Heterogeneous oxidative synthesis of quinazolines over OMS-2 under ligand-free conditions

Article abstract of DOI:10.1039/C8NJ02551G

A manganese oxide octahedral molecular sieve (OMS-2) prepared using urea as an additive was found to be an efficient recyclable catalyst for the synthesis of quinazolines via oxidation/cyclization. A broad range of substituted quinazolines were obtained from alcohols and amidines in good yields under ligand-free conditions. OMS-2 was characterized by XRD, BET, ICP-AES, SEM, TEM and XPS, which indicated that the superior catalytic ability might arise from enhanced surface area and crystallinity.

Full text of DOI:10.1039/C8NJ02551G

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Heterogeneous oxidative synthesis of quinazolines over OMS-2
under ligand-free conditions
Bo Li,*a Changming Li, a Liang Tian,a Jinbo Zhou,a Jianfeng Huang,a Xu Meng,*b
eceived 00th January 20xx,
Accepted 00th January 20xx
Manganese oxide octahedral molecular sieve (OMS-2) prepared using urea as additive was found to be an efficient
recyclable catalyst for the synthesis of quinazolines via oxidation/cyclization. A broad of substituted quinazolines were
obtained from alcohols and amidines in good yields under ligand-free conditions. OMS-2 was characterized by XRD, BET,
ICP-AES, SEM, TEM and XPS, which indicates that the superior catalytic ability might arise from enhanced surface area and
crystallinity.
DOI: 10.1039/x0xx00000x
www.rsc.org/
Mn3+ and Mn2+), OMS-2 has widely applied in oxidation of
alcohols, oxidative dehydrogenation, imination, cynation,
amidation, oxidative cyclization, and environmental
Introduction
Quinazolines are important nitrogen heterocycles because
they have showed remarkable bioactivities as anticancer,
antiviral and antitubercular reagents and they are cores of HIV
reverse transcriptase inhibitors.1 Over the past years, the
synthesis of quinazolines was realized through condensation of
2-aminobenzophenones with aldehydes, acyl chloride and
benzylamines.2 Recently, amidines were employed as starting
materials to construct quinazolines with aldehydes catalyzed
by Pd or promoted by microwave.3 Notably, nano-CuO-
catalyzed aerobic oxidative synthesis of quinazolines from
amidines and alcohols that acted as stable and cheap
precursors of aldehydes was developed with the help of
ligand.4 From an environmentally-friendly and economic point
of view, the development of heterogeneous catalytic system
based on elegantly designed recyclable catalysts under ligand-
free conditions for the synthesis of important heterocyclic
compounds is still desirable and challenging.
catalysis.6,7 Very recently, our group reported that several
practical and clean synthesis of N-containing heterocycles
catalyzed by OMS-2 which was prepared by different methods
with green oxidants under additive-, base- and ligand-free
conditions.8 Therefore, it is desirable to synthesize OMS-2-
based materials and construct the efficient and simple
catalytic systems based on them for the sustainable organic
molecular transformation.
In continuation of our research toward sustainable
catalysis,9 herein, we would like to describe that OMS-2-based
materials were prepared by different methods and employed
as heterogeneous catalysts for the aerobic synthesis of
quinazolines under ligand-free conditions (Scheme 1). The
optimal catalyst was fully characterized, which shows that
enhanced surface area and crystallinity resulted into the
excellent catalytic ability.
Manganese oxide octahedral molecular sieve (OMS-2) that
is composed of 2x2 edge- and corner-shared MnO6 octahedral
chains and tunnel K+ ions (Scheme 1), in recent years, has
captured broad attention because it demonstrates outstanding
practical ability in terms of catalysis, absorption, battery
materials and ion-exchange.5 Especially, due to its excellent
redox ability and existence of mixed valent manganese (Mn4+,
a.Lanzhou Petrochemical Research Center, PetroChina, Lanzhou 730060,
OMS-2
H
N
Ph
N
Ph
NH
O2
Mn
+
Ar
OH
N
toluene, 110 oC, 12 h
Ar
Scheme 1 OMS-2-catalyzed heterogeneous oxidative synthesis of quinazolines
under ligand-free conditions.
