Click reactions catalyzed by Cu(I) complexes supported with dihydrobis(2-mercapto-benzimidazolyl)borate and phosphine ligands

Article abstract of DOI:10.1016/j.ica.2020.119470

Four Cu(I) complexes bearing dihydrobis(2-mercapto-benzimidazolyl)borate and phosphine co-ligands were synthesized and their catalytic activity was investigated in azide-alkyne reactions. These complexes were tested as catalyst system and among them a Cu(

Full text of DOI:10.1016/j.ica.2020.119470

InorganicaChimicaActa506(2020)119470
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Research paper
Click reactions catalyzed by Cu(I) complexes supported with dihydrobis(2-
mercapto-benzimidazolyl)borate and phosphine ligands
Dariush Khalilia,⁎,1, Roya Evazia, Abdollah Neshatb,⁎,2, Jasem Aboonajmia, Farzane Osanloub
a Department of Chemistry, College of Sciences, Shiraz University, Shiraz 71467-13565, Iran
b Department of Chemistry, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan 45137-66731, Iran
A R T I C L E I N F O
A B S T R A C T
Keywords:
Four Cu(I) complexes bearing dihydrobis(2-mercapto-benzimidazolyl)borate and phosphine co-ligands were
synthesized and their catalytic activity was investigated in azide-alkyne reactions. These complexes were tested
as catalyst system and among them a Cu(I) complex bearing tricyclohexylphosphine ligand, [Cu(Bb)(PCy3],
showed superior catalytic activity in water. The introduced ligands are advantageous due to their nontoxicity,
strong σ-donating ability, and the ease of their handling process. The selected catalyst allowed the clean pre-
paration of triazoles in water which is considered a safe medium according to the principles of green chemistry.
These catalysts were prepared by reacting copper iodide with sodium precursor (NaBb) [Bb = dihydrobis(2-
mercapto-benzimidazolyl)borate in methanol in the presence of selected phosphine coligands (PPh3, PCy3,
PPh2Me, PPh2Py). All of the resulting Cu(I) complexes were formed as predominantly a single monomeric isomer
and were characterized using a combination of 1H, 13C{1H} and 31P{1H} NMR spectroscopy.
Cu(I) complex
Dihydrobis(2-mercapto-benzimidazolyl)borate
1,4-Disubstituted 1,2,3-triazole
Bioactive ligand
Epoxides
1. Introduction
major obstacles of exiting CuAAC methodologies include high reaction
temperatures, long reaction times and the presence of reducing agents.
Five-membered N-heterocycles, as important structural motifs, are
present in a large class of drugs, natural products, and biologically
active compounds. They also display various medicinal activities ran-
ging from antibiotic, antitumor, antibacterial, antifungal, and antiviral
properties. Considering these activities as well as being valuable in-
termediates in the synthesis of organic compounds, the facile and effi-
cient preparation of these compounds encourage further investigations
[1–3].
These issues restrict their applications in practical processes. To over-
come these issues, great efforts have been made by researchers in the
past several years. For example, Cu(I)-catalyzed azide-alkyne cycload-
dition (CuAAC), introduced by Sharpless and coworkers in 2001, has
found a widespread application in chemistry, biochemistry and mate-
rial science [26,27].
The Sharpless-Meldal CeN bond forming reactions are catalyzed by
a variety of copper sources and ligands. The importance of these ligands
in the formation of triazole products has promoted widespread studies
toward their synthesis. For instance, Sharpless et al. reported poly-
dentate triazole ligands in “click” reaction were responsible for en-
hanced catalytic activity of Cu(I) complexes through binding to the
metal [28]. Sharghi et al. studied the auxiliary effect of many ligands in
copper catalyzed Sharpless-Meldal CeN bond-forming reactions
[29–32].
Among N-heterocycles, the 1,2,3-triazole scaffolds have been well
exploited for the creation of numerous medicinal moieties exhibiting
anticancer, anti-HIV, and antibacterial properties [4–9]. There are
structurally diverse bioactive compounds bearing 1,2,3-triazole moiety
and some of them are also well acknowledged for their therapeutic
effects as elucidated in Fig. 1. Some of these compounds serve as im-
portant intermediates in numerous industrial and laboratory applica-
tions including corrosion inhibitors [10,11], agrochemicals [12], li-
gands [13–21], dendrimers, polymers [22,23], linkers, catalysts, and
pigments [24].
The derivatives of 2-mercaptobenzimidazole are associated with a
wide range of pharmacological activities including antihistaminic, an-
tiviral, anticancer, and antifungal activities [33–35]. They have also
been utilized as supporting ligands for late transition metals such as
copper ions [36–40]. We recently reported the synthesis,
Traditionally, triazole products have been prepared via thermal 1,3-
dipolar [3 + 2] cycloaddition of alkynes with organic azides [25]. The
⁎ Corresponding authors.
E-mail addresses: khalili@shirazu.ac.ir (D. Khalili), a.neshat@iasbs.ac.ir (A. Neshat).
1 0000-0003-2266-4492.
2 0000-0002-1424-2292.
https://doi.org/10.1016/j.ica.2020.119470
Received 12 December 2019; Received in revised form 24 January 2020; Accepted 25 January 2020
Availableonline31January2020
0020-1693/©2020ElsevierB.V.Allrightsreserved.

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Fig. 1. Chemical structure of some commercial drugs and bioactive molecules bearing triazole moiety.
characterization and photophysical properties of a series of Cu(I)
complexes supported with these types of compounds. In our work, two
2-mercaptobenzothiazole or 2-mercaptobenzimidazole moieties were
tethered to a bridgehead boron atom commonly providing a chelating
ligand system known as “scorpionate ligands” [41]. These softer con-
geners of multi-dentate borate based “scorpionate ligands” play a cru-
cial role in the development of stable coordination compounds [42,43].
The coordination chemistry of bipodal and tripodal sulfur donor scor-
pionate ligands with electron rich middle to late transition metals has
been the subject of extensive research studies. The main feature of
borate based ligands include their ability to act as bidentate or tri-
dentate ligands and to stabilize a multitude of metal ions with different
oxidation states. This feature has been demonstrated with a lot of re-
ports regarding synthesis and applications of metal complexes bearing
borate based ligands. The majority of literature reports regarding
polydentate N, P or S donor borate based ligands include description of
their interesting structural features [44–47], agostic interactions of
metal centers with B-H moiety of borate ligands [43,48–52], bioinor-
ganic aspects of metal complexes bearing such ligands, as well as their
catalytic activities [53–56]. Since active species in copper catalyzed
alkyne-azide reactions are Cu(I) ions, developments in the synthesis and
optimized reactions conditions including copper complexes of borate
based ligands has resulted in a surge in the application of borate based
copper and their closed counterparts based on silver complexes in click
reactions [57–59].
spectrophotometer were employed for characterization of the catalysts
and products. Melting points were determined in open capillary tubes
using a Barnstead electro thermal 9100 BZ circulating oil melting point
apparatus. The purity determination of the substrates and reaction
monitoring were accomplished by TLC on silica gel PolyGram SILG/UV
254 plate. Column Chromatography was carried out on columns of si-
lica gel 60 (70–230 mesh) in glass columns using 15–30 g of silica gel
per one-gram crude mixture.
2.2. General procedure for the “Click” synthesis of 1,4-Disubstitude 1,2,3-
Triazoles
A mixture of organic halide or epoxide (1.0 mmol), sodium azide
(1.2 mmol), and alkyne (1.0 mmol) was stirred in water (3.0 mL) as
solvent. Then, Cu(Bb)(PCy3) (5 mg) was added to the reaction mixture
and it was further stirred at 60 °C for a period of time. After completion
of the reaction (monitored by TLC), the reaction mixture was extracted
by ethyl acetate (5 mL, 3 times) and dried over anhydrous Na2SO4 and
the procedure was followed by concentration under reduced pressure.
The crude products were purified by column chromatography on silica
gel (silica gel, n-hexane-EtOAc) to give the pure products.
2.3. General procedure for the synthesis of 1, 2, 3 and 4
In this study. we explored the catalytic activities of a series of Cu(I)
complexes supported with bidentate sulphur donor ligands based on 2-
mercaptobenzimidazole and phosphine co-ligands for the efficient
synthesis of 1,2,3-triazole compound via a three-component coupling
reaction of various alkyl halides/epoxides with alkynes in the presence
of sodium azide. It is notable that in these reactions, no reducing agents
or bases were utilized. Besides, some non-activated terminal alkynes
were successfully employed in coupling reactions.
The synthesis of sodium dihydrobis(2-mercapto-benzimidazolyl)
borate (NaBb), and the catalysts tested in this study were carried out by
following the procedure described in the literature [41]. In summary,
NaBb (0.050 g, 0.148 mmol) and 1 equivalent of an appropriate phos-
phine were dissolved in methanol (5.0 mL) and to this solution was
added CuI (0.028 mg, 0.148 mmol). The solution turned cloudy with a
precipitate forming, and the mixture was stirred for 12 h. The pre-
cipitate was filtered and it was washed with 5.0 mL cold methanol. The
product was dried under vacuum, yielding 1, 2, 3 as white and 4 as
yellow solid. Yields: (1) 78%, (2) 55%, (3) 55%, (4) 53%.
2. Experimental section
2.1. Instrumentation, analyses, and starting material
2.4. 1-Benzyl-4-phenyl-1H-1,2,3-triazole (7a)
NMR spectra were recorded on a Brucker Avance DPX-250 (1H NMR
250 MHz and 13C NMR 62.9 MHz) and DPX-400 (1H NMR 400 MHz and
13C NMR 100 MHz) spectrometer in pure deuterated chloroform
(CDCl3) and deuterated dimethylsulfoxide (DMSO‑d6) solutions with
tetramethylsilane (TMS) as an internal standard. Chemical shifts were
reported in ppm (δ) and coupling constants in Hz (J). Fourier-transform
White solid, mp 126–128 °C (lit. [60] mp 128–131 °C); FT-IR (KBr
cm−1): 3093, 2901, 1612, 1458, 1357, 1072, 763, 478; 1H NMR
(400 MHz, CDCl3) δ (ppm) 5.59 (s, 2H), 7.32–7.36 (m, 3H), 7.40–7.44
(m, 5H), 7.71 (s, 1H), 7.83 (d, J = 7.3 Hz, 2H); 13C NMR (100 MHz,
CDCl3) δ (ppm) 54.2, 119.6, 125.7, 128.1, 128.2, 128.8, 128.9, 129.2,
130.6, 134.7, 148.2.
infrared (FT-IR) spectroscopy with
a
Shimadzu FTIR-8300
2

