Synthesis of 1,3-Diynes Using Calcium Carbide as an Alkyne Source

Article abstract of DOI:10.1002/ejoc.202001324

A simple method for the synthesis of 1,3-diynes from iodoarenes using calcium carbide as an alkyne source and air as an oxidant is described. A series of 1,4-diarylbuta-1,3-diynes were efficiently synthesized by this strategy. The salient features of this protocol are the use of inexpensive and easy-to-handle alkyne source, broad substrate scope, open-air condition, and simple operation procedure.

Full text of DOI:10.1002/ejoc.202001324

European Journal of Organic Chemistry
Accepted Article
Accepted Article
Title: Synthesis of 1,3-diynes Using Calcium Carbide as an Alkyne
Source
Authors: Zhenrong Liu and Zheng Li
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To be cited as: Eur. J. Org. Chem. 10.1002/ejoc.202001324
Link to VoR: https://doi.org/10.1002/ejoc.202001324
01/2020

10.1002/ejoc.202001324
European Journal of Organic Chemistry
Full Paper
Synthesis of 1,3-diynes Using Calcium Carbide as an Alkyne
Source
Zhenrong Liu[a], Zheng Li*[a]
chemistry, and a considerable number of pioneering work has
been reported.[11] Our research group has devoted great efforts
Abstract: A simple method for the synthesis of 1,3-diynes from
to the research on organic synthesis direct using calcium
carbide as an alkyne source, and reported the synthesis of
propen-2-yl sulfones,[12] terminal allenes,[13] internal alkynes,[14]
iodoarenes using calcium carbide as an alkyne source and air as an
oxidant is described. A series of 1,4-diarylbuta-1,3-diynes were
efficiently synthesized by this strategy. The salient features of this
protocol are the use of inexpensive and easy-to-handle alkyne
source, broad substrate scope, open-air condition, and simple
operation procedure.
2-methylbenzofurans;[15]
unsaturated
ketones,[17]
triarylacrylonitriles;[16] β-cyano-α,β-
diarylethynes[18]
and 1,3,5-
triaroylcyclohexanes.[19] Although calcium carbide is safer, easier
to operate in organic synthesis, exploring more effective organic
reactions involving calcium carbide is still a very challenging
subject.
Introduction
1,3-Diynes are widely used as building blocks for the
synthesis of important cyclic polymers,[1] nitrogen-, oxygen- and
sulfur-heterocycles,[2] and many functional compounds.[3] The
reported methods for 1,3-diynes include: i) the homo- or
heterocoupling of terminal alkynes catalyzed by transition metals
(Cu, Pd, Au, Ni, etc.);[4] ii) the palladium-catalyzed homocoupling
reactions of 1-haloalkynes;[5] iii) the transition-metal (Cu, Ni, Mn)
catalyzed tandem reactions of alkynyl element-organic
complexes (Mg, B, Al, Si, Sn);[6] iv) the transition-metal (Pd, Rh,
Cu) catalyzed decarbonyl coupling of ynones;[7] v) the copper-
catalyzed aerobic oxidative transformation of ketone-derived N-
tosyl hydrazones[8] (Scheme 1). However, these routes present
intrinsic drawbacks, namely the need for prefunctionalization of
substrates. Therefore, the exploration of concise and effective
methods using commercial available starting materials is still
necessary.
Calcium carbide (CaC2)[9] as an inexpensive industrial
material is widely utilized to prepare acetylene gas through
hydrolysis. Then acetylene[10] is used as a versatile building
block to synthesize many important organic chemicals. However,
due to the danger of explosion and the requirements for complex
equipment, the application of gaseous acetylene in daily
research and practice is still quite limited. Recently, the direct
using solid calcium carbide as an acetylene source in organic
synthesis bring a new dimension to the powerful acetylene
Scheme 1. The representative synthetic routes for 1,3-diynes
In this paper, we report an efficient method for the synthesis
of 1,4-diarylbuta-1,3-diynes direct using calcium carbide as an
alkyne source, iodoarenes as starting materials and air as an
oxidant under mild conditions.
[a]
Zhenrong Liu, Prof. Dr. Zheng Li.
College of Chemistry and Chemical Engineering, Northwest Normal
University, Lanzhou, Gansu, 730070, P. R. China.
E-mail: lizheng@nwnu.edu.cn. URL:
https://chem.nwnu.edu.cn/2012/0420/c373a20148/page.htm
Results and Discussion
†Electronic supplementary information (ESI) available: 1H NMR, 13
C
NMR and 19F NMR spectra of all products are available.
Initially, the reaction of iodobenzene (1a) and calcium
carbide was selected as a model reaction to screen the reaction
conditions. The reaction first tested in the absence of a catalyst
Supporting information for this article is given via a link at the end of
the document.
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10.1002/ejoc.202001324
European Journal of Organic Chemistry
Full Paper
in DMF at 65 oC, none of the desired product was obtained
(Table 1, entry 1). Then a combination of Pd(OAc)2-CuBr2 as a
catalyst and 1,4-bis(diphenylphosphino)butane (dppb) as a
ligand were attempted. A product, 1,4-diphenylbuta-1,3-diyne
(2a), was isolated in 23% yield (Table 1, entry 2). In order to
improve the yield of 2a, various combinations of Pd(OAc)2 with
Cu(II) salts, such as CuCl2, Cu(NO3)2 and Cu(OAc)2, and Cu(I)
salts, such as CuI, CuBr and CuCl, as catalysts were examined
respectively (Table 1, entries 3−8). It was found that the product
2a could be obtained in low to high yield. Among them the best
yield (83%) for 2a was obtained by using the combination of
Pd(OAc)2-CuCl as catalysts (Table 1, entry 8). Various palladium
complexes also had a certain effect on the yield of 2a. Besides
Pd(OAc)2-CuCl, other combinations of palladium complexes,
such as PdCl2, tris(dibenzylideneacetone) dipalladium
Table 1. Optimization of reaction conditionsa
Catalyst
Temperature
(oC)
Yield
Entry
Ligand
Solvent
combination
None
(%)b
1
2
3
None
dppb
dppb
DMF
DMF
DMF
65
65
65
0
Pd(OAc)2-CuBr2
Pd(OAc)2-CuCl2
23
15
Pd(OAc)2-
Cu(NO3)2
Pd(OAc)2-
Cu(OAc)2
4
5
dppb
dppb
DMF
DMF
65
65
49
64
6
Pd(OAc)2-CuI
Pd(OAc)2-CuBr
Pd(OAc)2-CuCl
PdCl2-CuCl
dppb
dppb
dppb
dppb
dppb
DMF
DMF
DMF
DMF
DMF
65
65
65
65
65
17
37
83
35
65
7
(Pd2(dba)3),
dichlorobis(cinnamyl)
dipalladium
8
([(Cinnamyl)PdCl]2)
and 1,1'-bis(di-tert-butylphosphino)
9
ferrocene palladium dichloride (PdCl2(dtbpf)), with CuCl as
catalysts were also tested for the catalytic activities (Table 1,
entries 9−12). However, no higher yield than Pd(OAc)2-CuCl
were observed. Several other phosphine ligands were tested for
the reaction (see SI, Table S1). Among them Xantphos and
BINAP could give the desired product 2a in low to moderate
yield (Table 1, entries 13, 14). The solvents also played
significant roles in the reaction (see SI, Table S2). It was found
that the reaction in THF, MeCN and EtOH only gave a trace or
small amount of 2a (Table 1, entries 15−17). DMSO as solvent
afforded 2a in moderate yield (Table 1, entry 18). The
appropriate reaction temperature was also necessary for the
reaction (Table 1, entries 8,19, 20). It was found that the higher
or lower temperature than 65 oC were not in favor of the
reaction. In addition, the reaction under nitrogen atmosphere
obviously inhibited the formation of product 2a, and only
phenylethyne was observed (Table 1, entry 21). In the case of
using K2CO3 as a base, the reaction could not afford 2a (Table 1,
entry 22). The reaction was also affected by the amount of water.
