K5[PW11ZnO39].23H2O-catalyzed acylation/ring expansion of ketoaziridines in a single pot: A new regio- and stereo-selective route for the synthesis of oxazolines

Article abstract of DOI:10.1007/s13738-015-0678-9

A new and one-pot synthesis of oxazolines has been accomplished by K₅[PW₁₁ZnO₃₉].23H₂O - catalyst acylation followed by C-N ring opening/C-O bond formation in NH ketoaziridines. This regio- and stereo-selective reaction presumably proceeds via a domino sequence resulting in the in situ generation of acyl aziridine which undergoes a ring expansion reaction via an initial C-N rupture of aziridine ring followed by ring closure to the oxazolines. The methodology provided novel one-pot procedure for the synthesis of trans-2,5-diaryl-4-aroyloxazolines.

Full text of DOI:10.1007/s13738-015-0678-9

J IRAN CHEM SOC
DOI 10.1007/s13738-015-0678-9
ORIGINAL PAPER
K [PW ZnO ].23H O‑catalyzed acylation/ring expansion
5
11
39
2
of ketoaziridines in a single pot: a new regio‑ and stereo‑selective
route for the synthesis of oxazolines
1
1
2
Heshmat A. Samimi · Akram Mostafavi · Mostafa Riahi Farsani
Received: 3 January 2015 / Accepted: 3 June 2015
©
Iranian Chemical Society 2015
Abstract A new and one-pot synthesis of oxazolines has
and synthesis of the derivatives of serines as a antibiotics
[13] synthesis of N–hydroxy-N-amino acids [14] and as
starting material in the synthesis of the neurotrophic fac-
tor Lactacystin [15, 16]. Moreover, various oxazolines with
biological activity have been isolated from marine organ-
isms [17, 18].
For many years, several synthetic methods have been
described for the synthesis of oxazolines [19–22]. On the
other hand, Aziridines are also well known as useful rea-
gents for the synthesis of many categories of nitrogen-
containing compounds, in particular N-heterocycles com-
pounds such as oxazolines, thiazolidinones, thiazolidine
thiones, and imidazolidinones [23].
been accomplished by K [PW ZnO ].23H O—catalyst
5
11
39
2
acylation followed by C–N ring opening/C–O bond for-
mation in NH ketoaziridines. This regio- and stereo-selec-
tive reaction presumably proceeds via a domino sequence
resulting in the in situ generation of acyl aziridine which
undergoes a ring expansion reaction via an initial C–N rup-
ture of aziridine ring followed by ring closure to the oxazo-
lines. The methodology provided novel one-pot procedure
for the synthesis of trans-2,5-diaryl-4-aroyloxazolines.
Keywords Aziridine · Ring expansion · Oxazoline ·
K [PW ZnO ].23H O
5
11
39
2
Among the synthetic applications of these compounds,
the rearrangement of N-activated aziridines has become the
object of attention only very recently [24]. Acyl aziridines
could rearrange to oxazolines through a ring expansion
reaction [25–29]. The ring expansion of N-acyl aziridines
to oxazolines can be promoted by thermal, acidic, or nucle-
ophilic conditions [30–38].
However, catalytic examples for the synthesis of oxa-
zolines are rare [39]. Here we report synthesis of N-acyl
ketoaziridines from the corresponding ketoaziridines with
acyl chlorides. Then N-acyl ketoaziridines in the presence of
a nucleophilic and Lewis acids afforded oxazolines [40–42].
Although a few methods have been described for the
preparation of N-acyl aziridines none of them described
direct synthesis of oxazolines from N–H aziridines with
carboxylic acid [24–48].
Introduction
Polyoxometalates and their transition-metal-substituted
derivatives are metal oxygen cluster species which is
unique in its topological and electronic diversity [1]. Dif-
ferent types of these compounds have been used in catal-
ysis, photochemistry, medicine, electrical conductivity,
magnetism, nuclear waste treatment, antiviral therapy, pho-
tocatalysis, and nanotechnology [2–4].
