E-Selective dimerization of phenylacetylene catalyzed by cationic tris(μ-hydroxo)diruthenium(II) complex and the mechanistic insight: The role of two ruthenium centers in catalysis

Article abstract of DOI:10.1016/j.molcata.2016.08.027

A dinuclear complex [(Me₃P)₃Ru(μ-OH)₃Ru(PMe₃)₃]⁺[OPh]^? (1) (0.5 mol%) catalyzes E-selective dimerization of phenylacetylene, which involves the C–H bond cleavage of phenylacetyle

Full text of DOI:10.1016/j.molcata.2016.08.027

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Editor’s choice paper
E-Selective dimerization of phenylacetylene catalyzed by cationic
tris(␮-hydroxo)diruthenium(II) complex and the mechanistic insight:
The role of two ruthenium centers in catalysis
Sayori Kiyota, Hirofumi Soeta, Nobuyuki Komine, Sanshiro Komiya1, Masafumi Hirano∗
Department of Applied Chemistry, Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-26 Nakacho, Koganei, Tokyo
184-8588, Japan
a r t i c l e i n f o
a b s t r a c t
A dinuclear complex [(Me3P)3Ru(␮-OH)3Ru(PMe3)3]+[OPh]− (1) (0.5 mol%) catalyzes E-selective dimer-
ization of phenylacetylene, which involves the C–H bond cleavage of phenylacetylene and resulting
stereospecific C–C bond forming reaction, at 100 ◦C for 2 h to give (E)-1,4-diphenylbut-3-en-1-yne in
quantitative yield (E/Z = 91/9). Similar reactions using 4-nitro-, 4-cyano-, 4-trifluoromethyl-, 4-acetyl-
, and 4-methylphenylacetylene give the corresponding enynes. The kinetic study for dimerization of
phenylacetylene shows the second-order and first-order reactions with regard to the phenylacetylene
and 1 concentrations, respectively, suggesting this reaction to be catalyzed by a dinuclear ruthenium
complex. Addition of PMe3 to the catalytic system strongly discourages the dimerization. These features
are consistent with the scenario, where dissociation of a PMe3 ligand from 1 gives a coordinatively unsat-
urated diruthenium species and one of the ruthenium centers performs as a reaction site for the enyne
formation and the other ruthenium center behaves as a spectator in the catalysis.
Article history:
Received 30 May 2016
Received in revised form 26 August 2016
Accepted 28 August 2016
Available online xxx
This paper is dedicated to Prof. B.G. Shul’pin
on the occasion of his 70th birthday.
Keywords:
Tris(␮-hydroxo)diruthenium(II) complex
Dinuclear complex
C-H bond cleavage
Alkyne dimerizations
Kinetic study
© 2016 Elsevier B.V. All rights reserved.
1. Introduction
mation by this mechanism [15]. The third mechanism involves a
vinylidene intermediate (Scheme 1(C)). Although migration of the
Conjugated enynes are key motifs of building blocks particularly
for the biologically active compounds and the most straightforward
approach is dimerization of terminal alkynes [1]. A large number
of metal complexes have been reported to catalyze dimerization
of terminal alkynes giving enynes [2,3]. Such alkyne dimerizations
catalyzed by a mononuclear complex are generally proposed to
proceed by one of the three different mechanisms [4]. A typical
mechanism is the insertion of alkyne into the M–H bond followed
by the reductive elimination between the alkynyl and alkenyl
groups (Scheme 1(A)). Because the hydrometallation step is nor-
mally a syn addition, this mechanism produces E-enynes [5,6] or
2,4-disubstituted enynes [7], depending on the regioselectivity. The
second mechanism is insertion of alkyne into the alkynyl-metal
bond (Scheme 1(B)). The carbometallation is also a syn addition
and this process gives E-enynes [8–11] or the 2,4-disubstituted
enynes [12–14], with an exceptional report for the Z-enyne for-
alkynyl group to the ␣-carbon in vinylidene potentially yields both
E- [16] and Z-enynes [17–19], most of the Z-selective dimerizations
are explained by this mechanism.