Results and Discussion
China. Fax:
+ 96 931 7982685, Tel: + 86 931 7982686, E-
mail:libo931@petrochina.cn
OMS-2-based materials were synthesized through oxidation of
Mn2+ or reduction of Mn4+ by H2O2 under reflux conditions.
First of all, X-ray diffraction (XRD) was employed to
characterize the crystal structure and crystallinity of
conventional OMS-2, OMS-2-U and OMS-2-H. As shown in
Figure 1, all materials exhibited typical cryptomelane-type
manganese oxides with 2x2 tunnel (JCPDS 29-1020).5
b.State Key Laboratory for Oxo Synthesis and Selective Oxidation, Suzhou
Research Institute of LICP, Lanzhou Institute of Chemical Physics
(LICP), Chinese Academy of Sciences, Lanzhou 730000, China. Fax: +
96 931 8277008, Tel: + 86 931 4968688, E-mail: xumeng@licp.cas.cn
† Electronic Supplementary Information (ESI) available: [Experimental
details, spectra data of the products and copies of spectra]. See
DOI: 10.1039/b000000x/
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Specifically, OMS-2-U possessed higher crystallinity compared
with others because sharper and more intense diffraction
peaks were observed. Subsequently, the textural properties of
OMS-2-based materials were investigated by nitrogen
adsorption-desorption measurements and the corresponding
information was list in Table 1. Three OMS-2 materials all
exhibited type-II isotherm (Figure S1). Notably, conventional
OMS-2 and OMS-2-H exhibited similar surface area (75-79
m2/g), while OMS-2-U demonstrated significantly enhanced
surface area (113 m2/g) due to the use of urea as the additive.
Next, morphology and microstructure of them were probed
using SEM and TEM. From the images of SEM, it was found
that all materials exhibited nano-fiber morphology although
slight differences were observed (Figure 2). OMS-2-U and
OMS-2 shared very similar nano-fiber morphology on length
and width. OMS-2-H showed more uniform, thinner and longer
fiber-like morphology, which means it possessed the smallest
particle sizes. Similarly, TEM images illustrated typical uniform
nanorod morphologies, which was in agreement with previous
research (Figure 3).9a,10,11 More characterization information of
OMS-2-based materials was concluded in supporting
information.
Figure 2 SEM images of OMS-2 (a and b), OMS-2-U (c and d) and OMS-2-H (e and
f).
Figure 1 XRD patterns of OMS-2-based materials.
Table 1 Texture properties of OMS-2, OMS-2-H and OMS-2-U
Entry
Catalyst
BET surface Total pore
Average pore
area (m2/g)
volume (cm3/g)
size (nm)
Figure 3 TEM images of OMS-2 (a and b), OMS-2-U (c and d) and OMS-2-H (e and
f).
1
2
3
OMS-2
79
0.26
0.14
0.33
12
7
OMS-2-H
OMS-2-U
75
After investigation of physical properties of conventional
OMS-2, OMS-2-H and OMS-2-U, the oxidative synthesis of
quinazolines 3a between benzyl alcohol 1a and N-
phenylbenzimidamide 2a was studied in toluene under ligand-
free conditions (Table 2). Initially, blank experiment indicated
that the reaction did not occur in the absence of catalyst, while
a-MnO2 with short nanorod-like morphology12 could not
113
11
o
catalyze the oxidation at all in toluene at 110 C (entries 1 and
2). Delightedly, conventional OMS-2 proceeded the reaction
very well and the quinazoline 3a was obtained in 75% yield
under O2 (entry 3). Next, experiments indicated KMnO4 (10
mol%) or MnSO4 (10 mol%) which are raw of OMS-2 could not
play a role of catalyst in the reactions (entries 4 and 5).
