Combining oxidative N-heterocyclic carbene catalysis with click chemistry: A facile one-pot approach to 1,2,3-triazole derivatives

Article abstract of DOI:10.1002/asia.201300138

A combination of the oxidative N-heterocyclic carbene catalysis and click chemistry has been explored for the direct, one-pot synthesis of 1,2,3-triazole derivatives from aromatic aldehydes. This procedure was found to be very efficient and a variety of 1

Full text of DOI:10.1002/asia.201300138

FULL PAPER
DOI: 10.1002/asia.201300138
Combining Oxidative N-Heterocyclic Carbene Catalysis with Click
Chemistry: A Facile One-Pot Approach to 1,2,3-Triazole Derivatives
B. T. Ramanjaneyulu, Virsinha Reddy, Panjab Arde, Sriram Mahesh, and
R. Vijaya Anand*[a]
Abstract: A combination of the oxidative N-heterocyclic carbine catalysis and
click chemistry has been explored for the direct, one-pot synthesis of 1,2,3-triazole
Keywords: carbenes · click chemis-
derivatives from aromatic aldehydes. This procedure was found to be very efficient
try · esterification · oxidation · tria-
and a variety of 1,2,3-triazole derivatives could be accessed through their corre-
zoles
sponding propargyl esters in moderate-to-good yields under mild conditions.
Introduction
now, only one report has appeared in the literature for the
direct transformation of cinnamaldehyde into its corre-
sponding propargyl ester by using NHC as a catalyst under
oxidative conditions.[17] However, the desired propargyl
ester was only formed in 11% yield at room temperature
(45% yield at 708C). Surprisingly, there are no reports on
the direct NHC-catalyzed conversion of aromatic aldehydes
into their corresponding propargyl esters. Based on these
observations, we considered it worthwhile to develop
a method for the synthesis of propargyl esters under oxida-
tive NHC conditions and to elaborate those esters into their
1,2,3-triazole derivatives by using click chemistry in one pot
(Scheme 1).[18]
The inimitable reactivity of N-heterocyclic carbenes (NHCs)
towards carbonyl groups has led to the discovery of new or-
ganocatalytic C C bond-forming reactions in recent years.
[1]
À
Apart from the classic umpolung reaction,[1,2] the potential
of NHCs has been explored in redox reactions,[3] transesteri-
fications,[4] cycloadditions,[5] and CO2-fixation reactions,[6] as
well as in combination with photoredox catalysts,[7] cascade
catalysis,[8] and in co-operative catalysis.[9] Recently, oxida-
tive NHC catalysis,[10] an interesting sub-area of NHC catal-
À
ysis, was uncovered for the construction of carbon heteroa-
tom bonds, by employing a NHC in combination with an ex-
ternal oxidant. This remarkable method was successfully ap-
plied to fundamental transformations, such as esterifica-
tion,[11] amidation,[12] and lactone-ring-formation reactions.[13]
Recently, we developed an efficient organocatalytic route
for the direct conversion of aromatic aldehydes into aryl
esters by using aryl boronic acids under oxidative NHC-cat-
alyzed conditions.[14] Although aryl esters were obtained in
excellent yields, this method did not allow us to access ali-
phatic esters because aliphatic boronic acids did not react
with the aldehydes under the optimized reaction conditions.
Consequently, we became interested in developing a compe-
tent method for the synthesis of aliphatic esters, in particu-
lar, propargyl esters, because these esters could be derivat-
ized in a straightforward manner to afford worthwhile com-
pounds by using click chemistry[15] or gold catalysis.[16] Until
Scheme 1. Proposed one-pot approach to 1,2,3-triazole derivatives.
Results and Discussion
Before exploring the one-pot process for the synthesis of
1,2,3-triazoles, we considered it necessary to optimize the
first step, that is, the formation of the propargyl ester. Thus,
we performed optimization studies for the first step by using
para-chlorobenzaldehyde (1) and propargyl bromide (2)
under oxidative NHC-catalyzed conditions. All of the reac-
tions were conducted in an open atmosphere to ensure that
sufficient oxygen was available for the oxidation reaction to
take place. The results of the optimization studies are shown
in Table 1.
[a] B. T. Ramanjaneyulu, V. Reddy, P. Arde, S. Mahesh, Dr. R. V. Anand
Department of Chemical Sciences
Indian Institute of Science Education and
Research (IISER) Mohali
Sector 81, Knowledge City, S.A.S Nagar
Punjab - 140306 (India)
Fax : (+91)172-2240266
E-mail: rvijayan@iisermohali.ac.in
A variety of NHCs (4–8) were used for this transforma-
tion. After careful screening, NHC 7 was found to be the
Supporting information for this article is available on the WWW
under http://dx.doi.org/10.1002/asia.201300138.
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R Vijaya Anand et al.
Table 1. Optimization studies.
Table 2. Substrate scope in oxidative esterification reaction of aldehydes with propargyl
bromide.[a]
Entry[a]
NHC
Base
Solvent
t [h]
Yield [%][b]
1
2
3
4
5
6
7
8
4
5
6
7
8
7
7
7
7
7
7
7
7
7
DBU
DBU
DBU
DBU
DBU
Li2CO3
Cs2CO3
Et3N
DBU
DBU
DBU
DBU
DBU
DBU
THF
THF
THF
THF
THF
THF
THF
THF
toluene
MeCN
DME
DMF
DCE
24
24
24
3
<5
12
40
82
10
N.R.
10
5
67
28
60
10
25
24
15
14
24
15
15
15
15
15
15
9
10
11
12
13
14
1,4-dioxane
54
[a] Reaction conditions: 0.1m solution of compound 1 in solvent, RT=
32–358C. [b] Yield of isolated product. N.R.=no reaction; DME=1,2-di-
methoxyethane; DCE=1,2-dichloroethane.
best catalyst and the conditions shown in Table 1, entry 4
were found to be the optimal conditions for this transforma-
tion. Next, because this particular oxidative esterification
had not previously been reported, we examined the scope of
this reaction with a variety of aldehydes and the results are
summarized in Table 2.
[a] Reaction conditions: 0.1m solution of the aldehyde in THF, RT=32–358C.
Table 3. Optimization studies of one pot reaction.