This alkyne dimerization is also catalyzed by din-
uclear complexes and the reported examples involve
[Zr2{␬3-(OC(NiPr)NCH2)2CMe2}2(␮-NPh)(␮-NHPh)(NHPh)]
[20],
[Ru2Cp*2Cl2(␮-SR)2]
[21],
[Ru2(␮-CH2)(CO)4(␮-
dppm)2]
[22],
[Y2(␮-C≡CR)4{PhC(NSiMe3)}4]
[12b],
and
To
[Lu2(C5Me4SiMe2NAr-␩5,␬1-N)2(␮-C≡CPh)2]
[23],
[24].
[Y2(C5Me4SiMe2NAr-␩5,␬1-N)2(␮-C≡CPh)2(THF)2]
our best knowledge, the dinuclear catalysts dominantly give
(Z)-1,4-disubstituted enynes and/or 2,4-disubstituted enynes and
the selective formation of (E)-1,4-disubstituted enynes has not
yet been documented, probably because the alkynyl group on a
metal center attacks the adjacent coordinated alkyne or vinylidene
group on the other metal center from the exo side. However, such
dinuclear catalyzes are still limited and the detailed mechanism
remains largely unknown. In some case the dinuclear complex
is converted into a mononuclear species under the catalytic
conditions, which is believed to act as the active species [12b,16d].
∗
Corresponding author.
E-mail address: hrc@cc.tuat.ac.jp (M. Hirano).
1
Current address: Tokyo Metropolitan University.
http://dx.doi.org/10.1016/j.molcata.2016.08.027
1381-1169/© 2016 Elsevier B.V. All rights reserved.
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(A)
(A)
(B)
(B)
(C)
(C)
Scheme 1. Alkyne dimerization mechanisms catalyzed by mononuclear complexes.
The alkyne dimerization catalyzed by a dinuclear complex is also
proposed to proceed by the following mechanisms (Scheme 2).
The mechanism (Scheme 2(A)) starts from an (alkynyl)(hydrido)
complex A1 to which an alkyne inserts into the M–H bond.
In this step, both 1,2- and 2,1-insertions are potentially pos-
sible but actually only an example for 2,1-insertion giving
2,4-disubstituted enynes has been reported [22]. The second mech-
anism (Scheme 2(B)) involves the (alkynyl)(alkyne) intermediate
(B2). The alkynyl group attacks the coordinated alkyne on the other
metal center from the exo side, and the resulting enynyl group in
B3 is protonated by upcoming 2 to give Z-enynes with recovery of
B1. This mechanism well explains the Z-selectivity in the forma-
tion of 3 [23,24]. The third mechanism (Scheme 2(C)) involves a
dinuclear complex C1 having an alkynyl and alkyne in each metal
center, whose alkyne moiety is transformed to the vinylidene group
C2, and resulting C3 is eventually protonated by 2 to release 3 with
recovery of C1 [21]. This mechanism potentially produces Z- and
E-enynes, but actually this mechanism is proposed only for the Z-
enynes formation. In these mechanisms, some dinuclear complexes
that mimics proposed intermediates such as A1 [12b,23,24] and C3
[25] have been isolated.
Scheme 2. Alkyne dimerization mechanisms catalyzed by dinuclear complexes.
related tris(␮-hydroxo)diruthenium(II) complexes were reported
[27], their catalytic activity was unexplored before. As an exten-
sion of the catalytic hydration of nitriles, we explored hydration
of alkyne. However, 1 did not have any catalytic activity toward
alkyne hydration. During course of these studies we accidentally
found 1 to catalyze dimerization of phenylacetylene (2a) giving
(E)-1,4-diphenylbut-3-en-1-yne (E-3a), which involve a C–H bond
cleavage step of terminal alkyne. It is hard to explain the E-selective
dimerization catalyzed by a dinuclear complex based on above
mechanisms. This prompted us to reveal the new mechanism for
the dinuclear complex. Herein we describe the detailed kinetic
studies for E-selective dimerization of 2a catalyzed by 1, and pro-
pose a new mechanism where the two ruthenium centers act
completely different roles in the catalysis.