It was observed that 2 equivalents of water based on calcium
carbide was an appropriate amount for the formation of 2a
(Table 1, entries 8, 23, 24 and SI, Table S3).
10
Pd2(dba)3-CuCl
[(Cinnamyl)PdCl]2-
CuCl
11
dppb
DMF
65
37
12
13
14
15
16
17
18
19
20
21c
22d
23e
24f
PdCl2(dtbpf) -CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
Pd(OAc)2-CuCl
dppb
Xantphos
BINAP
dppb
dppb
dppb
dppb
dppb
dppb
dppb
dppb
dppb
dppb
DMF
DMF
DMF
THF
65
65
65
65
65
65
65
100
r.t.
65
65
65
65
45
15
47
Trace
Trace
26
MeCN
EtOH
DMSO
DMF
DMF
DMF
DMF
DMF
DMF
68
53
48
0
72
49
80
a Reaction condition: 1a (0.5 mmol), CaC2 (3 mmol), H2O (6 mmol), Pd complex
(0.05 mmol), Cu salt (0.6 mmol) and phosphine ligand (0.05 mmol) in solvent (4
mL) were stirred at appropriate temperature for 4 h under air condition.
bIsolated yield. cUnder N2. dK2CO3 was added. eH2O (3 mmol) was added. fH2O (9
mmol) was added.
Using the optimized conditions, synthesis of a series of 1,4-
diarylbuta-1,3-diynes were conducted by the reactions of various
iodoarenes with calcium carbide at 65 oC in DMF using
Pd(OAc)2-CuCl as catalysts and dppb as a ligand. The results
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10.1002/ejoc.202001324
European Journal of Organic Chemistry
Full Paper
are summarized in Table 2. It was found that the substrates,
iodoarenes, could tolerate many different substituents on the
aromatic rings, and afforded the desired 1,3-diynes in good to
high yield. Iodoarenes bearing electron-donating groups (Me, Et,
Pr, Bu, OMe, NH2) on aromatic rings gave 1,3-diynes in high
yield (78−89%) (2b−2i). In contrast, iodoarenes bearing
electron-withdrawing groups (F, Cl, Br, NO2) on aromatic rings
yielded the corresponding products in slightly lower yield
(60−78%) (2j−2q). The reaction was also suitable to the
substrate including heterocycle, such as 2-iodothiophene, and
produced the corresponding product in good yield (2r). However,
the attempt using 4-iodopyridine as a substrate was not
successful possibly because of the strong coordinating ability of
pyridine ring with transition metals. In addition, the other
halobenzenes, such as bromobenzene and chlorobenzene,
instead of iodobenzene as substrates could not participate in the
corresponding reactions (see SI, Table S4).
With the ubiquitous success of this protocol, the synthesis
of 2h by reaction of 4-methoxyiodobenzene (1h) and calcium
carbide could also be carried out on a gram scale. The reaction
of 1.17 g of 1h and 1.92 g of calcium carbide in 15 mL of DMF
was performed under standard conditions to give 1.01 g of 2h in
77 % isolated yield. The success of this gram-scale reaction
further demonstrated the effectiveness of the optimized
conditions for the bulk process (Scheme 2).
Scheme 2. Gram-scale synthesis of 2h. Reaction Conditions: 4-
methoxyiodobenzene (1h) (5 mmol), CaC2 (30 mmol), H2O (60 mmol), Pd(OAc)2
(0.2 mmol), CuCl (6 mmol) and dppb (0. 2 mmol) in DMF (15 mL) were stirred at
65 oC for 4 h under air condition.
The synthesized products, 1,4-diarylbuta-1,3-diynes, can
find many applications in organic synthesis, especially for the
construction of heterocycles (Scheme 3). For example, product
2a could respectively react with hydroxylamine hydrochloride
and sodium azide to synthesize 3-benzyl-5-phenylisoxazole (3a)
and 5-phenyl-4-(phenylethynyl)-1H-1,2,3-triazole (4a) in high
yield. These heterocycles will find many applications because of
their broad spectrum of biological activities.[20, 21]
Table 2. Synthesis of 1,4-diarylbuta-1,3-diynesa
Scheme 3. Applications of 2a. Conditions for the synthesis of 3a: 2a (0.4 mmol),
hydroxyamine hydrochloridde (1.0 mmol) and triethylamine (1.6 mmol) in 3 mL
of DMSO were stirred at 110 °C for 20 h. Conditions for the synthesis of 4a: 2a
(0.2 mmol) and sodium azide (1.2 mmol) in 2 mL of DMSO were stirred at
110 °C for 18 h.
In order to insight into the possible mechanism of reaction,
two control experiments were conducted (Scheme 4).
Iodobenzene (1a) first reacted with calcium carbide catalyzed by
Pd(OAc)2 using dppb as a ligand in DMF in the absence of CuCl
for 15 min under nitrogen atomosphere,
a
product,
phenylacetylene (5a), could be obtained (Scheme 4, equation 1).