A range of propargyl esters of aromatic acids could be
readily accessed in good yields by using this method. Elec-
tron-poor aldehydes (9d–9 f) reacted at faster rates than
electron-rich aldehydes (9h) and benzaldehyde (9c). To our
surprise and in contrast to a literature report, cinnamalde-
hyde gave its corresponding propargyl ester in 72% yield
under the standard conditions; of course, our reaction condi-
tions were slightly different to those in the previous
report.[17] This method also worked efficiently for the reac-
tions of aliphatic aldehydes, such as dihydrocinnamaldehyde
(9j) and cyclohexane carboxaldehyde (9k), and the corre-
sponding esters were obtained in moderate yields. The
scope of the reaction was extended to internal (9l–9n) and
secondary propargyl bromides (9o). In all of those cases, the
required propargyl esters were isolated in satisfactory yields.
Encouraged by these results in the formation of the prop-
argyl esters, we shifted our attention towards developing
a one-pot procedure for the synthesis of 1,2,3-triazole deriv-
atives[19] from aldehydes by combining the oxidative NHC
catalysis with copper-catalyzed click chemistry. Standardiza-
tion experiments were performed by using benzyl azide and
a copper catalyst, which were added immediately into the
reaction mixture after the first step was complete (by TLC);
the results are summarized in Table 3.
Entry[a]
Azide [equiv]
Solvent
t [h] (steps 1+2)
Yield [%][b]
1[c]
2[c]
3[c]
4
1.3
1.5
2
1.5
2
THF/H2O
THF/H2O
THF/H2O
THF
THF
THF
3+10
3+6
3+3
3+16
3+12
3+24
3+10
49
55
60
65
78
65
44
5
6[d]
7[e]
2
2
THF
[a] Reaction conditions: 0.1m solution of compound 1 in THF, RT=32-
358C. [b] Yield of isolated product over two steps. [c] Water (1 mL) was
added with the copper catalyst. [d] CuI (20 mol%) was used instead of
Cu2O. [e] CuSO4·5H2O (10 mol%) and sodium ascorbate (20 mol%)
were used instead of Cu2O.
From the optimization studies, it was clear that the de-
sired 1,2,3-triazole derivatives were formed under all of the
reaction conditions that were tested (Table 3). However, the
highest yield of compound 10 was obtained when two equiv-
alents of the azide and 20 mol% of Cu2O were used
(Table 3, entry 5); thus, these conditions were employed as
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R Vijaya Anand et al.
Table 4. Substrate scope in the one-pot synthesis of 1,2,3-triazole derivatives.[a]
the standard conditions. No
product was observed without
a copper catalyst. These opti-
mized conditions were investi-
gated for the synthesis of
a
wide range of substituted
1,2,3-triazoles from a variety of
aromatic aldehydes and azides
(Table 4).
The scope of this one-pot
method was also determined, as
shown in Table 4, and 1,2,3-tria-
zole derivatives were obtained
in moderate-to-good yields in
a regioselective manner. Elec-
tron-poor aldehydes (11d, 11e,
and 11g), except for para-nitro-
benzaldehyde (11 f), were trans-
formed into the desired prod-
ucts at relatively faster rates
than electron-rich aldehydes
(11h–11j). This method was
also employed for converting
few heteroaromatic aldehydes
into their corresponding 1,2,3-
triazole derivatives in moderate
yields (11k and 11l). As well as
benzyl azide, this method was
also found to be equally effec-
tive for aromatic and other
azides (11q–11x).
Since the NHC-catalyzed oxi-
dation of aldehydes into their
respective acids is precedented
in the literature,[20] we anticipat-
ed that the first step in our
method proceeded through the
initial formation of the corre-
sponding acid, followed by al-
kylation with propargyl bro-
mide. To confirm this assump-
tion, some experiments were
performed. In one experiment,
[a] Reaction conditions: 0.1m solution of the aldehyde in THF, RT=32–358C.
para-chlorobenzaldehyde was treated with
a
catalytic
at the same time, under one-pot reaction conditions, benzal-
dehyde gave 1,2,3-triazole derivative 11a in 60% overall
yield. This result clearly implies that the triazole-formation
step is almost quantitative in this case. However, when prop-
argyl ester 9c was directly treated with Cu2O and benzyl
azide in the absence of compound 7, the product 11a was
only obtained in 60% yield, even after 28 h (Scheme 2). The
reaction rate and the yield of compound 11a were increased
by the addition of 15 mol% of compound 7 to the reaction
mixture (Scheme 2).
amount of compound 7 and 1,8-diazabicyclo[5.4.0]undec-7-
AHCTUNGTRENNUNG
ene (DBU, 1.5 equiv) in air, thereby affording the isolated
product (para-chlorobenzoic acid) in 80% yield within 3 h.
In another experiment, para-chlorobenzoic acid was treated
with propargyl bromide (1.5 equiv) in the presence of DBU
(1.5 equiv) and the propargyl ester 3 was formed in almost
quantitative yield within 5 h. Based on these observations,
we strongly believe that the reaction proceeds through the
oxidation of the aldehyde into the corresponding acid, fol-
lowed by propargylation.
Based on these observations, we presume that the NHC
also influences the triazole-formation step, probably through
the formation of a complex with the copper catalyst, thereby
increasing its catalytic activity.[21]
Another interesting point was observed during the stand-
ardization of this method. As shown in Table 2, benzalde-
hyde was converted into its propargyl ester 9c in 60% yield;
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R Vijaya Anand et al.
Prop-2-yn-1-yl-4-chlorobenzoate (3)[24]
82% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.00 (d, J=
8.72 Hz, 2H), 7.42 (d, J=8.72 Hz, 2H), 4.92 (d, J=2.48 Hz, 2H),
2.53 ppm (t, J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=165.0,
ꢀ
139.9, 131.2, 128.8, 127.8, 77.5, 75.2, 52.7 ppm; FTIR: n˜ =3299 ( CH),
2131 (C C), 1722 cmÀ1 (C=O).
ꢀ
Prop-2-yn-1-yl-4-bromobenzoate (9a)[25]
Scheme 2. Formation of 1,2,3-triazoles under different conditions. Reac-
85% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=7.93 (d, J=
8.72 Hz, 2H), 7.59 (d, J=8.72 Hz, 2H), 4.92 (d, J=2.48 Hz, 2H),
2.53 ppm (t, J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=165.1,
tion conditions: 0.1m solution of compound 9c in THF, RT=32–358C.