2. Results and discussion
2.1. Catalytic dimerization of terminal alkynes
We recently reported synthesis of and catalytic hydration
of nitriles by a cationic tris(␮-hydroxo)diruthenium(II) complex,
[(Me3P)3Ru(␮-OH)3Ru(PMe3)3]+[OPh]− (1) [26]. While a handful of
Tris(␮-hydroxo)diruthenium(II)
complex
[(Me3P)3Ru(␮-
OH)3Ru(PMe3)3]+[OPh]− (1) (0.5 mol%) catalyzed the tail-to-tail
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Table 1
Dimerizations of terminal alkynes 2 catalyzed by 1.
1 (0.5 mol%)
R
+
+
R
R
R
R
100 ˚C, 2 h
R
R
2
E-3
Z-3
4
entry
alkyne
solvent
conv./%
yield/%
2
E-3
Z-3
4
1
none
100
89
84
5
94
77
74
1
9
0
2
toluene
7
0
0
0
3
1,4-dioxane
toluene
9
4a
trace
5
1,4-dioxane/H2O (9/1)
1,4-dioxane/KOH
toluene
48
77
97
80
45 (40)b
2 (3)b
0 (0)b
6c
53
3
0
0
0
0
7
94
4
8
toluene
67
3
9d
benzene
100
83
15
10
11
toluene
none
87
82
94
5
5
0
0
100
12
none
100
68
14
0
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Table 1 (Continued)
1 (0.5 mol%)
R
+
+
R
R
R
R
100 ˚C, 2 h
R
R
2
E-3
Z-3
4
entry
alkyne
solvent
conv./%
100
yield/%
2
E-3
Z-3
4
13e
toluene
7
40
11
In addition to these products, 3 isomers of the trimers were observed by GC–MS analysis.
a
10 equiv/1 of PMe3 was added. time = 2 h.
1,4-dioxane and D2O (9/1) were used for the solvent.
b
c
[1]/[KOH] = 1/8.
d
1 = 10.0 mol%. temp = 50 ◦ C. time = 20 h.
e
1 = 2.0 mol%. time = 12 h.
Table 2
Cross-dimerizations of phenylacetylene (2a) with alkyne 5.
R2
R1
Ph
Ph
Ph
R1
Ph
R2
1 (2.0 mol%)
6
7
+
R1
R2
Ph
toluene
Ph
conv./%a
83
2a
5
100 ˚C, 3 h
Ph
Z-3a
Chart 1. Deuterium Contents in E-3a.
E-3a
dimerization of phenylacetylene (2a) at 100 ◦ C without use of
additional base to give (E)-1,4-diphenylbut-1-en-3-yne (E-3a)
with high regio- and E-selectivities (Table 1, entry 1). 2,4-
Diphenylbut-1-en-3-yne (4a) was not observed in this reaction at
all.
entry
yield/%
5
6
7
E-3a
Z-3a
1
63
–
2
3
This reaction proceeded in toluene and 1,4-dioxane to give E-
3a dominantly in high yield (entries 2 and 3). Addition of PMe3 to
this system significantly disturbed the catalysis, suggesting prior
dissociation of a PMe3 from 1 to give the active species (entry 4).
This reaction was also suppressed in the presence of water or D2O
(entry 5). Notably, in spite of the presence of excess D2O, only mod-
est incoporation of deuterium was observed at the 1- and 2-protons
in the product E-3a (Chart 1).
Since the H/D exchange reaction of 2a does not occur without
use of 1 under these conditions, this result suggests slow and prior
H/D exchange reaction of the alkynyl proton in 2a with D2O by 1.
Moreover, this result also excludes the protonolysis of a putative
(1,4-diphenylbut-3-yn-1-enyl)ruthenium species by the hydroxo
group, putative aqua group or D2O, and it strongly supports the
protonolysis of the intermediate by 2a [Eq. (1)]. Similar protonolysis
by incoming terminal alkyne are also documented [15,18a,18c].