This result indiacated that CuCl might be irrelevant to the
formation of 5a. If pure 5a in the presence of CuCl was stirred in
open-air condition, 2a could be isolated as a sole product in 93%
a Reaction condition: iodoarene (0.5 mmol), calcium carbide (3 mmol), H2O (6
mmol), Pd(OAc)2 (0.05 mmol), CuCl (0.6 mmol) and dppb (0.05 mmol) in DMF (4
mL) were stirred at 65 oC for 4 h under air condition.
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10.1002/ejoc.202001324
European Journal of Organic Chemistry
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yield (Scheme 4, equation 2). This result implied that
phenylacetylene (5a) might be the intermediate of the reaction,
air might be an oxidant for the system, and CuCl could promote
the formation of 2a. Furthermore this result could be further
proved by first conducting the reaction of 1a with calcium
carbide in the absence of CuCl for 15 min under nitrogen
atmosphere, then continual stirring in open-air condition after the
addition of CuCl (Scheme 4, equation 3).
Scheme 4. Control experiments. Reaction condition for equation 1: 1a (0.5 mmol),
calcium carbide (3 mmol), H2O (6 mmol), Pd(OAc)2 (0.05 mmol), and dppb (0.05
mmol) in DMF (4 mL) were stirred at 65 oC for 15 min under N2 atomosphere.
Reaction condition for equation 2: 5a (0.5 mmol) and CuCl (0.6 mmol) was
stirred at 65 oC for 4 h under open-air condition. Reaction condition for
equation 3: 1a (0.5 mmol), calcium carbide (3 mmol), H2O (6 mmol), Pd(OAc)2
(0.05 mmol), and dppb (0.05 mmol) in DMF (4 mL) were stirred at 65 oC for 15
min under N2 atomosphere. Then CuCl (0.6 mmol) was added, and the mixture
was further stirred at 65 oC for 4 h under open-air condition.
Scheme 5. Proposed mechanism for the synthesis of 1,3-diyne 2
Conclusions
In conclusion, an efficient method for the synthesis of 1,3-
diynes from iodoarenes using inexpensive and easy-to-handle
calcium carbide as an alkyne source and air as an oxidant has
developed. A series of 1,4-diarylbuta-1,3-diynes are synthesized
using various commercial available iodoarenes bearing electron-
donating and electron-withdrawing groups in good to high yield.
The protocol has the advantage of use of concise alkyne source
and commercial available substrates, mild and open air
condition, simple operation procedure.
Based on the above control experiments, a plausible
mechanism is proposed for the synthesis of 1,3-diyne 2
(Scheme 5). Oxidative addition of iodoarene 1 to a Pd(0)
species, which is generated most commonly from the reaction of
palladium(II) diacetate with dppb,[22] forms an arylpalladium
iodide (A). Meanwhile calcium carbide is hydrolyzed to yield
acetylene calcium hydroxide (B).[23] A reacts with B to obtain
palladium complex C. C undergoes reductive elimination to give
arylacetylene calcium hydroxide D and lose Pd(0) to enter a new
Experimental Section
1
General Information: H NMR and 13C NMR spectra were
recorded on a Mercury-400 MB or Mercury-600 MB instrument
using CDCl3 or DMSO-d6 as solvent and Me4Si as an internal
standard. High-resolution mass spectra (HRMS) (ESI) were
obtained with a Bruker Daltonics APEX II 47e and Orbitrap Elite
mass spectrometer. Melting points were observed in an
electrothermal melting point apparatus (X-5, Beijing Tech
Instrument Co. Ltd, China). Calcium carbide was purchased
from Shanghai Macklin Biochemical Company (purity: 98%), and
ground into powder (ca. 50-100 mesh) in a mortar prior to use.
The solvents were reagent grade and used after dry using
molecular sieve and anhydrous magnesium sulfate. Column
chromatography was carried out on a flash chromatographic
system using silica gel, and petroleum ether and ethyl acetate
as eluent. For thin layer chromatography (TLC), silica gel plates
precoated with GF-254 were used.
cycle. D is hydrolyzed in the presence of water to give
17]
arylacetylene E.[11o,
E further reacts with CuCl to form
arylacetylene Cu(I) complex F. F is oxidized by air to give
arylacetylene Cu(II) complex G. Two moles of are
G
disproportionated to generate diarylacetylene Cu(III) complex H
and a Cu(I) species.[24] H undergoes reductive elimination to give
the final product 1,3-diyne 2, and release a second Cu(I) species
to enter a new cycle.
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10.1002/ejoc.202001324
European Journal of Organic Chemistry
Full Paper
The General Procedure for the Synthesis of 1,3-Diynes
2a-r：Iodoarene (0.5 mmol), calcium carbide (3.0 mmol, 192
mg), palladium acetate (0.05 mmol, 11 mg), cuprous chloride
(0.6 mmol, 59 mg), 1,4-bis(diphenylphosphino)butane (0.05
mmol, 21 mg) and water (6.0 mmol, 108 mg) in 4 mL of DMF
were stirred at 65 oC for 4 h under air condition. After the
reaction was complete, the resulting mixture was filtered to
remove the solid, and the liquor was extracted with ethyl acetate
(3×10 mL), and washed with saturated brine (3×10 mL). The
resulting organic phase was dried with anhydrous sodium sulfate,
and concentrated under reduced pressure. The residue was
isolated by column chromatography using petroleum ether/ethyl
acetate (10:1) as eluent to give the pure products.
1,4-Bis(4-butylphenyl)buta-1,3-diyne (2f):[26] Yellow solid (70
o
mg, 89%); M.p.: 58 – 59 C. Petroleum ether/EtOAc (10:1) as
1
eluent. H NMR (600 MHz, CDCl3): δ 7.51 (d, J = 8.3 Hz, 4H),
7.21 (d, J = 8.3 Hz, 4H), 2.64 (t, J = 7.8 Hz, 4H), 1.61 – 1.54 (m,
4H), 1.35 – 1.32 (m, 4H), 0.92 (t, J = 7.4 Hz, 6H). 13C NMR (151
MHz, CDCl3): δ 147.4, 132.4, 129.6, 119.0, 81.6, 73.5, 35.7,
33.3, 22.3, 13.8. HRMS (ESI): m/z calcd for C24H27 [M+H]+,
315.2107; found, 315.2105.