However, when OMS-2-H was used as the catalyst, a very low
yield of desired product was observed (entry 5). It was found
that OMS-2-H hardly proceeded the oxidation of benzyl
alcohol even using O2 as the oxidant due to the unique surface
2 | J. Name., 2012, 00, 1-3
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properties (entry 6), such as the existence of different planes,
After the optimization, we wondered whether the
which was in agreement of the results of Suib`s group on the observed catalysis was derived from the solid OMS-2-U rather
research of OMS-2-H.13 Nevertheless, OMS-2-U with enhanced than the leached manganese species in the solution. The hot-
surface area and crystallinity successfully catalyzed the filtration experiment was performed, which proved that the
reaction and led to 82% yield of 3a under the standard catalysis was truly heterogeneous (For experimental details,
conditions (entry 7). Then, we found that OMS-2-U-catalyzed see SI). Therefore, the recyclability of OMS-2-U was examined
reaction could not work very well under N2 and a very poor on the synthesis of quinazoline 3a (Table 3). After each run,
o
result was obtained, which means that the reaction was the catalyst was filtered, washed by water and dried at 120 C
aerobic oxidation and O2 played a role of the terminal oxidant for the next run. It was found that the catalyst remained the
(entry 8). On the other hand, a slightly low yield was realized catalytic ability and was able to reuse at least 4 times.
using air as the terminal oxidant instead of O2 and H2O2 failed Meanwhile, the retrieved catalyst after the first run was
the reaction at all (entries 9 and 10). It was worthy to note that characterized by XRD, which indicates that the crystal
the reaction temperature affected the reaction significantly structure of OMS-2-U remained very well (Fig. 4).
o
and the reaction did not occur below 110 C because OMS-2-
Table 3 The recyclability of OMS-2-Ua
catalyzed oxidation of benzyl alcohol 1a barely carried out
H
N
N
Ph
(entry 11). Very recently, we reported that Cu/OMS-2-
catalyzed synthesis of dihydro-1,3,5-triazines using the same
substrates at 90 oC, which indicates that the interaction
between Cu and Mn made oxidation of alcohols occur at a low
OMS-2-U
toluene
110 oC, O2, 12 h
Ph
NH
Ph
+
OH
N
Ph
1a
3a
2a
o
Run
Isolated yield (%)
1
2
3
4
5
temperature (90 C) and resulted into the synthetic selectivity
82
86
83
80
82
between alcohols and N- phenyl amidines. Therefore, the
a Reaction conditions: 1a (0.2 mmol), 2a (0.25 mmol), OMS-2-U (20 mg, 13 mol%),
toluene (1 mL), O2 balloon, 110 oC, 12 h.
Table 2 Optimization of oxidative synthesis of quinazoline 3a from alcohol 1a and N-
phenyl aimidine 2aa
H
N
N
Ph
MnO2-based catalyst
solvent
110 oC, oxidant, 12 h
Ph
NH
Ph
+
OH
N
Ph
1a
3a
2a
Entry
1
Catalyst
-
Oxidant
O2
Solvent
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
toluene
DMSO
Yieldb (%)
N.R.
2
α-MnO2
OMS-2
KMnO4
MnSO4
O2
0
3
O2
75
4
O2
0
5
O2
0
6
OMS-2-H
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
OMS-2-U
O2
29
7
8c
O2
82
-
15
9
air
H2O2
O2
70
Figure 4 XRD patterns of fresh OMS-2-U and OMS-2-U after the first run.
10
11d
12
13
14
15e
0
N.R.
With the optimized conditions in hand, the scope of
reaction was investigated by performing the reaction with
substituted alcohols and amidines in toluene with OMS-2-U.
Generally, substituted benzyl alcohols reacted with various N-
phenyl amidines smoothly and corresponding quinazolines
with good to excellent yields were obtained (Table 4). On the
other hand, a broad of benzyl alcohols with different
functional groups were able to react with N-
phenylbenzimidamide 2a (Table 5). Specifically, steric
hindrance effect influenced the reaction very much and 2-
chloro benzyl alcohol gave desired product 3n in moderate
yield (entry 3). Furthermore, benzyl alcohols with electron-
withdrawing groups resulted into better results than ones with
electron-donating groups. (3,4-Dimethoxyphenyl)methanol
failed the reaction and the corresponding aldehyde was
observed after the reaction (entry 8). And, aromatic
heterocyclic alcohol also participated the reaction successfully
and the corresponding quinazoline 3t were observed in 71%
yield (entry 9).
O2
0
O2
Dioxane
EtOH
0
O2
0
O2
toluene
38 (85f)
a
Reaction conditions: 1a (0.2 mmol), 2a (0.25 mmol), catalyst (20 mg, 13
b
mol% was used for OMS-2), solvent (1 mL), 12 h, O2 balloon or under air.
c
d
e
Isolated yields. Under N2 (1 atm)
used. f OMS-2-U (50 mg, 32 mol%) was used.