2b
3c
96
40
59
28
18
11
0
25
6
4
1
8
80
4
100
60
5d,e
96
99
2
0
0
–
78
63
16
10
6d
H(D)
Ph
H(D)
H(D)
Ph
Ph
Ph
Ph
+
Ru
Ph
a
Ru
based on 2a.
time = 6 h.
2a/5b = 1/2.
time = 4 h.
(D)H
b
c
(1)
d
e
Complex 1 showed tolerance to the functional groups at the
concentration of 1 = 1.0 mol%.
para-position in phenylacetylene (entries 7–11) and no significant
electronic effect was observed both in the selectivity and yield.
The ortho-substituent diminished the yield and E-selectivity prob-
ably owing to the steric hindrance (entry 12). Dimerization of
1-octyne exceptionally gave the Z-dimer Z- h3 as a dominant prod-
uct with small amount of the tail-to-head dimer 4h. One of the
possible explanations for this selectivity is the electron rich alky-
lalkynes probably owing to the different mechanism from 2a such
as Scheme 2(C) (entry 13) [28].
dimerizations between phenylacetylene (2a) and several alkynes
were performed (Table 2). Complex 1 also catalyzed the cross-
dimerization between 2a and DMAD (5a) to give the syn-product
(Z)-PhC≡CC(CO2Me)=CHCO2Me (Z-6a) as a dominant product with
sparing formation of the homo-dimers 3a (entry 1). Treatment
of 2a with propargyl alcohol (5b) also gave the cross-dimer (E)-
PhC≡CCH=CHCH2OH (E-6b)in moderate yield but the product
contains the regioisomer 7 and the homo-dimers 3a (entry 2). How-
ever, the yield and selectivity of E-6b were improved when twice
The cross-dimerization of alkynes is still limited to date
[17,29,30]. To evaluate the scope of this catalysis, the cross-
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Fig. 1. Time-course curves for dimerization of phenylacetylene (2a) catalyzed by 1.
Conditions: [1] = 5.0 mM, [2a]0 = 1.00 M, temp = 100 ◦ C, solvent = toluene.
Fig. 3. Dependence of reciprocal concentration of 2a on the reaction time. [1] = 2.5
(ꢀ), 5.0 (᭿), 7.6 (ꢁ), 10.0 (᭹) and 15.0 mM (ꢀ), [2a]0 = 1.00 M, temp = 100 ◦ C, sol-
vent = toluene.
Fig. 2. Time-course curves for dimerization of arylacetylenes 2 catalyzed by 1.
(E)-1,4-diphenylbut-1-en-3-yne (E-3a: ᭹), (Z)-1,4-diphenylbut-1-en-3-yne (Z-3a:
ꢀ), (E)-1,4-bis(4-trifluoromethylphenyl)but-1-en-3-yne (E-3d: ꢀ), (Z)-1,4-bis(4-
trifluoromethylphenyl)but-1-en-3-yne (Z-3d: ♦), (E)-1,4-bis(4-methylphenyl)but-
1-en-3-yne (E-3f: ᭿), (Z)-1,4-bis(4-methylphenyl)but-1-en-3-yne (Z-3f: ᮀ), Condi-
tions: [1] = 18 mM, [2]0 = 0.18 M, temp = 50 ◦ C, solvent = benzene-d6.
Fig. 4. Dependence of catalyst concentration [1] on the observed rate constant kobsd
.
Fig. 3 shows the dependence of the reciprocal concentration of
2a on the reaction time under the various concentrations of catalyst
1. This linear relationship with the same intercept clearly suggests
the second-order reaction with regard to the concentration of 2a.
The observed second-order rate constants kobsd are proportional
to the concentration of 1 (Fig. 4), showing this dimerization reaction
to obey the first-order kinetics with regard to the concentration of
the dinuclear complex 1.