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
2.5. 1-(4-Fluorobenzyl)-4-phenyl-1H-1,2,3-triazole (7b)
1H NMR (400 MHz, CDCl3) δ (ppm) 1.62 (d, J = 6.8 Hz, 6H), 4.87 (sep,
J = 6.7 Hz, 1H), 7.33 (t, J = 7.4 Hz, 1H), 7.42 (t, J = 7.4 Hz, 2H), 7.82
(s, 1H), 7.86 (d, J = 7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm)
23.0, 53.1, 117.3, 125.7, 128.1, 128.8, 130.8, 147.5.
White solid, mp 128–130 °C (lit. [61] mp 129–131 °C); FT-IR (KBr
cm−1): 3085, 2923, 2854, 1604, 1510, 1458.1, 1350, 1226, 1072, 771,
694; 1H NMR (400 MHz, CDCl3) δ (ppm) 5.52 (s, 2H), 7.06 (t,
J = 8.6 Hz, 2H), 7.28–7.35 (m, 3H), 7.41 (t, J = 7.5 Hz, 2H), 7.73 (s,
1H), 7.82 (d, J = 7.3 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 53.4,
116.11 (d, J = 21.2 Hz), 119.6, 125.7, 128.3, 128.9, 129.96 (d,
J = 9.1 Hz), 130.5, 130.65 (d, J = 3.0 Hz), 148.3, 162.83 (d,
J = 248.5 Hz).
2.12. 1-(sec-Butyl)-4-phenyl-1H-1,2,3-triazole (7j)
Yellow solid, mp 55–57 °C (lit. [66] mp 54–55 °C); FT-IR (KBr
cm−1): 3078, 2970, 2877, 1643, 1458, 1365, 1226, 1080, 1049, 763,
694; 1H NMR (400 MHz, CDCl3) δ (ppm) 0.92 (t, J = 7.4 Hz, 3H), 1.63
(d, J = 6.8 Hz, 3H), 1.90–2.05 (m, 2H), 4.67 (sext, J = 6.7 Hz, 1H),
7.35 (t, J = 7.3 Hz, 1H), 7.45 (t, J = 7.5 Hz, 2H), 7.78 (s, 1H), 7.88 (d,
J = 7.5 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 10.5, 21.0, 30.4,
59.0, 117.4, 125.7, 128.0, 128.8, 130.9, 147.5.
2.6. 4-((4-Phenyl-1H-1,2,3-triazol-1-yl)methyl)benzonitrile (7c)
White solid, mp 132–135 °C (lit. [62] mp 132–134 °C); FT-IR (KBr
cm−1): 3085, 2923, 2854, 2229, 1612, 1465, 1434, 1342, 1218, 1188,
1080, 1041, 771, 694; 1H NMR (400 MHz, CDCl3) δ (ppm) 5.64 (s, 2H),
7.33–7.44 (m, 5H), 7.64 (d, J = 8.1 Hz, 2H), 7.80 (s, 2H), 7.82 (s, 1H);
13C NMR (100 MHz, CDCl3) δ (ppm) 53.4, 112.6, 118.3, 120.0, 125.7,
128.4, 128.5, 128.9, 130.2, 132.9, 140.0, 148.5.
2.13. 1-Cyclopentyl-4-phenyl-1H-1,2,3-triazole (7k)
Light yellow solid, mp 69–71 °C (lit. [66] mp 68–69 °C); FT-IR (KBr
cm−1): 3116, 2962, 2862, 1651, 1458, 1380, 1080, 972, 879, 763, 694;
1H NMR (400 MHz, CDCl3) δ (ppm) 1.75–1.85 (m, 2H), 1.90–2.00 (m,
2H), 2.08–2.16 (m, 2H), 2.27–2.35 (m, 2H), 4.96–5.03 (m, 1H),
7.33–7.37 (m, 1H), 7.44 (t, J = 7.6 Hz, 2H), 7.80 (s, 1H), 7.86 (d,
J = 7.2 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 24.1, 33.4, 62.0,
118.2, 125.7, 128.1, 128.9, 130.7, 147.6.
2.7. 1-(3-Fluorobenzyl)-4-phenyl-1H-1,2,3-triazole (7d)
White solid, mp 103–105 °C (lit. [63] mp 102–105 °C); FT-IR (KBr
cm−1): 3085, 2923, 1589, 1481, 1450, 1342, 1249, 1195, 1141, 1080,
972, 748, 694, 516; 1H NMR (250 MHz, CDCl3) δ (ppm) 5.56 (s, 2H),
6.96–7.09 (m, 3H), 7.30–7.45 (m, 4H), 7.71 (s, 1H), 7.79–7.83 (m, 2H);
13C NMR (100 MHz, CDCl3) δ (ppm) 53.6, 115.00 (d, J = 22.2 Hz),
115.81 (d, J = 21.2 Hz), 119.6, 123.52 (d, J = 3.0 Hz), 125.7, 128.3,
128.8, 130.3, 130.82 (d, J = 8.1 Hz), 137.04 (d, J = 8.1 Hz), 148.4,
163.02 (d, J = 248.5 Hz).
2.14. 1-Cyclohexyl-4-phenyl-1H-1,2,3-triazole (7l)
White solid, mp 107–110 °C (lit. [67] mp 107–108 °C); FT-IR (KBr
cm−1): 3124, 2931, 2854, 1651, 1458, 1373, 1218, 1080, 1002, 763,
694; 1H NMR (400 MHz, CDCl3) δ (ppm) 1.29–1.40 (m, 2H), 1.46–1.58
(m, 2H), 1.81–1.85 (m, 2H), 1.97–2.00 (m, 2H), 2.28–2.31 (m, 2H),
4.50–4.57 (m, 1H), 7.35 (t, J = 7.4 Hz, 1H), 7.45 (t, J = 7.6 Hz, 2H),
7.80 (s, 1H), 7.87 (d, J = 7.3 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ
(ppm) 25.2, 25.2, 33.6, 60.2, 117.3, 125.7, 128.0, 128.8, 130.9, 147.3.
2.8. 1-Allyl-4-phenyl-1H-1,2,3-triazole (7e)
White solid, mp 74–76 °C (lit. [64] mp 76–77 °C); FT-IR (KBr cm−1):
3121, 3095, 2943, 2428, 1855, 1611, 1464, 1445, 1354, 1334, 1223,
1204, 1169, 1076, 1050, 991, 976, 943, 827, 690, 511; 1H NMR
(250 MHz, CDCl3) δ (ppm) 5.02 (dt, J = 6.1, 1.4 Hz, 2H), 5.30–5.40 (m,
2H), 5.98–6.14 (m, 1H), 7.29–7.45 (m, 3H), 7.76 (s, 1H), 7.81–7.84 (m,
2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 52.3, 119.4, 120.3, 125.5,
128.0, 128.8, 130.7, 131.5, 147.5.
2.15. 1-Benzyl-4-((naphthalen-1-yloxy)methyl)-1H-1,2,3-triazole (7m)
Light brown solid, mp 127–130 °C (lit. [68] mp 128–129 °C); FT-IR
(KBr cm−1): 3082, 2926, 2874, 2516, 2110, 1578, 1459, 1378, 1329,
1307, 1268, 1240, 1213, 1125, 1098, 1070, 1054, 877, 791, 769, 723,
703; 1H NMR (250 MHz, CDCl3) δ (ppm) 5.20 (s, 2H), 5.34 (s, 2H), 6.79
(d, J = 7.5 Hz, 1H), 7.08–7.12 (m, 2H), 7.18–7.26 (m, 4H), 7.29–7.37
(m, 3H), 7.43 (s, 1H), 7.63–7.66 (m, 1H), 8.07–8.11 (m, 1H); 13C NMR
(100 MHz, CDCl3) δ (ppm) 54.3, 62.5, 105.5, 121.0, 121.7, 122.1,
122.8, 125.4, 125.7, 126.0, 126.6, 127.6, 128.1, 128.9, 129.2, 134.6,
144.8, 154.1.
2.9. 1-Butyl-4-phenyl-1H-1,2,3-triazole (7f)
White solid, mp 42–45 °C (lit. [61] mp 42–44 °C); FT-IR (KBr cm−1):
3085, 2960, 2869, 1651, 1465, 1380, 1080, 763, 694; 1H NMR
(400 MHz, CDCl3)
δ (ppm) 1.01 (t, J = 7.4 Hz, 3H), 1.43 (sext,
J = 7.4 Hz, 2H), 1.97 (quin, J = 7.3 Hz, 2H), 4.44 (t, J = 7.2 Hz, 2H),
7.36 (t, J = 7.3 Hz, 1H), 7.46 (t, J = 7.6 Hz, 2H), 7.78 (s, 1H), 7.87 (d,
J = 7.5 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 13.5, 19.7, 32.3,
50.2, 119.4, 125.7, 128.1, 128.8, 130.7, 147.7.
2.16. 1-(4-Fluorobenzyl)-4-((naphthalen-1-yloxy)methyl)-1H-1,2,3-
triazole (7n)
White solid, mp 99–101 °C; FT-IR (KBr cm−1): 3129, 3091, 3057,
2947, 1581, 1509, 1390, 1265, 1227, 1157, 1128, 1094, 1059, 1017,
840, 810, 787, 765, 530; 1H NMR (400 MHz, CDCl3) δ (ppm) 5.40 (s,
2H), 5.50 (s, 2H), 6.98 (d, J = 7.5 Hz, 1H), 7.05–7.11 (m, 2H),
7.25–7.29 (m, 2H), 7.40 (t, J = 7.9 Hz, 1H), 7.45–7.53 (m, 3H), 7.61 (s,
1H), 7.82–7.84 (m, 1H), 8.24–8.26 (m, 1H); 13C NMR (100 MHz, CDCl3)
δ (ppm) 53.5, 62.5, 105.5, 116.16 (d, J = 22.2 Hz), 120.9, 122.0,
122.5, 125.3, 125.6, 125.8, 126.5, 127.5, 129.97 (d, J = 8.1 Hz),
130.44 (d, J = 3.0 Hz), 134.6, 144.9, 153.9, 162.88 (d, J = 248.5 Hz).
2.10. 1-Octyl-4-phenyl-1H-1,2,3-triazole (7g)
White solid, mp 76–79 °C (lit. [64] mp 78–79 °C); FT-IR (KBr cm−1):
3121, 3094, 2955, 2919, 2849, 1599, 1460, 1217, 1191, 1079, 839,
762, 695; 1H NMR (400 MHz, CDCl3) δ (ppm) 0.91 (t, J = 6.7 Hz, 3H),
1.30–1.38 (m, 10H), 1.98 (quin, J = 7.2 Hz, 2H), 4.43 (t, J = 7.2 Hz,
2H), 7.36 (t, J = 7.4 Hz, 1H), 7.46 (t, J = 7.6 Hz, 2H), 7.78 (s, 1H), 7.87
(d, J = 7.3 Hz, 2H); 13C NMR (100 MHz, CDCl3) δ (ppm) 14.1, 22.6,
26.5, 29.0, 29.1, 30.4, 31.7, 50.5, 119.4, 125.7, 128.1, 128.8, 130.8,
147.7.
2.17. 4-((4-((Naphthalen-1-yloxy)methyl)-1H-1,2,3-triazol-1-yl)methyl)
benzonitrile (7o)
2.11. 1-Isopropyl-4-phenyl-1H-1,2,3-triazole (7i)
Yellow solid, mp 99–100 °C; FT-IR (KBr cm−1): 3152, 2924, 2854,
2229, 2106, 1574, 1504, 1458, 1388, 1265, 1226, 1095, 1056, 987,
760, 547; 1H NMR (250 MHz, CDCl3) δ (ppm) 5.34 (s, 2H), 5.52 (s, 2H),
Yellow solid, mp 42–45 °C (lit. [65] mp 43.5 °C); FT-IR (KBr cm−1):
3124, 2939, 1612, 1458, 1365, 1226, 1188, 1080, 1033, 972, 763, 694;
3

