One-pot Solvent-free Catalytic Dimerization Reaction of Phenylacetylene to 1-Phenylnaphthalene

Article abstract of DOI:10.1007/s12039-015-0926-7

In this study, we report a smooth one-pot, solvent-free catalytic dimerization of phenylacetylene (1) to 1-phenylnaphthalene (2) by Cu/C at room temperature in good yield (～100%). In the computational study, the structure of the 1-phenylnaphthalene was optimized by DFT-B3LYP/6-31Gmethod. The rotation barrier around C-C of the phenyl and naphthalene parts of the molecule and its UV-Visible spectrum were calculated. The modelling of the mechanism of production of 2 from 1 was performed with and without Cu/C catalyst. The data of EDS and SEM of the Cu/C catalyst surface are also reported.

Full text of DOI:10.1007/s12039-015-0926-7

c
J. Chem. Sci. ꢀ Indian Academy of Sciences.
DOI 10.1007/s12039-015-0926-7
One-pot Solvent-free Catalytic Dimerization Reaction of Phenylacetylene
to 1-Phenylnaphthalene
AVAT (ARMAN) TAHERPOURa,b,∗, SEPEHR TABANc and AKO YARIa
aDepartment of Organic Chemistry, Faculty of Chemistry, Razi University, P.O. Box: 67149-67346,
Kermanshah, Iran
bMedical Biology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
cChemistry Department, Science Faculty, Islamic Azad University, Arak Branch, P.O. Box 38135-567,
Arak, Iran
e-mail: avatarman.taherpour@gmail.com
MS received 21 September 2014; revised 28 April 2015; accepted 29 April 2015
Abstract. In this study, we report a smooth one-pot, solvent-free catalytic dimerization of phenylacetylene
(1) to 1-phenylnaphthalene (2) by Cu/C at room temperature in good yield (∼100%). In the computational
study, the structure of the 1-phenylnaphthalene was optimized by DFT-B3LYP/6-31G* method. The rotation
barrier around C-C of the phenyl and naphthalene parts of the molecule and its UV-Visible spectrum were
calculated. The modelling of the mechanism of production of 2 from 1 was performed with and without Cu/C
catalyst. The data of EDS and SEM of the Cu/C catalyst surface are also reported.
Keywords. Catalytic reactions; Phenylacetylene; 1-Phenylnaphthalene; Copper(0)-Carbone catalyst; Solvent
free synthesis; EDS; SEM; Molecular modelling.
1. Introduction
An efficient organocatalytic method for constructing
biaryls through aromatic C-H activation is reported by
Sun et al. in 2010.8 They have described the identifica-
tion of a cross-coupling between aryl iodides/bromides
and the C–H bonds of arenes that is mediated solely by
the presence of 1,10-phenanthroline as catalyst in the
presence of KOt-Bu as a base. This apparently tran-
sition metal-free process provides a new strategy to
achieve direct C–H functionalization.8
In 2011, the dimerization reaction of phenylacety-
lene (1) in presence of Pd(0) nanoparticles was reported
by Firuzabadi et al.9 In this reaction 1,4-diphenyl-but-
1-en-3-yne was produced. It is demonstrated in that
report that the nanoparticles show high catalytic activity
for the Sonogashira–Hagihara coupling reaction of var-
ious aryl halides as well as heteroaryl halides and also
β-bromo styrene with phenylacetylene under copper-,
ligand- and amine-free conditions.9–14 It is also reported
that the reactions were carried out at 100◦C in molten
tetrabutylammonium bromide (TBAB) or polyethylene
glycol in the presence of potassium acetate as a base in
argon atmosphere. Dimerization of phenylacetylene in
similar conditions in air was also previously described
by Firuzabadi et al.9
Polycyclic aromatic hydrocarbons (PAHs) have been
attracting a lot of attention in recent years.1–6 They are
formed as a result of burning organic compounds and in
natural thermal geological reactions. PAHs occur in oil,
coal, and tar deposits, and are produced as by-products
of fuel burning (fossil fuel or biomass).1–3 PAHs are
found primarily in soil, sediment and oily substances,
as opposed to water or air.4 1-phenylnaphthalene was
prepared by the reaction of α-halonaphthalenes with
mercury diphenyl,7a,b or with benzene in the pres-
ence of aluminum chloride,7a,b and by means of a
Grignard synthesis, starting with either bromobenzene,
or cyclohexyl chloride and α-tetralone,7a,c,d or with
α-bromonaphthalene and cyclohexanone.7a,c-e A 60%
yield is reported for the Grignard preparation from
cyclohexanone.7a,g The formation of the hydrocarbon
through the diazo reaction,7a,g-j appears to be less attrac-
tive than the described method. Dehydrogenation of
the reduced naphthalene is accomplished by the use of
sulfur,7a,c bromine,7a,e platinum black, or selenium.7a,b 1-
Phenylnaphthalene has also been prepared by oxidation
of 1-Phenyldialin.7a
The dimerization of arylethynes catalyzed by vana-
dium phthalocyanine to give substituted biaryls have
been previously investigated.15 In 2009, the dimerization
∗For correspondence

Avat (Arman) Taherpour et al.