This fact draws an important conclusion. Namely, the dinuclear
ruthenium species does catalyze the dimerization of 2a, and the
catalysis promoted by in situ generated mononuclear species is
ruled out. The overall experimental rate formula is expressed as
shown in Eq. (2).
amount of 5b was employed in this reaction (entry 3). In sum-
mary of this section, although electron-rich internal alkynes are
not effective for this cross-dimerization (entries 5 and 6), highly
electron-deficient alkynes seems to be effective for the cross-
dimerization (entry 1).
2.2. Kinetic study
To shed light on the mechanism for this dimerization, time-
course for the reaction of 2a catalyzed by 1 (0.5 mol%) was
monitored by GLC. As shown in Fig. 1, E-3a is dominantly produced
during course of the reaction and the isomerization from Z-3a to
E-3a seems to be negligible.
rate = k[1][2a]2
(2)
2.3. Proposed mechanism for dimerization of phenylacetylene
A similar trend has been observed for the reaction using
phenylacetylene (2a), 4-trifluorophenylacetylene (2d) and 4-
methylphenylacetylene (2f) (Fig. 2). Namely, the conversion of E-3
into Z-3 is also negligible for these substrates. These formation
rates are roughly the same but those for E-3 seems to be slightly
promoted by an electron-rich alkyne 2f. Thus, the protonolysis
of an intermediate by 2 may not be the rate-determining step
in the catalysis. The formation of Z-3 is slightly promoted for 2d
compared to the other alkynes. However, since the yields of Z-3
are not particularly high for 4-nitrophenylacetylene (2b) (Table 1,
entry 7), 4-cyanophenylacetylene (2c) (Table 1, entry 8) and 4-
acetylphenylacetylene (2e) (Table 1, entry 10), this is not simply
reasoned for the electronic effect.
The present catalysis has the following features: (i) the present
catalysis dominantly produces the E-1,4-disubstituted enynes,
(ii) the reaction is discouraged by addition of PMe3, (iii) this
reaction probably involves protonolysis of (1,4-diphenylbut-3-yn-
1-enyl)ruthenium species by phenylacetylene (2a), and (iv) this
catalysis obeys the first- and second-order kinetics with regard to
[1] and [2a], respectively, and the dinuclear ruthenium species is
responsible to the active catalyst. All these experimental data are
consistent with the mechanism as illustrated in Scheme 3: (step 1)
the catalyst precursor 1 releases the PMe3 ligand to give a coordi-
natively unsaturated species A [32], (step 2) A reacts with 2a and
the ␮-hydroxo group abstracts the alkynyl proton to give B, (step 3)
the second 2a coordinates to the resulting vacant site in the same
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d[3a]
dt
k4k5K1[Ru2]total[2a]2
{k5/(K2K3)}(K1 + [PMe3]) + (K1/K3){k5 + K3(k4 + k5[2a])}[2a]
=
(4)
The intermediates A and B are coordinatively unsaturated
species and these equilibriums between 1 and A, and between B
and C must lie far to the 1 and C sides, respectively. We therefore
assume the equilibrium constants are K1 « 1 and K3 » 1. The term
K1/K3 approximates to zero and the rate equation is reduced to Eq.
(5). This formula is consistent with the experimental equation [Eq.
(2)].
d[3a]
dt
k4K1K2K3[Ru2]total[2a]2
K1 + [PMe3]
=
(5)
This is the first kinetic study for the alkyne dimerizations
catalyzed by a dinuclear complex, although the kinetic studies
by mononuclear complexes have been reported [11,12a,b,33a–e].
Compared with the other proposed mechanisms shown in
Scheme 2, one of the features in this catalysis is that one of the
ruthenium centers acts as the reaction site and the other ruthenium
center eventually behaves as a spectator in the present dinuclear
catalysis.