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InorganicaChimicaActa506(2020)119470
6.87 (d, J = 7.5 Hz, 1H), 7.17–7.19 (m, 1H), 7.23–7.29 (m, 2H),
7.33–7.44 (m, 3H), 7.55–7.60 (m, 3H), 7.72 (d, J = 7.8 Hz, 1H), 8.12
(d, J = 8.5 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 53.3, 62.3,
105.5, 112.5, 118.3, 121.0, 121.9, 123.2, 125.4, 125.9, 126.6, 127.6,
128.4, 132.6, 132.8, 134.5, 139.8, 145.0, 153.8.
2.23. 4-((4-Benzylphenoxy)methyl)-1-(3-fluorobenzyl)-1H-1,2,3-triazole
(7u)
Yellow Solid, mp 57–59 °C; FT-IR (KBr cm−1): 3741, 3070, 3024,
2916, 1697, 1589, 1512, 1450, 1243, 1172, 1049, 794, 694, 509; 1H
NMR (250 MHz, CDCl3) δ (ppm) 3.82 (s, 2H), 5.07 (s, 2H), 5.40 (s, 2H),
6.64–6.67 (m, 1H), 6.77–6.95 (m, 5H), 6.97–7.06 (m, 4H), 7.15–7.22
(m, 3H), 7.45 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 41.1, 53.3,
62.0, 114.9, 114.94 (d, J = 46.5 Hz), 115.68 (d, J = 23.2 Hz), 123.4,
123.72 (d, J = 3.0 Hz), 126.2, 128.6, 129.0, 130.0, 130.66 (d,
J = 9.1 Hz), 130.85 (d, J = 8.1 Hz), 134.1, 141.6, 144.7, 156.8, 162.96
(d, J = 248.5 Hz).
2.18. 1-(3-Fluorobenzyl)-4-((naphthalen-1-yloxy)methyl)-1H-1,2,3-
triazole (7p):
White solid, mp 83–85 °C; FT-IR (KBr cm−1): 3055, 2900, 2854,
1612, 1573, 1458, 1396, 1242, 1103, 1041, 802, 779; 1H NMR
(250 MHz, CDCl3) δ (ppm) 5.31 (s, 2H), 5.43 (s, 2H), 6.84–6.90 (m,
2H), 6.93–7.00 (m, 2H), 7.16–7.25 (m, 1H), 7.27–7.31 (m, 1H),
7.34–7.43 (m, 3H), 7.53 (s, 1H), 7.69–7.72 (m, 1H), 8.11–8.15 (m, 1H);
13C NMR (100 MHz, CDCl3) δ (ppm) 53.5, 62.4, 105.4, 115.00 (d,
J = 22.2 Hz), 115.82 (d, J = 21.2 Hz), 120.9, 122.0, 122.7, 123.54 (d,
J = 3.0 Hz), 125.3, 125.6, 125.8, 126.5, 127.5, 130.82 (d, J = 8.1 Hz),
134.5, 136.94 (d, J = 8.1 Hz), 145.0, 153.9, 163.00 (d, J = 248.5 Hz).
2.24. 1-Allyl-4-((4-benzylphenoxy)methyl)-1H-1,2,3-triazole (7v):
White solid, mp 59–61 °C; FT-IR (KBr cm−1): 3128, 3082, 3025,
2919, 2870, 1607, 1508, 1493, 1380, 1291, 1243, 1181, 1107, 1057,
1019, 987, 937, 834, 793, 726, 695, 598; 1H NMR (250 MHz, CDCl3) δ
(ppm) 3.93 (s, 2H), 4.94–4.98 (m, 2H), 5.17–5.19 (m, 2H), 5.24–5.38
(m, 2H), 5.93–6.10 (m, 1H), 6.89–6.93 (m, 2H), 7.08–7.29 (m, 7H),
7.58–7.60 (m, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 41.1, 52.8,
62.2, 114.8, 120.3, 122.6, 126.1, 128.5, 128.9, 130.0, 131.2, 134.0,
141.5, 144.6, 156.7.
2.19. 1-Allyl-4-((naphthalen-1-yloxy)methyl)-1H-1,2,3-triazole (7q)
Yellow solid, mp 78–80 °C; FT-IR (KBr cm−1): 3136, 3056, 2932,
1584, 1591, 1460, 1393, 1268, 1239, 1178, 1156, 1097, 1068, 1050,
1019, 987, 793, 772, 572; 1H NMR (400 MHz, CDCl3) δ (ppm) 5.01 (d,
J = 5.9 Hz, 2H), 5.31–5.40 (m, 2H), 5.44 (s, 2H), 6.00–6.10 (m, 1H),
6.99 (d, J = 7.6 Hz, 1H), 7.41 (t, J = 7.9 Hz, 1H), 7.48–7.52 (m, 3H),
7.69 (s, 1H), 7.83 (d, J = 7.9 Hz, 1H), 8.29 (d, J = 7.8 Hz, 1H); 13C
NMR (100 MHz, CDCl3) δ (ppm) 52.8, 62.4, 105.4, 120.4, 120.9, 122.0,
122.5, 125.3, 125.6, 125.9, 126.5, 127.5, 131.1, 134.6, 144.6, 154.0.
2.25. 4-((4-Benzylphenoxy)methyl)-1-butyl-1H-1,2,3-triazole (7w)
Yellow solid, mp 51–53 °C; FT-IR (KBr cm−1): 3133, 3084, 3028,
1605, 1508, 1466, 1383, 1298, 1243, 1177, 1110, 1037, 1011, 844,
796, 696, 594; 1H NMR (400 MHz, CDCl3) δ (ppm) 0.98 (t, J = 7.3 Hz,
3H), 1.31–1.38 (m, 2H), 1.83–1.90 (m, 2H), 3.95 (s, 2H), 4.31 (t,
J = 7.0 Hz, 2H), 5.19 (s, 2H), 6.97 (d, J = 8.2 Hz, 2H), 7.15 (d,
J = 8.2 Hz, 2H), 7.21–7.23 (m, 3H), 7.29–7.34 (m, 2H), 7.61 (s, 1H);
13C NMR (100 MHz, CDCl3) δ (ppm) 13.5, 19.7, 32.2, 41.1, 50.1, 62.1,
114.9, 122.8, 126.1, 128.5, 128.9, 130.0, 133.9, 141.5, 144.1, 156.8.
2.20. 1-Benzyl-4-((4-benzylphenoxy)methyl)-1H-1,2,3-triazole (7r)
White solid, mp 101–102 °C; FT-IR (KBr cm−1): 3741, 3031, 2877,
1612, 1512, 1458, 1380, 1242, 1180, 1110, 1002, 833, 725; 1H NMR
(250 MHz, CDCl3) δ (ppm) 3.92 (s, 2H), 5.16 (s, 2H), 5.52 (s, 2H),
6.85–6.91 (m, 2H), 7.08–7.25 (m, 6H), 7.27–7.40 (m, 6H), 7.51 (s, 1H);
13C NMR (100 MHz, CDCl3) δ (ppm) 41.1, 54.3, 62.2, 114.8, 122.6,
126.1, 128.2, 128.5, 128.9, 129.2, 129.9, 133.9, 134.5, 141.5, 144.8,
156.6.
2.26. 4-((4-Benzylphenoxy)methyl)-1-cyclopentyl-1H-1,2,3-triazole (7x)
White solid, mp 73–75 °C; FT-IR (KBr cm−1): 3071, 3025, 2966,
2869, 1601, 1507, 1313, 1248, 1177, 1106, 1045, 839, 792, 729, 695,
598; 1H NMR (400 MHz, CDCl3) δ (ppm) 1.76–1.98 (m, 4H), 2.04–2.23
(m, 4H), 3.97 (s, 2H), 4.95 (quin, J = 8.2, 7.6 Hz, 1H), 5.22 (s, 2H),
6.98 (d, J = 8.5 Hz, 2H), 7.16 (d, J = 8.4 Hz, 2H), 7.22–7.26 (m, 3H),
7.33 (t, J = 7.3 Hz, 2H), 7.65 (s, 1H); 13C NMR (100 MHz, CDCl3) δ
(ppm) 24.1, 33.4, 41.1, 62.0, 62.3, 114.8, 121.3, 126.1, 128.5, 128.9,
130.0, 133.9, 141.5, 144.0, 156.8.
2.21. 4-((4-Benzylphenoxy)methyl)-1-(4-fluorobenzyl)-1H-1,2,3-triazole
(7s)
White solid, mp 107–108 °C; FT-IR (KBr cm−1): 3085, 2908, 1604,
1512, 1450, 1249, 1172, 1110, 1049, 840, 732, 694; 1H NMR
(400 MHz, CDCl3) δ (ppm) 3.96 (s, 2H), 5.20 (s, 2H), 5.52 (s, 2H), 6.93
(d, J = 8.4 Hz, 2H), 7.07–7.15 (m, 4H), 7.20–7.25 (m, 3H), 7.28–7.34
(m, 4H), 7.55 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 41.1, 53.5,
62.2, 114.8, 116.17 (d, J = 21.2 Hz), 122.5, 126.1, 128.5, 128.8,
129.97 (d, J = 2.0 Hz), 130.1, 130.41 (d, J = 3.0 Hz), 134.0, 141.4,
144.9, 156.6, 162.90 (d, J = 249.5 Hz).
2.27. 2-Phenyl-2-(4-phenyl-1H-1,2,3-triazol-1-yl)ethan-1-ol (9a)
White solid, mp 126–128 °C (lit. [69] mp 125–127 °C); FT-IR (KBr
cm−1): 3402, 3085, 2931, 1959, 1890, 1604, 1458, 1380, 1226, 1180,
1072, 910, 833, 763, 694, 555; 1H NMR (400 MHz, CDCl3) δ (ppm)
4.00–4.10 (m, 1H), 4.24–4.27 (m, 1H), 4.63–4.68 (m, 1H), 5.72 (dd,
J = 8.2, 3.6 Hz, 1H), 7.32–7.35 (m, 2H), 7.39–7.42 (m, 6H), 7.73–7.75
(m, 2H), 7.77 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 65.0, 67.4,
120.6, 125.7, 127.2, 128.3, 128.8, 129.0, 129.1, 130.2, 136.1, 147.6.
2.22. 4-((4-((4-Benzylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)methyl)
benzonitrile (7t)
2.28. 2-(4-Phenyl-1H-1,2,3-triazol-1-yl)cyclopentan-1-ol (9b)
Gray solid, mp 99–101 °C; FT-IR (KBr cm−1): 3093, 2908, 2229,
1612, 1512, 1450, 1242, 1180, 1110, 1049, 840, 810, 732, 694; 1H
NMR (400 MHz, CDCl3) δ (ppm) 3.95 (s, 2H), 5.20 (s, 2H), 5.59 (s, 2H),
6.92 (d, J = 8.5 Hz, 2H), 7.14 (d, J = 8.4 Hz, 2H), 7.20–7.25 (m, 3H),
7.30–7.35 (m, 4H), 7.64 (d, J = 4.0 Hz, 2H), 7.66 (s, 1H); 13C NMR
(100 MHz, CDCl3) δ (ppm) 41.1, 53.4, 62.1, 112.7, 114.8, 118.2, 123.0,
126.1, 128.4, 128.5, 128.9, 130.0, 132.9, 134.1, 139.8, 141.4, 145.2,
156.6.
White solid, mp 162–164 °C (lit. [70] mp 165–167 °C); FT-IR (KBr
cm−1): 3841, 3134, 2914, 2876, 1609, 1460, 1429, 1375, 1315, 1247,
1221, 1080, 1071, 1041, 828, 769, 697, 512; 1H NMR (400 MHz,
CDCl3) δ (ppm) 1.73–1.82 (m, 1H), 1.84–1.91 (m, 2H), 2.10–2.20 (m,
2H), 2.27–2.35 (m, 1H), 4.53–4.59 (m, 2H), 5.18 (s, 1H), 7.27–7.36 (m,
3H), 7.61 (d, J = 7.0 Hz, 2H), 7.68 (s, 1H); 13C NMR (100 MHz, CDCl3)
δ (ppm) 20.2, 29.5, 31.8, 68.8, 77.6, 119.6, 125.5, 128.1, 128.8, 130.2,
146.9.
4