1,4-Bis(4-pentylphenyl)buta-1,3-diyne (2g):[25] White solid (72
o
mg, 84%); M.p.: 82 – 83 C. Petroleum ether/EtOAc (10:1) as
1
eluent. H NMR (400 MHz, CDCl3): δ 7.45 (d, J = 8.2 Hz, 4H),
7.15 (d, J = 8.3 Hz, 4H), 2.61 (t, J = 7.5 Hz, 4H), 1.65 – 1.57 (m,
4H), 1.34 – 1.30 (m, 8H), 0.90 (t, J = 6.9 Hz, 6H). 13C NMR (101
MHz, CDCl3): δ 144.7, 132.6, 128.8, 119.2, 81.8, 73.7, 36.2,
31.7, 31.1, 22.8, 14.3. HRMS (ESI): m/z calcd for C26H31 [M+H]+,
343.2420; found, 343.2424.
1,4-Bis(4-methoxyphenyl)buta-1,3-diyne (2h):[25] White solid
(54 mg, 82%); M.p.: 140 – 141 oC. Petroleum ether/EtOAc (10:1)
as eluent. 1H NMR (600 MHz, CDCl3): δ 7.45 (d, J = 8.9 Hz, 4H),
6.84 (d, J = 8.9 Hz, 4H), 3.81 (s, 6H). 13C NMR (151 MHz,
CDCl3): δ 160.2, 134.0, 114.1, 113.9, 81.2, 72.9, 55.3. HRMS
(ESI): m/z calcd for C18H15O2 [M+H]+, 263.1067; found, 263.1063.
3,3'-(Buta-1,3-diyne-1,4-diyl)dianiline (2i):[25] Yellow solid (46
1,4-Diphenylbuta-1,3-diyne (2a):[25] White solid (42 mg, 83%);
o
M.p.: 82 – 83 C. Petroleum ether/EtOAc (10:1) as eluent. 1H
NMR (400 MHz, CDCl3): δ 7.55 (dd, J = 7.8, 1.6 Hz, 4H), 7.39 –
7.33 (m, 6H). 13C NMR (151 MHz, CDCl3): δ 132.5, 129.1, 128.4,
121.8, 81.5, 73.9. HRMS (ESI): m/z calcd for C16H11 [M+H]+,
203.0855; found, 202.0853.
1,4-Di-m-tolylbuta-1,3-diyne (2b):[6d] Yellow solid (46 mg,
80%); M.p.: 69 – 71 oC. Petroleum ether/EtOAc (10:1) as eluent.
1H NMR (600 MHz, CDCl3): δ 7.34 – 7.33 (m, 4H), 7.22 – 7.21
(m, 4H), 2.33 (s, 6H). 13C NMR (151 MHz, CDCl3): δ 138.2,
133.4, 130.6, 130.1, 128.4, 120.8, 78.7, 74.1, 21.2. HRMS (ESI):
m/z calcd for C18H15 [M+H]+, 231.1168; found, 231.1165.
1,4-Di-p-tolylbuta-1,3-diyne (2c):[25] White solid (49 mg, 84%);
o
mg, 80%); M.p.: 129 – 130 C. Petroleum ether/EtOAc (1:1) as
eluent. 1H NMR (400 MHz, DMSO-d6) δ 7.03 (t, J = 7.8 Hz, 2H),
6.71 – 6.68 (m, 4H), 6.64 (d, J = 8.1 Hz, 2H), 5.31 (s, 4H). 13C
NMR (151 MHz, DMSO-d6) δ 149.3, 129.8, 121.1, 120.2, 117.1,
116.1, 82.8, 72.8. HRMS (ESI): m/z calcd for C16H13N2 [M+H]+,
233.1073; found, 233.1073.
1,4-Bis(2-fluorophenyl)buta-1,3-diyne (2j):[27] White solid (42
mg, 70%); M.p.: 123 – 124 oC. Petroleum ether/EtOAc (10:1) as
eluent. 1H NMR (400 MHz, CDCl3): δ 7.57 – 7.50 (m, 2H), 7.40 –
7.31 (m, 2H), 7.16 – 7.08 (m, 4H). 13C NMR (151 MHz, CDCl3): δ
163.7 (d, J = 253.9 Hz), 134.3, 131.1 (d, J = 8.0 Hz), 124.1 (d, J
= 3.6 Hz), 115.7 (d, J = 20.8 Hz), 110.4 (d, J = 15.2 Hz), 78.4,
75.8. 19F NMR (376 MHz, CDCl3): δ -108.8. HRMS (ESI): m/z
calcd for C16H9F2 [M+H]+, 239.0667; found, 239.0666.
o
1
M.p.: 180 – 181 C. Petroleum ether/EtOAc (10:1) as eluent. H
NMR (600 MHz, CDCl3): δ 7.42 – 7.39 (m, 4H), 7.14 – 7.12 (m,
4H), 2.36 (s, 6H). 13C NMR (151 MHz, CDCl3): δ 139.5, 132.4,
129.2, 118.8, 81.5, 73.4, 21.6. HRMS (ESI): m/z calcd for C18H15
[M+H]+, 231.1168; found, 231.1169.
1,4-Bis(4-ethylphenyl)buta-1,3-diyne (2d):[25] White solid (51
o
mg, 78%); M.p.: 91 – 92 C. Petroleum ether/EtOAc (10:1) as
eluent. 1H NMR (400 MHz, CDCl3): δ 7.47 – 7.45 (m, 4H), 7.19 –
7.17 (m, 4H), 2.67 (q, J = 7.5 Hz, 4H), 1.25 (t, J =7.5 Hz, 6H).
13C NMR (101 MHz, CDCl3): δ 146.0, 132.7, 128.3, 119.2, 81.8,
73.7, 29.2, 15.5. HRMS (ESI): m/z calcd for C20H19 [M+H]+,
259.1481; found, 259.1486.