ꢀ
131.8, 131.3, 128.6, 128.3, 77.5, 75.3, 52.7 ppm; FTIR: n˜ =3297 ( CH),
Conclusions
2130 (C C), 1721 cmÀ1 (C=O).
ꢀ
Prop-2-yn-1-yl-4-phenylbenzoate (9b)
In conclusion, a one-pot synthesis of 1,2,3-triazole deriva-
tives was achieved by combining oxidative N-heterocyclic
carbene catalysis with click chemistry. This method was uti-
lized for the synthesis of a diverse range of 1,2,3-triazole de-
rivatives from aldehydes under mild reaction conditions. Be-
cause one-pot syntheses are an integral part of making
chemistry more sustainable, we believe that this method will
find some applications in the near future.
72% Yield; white solid; M.p. 106–1078C; 1H NMR (400 MHz, CDCl3):
d=8.14 (d, J=8.60 Hz, 2H), 7.68 (d, J=8.60 Hz, 2H), 7.64–7.61 (m, 2H),
7.50–7.45 (m, 2H), 7.43–7.38 (m, 1H), 4.95 (d, J=2.48 Hz, 2H), 2.54 ppm
(t, J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=165.7, 146.1, 139.9,
130.4, 129.0, 128.3, 128.1, 127.3, 127.1, 77.8, 75.0, 52.5 ppm; FTIR: n˜ =
À1
ꢀ
ꢀ
3250 ( CH), 2121 (C C), 1713 cm (C=O); HRMS (ESI): m/z calcd for
C16H13O2: 237.0915 [M+H]+; found: 237.0916.
Prop-2-yn1-ylbenzoate (9c)[24]
60% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.09–8.06 (m,
2H), 7.61–7.56 (m, 1H), 7.48–7.43 (m, 2H), 4.93 (d, J=2.44 Hz, 2H),
2.52 ppm (t, J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=165.8,
Experimental Section
ꢀ
133.4, 129.8, 129.4, 128.5, 77.7, 75.0, 52.5 ppm; FTIR: n˜ =3296 ( CH),
General Methods
2130 (C C), 1720 cmÀ1 (C=O).
ꢀ
Most of the reagents and starting materials were purchased from com-
mercial sources and used as received. NHC precursor 8 was prepared ac-
cording to a literature procedure.[22] All of the organic azides were pre-
pared according to a literature procedure.[23] 1H and 13C spectra were re-
corded in CDCl3 on a 400 MHz Bruker FT-NMR spectrometer equipped
with a PIKE MIRacle ATR. Chemical shifts are reported in parts per
million relative to TMS. High-resolution mass spectroscopy was per-
formed on a Waters Q-TOF Premier-HAB213 spectrometer. FTIR spec-
tra were recorded on a Brucker FTIR spectrometer. Thin-layer chroma-
tography was performed on Merck silica gel 60 F254 TLC plates by using
EtOAc/hexanes as an eluent. Column chromatography was performed on
silica gel (100–200 mesh).
Prop-2-yn-1-yl-4-cyanobenzoate (9d)[25]
75% Yield; white solid; M.p. 96–978C; 1H NMR (400 MHz, CDCl3): d=
8.18 (d, J=8.72 Hz, 2H), 7.76 (d, J=8.72 Hz, 2H), 4.96 (d, J=2.48 Hz,
2H), 2.55 ppm (t, J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=
164.2, 133.2, 132.3, 130.3, 117.9, 116.8, 77.2, 75.7, 53.2 ppm; FTIR: n˜ =
3267 ( CH), 2360 (C N), 2230 (C C), 1728 cmÀ1 (C=O).
ꢀ
ꢀ
ꢀ
Methyl prop-2-yn-1-ylterephthalate (9e)[26]
75% Yield; white solid; M.p. 88–898C; 1H NMR (400 MHz, CDCl3): d=
8.08–8.03 (m, 4H), 4.88 (d, J=2.48 Hz, 2H), 3.95 (s, 3H), 2.48 ppm (t,
J=2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=166.2, 165.0, 134.3,
General Procedure for the NHC-Catalyzed Aerobic Oxidation of Aryl
Aldehydes with Propargyl Bromide
ꢀ
133.1, 129.8, 129.6, 77.2, 75.4, 52.9, 52.5 ppm; FTIR: n˜ =3248 ( CH),
2130 (C C), 1720 cmÀ1 (C=O).
ꢀ
The aromatic aldehyde (1 mmol) was added to a suspension of NHC 7
(0.15 mmol) and DBU (1.5 mmol) in THF (10 mL) at RT (32–358C) and
the mixture was stirred for 30 min. Propargyl bromide (80% solution in
toluene, 1.5 mmol) was added to the reaction mixture in a dropwise
manner and the resulting suspension was stirred until most of the alde-
hyde had been consumed (by TLC). The suspension was then filtered,
washed with EtOAc (20 mL), and dried over anhydrous Na2SO4. The sol-
vent was removed under reduced pressure and the residue was purified
by column chromatography on silica gel (EtOAc/hexanes).
Prop-2-yn-1-yl-4-nitrobenzoate (9 f)[24]
60% Yield; pale-yellow solid; M.p. 96–978C; 1H NMR (400 MHz,
CDCl3): d=8.31 (d, J=9.04 Hz, 2H), 8.23 (d, J=9.04 Hz, 2H), 4.97 (d,
J=2.48 Hz, 2H), 2.56 ppm (t, J=2.48 Hz, 1H); 13C NMR (100 MHz,
CDCl3): d=164.0, 150.8, 134.7, 131.0, 123.7, 77.4, 75.8, 53.3 ppm; FTIR:
À1
ꢀ
ꢀ
n˜ =3288 ( CH), 2132 (C C), 1720 (C=O) 1608, 1523 cm
.