The oxazoline ring system has been known for more
than a century [5]. Recent years, various oxazolines have
been found widespread use in asymmetric reactions [6–12]
*
Heshmat A. Samimi
In continuation of our recent interest in the reaction of
ketoaziridines [48] and success for using Polyoxometalates
[49], herein, we report a one-pot regio- and stereo-selective
synthesis of trans-4-benzoyloxazolines, catalyzed by the
K [PW ZnO ].23H O catalytic system with moderate to
samimi-h@sci.sku.ac.ir
1
2
Department of Chemistry, Faculty of Sciences, The
University of Shahrekord, P. O. Box 115, Shahrekord, Iran
Young Researchers and Elite Club, Islamic Azad University,
Shahrekord Branch, Shahrekord, Iran
5
11
39
2
good yields under mild conditions.
1
3

J IRAN CHEM SOC
1
Results and discussion
It is noticeable that H NMR spectra show chemical shift
of H aziridine ring for 3a in CDCl at 4.1 and 4.3 ppm,
3
In our preliminary studies, trans-2-aroyl-3-aryl aziridines
their coupling constant in two doublet signals is 2.4 Hz.
The two hydrogen atoms at the CH groups of the oxazo-
lines (3a) ring were determined by H NMR spectrum reso-
(1a) were prepared as previously reported [50–52]. At the
1
outset of this study, we aimed to prepare N-acylaziridine by
an in situ generation from carboxylic acid. With the above
think in mind, we investigated the reaction of benzoic
acid in the presence of thionylchloride with ketoaziridine
nate as two doublets displaying resonance signals at about
1
3
5.5 and 6.4 ppm, their coupling constant is 4.0 Hz and
resonance signals at 80 and 81 ppm.
C
(
(
1a), but the reaction gave a mixture of unknown product
Table 1, entry 1). In another attempt, we examined the
With the above observation, we encourage to obtain an
optimization conditions for the direct synthesis of oxazo-
lines from aziridines and carboxylic acid in a one-pot reac-
tion. In order to evaluate the effect of some catalyst in the
reaction, we tried the reaction of 1a with benzoic acid in
the presence of DCC and catalyst as a model reaction.
These results showed that the ring expansion reac-
tion in the presence of BF , CuCl , AlCl , H BO , FeCl ,
reaction of benzoic acid and N,N-dicyclohexylcarbodiimide
DCC) with aziridine (1a) in acetonitrile at room tempera-
(
ture for 10 h. In this reaction, trans-2,5-diphenyl-4-benzoyl
oxazoline (4), trans-1,2-di-benzoyl-3-phenyl aziridines
(
3), and N,N-O-benzoyl isourea (2) as a intermediate were
obtained (Scheme 1).
3
2
3
3
3
3
Fe(NO ) , Silica sulfuric acid, and Dowex gave a mixture
3
3
Table 1 Optimization reaction of aziridine (1a) with benzoic acid in
the presence of DCC
of unknown products with a small amount of the desired
trans-4-benzoyloxazolines (10–56 %) oxazolines (Table 1,
entries 2–10).
a
Ph
Ph
O
H
N
PhCOOH/DCC
catalyt
Our study indicated that oxazolines have not been
synthesized with high yield in the presence of differ-
ent Lewis acid (entries 2–10). For this reason, we test
K [PW ZnO ].23H O as catalyst in this reaction. So, ring
O
N
O
+
N
Ph
CH CN
O
O
3
Ph
Ph
Ph
Ph
Ph
1
a
4a
3a
5
11
39
2
expansion of aziridine 1a with benzoic acid in the pres-
Entry
Catalyst
Yield (%)
ence of DCC and K [PW ZnO ].23H O were also studied
5
11
39
2
4
a
3a
(Table 1, entry 11). Surprisingly, K [PW ZnO ].23H O
5 11 39 2
(
0.5 mmol) was shown high catalytic performance in this
1
2
3
4
6
7
8
9
None
BF3
11
4
25
16
31
0
reaction and oxazolines synthesis with high yield (Table 1,
entry 11).