5
4
10
6
7
3
2
Cu/C
RT/darkness
Stirrer bar
Overnight
9
H
2
8
1
11
1-Phenylnaphthalene (2)
Phenylacetylene (1)
12
13
14
Figure 1. One-pot, solvent-free catalytic dimerization of
phenylacetylene (1) to 1-phenylnaphthalene (2) by Cu/C at
room temperature.
reaction of para-Cl-phenylacethylene in presence of
vanadium phthalocyanine was reported by Cicero
et al.15 The reaction had produced the chloro substituted
of 1-phenylnaphthalene. The reaction yield was always
high, and for many examples, it was only slightly
affected by the aryl substituent. It is reported that this
is related to results obtained with metalloporphyrins,
which give lower selectivity due to the presence of
variable amounts of triphenylbenzenes (figure 1).15
Herein, we report a smooth one-pot, solvent-free cat-
alytic dimerization of phenylacetylene 1 (H-C≡C-Ph)
to 1-phenylnaphthalene 2 by Cu/C in darkness and at
room temperature in good yield (∼100%). The com-
putational method employed covers density functional
theory (DFT) approaches. The structure of 2 was opti-
mized by DFT-B3LYP/6-31G* method. The barrier
rotation around C-C of the phenyl and naphthalene parts
of the molecule and its UV-Visible spectrum were cal-
culated by B3LYP/6-31G* method. The modelling of
the mechanism of formation of 1-phenylnaphthalene
from phenylacetylene was performed with and without
Cu/C catalyst. In this study, the data of EDS and SEM
of the Cu/C catalyst surface are reported as well.
Figure 2. Comparison of FT-IR spectra of phenylacetylene
(1) and 1-phenylnapthalene (2). The peaks at 3291 and 2110
cm−1 have disappeared in spectrum of 2.
per min till 250◦C on a Zebron capillary column ZB-5
(0.25 μm thickness, 0.32 mm diameter, 30 m length).
TLC experiment with CHCl3-petroleum ether-acetone
(1:1:1) on silica gel plate showed just one strong spot
for 2 in comparison with the starting material 1. No
details are given about the by-products and only the
final product was considered.