Prop-2-yn-1-yl-4-trifluoromethoxybenzoate (9g)[27]
71% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.14–8.10 (m,
2H), 7.29–7.26 (m, 2H), 4.93 (d, J=2.48 Hz, 2H), 2.53 ppm (t, J=
General Procedure for the NHC-Catalyzed One-Pot Synthesis of 1,2,3-
Triazole Derivatives
2.48 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=164.6, 152.9 (d, J
ACHTUNGTRENNUNG
The aromatic aldehyde (1 mmol) was added to a suspension of NHC 7
(0.15 mmol) and DBU (1.5 mmol) in THF (10 mL) at room temperature
(32–358C) and the mixture was stirred for 30 min. Propargyl bromide
(80% solution in toluene, 1.5 mmol) was added in a dropwise manner
and the resulting suspension was stirred until most of the aldehyde had
been consumed (by TLC). Cu2O (0.2 mmol) and the azide (2 mmol) were
added to the reaction and stirring was continued until most of the prop-
argyl ester that had formed during the first step had been consumed. The
precipitate was then filtered, washed with EtOAc (20 mL), and dried
over anhydrous Na2SO4. The solvent was removed under reduced pres-
sure and the residue was purified by column chromatography on silica
gel (EtOAc/hexanes).
2.0 Hz), 131.9, 127.8, 120.3 (q,
JACHTUNGTRENNUNG
À1
ꢀ
ꢀ
52.7 ppm; FTIR: n˜ =3306 ( CH), 2132 (C C), 1727 cm (C=O).
Prop-2-yn-1-yl-3,4-methylenedioxybenzoate (9h)
60% Yield; off-white solid; M.p. 59–608C; 1H NMR (400 MHz, CDCl3):
d=7.68 (dd, J=8.20, 1.68 Hz, 1H), 7.48 (d, J=1.68 Hz, 1H), 6.84 (d, J=
8.20 Hz, 1H), 6.04 (s, 2H), 4.88 (d, J=2.44 Hz, 2H), 2.52 ppm (t, J=
2.45 Hz, 1H); 13C NMR (100 MHz, CDCl3): d=165.2, 152.0, 147.8, 125.8,
ꢀ
123.3, 109.7, 108.1, 101.9, 77.8, 75.0, 52.4 ppm; FTIR: n˜ =3245 ( CH),
À1
ꢀ
2128 (C C), 1708 cm (C=O); HRMS (ESI): m/z calcd for C11H9O4:
205.0501 [M+H]+; found: 205.0504.
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R Vijaya Anand et al.
Prop-2-yn-1-ylcinnamate (9i)[24]
(m, 3H), 7.51–7.46 (m, 2H), 7.44–7.37 (m, 4H), 7.35–7.30 (m, 2H), 5.56
(s, 2H), 5.50 ppm (s, 2H); 13C NMR (100 MHz, CDCl3): d=166.4, 145.9,
143.4, 139.9, 134.4, 130.3, 129.2, 129.0, 128.9, 128.4, 128.2, 128.2, 127.3,
127.1, 123.9, 58.1, 54.3 ppm; FTIR: n˜ =1714 cmÀ1; HRMS (ESI): m/z
calcd for C23H20N3O2: 370.1555 [M+H]+; found: 370.1551.
72% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=7.75 (d, J=
16.0 Hz, 1H), 7.55–7.51 (m, 2H), 7.41–7.38 (m, 3H), 6.47 (d, J=16.0 Hz,
1H), 4.82 (d, J=2.48 Hz, 2H), 2.52 ppm (t, J=2.48 Hz, 1H); 13C NMR
(100 MHz, CDCl3): d=166.1, 146.0, 134.2, 130.6, 129.0, 128.2, 117.0, 77.8,
74.9, 52.1 ppm; FTIR: n˜ =3293 ( CH), 2129 (C C), 1712 cmÀ1 (C=O).
ꢀ
ꢀ
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-bromobenzoate (11c)
Prop-2-yn-1-yl-3-phenylpropanoate (9j)[24]
80% Yield; white solid; M.p. 114–1158C; 1H NMR (400 MHz, CDCl3):
d=7.87 (d, J=8.64 Hz, 2H), 7.60 (s, 1H), 7.55 (d, J=8.64 Hz, 2H), 7.41–
7.36 (m, 3H), 7.30–7.27 (m, 2H), 5.53 (s, 2H), 5.43 ppm (s, 2H);
13C NMR (100 MHz, CDCl3): d=165.8, 143.0, 134.3, 131.8, 131.3, 129.2,
56% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=7.32–7.28 (m,
2H), 7.23–7.20 (m, 3H), 4.69 (d, J=2.48 Hz, 2H), 2.98 (t, J=7.56 Hz,
2H), 2.69 (t, J=7.56 Hz, 2H), 2.48 ppm (t, J=2.48 Hz, 1H); 13C NMR
(100 MHz, CDCl3): d=172.2, 140.3, 128.7, 128.4, 126.5, 77.8, 75.0, 52.1,
128.9, 128.6, 128.4, 128.2, 123.9, 58.2, 54.3 ppm; FTIR: n˜ =1730 cmÀ1
;
HRMS (ESI): m/z calcd for C17H15BrN3O2: 372.0347 [M+H]+; found:
35.7, 30.9 ppm; FTIR: n˜ =3288 ( CH), 2126 (C C), 1740 cmÀ1 (C=O).
ꢀ
ꢀ
372.0343.
Prop-2-yn-1-ylcyclohexanecarboxylate (9k)[28]
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-cyanobenzoate (11d)
48% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=4.66 (d, J=
2.48, 2H), 2.45 (t, J=2.48 Hz, 1H), 2.38–2.31 (m, 1H), 1.93–1.25 ppm (m,
10H), 13C NMR (100 MHz, CDCl3): d=175.4, 78.1, 74.8, 51.8, 43.0, 29.0,
62% Yield; pale-orange solid; M.p. 131–328C; 1H NMR (400 MHz,
CDCl3): d=8.12 (d, J=8.60 Hz, 2H), 7.71 (d, J=8.60 Hz, 2H), 7.60 (s,
1H), 7.41–7.35 (m, 3H), 7.32–7.265 (m, 2H), 5.53 (s, 2H), 5.46 ppm (s,
2H); 13C NMR (100 MHz, CDCl3): d=164.8, 142.6, 134.2, 133.5, 132.2,
130.3, 129.2, 129.0, 128.2, 124.0, 118.0, 116.6, 58.6, 54.3 ppm; FTIR: n˜ =
25.8, 25.5 ppm; FTIR: n˜ =3292 ( CH), 2131 (C C), 1736 cmÀ1 (C=O).