3. Concluding remarks
Tris(␮-hydroxo)diruthenium(II) complex 1 catalyzed dimeriza-
tion of phenylacetylene (2a) to give (E)-1,4-diphenylbut-3-en-1-
yne (E-3a). The kinetic data suggest this catalysis to start by prior
dissociation of a PMe3 ligand from 1, and the dinuclear structure
remains intact during the catalysis. Because present catalysis dom-
inantly produces the E-enyne, the endo attack of the alkynyl group
to the coordinated alkyne (or vinylidene) is the most likely process.
Thus, only one of the ruthenium(II) centers in 1 acts as the reaction
site and the other ruthenium(II) center is coordinatively saturated
and behaves as a spectator in the catalytic cycle. This is the key for
the high E-selectivity of 3a in this dinuclear catalysis.
Although we started this chemistry as an extension of hydra-
tion of nitriles catalyzed by 1, 1 actually favored dimerization
rather than hydration for terminal alkynes. A perspective of alkyne
dimerizaitons is the cross-dimerizations. The catalytic cross-
dimerizations using alkynes will be documented in due course.
Scheme 3. A Possible mechanism for dimerization of phenylacetylene (2a).
ruthenium center in B to give C, (step 4) the endo side attack of the
alkynyl group to the coordinated phenylacetylene in C produces the
alkenyl intermediate D, and (step 5) the final step is protonolysis
of the (E)-1,4-diphenylbut-3-yn-1-enyl group by the incoming 2a
to release E-3a with recovery of B.
4. Experimental section
4.1. General
In this mechanism, we postulated that 2a initially gives an
acetylide intermediate B. In fact, a similar reaction of trans-
RuH(OH)(dmpe)2 with 2a has been reported to give an acetylide
complex trans-RuH(C≡CPh)(dmpe)2 [32]. Because the E-selective
formation of 3a arises from the carbon-carbon bond formation at
the same ruthenium center by the endo side attack, we believe the
aqua ligand in B remaining attached to avoid coordination of the
second 2a at the second ruthenium center. 2a may coordinate to A
to give B’ instead of B (Chart 2). In this case, B’ would exist prior
to give B, which is also a reasonable scenario. The intermediate C
may be expressed as an (alkynyl)(vinilydene) complex C’. In this
case D’ would be eventually formed from C’. Although C’ may exist
in the catalytic cycle instead of C for homo-dimerization of 2a, we
still favor to adopt C rather than C’ in Scheme 3 because present
system also catalyzes some cross-dimerizations between 2a and
an internal alkyne.
All manipulations and reactions were performed under dry
nitrogen atmosphere with use of standard Schlenk and vac-
uum line techniques. Preparation of dinuclear ruthenium complex
[(Me3P)3Ru(␮-OH)3Ru(PMe3)3]+[OPh]−·(HOPh)n [1·(HOPh)n] was
reported previously [24]. The cationic complex 1 bearing phe-
noxide anion contains phenol by hydrogen bonding and numbers
of the adjunct phenol were estimated by 1H NMR. Pheny-
lacetylene (2a) was purchased from the commercial supplier
and stored under nitrogen atmosphere after 3 freeze-pump-
thaw cycles. 4-Nitrophenylacetylene, 4-acylphenylacetylene, 4-
aminophenylacetylene and 4-cyanophenylacetylene were pre-
pared according to the literature procedure [34]. 1,4-Dioxane and
toluene were distilled over sodium benzophenone ketyl.
The NMR spectra were recorded on a JEOL LA300 and a JEOL
ECX400P spectrometers (300.4 MHz and 400.0 MHz for 1H). The
internal reference was either tetramethylsilane, triphenylmethane
or the residual solvent peak. Acetone-d6 was dried over Drierite and
distilled under nitrogen. Benzene-d6 was dried over sodium wire
and stored under vacuum. Chloroform-d1 was used as received.
IR spectra were recorded on a JASCO FT/IR-410 spectrometer.
GLC analysis was performed on a Shimadzu GC–14 B equipped
The rate law is derived by assuming the equilibriums among
1, A, B and C as shown in Scheme 3. With agreement, the rate
is expressed by Eq. (4), where [Ru2]total is the same as the initial
concentration of 1.