CuCl2
AlCl3
H BO
10
0
After obtaining the optimized reaction conditions, to
expand the scope of this novel methodology for synthesis
of trans-2,5-diaryl-4-aroyloxazolines (4a–g), the reaction
of trans-2-aroyl-3-aryl aziridines with benzoic acid in the
presence of DCC and K [PW ZnO ].23H O in CH CN
at room temperature (Table 2) was performed. The experi-
mental results are included in Table 2. All the products
were characterized by H, C NMR, and IR spectra.
On the basis of above experimental observations, a
plausible mechanism for these highly regio-selective
transformations is proposed. According to the mechanism
presented in Scheme 2, the reaction of benzoic acid with
DCC afforded 2a, which reacts with N-H ketoaziridines
in the presence of catalyst to give N-acyl aziridine. N-acyl
aziridine in the presence of catalyst undergoes a C–N bond
14
22
56
11
15
74
0
21
41
6
3
3
FeCl3
Fe(NO3)3
Dowex
5
11
39
2
3
19
45
11
0
1
1
1
0
1d
Silica sulfuric acid
K [PW ZnO ].23H O
1
13
5
11
39
2
b
2
K [PW ZnO ].23H O
5
11
39
2
a
Isolated yields. The reactions were performed in a ratio of 1:1:1:0.5
for the 1a/benzoic acid/DCC/Catalyst at room temperature for 10 h
b
The reaction was performed in the absence of DCC that gave an
unknown product in low yield and the starting material was recovered
c
The reaction was performed in the absence of DCC
d
The starting material was consumed for 4 h
Scheme 1 Reaction of benzoic
acid and DCC with aziridine in
acetonitrile at room temperature
Ph
Ph
O
H
N
R
O
HN
PhCOOH/DCC
O
N
N
+
O
+
Ph
Ph
O
N
R
O
O
CH CN, R.T.
Ph
Ph
3
Ph
Ph
3a:25%
Ph
1a
4
a:11%
2a: 64%
1
3

J IRAN CHEM SOC
Table 2 Reaction of trans-2-aroyl-3-aryl aziridines (1a–g) with
were characterized by comparison with authentic sam-
ples (IR and HNMR spectra, TLC, melting, and boiling
benzoic acid in the presence of DCC and K [PW ZnO ].23H O
1
5
11
39
2
Ph
points). NMR spectra were recorded on a Bruker AMX-
400 spectrometer ( H at 400 MHz and C at 100 MHz) in
PhCOOH/DCC
H
N
1
13
K
[PW11ZnO39].23H
O
5
2
O
N
O
Ar1
CDCl with chemical shift values in ppm downfield from
CH CN
3
3
O
Ar1
Ar2
TMS and IR spectra also recorded on FTIR spectroscope
JASCO, FT/IR-6300. All solvents used were dried and dis-
tilled according to the standard procedures.
Ar2
1
a-g
4
a-g
Entrya
Ar1
Ar2
Yield(%)b
a
b
c
d
e
f
C H
C H
74ref
83ref
72ref
85
6
5
6
5
5
5
Synthesis and characterization of
K [PW ZnO ].23H O [50–53]
4-ClC H
C H
6
4
6
5
11
39
2
2,4-Cl C H
C H
2
6
3
6
5
−
Aqueous solution of the [PW ZnO ] anions were pre-
11 39
C H
4-ClC H
6
5
6
4
4-ClC H
4-ClC H
76
pared by mixing of Na HPO (9.1 mol), Na WO .2H O
6
4
6
4
2 4 2 4 2
4-BrC H
C H
71
72ref
(100 mmol), and the Zn(NO ) (12 mmol) in 200 mL of
6
4
6
5
5
3 2
g
3-NO C H
C H
water and adjusting the pH to 4.8. An aqueous solution of
KCl (45 mmol in 20 mL) was added dropwise, with stir-
ring, at 80–85 °C FTIR of the potassium salt: 1090, 1055,
2
6
4
6
a
The reaction was performed for 4 h at room temperature
Isolated yield after purification
b
−1
9
54, 886, 824, 759, 712, 507 cm .