ꢀ
ꢀ
But-2-yn-1-ylbenzoate (9l)[29]
2231, 1719 cmÀ1
; HRMS (ESI): m/z calcd for C18H15N4O2: 319.1195
78% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.09–8.06 (m,
2H), 7.59–7.55 (m, 1H), 7.47–7.42 (m, 2H), 4.89 (q, J=2.44 Hz, 2H),
1.88 ppm (t, J=2.44 Hz, 3H); 13C NMR (100 MHz, CDCl3): d=166.1,
[M+H]+; found: 319.1197.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-methylterephthalate (11e)
ꢀ
133.3, 129.9, 129.8, 128.5, 83.4, 73.4, 53.4, 3.8 ppm; FTIR: n˜ =2240 (C C),
70% Yield; off-white solid; M.p. 140–1418C1; 1H NMR (400 MHz,
CDCl3): d=8.08 (s, 4H), 7.62 (s, 1H), 7.40–7.36 (m, 3H), 7.30–7.28 (m,
2H), 5.54 (s, 2H), 5.46 (s, 2H), 3.94 ppm (s, 3H); 13C NMR (100 MHz,
CDCl3): d=166.2, 165.7, 142.9, 134.3, 134.1, 133.5, 129.8, 129.6, 129.2,
128.9, 128.2, 124.0, 58.4, 54.3, 52.5 ppm; FTIR: n˜ =2231, 1716 cmÀ;
HRMS (ESI): m/z calcd for C18H17N3O4: 352.1297 [M+H]+; found:
352.1299.
1721 cmÀ1 (C=O).
Pent-2-yn-1-ylbenzoate (9m)[30]
82% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.09–8.06 (m,
2H), 7.59–7.54 (m, 1H), 7.46–7.42 (m, 2H), 4.91 (t, J=2.20 Hz, 2H), 2.26
(qt, J=7.54, 2.20 Hz, 2H), 1.15 ppm (t, J=7.54 Hz, 3H); 13C NMR
(100 MHz, CDCl3): d=166.1, 133.2, 130.2, 129.9, 128.5, 89.1, 73.5, 53.4,
13.7, 12.6 ppm; FTIR: n˜ =2242 (C C), 1721 cmÀ1 (C=O).
ꢀ
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-nitrobenzoate (11 f)
57% Yield; pale-yellow solid; M.p. 140–1418C; 1H NMR (400 MHz,
CDCl3): d=7.88 (d, J=8.64 Hz, 2H), 7.60 (s, 1H), 7.55 (d, J=8.68 Hz,
2H), 7.41–7.34 (m, 3H), 7.31–7.27 (m, 2H), 5.53 (s, 2H), 5.43 ppm (s,
2H); 13C NMR (100 MHz, CDCl3): d=164.6, 150.7, 135.1, 134.2, 130.9,
129.2, 129.0, 128.2, 123.6, 77.3, 58.8, 54.6, 54.4 ppm; FTIR: n˜ =1719, 1519,
1347 cmÀ1; HRMS (ESI): m/z calcd for C17H15N4O4: 339.1093 [M+H]+;
found: 339.1092.
3-Phenylprop-2-yn-1-ylbenzoate (9n)[31]
60% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.13–8.10 (m,
2H), 7.60–7.56 (m, 2H), 7.50–7.44 (m, 5H), 7.34–7.33 (m, 1H), 5.17 ppm
(s, 2H); 13C NMR (100 MHz, CDCl3): d=166.1, 133.4, 132.1, 130.0, 129.9,
ꢀ
128.9, 128.6, 128.4, 122.3, 86.7, 83.2, 53.5 ppm; FTIR: n˜ =2130 (C C),
1722 cmÀ1 (C=O).
4-Phenylbut-3-yn-2-ylbenzoate (9o)[31]
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-(trifluoromethoxy)benzoate
(11g)
58% Yield; colorless oil; 1H NMR (400 MHz, CDCl3): d=8.13–8.10 (m,
2H), 7.60–7.56 (m, 1H), 7.49–7.44 (m, 4H), 7.33–7.29 (m, 3H), 5.95 (q,
J=6.68 Hz, 1H), 1.73 ppm (d, J=6.68 Hz, 3H); 13C NMR (100 MHz,
70% Yield; pale-yellow solid; M.p. 110–1118C; 1H NMR (400 MHz,
CDCl3): d=8.06 (d, J=8.96 Hz, 2H), 7.60 (s, 1H), 7.41–7.34 (m, 3H),
7.31–7.23 (m, 4H), 5.53 (s, 2H) 5.44 ppm (s, 2H); 13C NMR (100 MHz,
CDCl3): d=165.3, 152.8, 143.0, 134.3, 131.8, 129.3, 129.2, 128.9, 128.2,
128.1, 123.9, 120.3, 58.3, 54.3 ppm; FTIR: n˜ =1719 cmÀ1; HRMS (ESI):
m/z calcd for C18H15F3N3O3: 378.1065 [M+H]+; found: 378.1067.
CDCl3): d=165.7, 133.3, 132.0, 130.1, 129.9, 128.7, 128.5, 128.4, 127.8,
À1
ꢀ
87.6, 84.9, 61.5, 21.8 ppm; FTIR: n˜ =2229 (C C), 1722 cm (C=O).
