazm M, Ghorbani-Choghamarani A, Khanmoradi M (2016)
RSC Adv 6:56549–56561
8. Ghorbani-Choghamarani A, Tahmasbi B, Arghand F, Faryadi S
(
2015) RSC Adv 5:92174–92183
43. Benhamou A, Baudu M, Derriche Z, Basly JP (2009) J Hazard
Mater 171:1001–1008
3
4
4
9. Ghorbani-Choghamarani A, Moradi P, Tahmasbi B (2016) RSC
Adv 6:56458–56466
44. Hajjami M, Yousofvand Z (2015) Catal Lett 145:1733–1740
45. Tamoradi T, Ghorbani-Choghamarani A, Ghadermazi M (2017)
New J Chem 41:11714–11721
0. Ghorbani-Choghamarani A, Ghasemi B, Safari Z, Azadi G (2015)
Catal Comm 60:70–75
1. Noori N, Nikoorazm M, Ghorbani-Choghamarani A (2016)
Microporous Mesoporous Mater 234:166–175
46. Ghorbani-Choghamarani A, Rabiei H, Tahmasbi B, Ghasemi B,
Mardi F (2016) Res Chem Intermed 42:5723–5737
Affiliations
Somayeh Molaei · Taiebeh Tamoradi · Mohammad Ghadermazi · Arash Ghorbani‑Choghamarani2
1
1
1,2
1
*
Mohammad Ghadermazi
mghadermazi@yahoo.com
Department of Chemistry, Faculty of Science, University
of Kurdistan, Sanandaj, Iran
2
Arash Ghorbani-Choghamarani
Department of Chemistry, Faculty of Science, Ilam
University, P.O. Box, 69315516, Ilam, Iran
arashghch58@yahoo.com; a.ghorbani@ilam.ac.ir
1
3