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InorganicaChimicaActa506(2020)119470
2.29. 2-(4-Phenyl-1H-1,2,3-triazol-1-yl)cyclohexan-1-ol (9c)
2.35. 1-Isopropoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9i)
White solid, mp 177–180 °C (lit. [71] mp 177–179 °C); FT-IR (KBr
cm−1): 3309, 3116, 2939, 2862, 1612, 1558, 1442, 1365, 1234, 1080,
848, 771, 702, 640, 516; 1H NMR (400 MHz, CDCl3) δ (ppm) 1.43–1.58
(m, 3H), 1.89–1.94 (m, 2H), 2.02–2.06 (m, 1H), 2.21–2.28 (m, 2H),
4.02 (brs, 1H), 4.11–4.21 (m, 2H), 7.31–7.34 (m, 1H), 7.36–7.40 (m,
2H), 7.67–7.70 (m, 2H), 7.77 (s, 1H); 13C NMR (100 MHz, CDCl3) δ
(ppm) 24.1, 24.8, 31.6, 33.8, 67.3, 72.6, 119.8, 125.5, 128.0, 128.8,
130.3, 146.8.
Yellow solid, mp 61–63 °C (lit. [68] mp 62–64 °C); FT-IR (KBr
cm−1): 3201, 2970, 2869, 1643, 1558, 1463, 1365, 1334, 1303, 1226,
1072, 979, 925, 825, 763, 702, 516; 1H NMR (400 MHz, CDCl3) δ (ppm)
1.17 (d, J = 3.2 Hz, 3H), 1.19 (d, J = 3.2 Hz, 3H), 3.42 (dd, J = 9.6,
5.7 Hz, 1H), 3.52 (dd, J = 9.6, 5.0 Hz, 1H), 3.62 (hep, J = 6.1 Hz, 1H),
3.74 (brs, 1H), 4.21–4.30 (m, 1H), 4.43 (dd, J = 14.0, 7.1 Hz, 1H), 4.60
(dd, J = 14.0, 3.6 Hz, 1H), 7.30–7.36 (m, 1H), 7.40 (t, J = 7.4 Hz, 2H),
7.75–7.78 (m, 2H), 7.90 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
22.0, 53.3, 69.0, 69.4, 72.5, 121.3, 125.6, 128.1, 128.8, 130.5, 147.4.
2.30. 1-(4-Phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9d)
2.36. 1-Phenoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9j)
White solid, mp 117–120 °C (lit. [72] mp 118–120 °C); FT-IR (KBr
cm−1): 3255, 3139, 2962, 2923, 1612, 1465, 1434, 1365, 1226, 1141,
1087, 979, 817, 760, 694, 509; 1H NMR (250 MHz, CDCl3) δ (ppm) 1.32
(d, J = 6.2 Hz, 3H), 3.21–3.25 (m, 1H), 4.22 (dd, J = 13.3, 7.8 Hz, 1H),
4.31–4.42 (m, 1H), 4.47 (dd, J = 13.3, 2.6 Hz, 1H), 7.32–7.42 (m, 3H),
7.70–7.74 (m, 2H), 7.81 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
20.5, 57.6, 66.4, 121.2, 125.4, 128.1, 128.8, 130.1, 147.1.
White solid, mp 125–126 °C (lit. [69], mp 125–127 °C); FT-IR (KBr
cm−1): 3417, 3085, 2923, 2877, 1697, 1596, 1488, 1373, 1296, 1242,
1172, 1118, 1080, 1041, 879, 833, 756, 686, 516; 1H NMR (250 MHz,
CDCl3) δ (ppm) 3.93–3.96 (m, 2H), 4.26 (brs, 1H), 4.37–4.47 (m, 2H),
4.58–4.65 (m, 1H), 6.81–6.91 (m, 3H), 7.21–7.31 (m, 5H), 7.55–7.60 (m,
2H), 7.76 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 29.7, 53.3, 68.9,
114.6, 121.5, 125.6, 128.2, 128.9, 129.5, 129.7, 130.2, 147.5, 158.2.
2.31. 1-(4-Phenyl-1H-1,2,3-triazol-1-yl)butan-2-ol (9e)
2.37. 1-(Allyloxy)-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9k)
White solid, mp 145–147 °C (lit. [73] mp 148–150 °C); FT-IR (KBr
cm−1): 3247, 3139, 2962, 2931, 1651, 1612, 1458, 1373, 1226, 1134,
1095, 979, 918, 825, 763, 694, 516; 1H NMR (250 MHz, CDCl3) δ (ppm)
1.06 (t, J = 7.4 Hz, 3H), 1.55–1.67 (m, 2H), 3.15 (d, J = 4.6 Hz, 1H),
4.05–4.11 (m, 1H), 4.20–4.29 (m, 1H), 4.50 (dd, J = 13.8, 2.7 Hz, 1H),
7.30–7.41 (m, 3H), 7.70–7.74 (m, 2H), 7.83 (s, 1H); 13C NMR
(100 MHz, CDCl3) δ (ppm) 9.8, 27.5, 56.1, 71.7, 121.3, 125.6, 128.1,
128.8, 130.1.
White solid, mp 71.5–72 °C (lit. [75], mp 71.4 °C); FT-IR (KBr
cm−1): 3240, 3139, 2931, 2869, 1651, 1612, 1434, 1357, 1234, 1087,
995, 918, 871, 825, 763, 694, 509; 1H NMR (250 MHz, CDCl3) δ (ppm)
3.28 (d, J = 4.9 Hz, 1H), 3.43 (dd, J = 9.7, 5.9 Hz, 1H), 3.54 (dd,
J = 9.7, 4.7 Hz, 1H), 4.03 (dt, J = 5.7, 1.4 Hz, 2H), 4.23–4.33 (m, 1H),
4.44 (dd, J = 14.0, 6.9 Hz, 1H), 4.60 (dd, J = 14.0, 3.6 Hz, 1H),
5.19–5.33 (m, 2H), 5.82–5.98 (m, 1H), 7.29–7.44 (m, 3H), 7.75–7.80
(m, 2H), 7.88 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 53.5, 69.1,
71.3, 72.4, 117.6, 121.5, 125.5, 128.1, 128.8, 130.3, 134.3, 147.2.
2.32. 1-(4-Phenyl-1H-1,2,3-triazol-1-yl)decan-2-ol (9f)
White solid, mp 99–101 °C; IR (KBr cm−1): 3402, 3245, 3144, 2928,
2854, 1674, 1457, 1231, 1136, 1105, 1090, 823, 765, 695, 512; 1H
NMR (250 MHz, CDCl3) δ (ppm) 0.81 (t, J = 6.4 Hz, 3H), 1.17–1.45 (m,
14H), 3.22 (brs, 1H), 4.02–4.20 (m, 2H), 4.42 (dd, J = 13.3, 2.1 Hz,
1H), 7.19–7.34 (m, 3H), 7.61–7.68 (m, 2H), 7.75 (s, 1H); 13C NMR
(100 MHz, CDCl3) δ (ppm) 14.2, 22.7, 25.6, 29.3, 29.6, 29.6, 31.9, 34.5,
56.5, 70.3, 121.4, 125.4, 128.0, 128.8, 130.2, 147.0.
2.38. 1,3-Bis(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9l)
White solid, mp 231–233 °C (lit. [69] mp 233–233 °C); 1H NMR
(400 MHz, CDCl3) δ (ppm) 3.58–3.66 (m, 2H), 3.75–3.79 (m, 1H), 4.25
(brs, 1H), 4.45–4.51 (m, 1H), 4.56–4.60 (m, 1H), 7.33–7.38 (m, 2H),
7.42 (t, J = 7.4 Hz, 3H), 7.72–7.98 (m, 5H), 8.02 (s, 2H).
2.39. 2-(4-((Naphthalen-1-yloxy)methyl)-1H-1,2,3-triazol-1-yl)-2-