Elemental analyses (%) calcd.: H, 1.38; K, 5.83; O,
rupture and followed the C–O bond formation to afford
trans-oxazolines. In the absence of catalyst, 2a as a product
was isolated in 64 % yield.
29.59; P, 0.92; W, 60.32; Zn, 1.95. Found: H, 1.35; K, 5.89;
P, 0.90; W, 59.14; Zn, 1.91.
Since the result shows only the formation of one regio-
isomer of oxazolines, therefore, the mechanism of the
isomerization of N-acyl aziridine to oxazolines probably
includes a four-center displacement or the SNi. The aryl at
position C-3 makes it a suitable position containing a par-
tial positive carbon on C-3 for intra-nucleophilic reaction
of oxygen to give oxazoline3. Consequently, the reaction
of stereo- and regio-selective as well as retention of con-
figuration at the two carbon atom in ring confirmed that the
reaction proceeds via an intermolecular reaction. In this
reaction, it assumes that catalyst has an important role in
progress of two steps. Catalyst can activate intermediate 2
to react with aziridine. In addition, catalyst could rearrange
trans-N-acyl-1-aryl-2-aroylaziridines to the product 4 by
binding to nitrogen followed by the intra-nucleophilic addi-
tion of oxygen.
General Procedure for Preparation of 2,5‑dia‑
ryl‑4‑aroyloxazolines (3a–g)
K [PW ZnO ].23H O (0.5 mmol) and DCC (1 mmol)
5
11
39
2
were added into a solution of aziridine1 (1.0 mmol)
and benzoic acid (1.0 mmol) in CH CN (15 mL) and
3
the mixture was stirred at room temperature for 4 h.
The progress of the reaction was monitored by TLC
(EtOAc-Hexane: 1/4). After completion of the reac-
tion, organic layer was rinsed twice with water and
dried with anhydrous Na SO . Evaporation of the sol-
2
4
vent under reduced pressure and subsequent purifica-
tion of the residue by column chromatography (silica
gel, EtOAc-Hexane: 1/4) provided 4-benzoyloxazoline
4 (71–85 %) (Table 2).
N,N‑dicyclohexylimidic benzoate (2a)
Experimental section
1
White solid, Mp 120–122 °C; H NMR (400 MHz, CDCl )
3
All yields refer to isolated products after purification by
column chromatography or distillation in vacuum. Products
(δ, ppm): 0.87–0.21 (m, 20H), 3.4 (m, 1H), 4.0 (tt,
J = 11.9, 3.6 Hz, 1H), 6.1 (d, J = 5.8 Hz, 1H), 7.39–7.47
Scheme 2 Suggest a mecha-
nism for synthesis of oxazolines
Ph
N
Ph
R
Ph
O
O
HN
catalyst
O
O
catalyst
O
N
PhCOOH/DCC
N
Ph
O
N
R
O
O
Ph
Ph
Ph
H
Ph
Ph
Ph
N
O
Ph
Ph
1
3

J IRAN CHEM SOC
1
3
(
m, 3H), 7.55 (d, J = 6.9 Hz, 1H); C NMR(400 MHz,
Acknowledgments We are thankful to Research Council of Shahre-
kord University for supporting this work.
CDCl ) (δ, ppm): 24.5, 25.2, 25.3, 26.2, 30.7, 32.3, 33.9,
3
4
9.5, 57.6, 126.6, 128.5, 130.7, 154.3, 171.4
References
trans‑1,2‑di‑benzoyl‑3‑phenylaziridine (3a)
1
.