2.2 Procedures
2.2a Synthesis of 1-Phenylnaphthalene (2): A mix-
ture of phenylacetylene (1) (2 mL, 1.86 g, 0.018 mol)
and the catalyst Cu/C (0.1 mg) was made in a dried
tube with a small magnetic stirrer bar. The tube was
sealed and then stirred overnight (about 12 h) at room
temperature and in darkness. A yellowish oily liquid
was afforded after filtration and separation of the cat-
alyst. The product 2 was identified by the analytical
data and comparing with the authentic sample data.16
The workup and GC yields were about ∼100% (2
2. Experimental
2.1 Materials, methods and instruments
The synthesized 1-phenylnaphthalene 2 is a known mL, 1.85 g, 0.009 mol). See figures 2, S1 and S2 (S1
compound (with CAS# 605-02-7) and its physical data, and S2 are in supplementary information.). B.p.: 322–
1
infrared and H-NMR spectra are essentially identi- 324◦C (lit. B.p.= 324–325◦C).16 FT-IR (KBr, cm−1):
cal with that of authentic sample.16 The FT-IR spectra 3000–3060(C-H; Ar.), 1812–2000(H-C; Ar. ring),
were recorded on a Shimadzu FT-IR 8000 spectrom- 1594, 1487, 1443(C=C; Ar. ring), 780, 754 and 702
1
1
eter. H-NMR and 13C-NMR spectra were determined cm−1(OOP of C-H; Ar. ring). H-NMR δH (CDCl3):
on a 300 MHz Brüker spectrometer. The solvent for 7.87–7.91(m, H8), 7.83–7.85(m, H2), 7.51–7.53(m,
NMR recording was CDCl3. The product was exam- H5), 7.48–7.50(m, H4), 7.47(d, H12, 6Hz), 7.45–
ined by GC-MS (figures S1 and S2 in Supplementary 7.47(dd, H3, 6Hz), 7.42(m, H7), 7.40(m, H6), 7.34–
Information). GC and GC-MS analysis were performed 7.36(t, H13, 6Hz) and 7.30–7.32(d, H14, 6Hz). 13C-
on a Shimadzu QP5050A GCMS instrument, injector at NMR: 132.5(C11), 131.4(C1), 130.1(C10), 128.4(C9),
200◦C; temperature program: 100◦C (2 min), then 16◦C 128.2(C13), 128.0(C8), 127.6(C5), 126.9(C4), 126.2(C14),

Catalytic Dimerization of Phenylacetylene to 1-Phenylnaphthalene
126.1(C12), 126.0(C7), 125.4(C6), 125.3(C2) and form (φ10,1,11,16 = 0◦). The steric restraint and the strains
125.2(C3). MS: m/z (relative intensity), MW=204; 204 in the barrier form have made some changes in bond
(M+, 94.9), 203(100), 202(60.5), 189(2.3), 176(4.5), lengths and bond angles as compared to the ground state
126(2.2), 102(8.1), 101(53.5), 88(18.6) and 76(10.5). form. By increasing the steric restraint and the strains
Molecular formula is C16H12.
in the barrier form, the bond length of C1-C11, H23-
H24 and H17-H24 were changed from 1.497, 3.416 and
3.524Å (in ground state) to 1.523, 0.899 and 1.787Å (in
barrier form), respectively. Likewise, by increasing the
2.3 Molecular Modeling
The calculations on the structure of 1-phenylnaph- steric restraint and the strains in the barrier form, the
thalene 2 were performed by appropriate quantum bond angles of C2C1C10, C10C1C11, C1C11C12 and
mechanical method. In this study, the employed com- C12C11C16 were changed from 119.4, 121.0, 120.7
putational method covers density functional theory and 118.0◦(in ground state) to 118.2, 123.1, 122.1 and
(DFT) approaches. The structure of 2 was optimized 116.8 (in barrier form), respectively. The barrier energy
by DFT-B3LYP/6-31G* method. All of the calcu- for bond rotation aroundφ10,1,11,16 was calculated 52.92
lations have been performed by Spartan ‘10 pack- kcal mol−1 by B3LYP/6-31G* method (figure 4).
age that was implemented on a HP-Proliant-DL180-
G6(12 cores) Server.17 The graphing operation for for 2. The calculated λmax in vacuum by DFT-B3LYP/
barrier rotation (φ10,1,11,16) around C1-C11 in 2 was 6-31G* method was achieved 269.2 nm (lit λmax
performed using the Microsoft Office Excel-2013 285 nmin n-hexane). The energies of the boundary MOs
program.