phenylethan-1-ol (9m)
2.33. 1-(4-Phenyl-1H-1,2,3-triazol-1-yl)hex-5-en-2-ol (9g)
White solid, mp 104–106 °C (lit. [74] mp 104.9–107.9 °C); FT-IR
(KBr cm−1): 3393, 3233, 3141, 2934, 2920, 1636, 1441, 1228, 1206,
1160, 1110, 1091, 1023, 910, 826, 767, 696, 513; 1H NMR (400 MHz,
CDCl3) δ (ppm) 1.63–1.68 (m, 2H), 2.20–2.39 (m, 2H), 4.17–4.20 (m,
1H), 4.22–4.24 (m, 1H), 4.29 (brs, 1H), 4.45–4.48 (m, 1H), 5.01–5.04
(m, 1H), 5.07–5.12 (m, 1H), 5.81–5.91 (m, 1H), 7.29–7.38 (m, 3H),
7.63–7.65 (m, 2H), 7.80 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
29.7, 33.5, 56.4, 69.7, 115.4, 121.3, 125.5, 128.1, 128.8, 130.2, 137.8,
147.1.
Light yellow solid, mp 103–105 °C; FT-IR (KBr cm−1): 3271, 3063,
2935, 2873, 1580, 1457, 1387, 1333, 1269, 1242, 1131, 1096, 1061,
983, 796, 774, 703, 530; 1H NMR (400 MHz, CDCl3) δ (ppm) 4.21–4.24
(m, 1H), 4.32 (brs, 1H), 4.56–4.61 (m, 1H), 5.30 (s, 2H), 5.69–5.71 (m,
1H), 6.93 (d, J = 7.5 Hz, 1H), 7.21–7.30 (m, 2H), 7.35–7.40 (m, 4H),
7.43–7.52 (m, 3H), 7.72 (s, 1H), 7.83 (d, J = 8.0 Hz, 1H), 8.26 (d,
J = 8.2 Hz, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm) 62.3, 64.7, 67.3,
105.5, 121.0, 122.1, 123.8, 125.4, 125.6, 125.9, 126.6, 127.2, 127.6,
128.9, 129.1, 134.6, 136.1, 144.0, 154.0.
2.34. 1-Butoxy-3-(4-phenyl-1H-1,2,3-triazol-1-yl)propan-2-ol (9h)
2.40. 2-(4-((4-Benzylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)-2-
phenylethan-1-ol (9n)
White solid, mp 60–62 °C; FT-IR (KBr cm−1): 3255, 3139, 2931,
2869, 1612, 1434, 1373, 1226, 1126, 1087, 979, 871, 825, 763, 694,
516; 1H NMR (250 MHz, CDCl3) δ (ppm) 0.92 (t, J = 7.3 Hz, 3H),
1.30–1.44 (m, 2H), 1.51–1.62 (m, 2H), 3.20 (brs, 1H), 3.36–3.54 (m,
4H), 4.19–4.30 (m, 1H), 4.43 (dd, J = 14.0, 6.8 Hz, 1H), 4.59 (dd,
J = 14.0, 3.7 Hz, 1H), 7.28–7.35 (m, 1H), 7.37–7.44 (m, 2H),
7.76–7.81 (m, 2H), 7.89 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
13.9, 19.2, 31.5, 53.5, 68.9, 71.3, 71.9, 121.7, 125.4, 127.9, 128.7,
130.3, 147.1.
White solid, mp 64–66 °C; FT-IR (KBr cm−1): 3309, 3062, 2916,
1604, 1504, 1380, 1342, 1296, 1242, 1180, 1126, 1049, 910, 840, 725,
694, 594, 532; 1H NMR (250 MHz, CDCl3) δ (ppm) 3.09–3.23 (m, 1H),
3.89–3.92 (m, 2H), 4.11–4.24 (m, 1H), 4.50–4.63 (m, 1H), 5.13–5.15
(m, 2H), 5.57–5.65 (m, 1H), 6.82–6.90 (m, 2H), 7.05–7.26 (m, 9H),
7.32–7.39 (m, 3H), 7.53–7.56 (m, 1H); 13C NMR (100 MHz, CDCl3) δ
(ppm) 41.1, 62.0, 64.8, 67.3, 114.8, 123.8, 126.1, 127.2, 128.5, 128.9,
129.0, 129.1, 130.0, 134.0, 136.1, 141.5, 144.0, 156.7.
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2.41. 1-(4-((4-Benzylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)-3-
phenoxypropan-2-ol (9o)
1.3 Hz, 2H), 4.05–4.15 (m, 1H), 4.26 (dd, J = 14.0, 7.1 Hz, 1H), 4.42
(dd, J = 14.0, 3.7 Hz, 1H), 5.01 (s, 2H), 5.05–5.19 (m, 2H), 5.68–5.84
(m, 1H), 6.75–6.81 (m, 2H), 6.97–7.02 (m, 2H), 7.04–7.11 (m, 3H),
7.14–7.19 (m, 2H), 7.63 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
41.1, 53.4, 61.8, 69.0, 71.3, 72.4, 114.9, 117.6, 124.8, 126.2, 128.6,
128.9, 130.1, 134.0, 134.4, 141.6, 143.7, 156.7.
White solid, mp 104–106 °C; FT-IR (KBr cm−1): 3255, 3025, 2919,
1594, 1495, 1292, 1253, 1232, 1182, 1115, 1038, 1015, 853, 813, 755,
693, 600; 1H NMR (250 MHz, CDCl3) δ (ppm) 3.01 (brs, 1H), 3.84 (s,
2H), 3.87–3.99 (m, 2H), 4.35–4.50 (m, 2H), 4.58–4.64 (m, 1H), 5.10 (s,
2H), 6.79–6.84 (m, 4H), 6.88–6.95 (m, 1H), 7.01–7.18 (m, 7H),
7.22–7.25 (m, 2H), 7.67 (s, 1H); 13C NMR (100 MHz, CDCl3) δ (ppm)
41.1, 53.2, 61.9, 68.8, 68.8, 114.6, 114.8, 121.6, 124.6, 126.1, 128.5,
128.9, 129.7, 130.0, 134.0, 141.5, 144.1, 156.6, 158.1.
3. Results and discussion
Cu(I) complexes 1–4 were synthesized according to our procedure
reported previously in the literature [41]. The characterization of
copper complexes was carried out by FT-IR, 1H NMR, 13C NMR, 31P
NMR and elemental analysis (Scheme 1).
2.42. 1-(Allyloxy)-3-(4-((4-benzylphenoxy)methyl)-1H-1,2,3-triazol-1-yl)
propan-2-ol (9p)
The molecular structure of 1 and 2 were reported previously [41].
In complex 1, copper atom adopts a trigonal geometry. Out of four Cu(I)
complexes, the Cu(Bb)(PCy3) (2) showed promising results in our initial
tests and it was selected as catalyst in the “click” reaction (Scheme 2).
Yellow oil; FT-IR (KBr cm−1): 3393, 2903, 2868, 1609, 1508, 1458,
1299, 1241, 1177, 1109, 1060, 1013, 928, 797, 726, 698, 599; 1H NMR
(250 MHz, CDCl3) δ (ppm) 3.28 (dd, J = 9.8, 5.6 Hz, 1H), 3.35 (dd,
J = 9.8, 4.9 Hz, 1H), 3.61 (brs, 1H), 3.80 (s, 2H), 3.87 (dt, J = 5.6,
Scheme 1. Synthesis of Cu (I) complexes.
Scheme 2. The one-pot three-component route to 1,4-disubstituted 1,2,3-triazoles.
6