Y. Hou, L. Xu, M.J. Cichon, S. Lense, K.I. Hardcastle, C.L. Hill,
inorg. Chem 4, 4125 (2010)
White solid, Mp 86–88 °C; IR (KBr): 3060, 1675, 1596,
−
1 1
1
452, 1328, 1228 cm . H NMR (400 MHz, CDCl ) (δ,
2. J. Niu, F. Li, J. Zhao, P. Ma, D. Zhang, B. Bassil, U. Kortz, J.
3
ppm): 4.12 (d, 1H, J = 2.1 Hz), 4.37 (d, 1H, J = 2.1 Hz),
.4–7.8 (m, 11H), 8.00–8.01 (m, 4H); C NMR(400 MHz,
CDCl ) (δ, ppm): 48.0, 48.97, 126.93, 128.84, 128.86,
Wang, Chem. Eur. J. 20, 9852 (2014)
3. M.R. Farsani, B. Yadollahi, J. Mol. Catal. A: Chem. 392, 8
1
3
7
(
2014)
3
4. F. Jalilian, B. Yadollahi, M.R. Farsani, S. Tangestaninejad, H.A.
Rudbari, R. Habibi, Catal. Commun. 66, 107 (2015)
5. R. Andreasch, Monatsh. Chem. 5, 33 (1664)
1
1
28.92, 129.10, 129.23, 129.33, 132.90, 134.11, 136.18,
36.82, 176.12, 192.15; Anal. Calcd. for C H NO
2
2
17
2
6
.
B.F. Bonini, E. Capito, M. Franchini, M. Fochi, A. Ricci, B.
Zwanenburg, Tetrahedron Asymmetry 17, 3135 (2006)
X. Zhang, W. Lin, L. Gong, A. Mi, X. Cui, Y. Jiang, M.C.K.
Choi, A.S.C. Chan, Tetrahedron Lett. 43, 1535 (2002)
(
5
327.13): C, 80.73; H, 5.20; N, 4.28. found: C, 80.82; H,
.15; N, 4.25.
7
.
trans‑4‑(4‑chlorobenzoyl)‑2,5‑diphenyloxazoline (4d)
8. Z. Chai, X.Y. Liu, X.Y. Wu, G. Zhao, Tetrahedron Asymmetry
1
7, 2442 (2006)
9
.
J.I. Garcia, J.A. Mayoral, E. Pires, I. Villalba, Tetrahedron
Asymmetry 17, 2270 (2006)
Yellow solid, Mp 132–135 °C; IR (KBr): 3062, 2925, 1686,
−1 1
1645, 1597, 1476, 1447, 1258, 1088, 974, 826, 691 cm ; H
10. H.A. McManus, P.I. Guiry, Chem. Rev. 104, 4151 (2004)
NMR(400 MHz, CDCl ) (δ, ppm): 5.4 (d, J = 7.2 Hz, 1H),
11. S.F. Lu, D.M. Du, S.W. Zhang, J. Xu, Tetrahedron Asymmetry
3
1
5, 3433 (2004)
6
.2 (d, J = 7.2 Hz, 1H), 7.17–7.36 (m, 9H), 7.40–7.53 (m,
1
2. D.A. Evans, T. Rovis, M.C. Kozlowski, C.W. Downey, J.S. Ted-
13
1H), 7.9 (d, J = 8.1, Hz, 2H), 8.1 (d, J = 8.0, 2H);
C
row, J. Am. Chem. Soc. 122, 9134 (2000)
13. P. Kisanga, P. Ilankumaran, J.G. Verkade, Tetrahedron Lett. 42,
NMR(100 MHz, CDCl ) (δ, ppm): 80.1, 81.1, 123.1, 127.3,
3
1
1
7
29.0, 129.3, 129.7, 131.3, 131.4, 132.5, 133.3, 137.9,
6263 (2001)