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate (10)
78% Yield; pale-yellow solid; M.p. 114–1158C; 1H NMR (400 MHz,
CDCl3): d=7.95 (d, J=8.64 Hz, 2H), 7.60 (s, 1H), 7.40–7.35 (m, 5H),
7.31–7.27 (m, 2H), 5.53 (s, 2H), 5.43 ppm (s, 2H); 13C NMR (100 MHz,
CDCl3): d=165.6, 143.1, 139.7, 134.3, 131.2, 129.2, 128.9, 128.8, 128.2,
128.1, 123.9, 58.2, 54.3 ppm; FTIR: n˜ =1719 cmÀ1; HRMS (ESI): m/z
calcd for C17H14ClN3O2: 350.0673 [M+Na]+; found: 350.0678.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-ethylbenzoate (11h)
54% Yield; pale-yellow solid; M.p. 98–998C; 1H NMR (400 MHz,
CDCl3): d=7.93 (d, J=8.32 Hz, 2H), 7.60 (s, 1H), 7.40 À7.35 (m, 3H),
7.30–7.26 (m, 2H), 7.23 (d, J=8.32 Hz, 2H), 5.52 (s, 2H), 5.43 (s, 2H),
2.68 (q, J=7.64 Hz, 2H), 1.23 ppm (t, J=7.64 Hz, 3H); 13C NMR
(100 MHz, CDCl3): d=166.5, 150.2, 143.5, 134.4, 129.9, 129.2, 128.9,
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-benzoate (11a)[32]
128.2, 127.9, 127.2, 123.8, 57.9, 54.3, 29.0, 15.2 ppm; FTIR: n˜ =1702 cmÀ1
;
HRMS (ESI): m/z calcd for C18H16N3O4: 322.1555 [M+H]+; found:
60% Yield; white solid; M.p. 122–1238C; 1H NMR (400 MHz, CDCl3):
d=8.02 (dd, J=8.48, 1.40 Hz, 2H), 7.61 (s, 1H), 7.57–7.53 (m, 1H), 7.43–
7.34 (m, 5H), 7.31–7.27 (m, 2H), 5.53 (s, 2H), 5.44 ppm (s, 2H);
13C NMR (100 MHz, CDCl3): d=166.5, 143.4, 134.4, 133.2, 129.8, 129.7,
322.1552.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-4-(tert-butyl)benzoate (11i)
129.2, 128.9, 128.4, 128.2, 123.9, 58.1, 54.3 ppm; FTIR: n˜ =1710 cmÀ1
.
59% Yield; pale-yellow solid; M.p. 98–998C; 1H NMR (400 MHz,
CDCl3): d=7.95 (d, J=8.64 Hz, 2H), 7.60 (s, 1H), 7.43 (d, J=8.64 Hz,
2H), 7.40–7.35 (m, 3H), 7.29–7.26 (m, 2H), 5.52 (s, 2H), 5.43 (s, 2H),
1.32 ppm (s, 9H); 13C NMR (100 MHz, CDCl3): d=166.5, 156.9, 143.5,
134.4, 129.6, 129.2, 128.9, 128.2, 126.9, 125.4, 123.8, 57.9, 54.3, 35.1,
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-[1,1’-biphenyl]-4-carboxylate (11b)
60% Yield; golden-yellow solid; M.p. 153–1548C; 1H NMR (400 MHz,
CDCl3): d=8.11 (d, J=8.56 Hz, 2H), 7.66 (d, J=8.59 Hz, 2H), 7.65–7.62
5
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Chem. Asian J. 2013, 00, 0 – 0
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ

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R Vijaya Anand et al.
31.1 ppm; FTIR: n˜ =1708 cmÀ1; HRMS (ESI): m/z calcd for C21H24N3O2:
350.1868 [M+H]+; found: 350.1862.
1717 cmÀ1; HRMS (ESI): m/z calcd for C17H15FN3O2: 312.1148 [M+H]+;
found: 312.1146.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-benzo[d]ACHTUNGRTEN[NUNG 1,3]dioxole-5-carboxylate
(1-(4-Methoxybenzyl)-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate
(11j)
(11q)
60% Yield; off-white solid; M.p. 148–1498C; 1H NMR (400 MHz,
CDCl3): d=7.63 (dd, J=8.20, 1.72 Hz, 1H), 7.59 (s, 1H), 7.44 (d, J=
1.68 Hz, 1H), 7.41- 7.35 (m, 3H), 7.30–7.27 (m, 2H), 6.81 (d, J=8.12 Hz,
1H), 6.02 (s, 2H), 5.52 (s, 2H), 5.40 ppm (s, 2H); 13C NMR (100 MHz,
CDCl3): d=165.8, 151.8, 147.7, 143.4, 134.4, 129.2, 128.9, 128.2, 125.7,
55% Yield; off-white solid; M.p. 119–1208C; 1H NMR (400 MHz,
CDCl3): d=7.96 (d, J=8.60 Hz, 2H), 7.56 (s, 1H), 7.38 (d, J=8.60 Hz,
2H), 7.24 (d, J=8.64 Hz, 2H), 6.89 (d, J=8.64 Hz, 2H), 5.46 (s, 2H),
5.41 (s, 2H), 3.80 ppm (s, 3H); 13C NMR (100 MHz, CDCl3): d=165.6,
160.0, 143.0, 139.7, 131.2, 129.8, 128.7, 128.2, 126.3, 123.7, 114.5, 58.2,
123.8, 123.7, 109.6, 108.0, 101.8, 58.0, 54.3 ppm; FTIR: n˜ =1711 cmÀ1
;
55.4, 53.9 ppm; FTIR: n˜ =1716 cmÀ1
; HRMS (ESI): m/z calcd for
HRMS (ESI): m/z calcd for C18H16N3O4: 338.1141 [M+H]+; found:
C17H15ClN3O3: 358.0958 [M+H]+; found: 358.0965.
338.1142.
(1-(4-Methylbenzyl)-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate (11r)
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-thiophene-2-carboxylate (11k)
67% Yield; pale-yellow solid; M.p. 110–1118C; 1H NMR (400 MHz,
CDCl3): d=7.95 (d, J=8.64 Hz, 2H), 7.57 (s, 1H), 7.38 (d, J=8.64 Hz,
2H), 7.18 (s, 4H), 5.48 (s, 2H), 5.42 (s, 2H) 2.35 ppm (s, 3H); 13C NMR
(100 MHz, CDCl3): d=165.6, 143.0, 139.7, 138.9, 131.3, 131.2, 129.9,
48% Yield; off-white solid; M.p. 85–868C; 1H NMR (400 MHz, CDCl3):
d=7.78 (dd, J=3.78, 1.24 Hz, 1H), 7.61 (s, 1H), 7.55 (dd, J=5.0,
1.24 Hz, 1H), 7.40–7.34 (m, 3H), 7.30–7.26 (m, 2H), 7.07 (dd, J=5.0,
3.80 Hz, 1H), 5.52 (s, 2H), 5.41 ppm (s, 2H); 13C NMR (100 MHz,
CDCl3): d=162.1, 143.2, 134.4, 133.9, 133.2, 132.9, 129.2, 128.9, 128.2,
127.8, 124.0, 58.2, 54.3 ppm; FTIR: n˜ =1707 cmÀ1; HRMS (ESI): m/z
calcd for C15H14N3O2S: 300.0806 [M+H]+; found: 300.0804.