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
3.1. The catalytic application of Cu(Bb)(PCy3) in azide-alkyne
cycloaddition
from Table 1, maximum yield of triazole product was obtained with
5 mg of the catalyst in water medium at 60 °C.
The initial results inspired us to investigate further experiments
with a wide range of organic halides or epoxides and terminal alkynes.
Under the optimized reaction condition, benzyl bromide 6a, was con-
verted into the 1-benzyl-4-phenyl-1H-1,2,3-triazole 7a in 97% yield
within 40 min. Benzyl chloride with electron-withdrawing groups such
as cyano and fluoro were successfully reacted with phenylacetylene,
yielding corresponding triazoles 7b-c in excellent yields
(Table 2,entries 2 and 3). Also, meta-substituted benzyl bromide af-
forded the corresponding product 7d with excellent yield (entry 4). For
further investigation of reaction scope, we found out that primary alkyl
halides in reaction with phenylacetylene can be transformed to the
corresponding 1,4-disustituted 1,2,3-triazole products 7e-g in good to
excellent yields (entries 5–8). Notably, when secondary aliphatic alkyl
halides such as 2-bromopropane, 2-bromobuatne, bromocyclopentane
and bromocyclohexane were employed as substrates, moderate yields
of triazoles 7i-l were obtained (entries 9–12). In addition to aromatic
alkyne, aliphatic alkynes also worked well and reacted with different
benzyl and alkyl halides in the presence of a catalytic amount of Cu(Bb)
(PCy3) to furnish the corresponding 1,4-disustituted 1,2,3-triazole de-
rivatives 7 m-x (Table 2,entries 13–24). The aliphatic alkynes are
known for their low reactivity in the “click” chemistry [76].
The “click” reaction was performed to investigate the catalytic ac-
tivity of Cu (I) complexes as depicted in Scheme 1. For this purpose, the
one-pot three-component reaction between phenylacetylene 5a
(1.0 mmol), sodium azide (1.2), and benzyl bromide 6a (1.0 mmol) was
chosen as a model reaction to screen various conditions including sol-
vent, temperature, and catalytic amount of the Cu (I) complexes
(Table 1). First, the “click” reaction was performed in the absence of the
catalyst in water medium at 60 °C and no triazole product was observed
even after 12 h (Table 1, entry 1). In the next step, a series of Cu (I)
complexes, including Cu(Bb)(PPh3) (1), Cu(Bb)(PCy3) (2), Cu(Bb)
(PPh2Me) (3) and Cu(Bb)(PPh2Py) (4) were tested in this reaction
(Table 1, entries 2–5). Cu(Bb)(PCy3) complex proved to be highly active
in terms of yield, selectivity, and time for the synthesis of 1,4-dis-
ubstituted 1,2,3-triazole derivatives in water (Table 1, entry 2). Then,
various amounts of catalyst loading were studied. As shown in Table 1,
the highest reaction yield was achieved by using 5 mg of the catalyst
(Table 1, entries 6 and 7). After optimizing the catalyst loading, the
effect of various solvents was also investigated for the model reaction
(Table 1, entries 8–15). It was observed that water was the most ef-
fective solvent to furnish the coupled product 7a. This could be perhaps
due to better solublity of the catalyst in aquous medium via establishing
hydrogen bonding through NeH moiety of benzimidazole ring. Subse-
quently, the reaction temperature was also optimized and the best re-
sult was obtained at 60 °C (Table 1, entries 2, 16–18). As can be seen
It is noteworthy that in this process, alkyl halides play the roles of
synthetic equivalent of potentially explosive azides which are known to
be difficult to handle and store. Having successfully established the Cu
(Bb)(PCy3) catalyzed CuAAC click transformation for the synthesis of
1,4-disubstituted triazoles, it was suggested that β-hydroxy-1,2,3-tria-
zoles might also be synthesized under the same reaction conditions by
replacing alkyl halides with epoxides (Table 3). According to the lit-
erature reports, primary β-hydroxy triazole derivatives were formed
using styrene oxide derivatives and in these cases, electronic factors
predominate over steric factors, while secondary alcohols as another
possible regional isomers were formed using aliphatic oxide derivatives
(Scheme 3).
Table 1
Optimization of the reaction conditions for the synthesis of 1-benzyl-4-phenyl-
1H-1,2,3-triazole.
In the following step, bicyclic epoxides such as 1,2-
Epoxycyclopentane and 1,2-Epoxycyclohexane gave the corresponding
1,2,3-triazoles 9b-c in 89% and 92%, respectively (Table 3, entries 2
and 3). Moreover, alkyl substituted epoxides were also applicable to the
present transformation, and the corresponding 1,4-disubstituted 1,2,3-
triazoles 9d-f were obtained in excellent yields (Table 3, entries 4–6).
The results indicated that the epoxides with ether groups including 2-
Entry Catalyst
mg Solvent
Temp (oC) Time (h) Yielda (%)
1
2
3
–
–
5
5
H2O
H2O
H2O
60
60
60
12
0.7
3
0
Cu(Bb)(PCy3)
Cu(Bb)
97b
70
(butoxymethyl)oxirane,
2-(isopropoxymethyl)oxirane,
2-(phenox-
(PPh2Py)
ymethyl)oxirane and 2-((allyloxy)methyl)oxirane were tolerated in the
reaction and afforded the desired triazole products 9h-k in high yields.
(Table 3, entries 8–11). Surprisingly, aliphatic alkynes appeared as
good substrates under these conditions and reacted with epoxides to
give corresponding 1,4-disubstituted 1,2,3-triazoles 9m-p with rea-
sonable yields (Table 3, entries 13–16). Generally, all these “click” re-
actions proceeded efficiently and the corresponding triazole products
were achieved in aqueous medium in good to excellent yields.
Herein, according to the mechanistic studies reported in the litera-
ture regarding alternative “click” reactions [29], we proposed likely
mechanism for the one-pot synthesis of 1,4-disubstituted 1,2,3-triazole
compounds via a multicomponent reaction in the presence of Cu(Bb)
(PCy3) complex 2. In the first step of the catalytic cycle, Cu(I)-acetylide
intermediate A is created. In the next step, the azide intermediate is
coordinated to the copper(I) center to generate intermediate B. Finally,
the cyclization reaction of azide with activated alkyne along with
protonolysis is carried out to provide 1,4-disubstituted 1,2,3-triazole
compounds (Scheme 4).
4
5
Cu(Bb)(PPh3)
Cu(Bb)
5
5
H2O
H2O
60
60
4
6
63
58
(PPh2Me)
6
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
10
3
H2O
60
5
5
5
2
3
5
5
5
5
83
71
0
7
H2O
60
8
5
CH3CN
DMF
Reflux
80
9
5
54
46
85
0
10
11
12
13
14
5
THF
Reflux
Reflux
Reflux
Reflux
Reflux
5
EtOH
CH2Cl2
Dioxane
H2O/
Dioxane
5
5
0
5
60
15
16
17
18
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
Cu(Bb)(PCy3)
5
5
5
5
H2O/ t-BuOH 80
5
1
3
3
83
93
54
46
H2O
H2O
H2O
80
100
r.t.
a
b
Yield of pure isolated product.
Experimental conditions: phenylacetylene 5a (1.0 mmol), benzyl bromide
6a (1.0 mmol), sodium azide (1.2 mmol), Cu (I) complexes as catalyst (type
indicated), and H2O (3 mL).
7