1,4-Bis(3-fluorophenyl)buta-1,3-diyne (2k):[27] White solid (41
mg, 69%); M.p.: 121 – 122 oC. Petroleum ether/EtOAc (10:1) as
eluent. 1H NMR (400 MHz, CDCl3): δ 7.33 – 7.30 (m, 4H), 7.24 –
7.21 (m, 2H), 7.10 – 7.04 (m, 2H). 13C NMR (151 MHz, CDCl3): δ
162.4 (d, J = 247.0 Hz), 130.1 (d, J = 8.7 Hz), 128.4 (d, J = 3.1
Hz), 123.4 (d, J = 9.4 Hz) 119.2 (d, J = 23.2 Hz), 116.9 (d, J =
21.2 Hz), 80.6, 74.4. 19F NMR (376 MHz, CDCl3): δ -113.2.
1,4-Bis(4-propylphenyl)buta-1,3-diyne (2e):[25] Yellow solid (59
o
mg, 83%); M.p.: 60 – 61 C. Petroleum ether/EtOAc (10:1) as
1
eluent. H NMR (600 MHz, CDCl3): δ 7.43 (d, J = 7.7 Hz, 4H),
7.14 (d, J = 7.7 Hz, 4H), 2.59 (q, J = 7.2 Hz, 4H), 1.64 (m, 4H),
0.94 (t, J = 7.2 Hz, 6H). 13C NMR (151 MHz, CDCl3): δ 144.2,
132.4, 128.6, 119.0, 81.6, 73.5, 38.0, 24.2, 13.7. HRMS (ESI):
m/z calcd for C22H23 [M+H]+, 287.1794; found, 287.1790.
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HRMS (ESI): m/z calcd for C16H9F2 [M+H]+, 239.0667; found,
239.0669.
CDCl3): δ -106.8. HRMS (ESI): m/z calcd for C16H7Cl2F2 [M+H]+,
306.9887; found, 306.9883.
1,4-Bis(4-fluorophenyl)buta-1,3-diyne (2l):[25] White solid (44
mg, 74%); M.p.: 183 – 185 oC. Petroleum ether/EtOAc (10:1) as
eluent. 1H NMR (400 MHz, CDCl3): δ 7.53 – 7.49 (m, 4H), 7.06 –
7.02 (m, 4H). 13C NMR (151 MHz, CDCl3): δ 163.0 (d, J = 251.9
Hz), 134.5 (d, J = 8.5 Hz), 117.8 (d, J = 3.6 Hz), 115.9 (d, J =
24.7 Hz), 80.4, 73.5. 19F NMR (376 MHz, CDCl3): δ -108.9.
HRMS (ESI): m/z calcd for C16H9F2 [M+H]+, 239.0667; found,
239.0663.
1,4-Di(thiophen-2-yl)buta-1,3-diyne (2r):[25] Yellow solid (34 mg,
64%); M.p.: 88 – 89 oC. Petroleum ether/EtOAc (10:1) as eluent.
1H NMR (600 MHz, CDCl3): δ 7.34 (m, 2H), 7.32 (m, 2H), 7.01 –
6.99 (m, 2H). 13C NMR (151 MHz, CDCl3): δ 134.4, 128.9, 127.1,
121.9, 74.7, 76.6. HRMS (ESI): m/z calcd for C12H7S2 [M+H]+,
214.9984; found, 214.9982.
Gram-Scale Synthesis of 1,4-Bis(4-Methoxyphenyl)buta-
1,3-Diyne (2h) ： 4-Methoxyiodobenzene (5 mmol, 1.17 g),
calcium carbide (30 mmol, 1.92 g), palladium acetate (0.2 mmol,
0.044 g), cuprous chloride (6 mmol, 0.59 g), 1,4-
bis(diphenylphosphino)butane (0.2 mmol, 0.085 g) and water
(60 mmol, 1.08 g) in DMF (15 mL) were stirred at 65 oC for 4 h
under air condition. After the reaction was complete, the
resulting mixture was filtered to remove the solid, and the liquor
was extracted with ethyl acetate (3×30 mL), and washed with
saturated brine (3×30 mL). The resulting organic phase was
dried with anhydrous sodium sulfate, and concentrated under
reduced pressure. The residue was isolated by column
chromatography using petroleum ether/EtOAc (10:1) as eluent
to give the pure products.
1,4-Bis(2-chlorophenyl)buta-1,3-diyne (2m):[6d] Yellow solid
(53 mg, 78%); M.p.: 138 – 139 oC. Petroleum ether/EtOAc (10:1)
1
as eluent. H NMR (600 MHz, CDCl3): δ 7.58 – 7.54 (m, 2H),
7.42 – 7.40 (m, 2H), 7.33 – 7.29 (m, 2H), 7.25 – 7.23 (m, 2H).
13C NMR (151 MHz, CDCl3): δ 134.3, 132.2, 130.6, 129.7, 123.3,
80.5, 74.7. HRMS (ESI): m/z calcd for C16H9Cl2 [M+H]+,
271.0076; found, 271.0071.
1,4-Bis(3-chlorophenyl)buta-1,3-diyne (2n):[27] Yellow solid (46
o
mg, 72%); M.p.: 70 – 71 C. Petroleum ether/EtOAc (10:1) as
1
eluent. H NMR (400 MHz, CDCl3): δ 7.54 – 7.49 (m, 2H), 7.41
(m, 2H), 7.38 – 7.33 (m, 2H), 7.33 – 7.27 (m, 2H). 13C NMR (151
MHz, CDCl3): δ 132.2, 131.5, 130.6, 129.7, 128.8, 123.3, 80.5,
74.7. HRMS (ESI): m/z calcd for C16H9Cl2 [M+H]+, 271.0076;
found, 271.0077.
1,4-Bis(3-bromophenyl)buta-1,3-diyne (2o):[28] White solid (67
mg, 75%); M.p.: 96 – 97 oC. Petroleum ether/EtOAc (10:1) as
eluent. 1H NMR (600 MHz, CDCl3): δ 7.67 – 7.66 (m, 2H), 7.51 –
7.50 (m, 2H), 7.45 – 7.44 (m, 2H), 7.22 – 7.19 (m, 2H). 13C NMR
(151 MHz, CDCl3): δ 135.1, 132.6, 131.1, 130.2, 123.5, 122.2,
80.5, 74.8. HRMS (ESI): m/z calcd for C16H9Br2 [M+H]+,
358.9066; found, 358.9064.
Synthesis of 3-Benzyl-5-Phenylisoxazole (3a) ： A
reaction flask was charged with 1,4-diphenylbuta-1,3-diyne (2a,
0.4 mmol, 81 mg), hydroxyamine hydrochloride (1.0 mmol, 69
mg), triethylamine (1.6 mmol, 162 mg), and DMSO (3 mL). The
reaction mixture was stirred at 110 °C for 20 h, and then cooled
to room temperature. After water (10 mL) was added, the
resultant mixture was extracted with ethyl acetate (3×10 mL),
and the combined organic layer was washed with brine (3×10
mL). The solvent was removed under reduced pressure, and the
residue was purified via silica gel chromatography (eluent:
petroleum ether/ethyl acetate = 20:1) to afford 5-benzyl-3-
phenylisoxazole (3a) as a white solid.