[Ru2]total = [1] + [A] + [B] + [C] + [D]
(3)
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Chart 2. Alternative structures for B, C and D.
C6H4). Z-3c: 1H NMR (CDCl3): ı 6.10 (d, J = 12 Hz, 1H, =CH), 6.80
(d, J = 12 Hz, 1H, =CH), 7.5–7.7 (m, overlapped with resonances for
E-3c, C6H4), 7.94 (d, J = 8 Hz, 2H, C6H4).
with FID detector by use of glass capillary column (TC-wax,
0.25 mm␾ × 30 m). GC–MS was performed on a Shimadzu GC–MS
QP2010. Enyne products 3a [18,35], 3b [36], 3c [35,36], E-3d [10], Z-
3d [23], 3f [35,37], 3g [20,35,37], 3h [18f,38,39], 6a [40], 6b [41,42],
6c [43], and 6d [44], were characterized according to the literatures.
4.2.4. 4-Trifluoromethylphenylacetylene (2d)
2d (15.8 ␮L, 0.11 mmol) was treated with 1·(HOPh)0.4 (9.1 mg,
0.011 mmol) in benzene-d6 at 50 ◦ C for 20 h to give (E)-1,4-
bis(4-trifluoromethylphenyl)but-3-en-1-yne (E-3d) and (Z)-1,4-
bis(4-trifluoromethylphenyl)but-3-en-1-yne (Z-3d) in 83% and 15%
yields, respectively, based on triphenylmethane as an internal stan-
dard. These products were characterized by NMR. E-3d: 1H NMR
(CDCl3): ı 6.50 (d, J = 17 Hz, 1H, =CH), 7.13 (d, J = 17 Hz, 1H, over-
lapped with resonances for triphenylmethane, =CH), 7.55–7.65 (m,
8H, overlapped with resonances for Z-3d, C6H4). 1H NMR (C6D6, 50
◦ C): ı 6.10 (d, J = 16.3 Hz, 1H, =CH), 6.75 (d, J = 16.3 Hz, 1H, =CH),
7.12–7.30 (m, 8H, overlapped with resonances for Z-3d, C6H4).
19F NMR (376 MHz, CDCl3): ı −62.5 (s, CF3), −62.7 (s, CF3). Z-3d:
1H NMR (CDCl3): ı 6.08 (d, J = 12 Hz, 1H, =CH), 6.83 (d, J = 12 Hz,
1H, =CH), 7.54–7.70 (m, 6H, overlapped with resonances for E-3d,
C6H4), 8.02 (d, J = 8.0 Hz, 2H, C6H4). 1H NMR (C6D6, 50 ◦C): ı 5.71
(d, J = 12.0 Hz, 1H, =CH), 6.25 (d, J = 12.0 Hz, 1H, =CH), 7.12–7.44 (m,
6H, overlapped with resonances for E-3d, C6H4), 7.62 (d, J = 8.0 Hz,
2H, C6H4).
4.2. Catalytic dimerization by
[(Me3P)3Ru(ꢀ-OH)3Ru(PMe3)3]+[OPh]− (1)
4.2.1. Phenylacetylene (2a)
(method A) Complex 1·(HOPh)0.5 (4.3 mg, 0.0051 mmol) and 2a
(102.2 mg, 1.00 mmol) were placed in a test tube that was then
capped with a screw cap under nitrogen. The reaction system was
stirred at 100 ◦ C for 2 h. Then, dibenzyl (31.4 mg, 0.172 mmol) was
added into the solution as an internal standard and the products
were analyzed by GLC and GC–MS. Conversion of 2a: 100%. Yield of
(E)-1,4-diphenylbut-3-en-1-yne (E-3a): 94%, (Z)-1,4-diphenylbut-
3-en-1-yne (Z-3a): 9%. (method B) Similar treatment of 1·(HOPh)0.5
(4.3 mg, 0.0051 mmol) with 2a (102.4 mg, 1.00 mmol) in the pres-
ence of 1,4-dioxane (1.0 mL) gave E-3a (74%) and Z-3a (9%) with
84% conversion of 2a. (method C) Complex 1·(HOPh)0.5 (32.4 mg,
0.0381 mmol) was placed in a Schlenk tube under nitrogen into
which 2a (1.1 mL, 10 mmol) was added by a hypodermic syringe.