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Table 2
Synthesis of 1,2,3-triazoles by one-pot three-component reaction using homogeneous Cu(Bb)(PCy3) catalyst at 60 °C.a
Entry
Alkyne
Organic halide
Product
Time (min)
40
Yield (%)b
97
1
2
3
4
5
50
50
55
45
94
95
92
90
6
7
60
85
77
120
8
9
60
70
90
90
10
11
75
80
81
80
(continued on next page)
8

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Table 2 (continued)
Entry
12
Alkyne
Organic halide
Product
Time (min)
90
Yield (%)b
78
13
14
45
55
93
92
15
16
70
80
88
85
17
18
50
45
90
95
19
50
90
(continued on next page)
9

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Table 2 (continued)
Entry
20
Alkyne
Organic halide
Product
Time (min)
55
Yield (%)b
92
21
22
100
82
91
50
23
24
65
90
89
80
a
b
Reaction conditions: alkyne (1.0 mmol), organic halide (1.0 mmol), sodium azide (1.2 mmol), Cu(Bb)(PCy3) (5 mg) in water (3.0 mL), 60 °C.
Isolated yields.
10

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Table 3
Synthesis of 1,2,3-triazoles via a one-pot three-component reaction between epoxides, sodium azide and terminal alkynes using Cu(Bb)(PCy3).a
Entry
1
Alkyne
Epoxide
Product
Time (min)
35
Yieldb (%)
96
2
3
60
55
89
92
4
5
6
40
40
65
92
94
93
7
8
40
50
95
89
(continued on next page)
11

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Table 3 (continued)
Entry
9
Alkyne
Epoxide
Product
Time (min)
45
Yieldb (%)
90
10
70
75
11
12
65
88
65
120
13
14
70
80
91
93
15
16
80
80
75
110
a
b
Reagents and conditions: alkyne (1.0 mmol), epoxides (1.0 mmol), sodium azide (1.2 mmol), water (3.0 mL), Cu(Bb)(PCy3) (5 mg). 60 °C.
Isolated yield.
12

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
Scheme 3. Synthesis of 1,4-disubstituted 1,2,3-triazoles via phenyl acetylene, sodium azide and 2-phenyloxirane (path A) or 2-methyloxirane (path B).
Scheme 4. Proposed mechanism for the synthesis of 1,4-Disubstitude 1,2,3-Triazoles catalysed by Cu(Bb)(PCy3).
4. Conclusion
Appendix A. Supplementary data
In summary, a copper(I) complex containing homoscorpionate bis(2-
mercaptobenzimidazolyl) and tricyclohexylphosphine ligands was used
as a catalyst for the synthesis of 1,4-disubstitud 1,2,3-triazole derivatives
via one-pot and three-component reaction of organic halides or epoxides,
sodium azide, and terminal alkynes. The major advantages of this pro-
tocol include mild and green reaction conditions, short reaction times,
clean reaction profile, high diversity, and good to excellent yields.
Supplementary data to this article can be found online at https://
doi.org/10.1016/j.ica.2020.119470.
References
[1] W.B. Liu, H.F. Jiang, S.F. Zhu, W. Wang, Tetrahedron 65 (2009) 7985–7988.
[2] R. Shintani, G.C. Fu, J. Am. Chem. Soc. 125 (2003) 10778–10779.
[3] X.M. Zhang, M.L. Tong, X.M. Chen, Angew. Chem. 41 (2002) 1029–1031.
[4] M.J. Giffin, H. Heaslet, A. Brik, Y.C. Lin, G. Cauvi, C.H. Wong, D.E. McRee,
J.H. Elder, C.D. Stout, B.E. Torbett, J. Med. Chem. 51 (2008) 6263–6270.
[5] A. Brik, J. Alexandratos, Y.C. Lin, J.H. Elder, A.J. Olson, A. Wlodawer,
D.S. Goodsell, C.H. Wong, Chem. Bio. Chem. 6 (2005) 1167–1169.
[6] W.J. Yu, Q. Rao, M. Wang, Z. Tian, D. Lin, X.R. Liu, J.X. Wang, Leukemia. Res. 30
(2006) 575–582.
Acknowledgements
We gratefully appreciate the Shiraz University Research Council for
the financial support of this work.
[7] M. Nahrwold, T. Bogner, S. Eissler, S. Verma, N. Sewald, Org. Lett. 12 (2010)
1064–1067.
[8] I. Fichtali, M. Chraibi, F.E. Aroussi, A. Ben-Tama, E.M.E. Hadrami, K.F. Benbrahim,
S.E. Stiriba, Der. Pharma. Chem. 8 (2016) 236–242.
Conflicts of interest
[9] B.F. Abdel-Wahab, H.A. Mohamed, G.E.A. Awad, Eur. Chem. Bull. 4 (2015)
106–109.
Authors do not have any conflict of interest.
13