(HOMO and LUMO) of 2 are shown in Figure 5(b). The
Figure 5(a) shows the calculated UV/Visible spectra
=
Figures 3 to 9 and table 1 show the appropriate HOMO, LUMO and ꢀEHOMO−LUMO were calculated as:
model, operations and selected structural data. To cal- -5.73, -0.96 and 4.77 eV, respectively.
culate the barrier rotation around the C-C bond in
Figure 6 demonstrates the predicted mechanism of
1-phenylnaphthalene (on Cu/C catalyst) the appropri- reaction between two moles of phenyl-acetylene to
ate dihedral angle change (φ10,1,11,16) around the C1- produce 1-Phenylnaphthalene 2. The transition states
C11 bond was utilized and optimized in each step. (TS1 and TS2) and also the intermediate for a [1,5]H-
The Hartree energy was converted to kcal.mol−1 and shift are shown in figure 6. The hydrogen atom 19
relative energies were calculated. The graph in figure 4 has migrated from C10 to C4 by a [1,5]H-shift (sigma
demonstrates the appropriate data. The optimized struc- tropic) reaction. Table 1 shows the selected structural
tures of 1-phenylnaphthalene, transition states and data of the structures during the production of 2 calcu-
intermediate (with and without Cu/C catalyst pathways) lated by B3LYP/6-31G* method. The bond lengths and
were carried out by DFT-B3LYP/6-31G* method.
distances between the selected atoms C1-C2, C2-C3,
Figure 3 demonstrates the selected structural data of C3-C4, C4-C5, C5-C10, C1-C10, C1-C11, C10-H19,
2 in ground state (φ10,1,11,16 = 90.52◦) and the barrier H17-H18 and H18-H19 are: 1.295, 2.419, 1.277, 1.430,
Figure 3. The selected structural data of 1-Phenylnaphthalene (2) in ground state (ꢁ10,1,11,16 = 90.52◦)
and the barrier form (ꢁ10,1,11,16 = 0◦).

Avat (Arman) Taherpour et al.
mol−1, respectively, less stable than the precursor. The
calculated energy level of the product 2 is about 98 kcal
mol−1 more stable than the precursor 1 (figure 7).
Figure 7 shows the graph of the reaction between two
moles of 1 to produce one mole 2 with and without
Cu/C catalyst. With respect to the results, the first step
of this reaction was slow and rate determining. The acti-
vation energy of the first step was calculated to be about
107.42 kcal mol−1 without Cu/C catalyst. This activa-
tion energy for the first step and with Cu/C catalyst was
about 66.66 kcal mol−1 by B3LYP/6-31G* method. The
results show that the activation energy of this stage (by
utilizing Cu/C catalyst pathway) decreases by about 41
kcal mol−1. The results demonstrate that the slow and
first step of this reaction was affected by the adsorp-
tion of phenylacetylene and the [TS1] on Cu/C cata-
lyst surface. An imaginary structure of Cu surface was
constructed and optimized by B3LYP/6-31G* method,
to construct a model for adsorbing two molecules of 1
and their [TS1] on Cu/C catalyst surface. This model of
Cu surface includes 64 Cu atoms (8x8) with 24.60 Å
diagonal and 17.84 Å length. The optimized Cu-surface
shows a curvature across its diagonal. Figure 8 shows
the model of Cu-catalyst surface by B3LYP/6-31G*
method: (a) Ball and spoke model, b) Electron den-
sity model, c) Electrostatic potential model with natural
charges and d) Mulliken Charge map. The calculated
results demonstrate that the Mulliken and natural
charges have not been homogenized on the selected
Cu-surface. The natural charge map of the optimized
Cu-surface is shown in figure 4(C); the natural charges
were changed from +0.055 to −0.048 esu. The most
positive places are shown by blue color in figure 4(C)
with +0.055 to +0.040 esu. It seems that these posi-
tions are better locations to adsorb the electron den-
sity distribution (EDD) of the first step transition state
(TS1) among the selected Cu-surface. So, these posi-
tions were chosen for modelling of this stage with Cu-
catalyst with the phenylacetylene molecules. Figure 9
(a and b) presents the model of interaction between
[TS1] and the Cu-catalyst surface ((a) Space filling and
(b) ball and spoke models). In this figure, we can obvi-
ously see the changes about the Cu atom positions of
the Cu-model catalyst due to adsorption of the [TS1].