128.7, 128.3, 128.2, 123.8, 58.2, 54.1, 21.2 ppm; FTIR: n˜ =1719 cmÀ1
;
HRMS (ESI): m/z calcd for C17H15ClN3O2: 342.1009 [M+H]+; found:
342.1008.
(1-(4-(Methoxycarbonyl)benzyl)-1H-1,2,3-triazol-4-yl)methyl-4-
chlorobenzoate (11s)
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-furan-2-carboxylate (11l)
48% Yield; pale-brown solid; M.p. 84–858C; 1H NMR (400 MHz,
CDCl3): d=7.62 (s, 1H), 7.55 (s, 1H), 7.39–7.34 (m, 3H), 7.28–7.26 (m,
2H), 7.17–7.16 (m, 1H), 6.48–6.47 (m, 1H), 5.51 (s, 2H), 5.40 ppm (s,
2H); 13C NMR (100 MHz, CDCl3): d=158.5, 146.7, 144.1, 143.0, 134.3,
129.2, 128.9, 128.2, 124.1, 118.6, 111.9, 57.9, 54.3 ppm; FTIR: n˜ =
1702 cmÀ1; HRMS (ESI): m/z calcd for C15H14N3O3: 284.1035 [M+H]+;
found: 284.1034.
82% Yield; off-white solid; M.p. 175–1768C; 1H NMR (400 MHz,
CDCl3): d=8.03 (d, J=8.38 Hz, 2H), 7.94 (d, J=8.68 Hz, 2H), 7.64 (s,
1H), 7.39 (d, J=8.68 Hz, 2H), 7.32 (d, J=8.42 Hz, 2H), 5.58 (s, 2H),
5.44 (s, 2H), 3.91 ppm (s, 3H); 13C NMR (100 MHz, CDCl3): d=166.4,
165.6, 143.4, 139.8, 139.1, 131.2, 130.7, 130.4, 128.8, 128.1, 127.9, 124.1,
58.2, 53.8, 52.4 ppm; FTIR: n˜ =1723, 1709 cmÀ1; HRMS (ESI): m/z calcd
for C19H17ClN3O4: 386.0907 [M+H]+; found: 386.0901.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methylcinnamate (11m)
(1-(4-(Trifluoromethoxy)benzyl)-1H-1,2,3-triazol-4-yl)methyl-4-
65% Yield; white solid; M.p. 123–1248C; 1H NMR (400 MHz, CDCl3):
d=7.69 (d, J=16.00 Hz, 1H), 7.58 (s, 1H), 7.52 À7.47 (m, 2H), 7.41–7.35
(m, 6H), 7.30 À7.27 (m, 2H), 6.42 (d, J=16.04 Hz, 1H), 5.53 (s, 2H),
5.33 ppm (s, 2H); 13C NMR (100 MHz, CDCl3): d=166.8, 145.6, 134.4,
134.2, 130.5, 129.2, 128.9, 128.9, 128.2, 128.2, 123.7, 117.5, 77.2, 57.7,
54.3 ppm; FTIR: n˜ =1715 cmÀ1; HRMS (ESI): m/z calcd for C19H18N3O2:
320.1399 [M+H]+; found: 320.1399.
chlorobenzoate (11t)
80% Yield; pale-brown solid; M.p. 155–1568C; 1H NMR (400 MHz,
CDCl3): d=7.95 (d, J=8.68 Hz, 2H), 7.64 (s, 1H), 7.39 (d, J=8.72 Hz,
2H), 7.32 (d, J=8.72 Hz, 2H), 7.23–7.21 (m, 2H) 5.53 (s, 2H) 5.44 ppm
(s, 2H); 13C NMR (100 MHz, CDCl3): d=165.6, 149.5, 143.3, 139.8, 133.0,
131.1, 129.7, 128.8, 128.1, 124.0, 121.6, 119.1, 58.1, 53.4 ppm; FTIR: n˜ =
1712 cmÀ1
; HRMS (ESI): m/z calcd for C18H14ClF3N3O3: 412.0676
[M+H]+; found: 412.0678.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-3-chlorobenzoate (11n)
78% Yield; pale-orange solid; M.p. 104–1058C; 1H NMR (400 MHz,
CDCl3): d=7.99 (t, J=1.84 Hz, 1H), 7.91–7.89 (m, 1H), 7.60 (s, 1H),
7.51 (ddd, J=8.0, 2.20, 1.84 Hz, 1H), 7.40–7.26 (m, 6H), 5.53 (s, 2H),
5.44 ppm (s, 2H); 13C NMR (100 MHz, CDCl3): d=165.3, 143.0, 134.6,
134.3, 133.2, 131.4, 129.8, 129.7, 129.2, 128.9, 128.2, 127.9, 123.9, 58.4,
(1-(4-Methoxyphenyl)-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate
(11u)
52% Yield; pale-yellow solid; M.p. 132–1338C; 1H NMR (400 MHz,
CDCl3): d=8.04 (s, 1H), 8.00 (d, J=8.72 Hz, 2H), 7.65 (d, J=9.08 Hz,
2H), 7.41 (d, J=8.72 Hz, 2H), 7.02 (d, J=9.08 Hz, 2H), 5.54 (s, 2H),
3.87 ppm (s, 3H); 13CNMR (100 MHz, CDCl3): d=165.7, 160.0, 143.2,
139.8, 131.2, 128.8, 128.2, 122.5, 122.3, 114.8, 77.2, 58.2, 55.7 ppm; FTIR:
54.3 ppm; FTIR: n˜ =1721 cmÀ1
;
HRMS (ESI): m/z calcd for
C17H15ClN3O2: 328.0853 [M+H]+; found: 328.0855.
n˜ =1714 cmÀ1
[M+H]+; found: 344.0808.