D. Khalili, et al.
InorganicaChimicaActa506(2020)119470
[10] P.S. Desai, N.S. Indorwala, Int. J. Curr. Microbiol. Appl. Sci. 4 (2015) 928–938.
[11] L. Wang, M.J. Zhu, F.C. Yang, C.W. Gao, Int. J. Corros. 2012 (2012) 1–6.
[12] R.A. Silva, E.D. Quintela, G.M. Mascarin, J.A.F. Barrigossi, L.M. Lião, Sci. Agric. 70
(2013) 152–160.
[44] S. Gomosta, R. Ramalakshmi, C. Arivazhagan, A. Haridas, B. Raghavendra,
K. Maheswari, T. Roisnel, S. Ghosh, Z. anorg. allg. Chem. 645 (2019) 588–594.
[45] C. Nandi, K. Saha, S. Gomosta, V. Dorcet, S. Ghosh, Polyhedron 172 (2019)
191–197.
[13] G. Zhang, Y. Wang, X. Wen, C. Ding, Y. Li, Chem. Commun. 48 (2012) 2979–2981.
[14] H. Struthers, B. Spingler, T.L. Mindt, R. Schibli, Chem. Eur J. 14 (2008) 6173–6183.
[15] W. Hu, Y. Zhang, H. Zhu, D. Ye, D. Wang, Green Chem. 21 (2019) 5345–5351.
[16] W. Yao, C. Ge, Y. Zhang, X.-F. Xia, L. Wang, D. Wang, Chem. Eur. J. 25 (2019)
16099–16105.
[46] A. Neshat, H.R. Shahsavari, P. Mastrorilli, S. Todisco, M.G. Haghighi, B. Notash,
Inorg. Chem. 57 (2018) 1398–1407.
[47] A. Iannetelli, G. Tizzard, S.J. Coles, G.R. Owen, Organometallics 37 (2018)
2177–2187.
[48] K. Saha, R. Ramalakshmi, S. Gomosta, K. Pathak, V. Dorcet, T. Roisnel, J.-F. Halet,
S. Ghosh, Chem. Eur. J. 23 (2017) 9812–9820.
[17] C. Ge, X. Sang, W. Yao, L. Zhang, D. Wang, Green Chem. 20 (2018) 1805–1812.
[18] Q. Wu, L. Pan, G. Du, C. Zhang, D. Wang, Org. Chem. Fron. 5 (2018) 2668–2675.
[19] R. Huang, Y. Yang, D.-S. Wang, L. Zhang, D. Wang, Org. Chem. Fron. 5 (2018)
203–209.
[49] R.S. Anju, D.K. Roy, B. Mondal, K. Yuvaraj, C. Arivazhagan, K. Saha, B. Varghese,
S. Ghosh, Angew. Chem. Int. Ed. 53 (2014) 2873–2877.
[50] I.R. Crossley, A.F. Hill, A.C. Willis, Organometallics 24 (2005) 1062–1064.
[51] J.S. Figueroa, J.G. Melnick, G. Parkin, Inorg. Chem. 45 (2006) 7056–7058.
[52] H. Braunschweig, R.D. Dewhurst, A. Schneider, Chem. Rev. 110 (2010) 3924–3957.
[53] A. Looney, R. Han, K. McNeill, G. Parkin, J. Am. Chem. Soc. 115 (1993) 4690–4697.
[54] C. Kimblin, V.J. Murphy, T. Hascall, B.M. Bridgewater, J.B. Bonanno, G. Parkin,
Inorg. Chem. 39 (2000) 967–974.
[20] Z. Xu, D.-S. Wang, X. Yu, Y. Yang, D. Wang, Adv. Synth. Catal. 359 (2017)
3332–3340.
[21] Y. Yang, A. Qin, K. Zhao, D. Wang, X. Shi, Adv. Synth. Catal. 358 (2016)
1433–1439.
[22] A.R. Katritzky, Y. Song, R. Sakhuja, R. Gyanda, N.K. Meher, L. Wang, R.S. Duran,
D.A. Ciaramitaro, C.D. Bedford, J. Polym. Sci. Part A. Polym. Chem. 47 (2009)
3748–3756.
[55] B.S. Hammes, C.J. Carrano, Inorg. Chem. 38 (1999) 4593–4600.
[56] A. Otero, J. Fernández-Baeza, L.F. Sánchez-Barba, J. Tejeda, M. Honrado, A. Garcés,
A. Lara-Sánchez, A.M. Rodríguez, Organometallics 31 (2012) 4191–4202.
[57] L. Bahsis, H. Ben El Ayouchia, H. Anane, C. Ramirez de Arellano, A. Bentama,
M.E. El Hadrami, M. Julve, R.L. Domingo, S.-E. Stiriba, Catalysts 9 (2019).
[58] C. Nolte, P. Mayer, B.F. Straub, Angew. Chem. Int. Ed. 46 (2007) 2101–2103.
[59] S. Trofimenko, Chem. Rev. 93 (1993) 943–980.
[23] J.A. Johnson, M.G. Finn, J.T. Koberstein, N.J. Turro, Macromol. Rapid. Commun.
29 (2008) 1052–1072.
[24] F.T. Wolf, Nature 188 (1960) 164–165.
[25] R. Huisgen, Angew. Chem. Int. Ed. 2 (1963) 565–598.
[26] D.D. Diaz, S. Punna, P. Holzer, A.K. Mcpherson, K.B. Sharpless, V.V. Fokin,
M.G. Finn, J. Polym. Sci. Part A. Polym. Chem. 42 (2004) 4392–4403.
[27] W.G. Lewis, L.G. Green, F. Grynszpan, Z. Radic, P.R. Carlier, P. Taylor, M.G. Finn,
K.B. Sharpless, Angew. Chem. 114 (2002) 1095–1099.
[60] J.Q. Shang, H. Fu, Y. Li, T. Yang, C. Gao, Y.M. Li, Tetrahedron 75 (2019) 253–259.
[61] R. Bonyasi, M. Gholinejad, F. Saadati, C. Nájera, New. J. Chem. 42 (2018)
3078–3086.
[28] T.R. Chan, R. Hilgraf, K.B. Sharpless, V.V. Fokin, Org. Lett. 6 (2004) 2853–2855.
[29] H. Sharghi, P. Shiri, Synthesis 47 (2015) 1131–1146.
[30] H. Sharghi, P. Shiri, M. Aberi, Mol. Divers. 18 (2014) 559–575.
[31] H. Sharghi, M. Aberi, P. Shiri, Appl. Organometal. Chem. 32 (2018) e4446.
[32] H. Sharghi, P. Shiri, M. Aberi, Catal. Lett. 147 (2017) 2844–2862.
[33] M.A. Azam, B. Suresh, Sci. Pharm. 80 (2012) 789–823.
[34] W. Huang, G.F. Yang, Bioorg. Med. Chem. 14 (2006) 8280–8285.
[35] J.H. Lee, J.D. Kim, Bull. Korean. Chem. Soc. 18 (1997) 442–443.
[36] G.P. Voutsas, S.C. Kokkou, C.J. Cheer, P. Aslanidis, P. Karagiannidis, Polyhedron 14
(1995) 2287–2292.
[62] A. Adenot, E.B. Landstrom, F. Gallou, B.H. Lipshutz, Green Chem. 19 (2017)
2506–2509.
[63] S.B. Ötvös, I.M. Mándity, L. Kiss, F. Fülöp, Chem. Asian. J. 8 (2013) 800–808.
[64] X. Jia, G. Xu, Z. Du, Y. Fu, Polyhedron 151 (2018) 515–519.
[65] D. Seebach, D. Enders, R. Dach, R. Pieter, Chem. Ber. 110 (1977) 1879–1886.
[66] M. Israr, C. Ye, M.T. Muhammad, Y. Li, H. Bao, Beilstein, J. Org. Chem. 14 (2018)
2916–2922.
[67] J.H. Kim, S. Kim, RSC. Adv. 4 (2014) 26516–26523.
[68] M. Irfan, S. Alam, N. Manzoor, M. Abid, Plos. One. 12 (2017) e0175710.
[69] H. Naeimi, Z. Ansarian, Inorg. Chem. Commun. 466 (2017) 417–425.
[70] V.K. Vyas, B.M. Bhanage, Org. lett. 18 (2016) 6436–6439.
[71] H. Esmaeili-Shahri, H. Eshghi, J. Lari, S.A. Rounaghi, Appl. Organomet. Chem. 32
(2018) e3947.
[37] H.A. El-Asmy, I.S. Butler, Z.S. Mouhri, B.J. Jean-Claude, M. Emmam, S.I. Mostafa,
Inorg. Chim. Acta. 441 (2016) 20–33.
[38] Q.M. Qiu, M. Liu, Z.F. Li, Q.H. Jin, X. Huang, Z.W. Zhang, C.L. Zhang, Q.X. Meng, J.
Mol. Struct. 1062 (2014) 125–132.
[72] A. Salamatmanesh, M.K. Miraki, E. Yazdani, A. Heydari, Catal. Lett. 148 (2018)
3257–3268.
[39] P.J. Cox, P. Aslanidis, P. Karagiannidis, S. Khadjikakou, Polyhedron 18 (1999)
1501–1506.
[73] Y. Chen, W.Q. Zhang, B.X. Yu, Y.M. Zhao, Z.W. Gao, Y.J. Jian, L.W. Xu, Green
Chem. 18 (2016) 6357–6366.
[40] P. Aslanidis, P.J. Cox, P. Karagiannidis, S.K. Hadjikakou, C.D. Antoniadis, Eur. J.
Inorg. Chem. 2002 (2002) 2216–2222.
[74] F. Alonso, Y. Moglie, G. Radivoy, M. Yus, J. Org. Chem. 76 (2011) 8394–8405.
[75] M.N.S. Rad, S. Behrouz, M.M. Doroodmand, A. Movahediyan, Tetrahedron 68
(2012) 7812–7821.
[41] A. Neshat, S. Varestan, M.R. Halvagar, New. J. Chem. 42 (2018) 2036–2046.
[42] M. Garner, J. Reglinski, I. Cassidy, M.D. Spicer, A.R. Kennedy, Chem. Commun.
(1996) 1975–1976.
[76] X. Meng, X. Xu, T. Gao, B. Chen, Eur. J. Org. Chem. 2010 (2010) 5409–5414.
[43] C. Kimblin, T. Hascall, G. Parkin, Inorg. Chem. 36 (1997) 5680–5681.
14