As mentioned above the calculated results by the mod-
elling show that the activation energy of this stage (by
utilizing Cu/C catalyst pathway) to decrease by about
41 kcal mol−1.
Table 1. Selected structural data of the transition states
[TS1], [TS2] and the intermediate compound [In.].
[TS1] & [TS2] and [In.]
Selected data
[TS1]
[In.]
[TS2]
Bond length(Å)
C1-C2
C2-C3
C3-C4
C4-C5
1.295
2.419
1.277
1.430
1.403
1.404
1.389
2.802
1.426
1.071
1.07 4
1.082
3.114
4.352
1.372
1.444
1.359
1.356
1.428
1.564
1.489
1.504
1.482
1.088
1.091
1.115
2.527
4.472
1.368
1.432
1.408
1.418
1.432
1.520
1.499
1.502
1.480
1.090
1.095
1.457
2.419
2.585
C5-C6
C5-C10
C9-C10
C1-C10
C1-C11
C2-H17
C3-H18
C10-H19
H17-H18
H18-H19
Bond angle(◦)
C1C2C3
C2C3C4
C3C4C5
C4C5C6
C4C5C10
C2C1C10
C2C1C11
C10C1C11
C5C10C1
C5C10H19
C1C10H19
C1C2H17
C4C3H18
126.92
76.27
119.56
119.73
124.41
129.34
117.52
119.77
120.60
119.55
115.12
91.69
122.01
127.24
116.13
118.76
125.45
117.35
121.68
120.88
116.31
71.79
170.12
124.08
116.64
103.78
159.81
96.39
78.62
122.10
92.98
102.56
119.13
121.78
90.25
118.52
118.42
144.51
154.25
Torsional angle(◦)
C1C2C3C4
C2C3C4C5
27.39
−17.79
120.51
−3.97
−55.29
−19.01
−42.17
79.99
−24.28
14.26
3.80
1.88
169.37
0.16
−11.72
−65.84
−8.58
61.32
1.03
C3C4C5C6
−174.76
C3C2C1C10
C3C4C5C10
C4C5C10H19
C2C1C10C5
C2C1C10H19
H17C2C3H18
C5C10C1C11
17.97
1.15
−111.58
−2.92
95.00
34.19
138.66
−21.98
−179.52
174.76
1.404, 2.802, 1.426, 1.082, 3.114 and 4.352 Å, respec-
tively. For the intermediate [In.], the bond lengths and
distances between the selected atoms C10-H19, C1-
C10, C5-C10 and C1-C11 are: 1.115, 1.504, 1.564
and 1.482, respectively. In table 1 are shown, as well
as [TS1] and [In.] the selected bond lengths and dis-
tances C10-H19, C1-C10, C5-C10 and C1-C11 for
[TS2]: 1.457, 1.502, 1.520 and 1.480 Å, respectively.
2.4 EDS and SEM Results
The calculated energy levels of the [In.] and [TS2] Figure S3 (in SI) shows the EDS results. This figure
by B3LYP/6-31G* method, are: 8.09 and 27.13 kcal shows the copper atoms in the Cu/C catalyst. The

Catalytic Dimerization of Phenylacetylene to 1-Phenylnaphthalene
Figure 4. The rotation process in 1-phenylnaphthalene (2) in ground state
(ꢁ10,1,11,16 = 90.52◦) and the barrier form (ꢁ10,1,11,16 = 0◦).
(a)
(b)
Figure 5. (a) The calculated UV/Visible spectrum for 1-phenylnaphthalene (2). Calculated
λmax =269.2 nm in vacuum by DFT-B3LYP/6-31G* method (lit. λmax = 285 nm in nhexane).
(b) The energies of MOs (HOMO and LUMO) of 1-phenylnaphthalene (2).
Figure 6. The predicted mechanism of reaction between two moles of phenylacetylene (1) to produce one mole of 1-
phenylnaphthalene (2).

Avat (Arman) Taherpour et al.
Figure 7. The graph of the reaction of two moles of phenylacetylene to produce 1-Ppenylnaphthalene (2) with and without
catalyst Cu/C. With catalyst, the activation energy of the first step was calculated to be about 41 kcal mol−1 less than without
Cu/C catalyst.