; HRMS (ESI): m/z calcd for C17H15ClN3O3: 344.0802
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-3-fluorobenzoate (11o)
73% Yield; white solid; M.p. 126–1278C; 1H NMR (400 MHz, CDCl3):
d=7.83–7.80 (m, 1H), 7.71–7.68 (m, 1H), 7.60 (s, 1H), 7.42–7.35 (m,
4H), 7.31–7.22 (m, 3H), 5.53 (s, 2H), 5.45 ppm (s, 2H); 13C NMR
(1-ACTHNUGRTNEUNG(p-Tolyl)-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate (11v)
69% Yield; pale-brown solid; M.p. 73–748C; 1H NMR (400 MHz,
CDCl3): d=8.09 (s, 1H), 7.98 (d, J=8.68 Hz, 2H), 7.60 (d, J=8.44 Hz,
2H), 7.39 (d, J=8.68 Hz, 2H), 7.30 (d, J=8.08 Hz, 2H), 5.53 (s, 2H),
2.41 ppm (s, 3H); 13C NMR (100 MHz, CDCl3): d=165.7, 139.8, 139.2,
134.6, 131.2, 130.3, 129.3, 128.8, 128.2, 122.4, 120.6, 58.2, 21.1 ppm; FTIR:
(100 MHz, CDCl3): d=165.3 (d,
245.7 Hz), 163.7, 143.0, 134.3, 131.9 (d, J
7 Hz), 129.2, 128.9, 128.2, 125.5 (d, J(C,F)=3 Hz), 123.9, 120.3 (d, J-
J
N
JACHTUNGTRENNUNG
A
ACHTUNGTRENNUNG
AHCTUNGTRENNUNG
ACHTUNGTRENNUNG(C,F)=21 Hz), 116.6 (d, JACHTNUGTREG(NNNU C,F)=24 Hz), 58.4, 54.3 ppm; FTIR: n˜ =
1716 cmÀ1; HRMS (ESI): m/z calcd for C17H15FN3O2: 328.0853 [M+H]+;
n˜ =1708 cmÀ1
; HRMS (ESI): m/z calcd for C17H15ClN3O2: 328.0853
found: 328.0855.
[M+H]+; found: 328.0850.
(1-Benzyl-1H-1,2,3-triazol-4-yl)methyl-2-fluorobenzoate (11p)
(1-Mesityl-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate (11w)
62% Yield; pale-yellow oil; 1H NMR (400 MHz, CDCl3): d=7.94–7.90
(m, 1H), 7.63 (s, 1H), 7.54–7.48 (m, 1H), 7.40–7.26 (m, 5H), 7.20–7.09
(m, 2H), 5.53 (s, 2H), 5.45 ppm (s, 2H); 13C NMR (100 MHz, CDCl3):
65% Yield; pale-yellow solid; M.p. 132–1338C; 1H NMR (400 MHz,
CDCl3): d=8.00 (d, J=8.68 Hz, 2H), 7.74 (s, 1H), 7.40 (d, J=8.68 Hz,
2H), 6.98 (s, 2H), 5.56 (s, 2H), 2.34 (s, 3H), 1.94 ppm (s, 6H); 13C NMR
(100 MHz, CDCl3): d=165.6, 142.5, 140.2, 139.7, 135.0, 133.2, 131.2,
d=164.0 (d, J
(C,F)=9 Hz), 134.4, 132.2, 129.2, 128.9, 128.2, 124.0, 123.9 (d, J
7 Hz), 118.2, 117.0 (d, (C,F)=22 Hz), 58.4, 54.3 ppm; FTIR: n˜ =
ACHTUNGTRENNUNG(C,F)=3 Hz), 162.1 (d, JACTHUNGTRENNUNG
J
N
ACHTUNGTRENNUNG
J
A
129.1, 128.8, 128.2, 125.9, 58.4, 21.1, 17.3 ppm; FTIR: n˜ =1730 cmÀ1
;
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Chem. Asian J. 2013, 00, 0 – 0
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
ÝÝ These are not the final page numbers!

www.chemasianj.org
R Vijaya Anand et al.
HRMS (ESI): m/z calcd for C19H19ClN3O2: 356.1166 [M+H]+; found:
356.1162.
48, 4194–4197; c) X. Liu, C. Cao, Y. Li, P. Guan, L. Yang, Y. Shi,
Synlett 2012, 1343–1348.
[7] T. Rovis, D. A. DiRocco, J. Am. Chem. Soc. 2012, 134, 8094–8097.
[8] L. Candish, D. W. Lupton, Chem. Sci. 2012, 3, 380–383.
(1-Phenyl-1H-1,2,3-triazol-4-yl)methyl-4-chlorobenzoate (11x)
60% Yield; pale-brown solid; M.p. 84–858C; 1H NMR (400 MHz,
CDCl3): d=8.14 (s, 1H), 7.98 (d, J=8.72 Hz, 2H), 7.74–7.72 (m, 2H),
7.54–7.49 (m, 2H), 7.46–7.42 (m, 1H), 7.44 (d, J=8.72 Hz, 2H), 5.54 ppm
(s, 2H); 13C NMR (100 MHz, CDCl3): d=165.7, 143.4, 139.8, 131.2, 129.8,
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Acknowledgements
The authors gratefully acknowledge the Department of Science and
Technology, New Delhi (DST), and the IISER Mohali for financial sup-
port. B.T.R., V.R., and P.A. thank the CSIR, New Delhi, and S.M. thanks
the UGC, New Delhi, for a research fellowship. The NMR Research Fa-
cility at the IISER Mohali and the HRMS facility at the IIT Kanpur are
also gratefully acknowledged.
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Received: January 31, 2013
Revised: February 27, 2013
Published online: && &&, 0000
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ÝÝ These are not the final page numbers!

FULL PAPER
Click Chemistry
B. T. Ramanjaneyulu, Virsinha Reddy,
Panjab Arde, Sriram Mahesh,
R. Vijaya Anand*
&&&& — &&&&
Combining Oxidative N-Heterocyclic
Carbene Catalysis with Click Chemis-
try: A Facile One-Pot Approach to
1,2,3-Triazole Derivatives
NHCs click into place: A one-pot syn-
thesis of 1,2,3-triazoles has been devel-
oped by combining oxidative N-heter-
ocyclic carbene catalysis with click
chemistry. A range of 1,2,3-triazoles
were prepared in moderate-to-good
yields under mild conditions.
9
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Chem. Asian J. 2013, 00, 0 – 0
ꢀ 2013 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
These are not the final page numbers! ÞÞ