.
At 90 oC. OMS-2-U (5 mg, 3 mol%) was
catalytic method we described here could complement the
approach we reported previously. More optimizations proved
that toluene was the best solvent for the reaction (entries 12-
14). Moreover, controlled experiments showed that
decreasing amounts of catalyst led to poor yield and further
increasing amounts of OMS-2-U could not obviously better the
yield of 3a (entry 15). Finally, the optimal reaction conditions
were using OMS-2-U as the catalyst in toluene at 110 oC under
O2.
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Table 4 Scope of reactions between alcohols and substituted N-phenyl amidinesa
Conclusions
In summary, OMS-2-catalyzed heterogeneous oxidative
synthesis of quinazolines from alcohols and amidines under
ligand-free conditions was achieved. The characterization of
the catalyst indicated that enhanced surface area and
crystallinity might result into the excellent catalytic activity.
Moreover, the catalyst could be reused for many times
without the loss of activity. The exploration of more ligand-
and additive-free catalytic systems based on OMS-2 for the
sustainable organic synthesis is going on in our laboratory.
Entry
R1 =
R2 =
Ar =
Compound
Yieldb
(%)
85
H
H
H
H
H
H
4-OMe-Ph
4-OMe-Ph
4-OMe-Ph
4-OMe-Ph
3-OMe-Ph
3b
3c
3d
3e
3f
1
2
3
4
5
6
7
8
9
4-Br
4-Et
4-CF3
H
81
91
75
86
Experimental Section
H
4-Br
4-Cl-Ph
3g
3h
3i
78
82
86
88
95
H
4-OCF3 4-Cl-Ph
H
4-OEt
4-Cl-Ph
General information
4-CF3
3,4-di-
Cl
H
H
3-OMe-Ph
3-OMe-Ph
3j
All reagents were purchased from commercial suppliers and used
without further purification. All experiments were carried out under air
or using O2 balloon. Flash chromatography was carried out with
Merck silica gel 60 (200ꢀ300 mesh). Analytical TLC was performed
with Merck silica gel 60 F254 plates, and the products were
visualized by UV detection. 1H NMR and 13C NMR (400 and 100 MHz
respectively) spectra were recorded in CDCl3. Chemical shifts (δ) are
reported in ppm using TMS as internal standard, and spinꢀspin
coupling constants (J) are given in Hz.
3k
10
a Reaction conditions: 1 (0.2 mmol), 2 (0.25 mmol), OMS-2-U (20 mg, 13 mol%),
toluene (1 mL), O2 balloon, 110 oC, 12 h. b Isolated yields.
Table 5 Scope of reactions between alcohols and N-phenylbenzimidamidea
Preparation of MnO2-based catalysts
Conventional OMSꢀ2 was prepared according to our previous works.9a
Entry
R1 =
Compound
Yieldb (%)
1
2
3
4
5
4-Cl
3l
90
88
56
92
87
3-Cl
3m
3n
3o
3p
OMSꢀ2 synthesized using urea as the template was designated as OMSꢀ2ꢀ
2-Cl
U
and prepared according to the literature procedure with minor
modification.10 In a typical procedure, KMnO4 (32 mmol, 5.04 g) was
dissolved in 80 mL of deionized water. Urea (112 mmol, 6.72 g) was added
to the above solution, and the mixture was stirred at r.t. for 30 mins. Then,
the resulting solution was added dropwise to a vigorously stirred mixture of
60 mL of MnSO4 (42 mmol, 7.08 g) solution and concentrated HNO3 (2.4
mL). Next, the reaction mixture was refluxed for 24 h. Finally, the catalyst
was filtered, washed by water, dried at 120 oC and calcined at 350 oC for 2
h.
3,4-di-Cl
4-Br
6
7
8
9
4-F
3q
3r
3s
3t
90
75
0
4-Me
3,4-di-OMe
pyridin-2-yl
71
a Reaction conditions: 1 (0.2 mmol), 2a (0.25 mmol), OMS-2-U (20 mg, 13 mol%),
toluene (1 mL), O2 balloon, 110 oC, 12 h. b Isolated yields.