3-Benzyl-5-phenylisoxazole (3a):[2e] White solid (78 mg, 83%);
Petroleum ether/EtOAc (20:1) as eluent. 1H NMR (600 MHz,
CDCl3): δ 7.77 – 7.73 (m, 2H), 7.43 – 7.71 (m, 3H), 7.37 – 7.34
(m, 2H), 7.31 – 7.28 (m, 3H), 6.21 (s, 1H), 4.13 (s, 2H). 13C NMR
(151 MHz, CDCl3): δ 172.7, 162.4, 135.9, 129.8, 129.2, 128.0,
128.8, 128.8, 127.2, 126.7, 100.0, 33.3. HRMS (ESI): m/z calcd
for C16H14NO [M+H]+, 236.1070; found, 236.1073.
1,4-Bis(3-nitrophenyl)buta-1,3-diyne (2p):[25] Yellow solid (44
o
mg, 60%); M.p.: 150 – 151 C. Petroleum ether/EtOAc (5:1) as
eluent. 1H NMR (400 MHz, CDCl3): δ 8.38 – 8.24 (m, 4H), 7.85 –
7.83 (m, 2H), 7.56 (t, J = 8.0 Hz, 2H). 13C NMR (101 MHz,
CDCl3): δ 148.0, 137.8, 129.4, 127.0, 124.0, 123.6, 81.2, 79.9.
HRMS (ESI): m/z calcd for C16H9N2O4 [M+H]+, 293.0557; found,
293.0555.
1,4-Bis(2-chloro-4-fluorophenyl)buta-1,3-diyne (2q): Yellow
o
solid (59 mg, 77%); M.p.: 146 – 147 C. Petroleum ether/EtOAc
1
(10:1) as eluent. H NMR (600 MHz, CDCl3): δ 7.57 – 7.54 (m,
2H), 7.18 – 7.16 (m, 2H), 7.00 – 6.96 (m, 2H). 13C NMR (151
MHz, CDCl3): δ 162.6 (d, J = 254.8 Hz), 138.3 (d, J = 11.1 Hz),
135.6 (d, J = 18.12 Hz), 118.1 (d, J = 3.7 Hz), 117.3 (d, J = 25.5
Hz), 114.5 (d, J = 22.1 Hz), 78.3, 78.0. 19F NMR (376 MHz,
Synthesis
of
5-Phenyl-4-(Phenylethynyl)-1H-1,2,3-
Triazole (4a)：The mixture of 1,4-diphenylbuta-1,3-diyne (2a,
0.2 mmol, 40 mg) and sodium azide (1.2 mmol, 78 mg) in DMSO
(2 mL) was stirred at 110 oC under air atmosphere for 18 h. After
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10.1002/ejoc.202001324
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completion of the reaction, monitored by TLC, the mixture was
quenched with 20 mL of brine, and then extracted with ethyl
acetate (3×5 mL), and the combined organic layer was dried
with anhydrous sodium sulfate. The solvent was evaporated and
the crude product was purified by silica gel column
chromatography to give 5-phenyl-4-(phenylethynyl)-1H-1,2,3-
triazole (4a) as a product.
[3] (a) D. X. Li, Y. E. Kim, J. Yun, Org. Lett. 2015, 17, 860−863;
(b) X. Liu, T. Cong, P. Liu, P. Sun, J. Org. Chem. 2016, 81,
7256−7261; (c) N. O. Thiel, S. Kemper, J. F.Teichert,
Tetrahedron 2017, 73, 5023−5028; (d) J. Li, R. Hua, T. Liu, J.
Org. Chem. 2010, 75, 2966−2970; (e) N. O. Thiel, J. F.
Teichert, Org. Biomol. Chem. 2016, 14, 10660−10666; (f) R.
Singha, S. Dhara, J. K. Ray, RSC Adv. 2013, 3,
23989−23992; (g) R. Singha, S. Nandi, J. K. Ray,
Tetrahedron Lett. 2012, 53, 6531−6534.
5-Phenyl-4-(phenylethynyl)-1H-1,2,3-triazole (4a):[29] Yellow
1
solid (44 mg, 90%); Petroleum ether/EtOAc (5:1) as eluent. H
NMR (600 MHz, DMSO-d6) δ 8.05 (d, J = 7.6 Hz, 2H), 7.61 –
7.60 (m, 2H), 7.53 (t, J = 7.7 Hz, 2H), 7.44 – 7.42 (m, 4H), 3.35
(s, 1H). 13C NMR (151 MHz, CDCl3): δ 131.7, 129.1, 129.1,
128.8, 128.5, 126.8, 122.1, 110.0, 95.7, 78.7. HRMS (ESI): m/z
calcd for C16H12N3 [M+H]+, 240.1026; found, 240.1024.
[4] (a) L. Chaabane, E. Beyou, D. Luneau, M. H. V. Baouab, J.
Catal. 2020, 388, 91−103; (b) Z. Chen, R. Shen, C. Chen, J.
Li, Y. Li, Chem. Commun. 2018, 54, 13155−13158; (c) A.
Toledo, I. Funes-Ardoiz, F. Maseras, A. C. Albeniz, ACS
Catal. 2018, 8, 7495−7506; (d) H. Xu, K. Wu, J. Tian, L. Zhu,
X. Yao, Green Chem. 2018, 20, 793−797; (e) B. Vilhanova,
J. Vaclavik, L. Artiglia, M. Ranocchiari, A. Togni, J. A.
Bokhoven, ACS Catal. 2017, 7, 3414−3418; (f) S. Biswas, K.
Mullick, S. -Y. Chen, D. A. Kriz, M. D. Shakil, C. -H. Kuo, A.
M. Angeles-Boza, A. R. Rossi, S. L. Suib, ACS Catal. 2016,
6, 5069−5080; (g) L. Su, J. Dong, L. Liu, M. Sun, R. Qiu, Y.
Zhou, S. -F. Yin, J. Am. Chem. Soc. 2016, 138,
12348−12351; (h) G. Zhang, H. Yi, G. Zhang, Y. Deng, R.
Bai, H. Zhang, J. T. Miller, A. J. Kropf, E. E. Bunel, A. Lei, J.