(a)
(b)
(c)
(d)
Figure 8. The calculated model of Cu-catalyst surface by B3LYP/6-31G* method. a) Ball and spoke
model, b) Electron density model, c) Electrostatic potential model with natural charges and d) Mulliken
Charge map.
results of electron microscopy image of the copper- images of copper-impregnated carbon (Cu/C) catalyst.
impregnated carbon (Cu/C) sample with shows that the The SEM images show the establishment and adhe-
structure of the SEM image (100 μm) of free cop- sion capability of chemical and physical characteristics
per consisting of homogenous and porous structure of and mechanics of the porous surface of copper metal
Cu/C catalyst. Figures 10, S3 and S4 show the SEM particles (figure 11).

Catalytic Dimerization of Phenylacetylene to 1-Phenylnaphthalene
(a)
(b)
Figure 9. The model of interaction between [TS1] and the Cu-catalyst surface. (a) Space
filling and (b) ball and spoke models.
Figure 10. SEM image of copper-impregnated Carbon Figure 11. SEM image of copper-impregnated Carbon
(Cu/C) catalyst in scale of 100 μm.
(Cu/C) catalyst in scale of 10 μm. See Figure 10.
signal at chemical shift δ=2.16 ppm for acetylenic
3. Results and Discussion
H atom. This signal disappeared completely in the
1
The reaction was carried out as a one-pot, solvent- 1H-NMR spectrum of product 2. The H-NMR spec-
free catalytic dimerization of phenylacetylene 1 to 1- trum of 2 shows the NOE enhancement for H8 (peri-
phenylnaphthalene 2 by Cu/C at room temperature and hydrogen) as doublet-multiplet by H7 and phenyl sub-
in good yield (∼100%). The comparison of the struc- stituted group on C1 (figure S1 in supplementary infor-
tural and spectral data of 1 and the identified compound mation). The 13C-NMR spectrum of 2 showed fourteen
2 shows complete conversion of 1 to 2 under the reac- signals in accordance with its structure. A GC-Mass
tion conditions. There was no additional compound in experiment was carried out on product 2. The GC yield
the reaction vessel. The reactant vessel was under a dark of the experiment was about ∼100%. The mass spec-
cover during the time of reaction (overnight). So, the trum of 2 showed the molecular weight [M]+. signal at
reaction was not under photochemical conditions.
m/z=204. The signal of [M]+./2 appeared at 102 and
The FT-IR spectrum of 1 has two important peaks at a signal at 101 for [([M]+./2)-1] (figure S2 in supple-
2110 and 3291 cm−1 for stretching vibrational frequen- mentary information). The boiling point of the prod-
cies of –C≡C– and ≡C–H, respectively. These two sig- uct was measured by Emrich’s method.15 The boiling
nals disappeared in the FT-IR of the product 2. The FT- point of 2 was 322–324◦C (lit. B.p.= 324–325◦C).14
IR of the product just shows the aromatic signals (figure 2). These results confirm conversion of 1 to 2 under the
1
The H-NMR spectrum of phenylacetylene showed a mentioned conditions.

Avat (Arman) Taherpour et al.
3. Glenn R M 1995 In Activated carbon applications in
4. Conclusions
the food and pharmaceutical industries (Boca Raton FL:
CRC Press) p. 125
A smooth one-pot, solvent-free catalytic dimerization
of phenylacetylene to 1-phenylnaphthalene by Cu/C in
darkness at room temperature in good yield (∼100%)
is reported. The identification of the product was car-
4. Portella G, Poater J and Solà M 2005 J. Phys. Org.
Chem. 18 785
5. Luch A 2005 In The Carcinogenic Effects of Poly-
cyclic Aromatic Hydrocarbons (London: Imperial
College)
ried out by the physical data, FT-IR, H-NMR, 13C-
1
6. Hawley G G 1997 In Condensed Chemical Dictionary
13th Ed. (New York: Van Nostrand Reinhold Company
Inc.)