1
4. G. Cardillo, L. Gentilucci, M. Gianotti, A. Tolomelli, Eur. J. Org.
Chem. 2489(2000) (references cited therein)
5. J.S. Panek, C.E. Masse, Angew. Chem. Int. Ed. 38, 1093 (1999)
40.5, 159.7, 192.7; Anal. Calcd. for C H ClNO : C,
22
16
2
3.03; H, 4.46; Cl, 9.80; N, 3.87; O, 8.84. found: C, 73.07;
1
H, 4.48; Cl, 9.76; N, 3.85; O, 8.84.
16. G. Cardillo, L. Gentilucci, M. Gianotti, Tolomelli A. Tetrahedron
Asymmetry 1, 563 (2001)
1
1
7. B.S. Davidson, Chem. Rev. 93, 1771 (1993)
8. P. Wipf, P.C. Fritch, S.J. Geib, A.M. Selfer, J. Am. Chem. Soc.
trans‑4‑(4‑chlorobenzoyl)‑5‑(4‑chlorophenyl)‑2‑
phenyloxazoline (4e)
1
20, 4105 (1998)
1
9. H.A. McManus, P.I. Guiry, Chem. Rev. 104, 4151 (2004)
Yellow solid, Mp 138–140 °C; IR (KBr): 3062, 2924,
20. S.-F. Lu, D.-M. Du, S.-W. Zhang, J. Xu, Tetrahedron Asymmetry
1
5, 3433 (2004)
1
686, 1645, 1595, 1478, 1446, 1256, 1084, 975, 826,
2
1. A. Cwik, Z. Hell, A. Hegedus, Z. Finta, Z. Horvath, Tetrahedron
−1 1
693 cm ; H NMR(400 MHz, CDCl ) (δ, ppm): 5.4 (d,
3
Lett. 43, 3985 (2002)
22. T.G. Gant, A.I. Meyers, Tetrahedron 50, 2297 (1994) (references
J = 7.2 Hz, 1H), 6.4 (d, J = 7.2 Hz, 1H),7.28–7.53 (m, 7H),
1
3
8
8
1
.20–8.31 (m, 6H); C NMR(100 MHz, CDCl ) (δ, ppm):
cited therein)
3
2
3. F.N. Gladysheva, A.P. Sineokov, V.S. Etlis, Rus. Chem. Rev 39,
18 (1970)
4. W. McCoull, F.A. Davis, Synthesis 10, 1347 (2000)
0.3, 81.1, 123.6, 127.1, 129.0, 129.3, 129.7, 131.3, 131.4,
32.6, 133.3, 137.9, 140.6, 158.9, 190.8; Anal. Calcd. for
1
2
C H Cl NO :C, 66.68; H, 3.82; N, 3.53; found: C, 66.53;
25. G. Cardillo, L. Gentiluccu, A. Tolomelli, C.T. Tomasini, Tetrahe-
22
15
2
2
H, 3.75; N, 3.48.
dron Lett. 38, 6953 (1997)
2
2
6. G. Cardillo, L. Gentilucci, A. Tolomelli, Chem. Commun. 167 (1999)
7. G. Cardillo, L. Gentilucci, A. Tolomelli, Tetrahedron 55, 15151
1999)
trans‑4‑benzoyl‑5‑(4‑bromophenyl)‑2‑
pheyloxazoline (4f)
(
28. F.W. Eastwood, P. Perlmutter, Q.J. Yang, Chem. Soc., Perkin.
Trans. 1, 35 (1997)
2
9. F.W. Eastwood, P. Perlmutter, Q. Yang, Tetrahedron Lett. 35,
039 (1994)
Yellow solid, Mp 155–157 °C;IR (KBr): 3059, 2929,
2
−1 1
1
687, 1638 cm ; H NMR(400 MHz, CDCl ) (δ, ppm):