Am. Chem. Soc. 2014, 136, 924−926; (i) K. Yin, C. Li, J. Li,
X. Jia, Green Chem. 2011, 13, 591−593; (j) D. Wang, J. Li,
N. Li, T. Gao, S. Hou, B. Chen, Green Chem. 2010, 12,
45−48; (k) S. -N. Chen, W. -Y. Wu, F. -Y. Tsai, Green Chem.
2009, 11, 269−274; (l) S. Adimurthy, C. C. Malakar, U.
Beifuss, J. Org. Chem. 2009, 74, 5648–5651; (m) W. Yin, C.
He, M. Chen, H. Zhang, A. Lei, Org. Lett. 2009, 11, 709−712.
[5] (a) Z. Chen, H. Jiang, A. Wang, S. Yang, J. Org. Chem.
2010, 75, 6700–6703; (b) D. Kaldhi, N. Vodnala, R.
Gujjarappa, A. K. Kabi, S. Nayak, C. C. Malakar,
Tetrahedron Lett. 2020, 61, 151775; (c) S. V. Damle, D.
Seomoon, P. H. Lee, J. Org. Chem. 2003, 68, 7085−7087.
[6] (a) A. Krasovskiy, A. Tishkov, V. Amo, H. Mayr, P. Knochel,
Angew. Chem. Int. Ed. 2006, 45, 5010–5014; (b) Y.
Nishihara, M. Okamoto, Y. Inoue, M. Miyazaki, M. Miyasaka,
K.Takagi, Tetrahedron Lett. 2005, 46, 8661−8664; (c) G.
Zhang, K. Wu, C. Wen, Q. Li, J. Organomet. Chem. 2020,
906, 121040; (d) S. Tang, L. Li, X. Ren, J. Li, G. Yang, H.
Li, B. Yuan, Green Chem. 2019, 21, 2899−2904. (e) M. A.
Heuft, S. K. Collins, G. P. A. Yap, A. G. Fallis, Org. Lett.
2001, 3, 2883−2886; (f) S. -K. Kang, T. -G. Baik, X. H. Jiao,
Y. -T. Lee, Tetrahedron Lett. 1999, 40, 2383−2384.
Acknowledgments
The authors thank the National Natural Science Foundation of
China (21462038) for the financial support of this work.
Conflict of Interest
The authors declare no conflict of interest.
Keywords: calcium carbide; alkyne source; 1,3-diyne; synthesis
[1] (a) S. M. Weber, G. Hilt, Org. Lett. 2019, 21, 4106−4110; (b)
J. Garcia-Lacuna, G. Dominguez, J. Blanco-Urgoiti, J.
Perez-Castells, Org. Lett. 2018, 20, 5219−5223; (c) P. Lu, H.
Hong, G. Cai, P. Djurovich, W. P. Weber, M. E. Thompson, J.
Am. Chem. Soc. 2000, 122, 7480−7486.
[2] (a) M. Saito, S. Murakami, T. Nanjo, Y. Kobayashi, J. Am.
Chem. Soc. 2020, 142, 8130−8135; (b) Y. Wang, D. Wei, W.
Zhang, Y. Wang, Y. Zhu, Y. Jia, M. Tang, Org. Biomol.
Chem. 2014, 12, 7503−7514; (c) S. Kramer, J. L. H. Madsen,
M. Rottlander, T. Skrydstrup, Org. Lett. 2010, 12,
2758−2761; (d) L. Wang, X. Yu, X. Feng, M. Bao, J. Org.
Chem. 2013, 78, 1693−1698; (e) L. Wang, X. Yu, X. Feng,
M. Bao, Org. Lett. 2012, 14, 2418−2421; (f) R. Kinjo, B.
Donnadiem, G. Bertrand, Angew. Chem. Int. Ed. 2011, 50,
5560−5563; (g) V. Lavallo, G. D. Frey, B. Donnadieu, M.
Soleilhavoup, G. Bertrand, Angew. Chem. Int. Ed. 2008, 47,
5224−5228; (h) Q. Zheng, R. Hua, J. Jiang, L. Zhang,
Tetrahedron 2014, 70, 8252−8256; (i) J. Tang, X. Zhao,
RSC Adv. 2012, 2, 5488−5490; (j) F. M. Irudayanathan, G. C.
E. Raja, S. Lee, Tetrahedron 2015, 71, 4418−4425; (k) J. -L.
Tang, L. Ming, X. -M. Zhao, J. Heterocycl. Chem. 2016, 53,
1367−1370.
This article is protected by copyright. All rights reserved.

10.1002/ejoc.202001324
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Full Paper
[7] (a) J. Park, E. Park, A. Kim, S. -A Park, Y. Lee, K. -W. Chi, Y.
H. Jung, I. S. Kim, J. Org. Chem. 2011, 76, 2214–2219; (b)
D. X. Liu, F. -L. Li, H. -X. Li, W. -J. Gong, J. Gao, J. -P. Lang,
Eur. J. Org. Chem. 2014, 4817−4822; (c) L. Feng, T. Hu, S.
Zhang, H. -Y. Xiong, G. Zhang, Org. Lett. 2019, 21,
9487−9492; (d) A. Dermenci, R. E. Whittaker, G. Dong, Org.
Lett. 2013, 15, 2242–2245
Fierro, C. Bolm, J. G. Hernandez, Angew. Chem. Int. Ed.
2018, 57, 10718−10722; (s) V. V. Voronin, M. S.
Ledovskaya, E. G. Gordeev, K. S. Rodygin, V. P. Ananikov,
J. Org. Chem. 2018, 83, 3819−3828; (t) W. E. V. Beek, K.
Gadde, K. A. Tehrani, Chem. Eur. J. 2018, 24,
16645−16651; (u) M. S. Ledovskaya, K. S. Rodygin, V. P.
Ananikov, Org. Chem. Front. 2018, 5, 226–231; (v) K. S.
Rodygin, Y. A. Vikenteva, V. P. Ananikov, ChemSusChem
2019, 12, 1483–1516; (w) A. Hosseini, P. R. Schreiner, Org.
Lett. 2019, 21, 3746–3749.
[8] X. Li, X. Liu, H. Chen, W. Wu, C. Qi, H. Jiang, Angew. Chem.
Int. Ed. 2014, 53, 14485 –14489.
[9] (a) K. S. Rodygin, G. Werner, F. A. Kucherov, V. P. Ananikov,
Chem. Asian J. 2016, 11, 965−976; (b) S. P. Teong, Y.
Zhang, J. Bioresour. Bioprod. 2020, 5, 96–100.