NMR and mass spectra and compared with the authen-
tic sample data. The structure of 1-phenylnaphthalene
was optimized by DFT-B3LYP/6-31G* method. The
barrier rotation around C-C of the phenyl and naphtha-
lene parts of 1-phenylnaphthalene (52.92 kcal mol−1)
and its UV-Visible spectrum (λmax =269.2 nm) were
calculated by B3LYP/6-31G* method. The modelling
of the production mechanism of 1-phenylnaphthalene
from phenylacetylene was performed with and with-
out Cu/C catalyst. The calculated results by the mod-
elling showed that the activation energy (by utilizing
Cu/C catalyst) decreases by about 41 kcal mol−1. In this
study, the data of EDS and SEM of the Cu/C catalyst
surface are reported as well.
7. (a) Weiss R 1955 Org. Syntheses 3 729; (b) Chattaway
F D 1893 J. Chem. Soc. 63 1187; (c) Weiss R and
Woidich K 1925 Monatsh. Chem. 46 455; (d) Cook J
W and Lawrence C A 1936 J. Chem. Soc. 11 1431; (e)
Vesely V and Stursa F 1933 Collect. Czech. Chem. Com-
mun. 5 344; (f) Orchin M and Reggel L 1947 J. Am.
Chem. Soc. 69 505; (g) Grieve W S M and Hay D H 1938
J. Chem. Soc. 13 108; (h) Waters W H 1939 J. Chem.
Soc. 14 864; (i) Hodgson H H and Marsden E 1940 J.
Chem. Soc. 15 208; (j) Bachmann W E and Hofmann R
A 1944 Org. Reac. 2 248
8. Sun C L, Li H, Yu D G, Yu M, Zhou X, Lu X Y, Huang
K, Zheng S F, Li B J and Shi Z J 2010 Nature Chem. 2
1044
9. Firouzabadi H, Iranpoor N and Ghaderi A 2011 Org.
Biomol. Chem. 9 865
Supplementary Information
10. Sonogashira K, Tohda Y and Hagihara N 1975 Tetrahe-
dron Lett. 16 4467
11. Chinchilla R and Najera C 2007 Chem. Rev. 107
1H-NMR spectra of phenyl-acetylene, 1-phenylnaph-
thalene (figures S1 and S2), EDS analysis (figure S3)
and the SEM of Cu/C catalyst (figure S4) are shown
in the Supplementary Information which is available at
www.ias.ac.in/chemsci.
874
12. Gil-Molto J and Najera C 2006 Adv. Synth. Catal. 348
1874
13. Dudnik A and Gevorgyan V 2010 Angew. Chem. Int. Ed.
49 2096
14. Cicero D, Lembo A, Leoni A and Tagliatesta P 2009
New J. Chem. 33 2162
15. Vogel A 1986 In Vogel’s Textbook of Practical Organic
Chemistry. Including qualitative organic analysis (4th
Ed). (England: Longman Group Limited)
16. (a) Pouchert C L 1983 In The Aldrich Library
of NMR Spectra (2th Ed.). (Milwaukee, Wisconsin:
Aldrich Chemical Company Inc.) 1 pp. 2, 740-
2, 762; (b) Pouchert C L 1981 In The Aldrich
Library of Inferared Spectra 3th Ed. (Milwaukee,
Wisconsin: Aldrich Chemical Company Inc.) pp.
27, 40-2, 578; (c) 1-phenylnaphthalene http://www.
chemsynthesis.com/base/chemical-structure-5127.html
17. Spatran ’10-Quantum Mechanics Program: (PC/x86)
1.1.0 v4. 2011 (Irvine CA: Wavefunction Inc.)
Acknowledgements
A T gratefully acknowledges the colleagues in Chem-
istry Department of The University of Queensland-
Australia for their useful suggestions. The authors are
grateful to the Research and Computational Lab of
Theoretical Chemistry and Nano Structures of Razi
University Kermanshah-Iran for supporting this study.
References
1. Fetzer J C 2000 Polycycl. Aromat. Comp. 27 143
2. Herwig P T, Enkelmann V, Schmelz O and Müllen K
2000 Chem. Eur. J. 6 1834