OMSꢀ2 synthesized using H2O2 as the reductant in acidic condition was
designated as OMSꢀ2ꢀH and prepared according to the literature
procedure with minor modification.11 H2O2 (40 mL, 3.0 wt%) was added to
a buffer solution consisting of HOAc (5 mL) and 40 mL of KOAc (0.05 mol,
5 g) solution. 150 mL of KMnO4 (0.04 mol, 6.5 g) solution was then added
dropwise to the above mixture while stirring. The resulting solution was
refluxed for 24 h, and the product was finally filtered, washed and dried
under air at 120 oC.
Based on our previous work13 and reports from other
groups4, we proposed the reaction mechanism in Scheme 2.
Benzyl alcohol firstly was oxidized by OMS-2 with O2 to
corresponding benzaldehyde.6,14 After that, benzaldehyde
reacted with tautomeric amidine with the help of OMS-2,
which gave imtermediate
A
. Next, intermediate
B was
generated via cyclization of
A. Finally, OMS-2/O2-catalyzed
General procedure for OMS-2-U-catalyzed quinazolines synthesis
oxidative dehydrogenation occurred on intermediate
desired product quinazoline.
B to give
The aerobic oxidative synthesis of quinazolines was generally performed
as follows: MnO2ꢀbased catalyst (20 mg), alcohol (0.3 mmol) and amidine
(0.2 mmol) were added into a Schlenk tube with a stir bar. Then, the tube
was sealed followed by the removal of air and O2 was charged into it.
Toluene (1 mL) was added into the reaction mixture using a syringe under
O2. Subsequently, the reaction mixture was allowed to react at 110 oC for
12 h. After the reaction was completed, the catalyst was isolated by
filtration and washed with EtOH and deionized water. The filtrate was
removed under reduced pressure to get the crude product, which was
further purified by silica gel chromatography to yield corresponding product.
Scheme 2 Proposed reaction route.
4 | J. Name., 2012, 00, 1-3
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Y. Wang, X. Meng, G. Chen and P. Zhao, Catal. Commun.,
2018, 104, 106-111.
10 B. Sarmah, R. Srivastava, P. Manjunathan and G. V.
Conflicts of interest
There are no conflicts to declare.
Shanbhag, ACS Sustainable Chem. Eng., 2015, 3, 2933-2943.
11 J. C. Villegas, L. J. Garces, S. Gomez, J. P. Durand and S. L.
Suib, Chem. Mater., 2005, 17, 1910-1918.
12 J. Zhang, Y. Li, L. Wang, C. Zhang and H. He, Catal. Sci.
Acknowledgements
We gratefully acknowledge the National Natural Science
Foundation of China (Grant Nos. 21573261, 21403256), the
Suzhou Industrial Technology and Innovation Project (Grant
No. SYG201531) and the Youth Innovation Promotion
Association CAS (Grant No. 2018456).
Technol., 2015, 5, 2305-2313.
13 X. Meng, X. Bi, Y. Wang, G. Chen, B. Chen, Z. Jing and P. Zhao,
Catal. Commun., 2017, 89, 34-39.
14 (a) X.-F. Wu, Chem. Rec. 2015, 15, 949-963; (b) J.-B. Feng and
x.-F. Wu, Appl. Organomet. Chem. 2015, 29, 63-86.
Notes and references
1
G.-H. Zhou, L. Wang, Y.-D. Ma, L.-P. Wang, Y.-Y. Zhang and
W. Jiang, Bioorg. Med. Chem. Lett., 2011, 21, 5905-5909.
(a) S. K. Panja, N. Dwivedi and S. Saha, Tetrahedron Lett.,
2012, 53, 6167-6172; (b) S. Ferrini, F. Ponticelli and M.
2
Taddei, Org. Lett., 2007, 9, 69-72; (c) K. Karnakar, A. V.
Kumar, S. N. Murthy, K. Ramesh and Y. V. D. Nageswar,
Tetrahedron Lett., 2012, 53, 4613-4617.
3
4
(a) M. A. McGowan, C. Z. McAvoy and S. L. Buchwald, Org.
Lett., 2012, 14, 3800-3803; (b) V. Kumar, C. Mohan, M.