3
30. J. Legters, J.G.H. Willems, L. Thijs, B. Zwanenburg, Recl. Trav.
Chim. Pay-Bas 111, 59 (1992)
31. J. Legters, E. van Dienst, L. Thijs, B. Zwanenburg, Recl. Trav.
5
.4 (d, J = 5.6 Hz, 1H), 6.5 (d, 1H, J = 5.6 Hz), 7.3–7.6
13
(m, 9H), 7.96 (m, 2H), 8.1 (dd, J = 6.3, 1.1 Hz, 2H); C
Chim. Pay-Bas 111, 69 (1992)
2. B. Olofsson, U. Khamrai, P. Somfai, Org. Lett. 2, 4087 (2000)
3. W. McCoull, F.A. Davis, Synthesis 1347 (2000)
NMR(100 MHz, CDCl ) (δ, ppm):79.0, 125.0, 126.7, 127.5,
3
3
3
1
1
6
28.5, 128.8, 128.7, 129.6, 131.8, 132.0, 133.8, 134.6, 135.1,
36.9, 139.4, 165.0, 194.0; Anal. Calcd. for C H BrNO :C,
34. G. Cardillo, L. Gentilucci, G. PericotMohr, Eur. J. Org. Chem.
3545 (2001)
22
16
2
5.04; H, 3.97; N, 3.45; found: C, 64.71; H, 3.85; N, 3.50.
1
3

J IRAN CHEM SOC
3
5. Z. Kainan, C.R. Pramod, L. Janis, Tetrahedron Lett. 49, 4306
2008)
6. G. Cardillo, L. Gentilucci, A. Tolomelli, Aldrichim Acta 36, 39
2003)
7. B. Zwanenburg, L. Thijs, Pure Appl. Chem. 68, 735 (1996)
8. F.W. Eastwood, P. Perlmutter, Q. Yang, J. Chem. Soc., Perkin
Trans. 1, 35 (1997)
44. H.A. Samimi, S. Mohammadi, J. Iran. Chem. Soc. 11, 69 (2014)
45. H.A. Samimi, H. Kiyani, Z. Shams, J. Chem. Res. 37, 282
(2013)
46. H.A. Samimi, B.M.J. Yamin, J. Chem. Res. 38, 358 (2014)
47. H.A. Samimi, M.Y. Bohari, F. Saberi, Synthesis 47, 129 (2014)
48. M.R. Farsani, F. Jalilian, B. Yadollahi, H. Amiri, Rudbari. Appl.
Organomet. Chem. 29, 7 (2015)
(
3
(
3
3
3
4
4
9. B. Kang, A.W. Miller, S. Goyal, S.T. Nguyen, Chem. Commun,
49. S. Gabriel, Chem. Ber. 21, 1049 (1888)
3
928 (2009)
50. B.J.S. Johnson, A. Stein, Inorg. Chem. 40, 801 (2001)
51. M.R. Farsani, B. Yadollahi, H. Amiri Rudbari, A. Amini, T. Cara-
doc-Davis, J.R. Price, Inorg. Chem. Commun. 43, 39 (2014)
52. M.R. Farsani, E. Assady, F. Jalilian, B. Yadollahi, H. Amiri Rud-
bari, J. Iran Chem. Soc. 12, 1207 (2015)
0. H.A. Samimi, M. Mamaghani, K. Tabatabaeian, J. Heterocycl.
Chem. 45, 1765 (2008)
1. M. Mamaghani, K. Tabatabaeian, H.A. Samimi, Z. Kristallogr,
New Cryst. Struct. 223, 390 (2008)
4
4
2. H.A. Samimi, Z. Shams, J. Iran. Chem. Soc. 11, 979 (2014)
3. H.A. Samimi, S. Mohammadi, Synlett 24, 223 (2013)
53. H. Danafar, B. Yadollahi, Catal. Commun. 10, 842 (2009)
1
3