[12] L. Gao, Z. Liu, X. Ma, Z. Li, Org. Lett. 2020, 22, 5246−5250.
[13] L. Gao, Z. Li, Org. Chem. Front. 2020, 7, 702–708.
[14] L. Gao, Z. Li, Synlett 2019, 30, 1580–1584.
[10] (a) V. V. Voronin, M. S. Ledovskaya, A. S. Bogachenkov, K.
S. Rodygin, V. P. Ananikov, Molecules 2018, 23, 2442; (b) F. [15] R. Fu, Z. Li, Org. Lett. 2018, 20, 2342−2345.
Diederich, P. J. Stang, R. R. Tykwinski, Acetylene Chemistry: [16] G. Song, Z. Li, Eur. J. Org. Chem. 2018, 1326−1332.
[17] H. Lu, Z. Li, Adv. Synth. Catal. 2019, 361, 4474–4482.
[18] R. Fu, Z. Li, Eur. J. Org. Chem. 2017, 6648−6651.
[19] Z. Li, L. He, R. Fu, G. Song, W. Song, D. Xie, J. Yang,
Tetrahedron 2016, 72, 4321−4328.
Chemistry, Biology, and Material Science 2005 Wiley‐VCH
Verlag GmbH & Co. KgaA.
[11] (a) W. Zhang, H. Wu, Z. Liu, P. Zhong, L. Zhang, X. Huang,
J. Cheng, Chem. Commun. 2006, 4826−4828; (b) Y. Jiang,
C. Kuang, Q. Yang, Synlett 2009, 3163−3166; (c) P.
Chuentragool, K. Vongnam, P. Rashatasakhon, M.
Sukwattanasinitt, S. Wacharasindhu, Tetrahedron 2011, 67,
8177−8182; (d) Q. Yang, Y. Jiang, C. Kuang, Helv. Chim.
Acta 2012, 95, 448−454; (e) Z. Lin, D. Yu, Y. N. Sum, Y.
Zhang, ChemSusChem 2012, 5, 625−628; (f) D. Yu, Y. N.
Sum, A. C. C. Ean, M. P. Chin, Y. Zhang, Angew. Chem. Int.
Ed. 2013, 52, 5125−5128; (g) Y. N. Sum, D. Yu, Y. Zhang,
Green Chem. 2013, 15, 2718−2721; (h) N. Thavornsin, M.
Sukwattanasinitt, S. Wacharasindhu, Polym. Chem. 2014, 5,
48−52; (i) A. Hosseini, D. Seidel, A. Miska, P. R. Schreiner,
Org. Lett. 2015, 17, 2808−2811; (j) N. Kaewchangwat, R.
Sukato, V. Vchirawongkwin, T. Vilaivan, M. Sukwattanasinitt,
S. Wacharasindhu, Green Chem. 2015, 17, 460−465; (k) K.
S. Rodygin, V. P. Ananikov, Green Chem. 2016, 18,
482−486; (l) S. P. Teong, D. Yu, Y. N. Sum, Y. Zhang,
Green Chem. 2016, 18, 3499−3502; (m) E. Rattanangkool,
T. Vilaivan, M. Sukwattanasinitt, S. Wacharasindhu, Eur. J.
Org. Chem. 2016, 4347−4353; (n) A. Samzadeh-Kermani,
Synlett 2017, 28, 2126−2130; (o) A. Hosseini, A. Pilevar, E.
Hogan, B. Mogwitz, A. S. Schulze, P. R. Schreiner, Org.
Biomol. Chem. 2017, 15, 6800−6807; (p) G. Werner, K. S.
Rodygin, A. A. Kostin, E. G. Gordeev, A. S. Kashin, V. P.
Ananikov, Green Chem. 2017, 19, 3032−3041; (q) K. S.
Rodygin, Y. V. Gyrdymova, V. V. Zarubaev, Mendeleev
Commun. 2017, 27, 476−478; (r) M. Turberg, K. J. Ardila-
[20] (a) M. A. Barmade, P. R. Murumkar, M. K. Sharma, M. R.
Yadav, Curr. Top. Med. Chem. 2016, 16, 2863−2883; (b) D.
A. Patrick, S. A. Bakunov, S. M. Bakunova, T. Wenzler, R.
Brun, R. R. Tidwell, Bioorg. Med. Chem. 2014, 22, 559−576;
(c)
V.
B.
Tayde,
V.
S.
Jamode,
Asian
J.
Chem. 1998, 10, 1021−1022.
[21]. N. Singhal, P. K. Sharma, R. Dudhe, N. J. Kumar, Chem.
Pharm. Res. 2011, 3, 126–133; (b) J. F. Lagorce, F. Comby,
J. Buxeraud, C. Raby, Eur. J. Med. Chem. 1992, 27, 359–
368.
[22] T. Havashi, A. Kubo, F. Ozawa, Pure Appl. Chem. 1992, 64,
421–427.
[23] M. V. Polynski, M. D Sapova, V. P. Ananikov, Chem. Sci.
2020, https://doi.org/10.1039/D0SC04752J.
[24] (a) M. H. Vilhelmsen, J. Jensen, C. G. Tortzen, M. B.
Nielsen, Eur. J. Org. Chem. 2013, 701–711; (b) P. W. Seavill,
K. B. Holt, J. D. Wilden, Faraday Discuss. 2019, 220, 269–
281; (c) R. Akhtar, A. F. Zahoor, Synth. Commun. 2020, 50,
3337–3368.
[25] H. Xu, L. Wu, J. Tian, J. Wang, P. Wang, X. Y. Niu, X. Q.
Yao, Eur. J. Org. Chem. 2019, 39, 6690–6696.
[26] M. Singh, A. S. Singh, N. Mishra, A. K. Agrahari, V. K.
Tiwari, ACS Omega 2019, 4, 2418–2424.
[27] X. Ye, P. Zhao, S. Zhang, Y. Zhang, Q. Wang, C. Shan,
Angew. Chem. Int. Ed. 2019, 58, 17226–17230.
This article is protected by copyright. All rights reserved.

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[28] J. Wan, S. Cao, Y. Jing, Appl. Organomet. Chem. 2014, 28,
631–634.
[29] J. Tang, L. Ming, X. Zhao, J. Heterocycl. Chem. 2016, 53,
1367–1370.
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Entry for the Table of Contents
Calcium carbide: As a surrogate of gaseous acetylene, calcium carbide can be directly used as an easy-to-handle alkyne source for
the synthesis of 1,3-diynes under mild and open air condition.
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