Gupta and M. P. Mahajan, Tetrahedron, 2005, 61, 3533-
3538.
(a) W. Zhang, F. Guo, F. Wang, N. Zhao, L. Liu, J. Li and Z.
Wang, Org. Biomol. Chem., 2014, 12, 5752-5756, (b) L. Tang,
Y. Yang, L. Wen, S. Zhang, Z. Zha and Z. Wang, Org. Chem.
Front., 2015, 2, 114-118; (c) J. Zhang, C. Yu, S. Wang, C. Wan
and Z. Wang, Chem. Commun., 2010, 46, 5244-5246.
5
6
For reviews of OMS-2 materials, see: (a) S. L. Suib, Acc.
Chem. Res., 2008, 41, 479-487; (b) S. L. Suib, J. Mater. Chem.,
2008, 18, 1623-1631; (c) Y. F. Shen, R. P. Zerger, R. N.
DeGuzman, S. L. Suib, L. McCurdy, D. I. Potter and C. L.
O’Young, Science, 1993, 260, 511-515.
(a) Y.-C. Son, V. D. Makwana, A. R. Howell and S. L. Suib,
Angew. Chem., Int. Ed., 2001, 40, 4280-4283; (b) T. Uematsu,
Y. Miyamoto, Y. Ogasawara, K. Suzuki, K. Yamaguchi and N.
Mizuno, N. Catal. Sci. Technol., 2016,
Wang, J. Ma, M. Yu, Z. Zhang and F. Wang, Catal. Sci.
Technol., 2016, , 1940-1945; (d) X. Meng, J. Zhang, G. Chen,
B. Chen and P. Zhao, Catal. Commun., 2015, 69, 239-242; (e)
X. Jin, K. Yamaguchi and N. Mizuno, RSC Adv., 2014,
6, 222-233; (c) M.
6
4,
34712-34715; (f) K. Yamaguchi, H. Kobayashi, Y. Wang, T.
Oishi, Y. Ogasawara and N. Mizuno, Catal. Sci. Technol.,
2013,
ChemCatChem, 2013,
Yamaguchi and N. Mizuno, Angew. Chem., Int. Ed., 2012, 51
3
, 318-327; (g) K. Yamaguchi, Y. Wang and N. Mizuno,
5,
2835-2838; (h) Y. Wang, K.
,
7250-7253; (i) K. Yamaguchi, H. Kobayashi, T. Oishi and N.
Mizuno, Angew. Chem., Int. Ed., 2012, 51, 544-547; (j) M. M.
Najafpour, M. Holynska and S. Salimi, Coordination Chem.
Rev., 2015, 285, 65-75.
7
8
9
(a) M. Wei, Y. Ruan, S. Luo, X. Li, A. Xu and P. Zhang, New J.
Chem., 2015, 39, 6395-6403; (b) J. Ma, C. Wang, H. He, Appl.
Catal. B, 2017, 201, 503-510; (c) S. Luo, L. Duan, B. Sun, M.,
Wei, X. Li, A. Xu, Appl. Catal. B, 2015, 164, 92-99.
(a) X. Meng, Y. Wang, B. Chen, G. Chen, Z. Jing and P. Zhao,
Org. Process Res. Dev., 2017, 21, 2018-2024; (b) X. Meng, Y.
Wang, Y. Wang, B. Chen, Z. Jing, G. Chen and P. Zhao, J. Org.
Chem., 2017, 82, 6922-6931.
(a) X. Meng, J. Zhang, B. Chen, Z. Jing and P. Zhao, Catal. Sci.
Technol., 2016,
Zhao, Catal. Sci. Technol., 2015,
Wang, C. Yu and P. Zhao, RSC Adv., 2014,
X. Meng, C. Yu and P. Zhao, RSC Adv., 2014,
6
, 890-896; (b) X. Meng, C. Yu, G. Chen and P.
, 372-379; (c) X. Meng, Y.
, 27301-27307; (d)
, 8612-8616; (e)
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New Journal of Chemistry
Page 6 of 6
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DOI: 10.1039/C8NJ02551G
Graphic Abstract
OMS-2 is employed to synthesize heterocycles through selective
oxidation without the help of ligands.