The solution was heated at 100 ◦ C for 12 h. The resulting prod-
uct was extracted by hexane and all volatile matters were removed
under reduced pressure. After recrystallization of the resulting solid
gave pale orange microcrystals of E-3a in 69% yield (698.9 mg,
6.85 mmol). E-3a: 1H NMR (CDCl3): ı 6.31 (d, J = 16 Hz, 1H, CH),
6.96 (d, J = 16 Hz, 1H, CH), 7.2–7.3 (m, 6H, Ph), 7.3–7.5 (m, 4H,
Ph). Z-3a: 1H NMR (CDCl3): ı 5.84 (d, J = 12 Hz, 1H, CH), 6.63 (d,
J = 12 Hz, 1H, CH), 7.1–7.4 (m, overlapped with resonances for E-
3a, Ph), 7.85 (d, J = 7 Hz, 2H, Ph).
4.2.5. 4-Acetylphenylacetylene (2e)
2e (144.3 mg, 1.00 mmol) was treated by 1·(HOPh)0.2
(4.3 mg, 0.0052 mmol) at 100 ◦ C for 2 h to give
(E)-1,4-bis(4-acetylphenyl)but-3-en-1-yne (E-3e) and (Z)-1,4-
bis(4-acetylphenyl)but-3-en-1-yne (Z-3e) in 82% and 6% yields,
respectively. These products were characterized by GC and NMR.
E-3e: 1H NMR (CDCl3): ı 2.61 (s, 6H, Me), 6.51 (d, J = 16 Hz, 1H,
=CH), 7.11 (d, J = 16 Hz, 1H, =CH), 7.51 (d, J = 8 Hz, 2H, C6H4), 7.56
(d, J = 8 Hz, 2H, C6H4), 7.93-7.96 (m, 4H, C6H4). Z-3e: 1H NMR
(CDCl3): ı 6.10 (d, J = 12 Hz, 1H, =CH), 6.80 (d, J = 12 Hz, 1H, =CH),
the aromatic protons were obscured because of overlapping with
E-3e.
4.2.2. 4-Nitrophenylacetylene (2b)
Similar to the dimerization of 2a, 2b (147.7 mg, 1.00 mmol) was
treated by 1·(HOPh)0.2 (4.1 mg, 0.0050 mmol) at 100 ◦ C for 2 h
to give (E)-1,4-bis(4-nitrolphenyl)but-3-en-1-yne (E-3b) and (Z)-
1,4-bis(4-nitrolphenyl)but-3-en-1-yne (Z-3b) in 94% and 4% yields,
respectively. These products were characterized by GC and NMR. E-
3b: 1H NMR (CDCl3): ı 6.56 (d, J = 16 Hz, 1H, =CH), 7.16 (d, J = 16 Hz,
1H, =CH), 7.59 (d, J = 9 Hz, 2H, C6H4), 7.63 (d, J = 9 Hz, 2H, C6H4), 8.23
(d, J = 8 Hz, 4H, C6H4). Z-3b: 1H NMR (CDCl3): ı 6.17 (d, J = 12 Hz,
1H, =CH), 6.86 (d, J = 12 Hz, 1H, =CH), 7.5–7.8 (m, overlapped with
resonances for E-3b, C6H4), 8.01 (d, J = 9 Hz, 2H, C6H4).
4.2.6. 4-Methylphenylacetylene (2f)
2f (116.1 mg, 1.00 mmol) was treated by 1·(HOPh)0.5
(4.3 mg, 0.0051 mmol) at 100 ◦ C for 2 h to give
(E)-1,4-bis(4-methylphenyl)but-3-en-1-yne (E-3f) and (Z)-1,4-
bis(4-methylphenyl)but-3-en-1-yne (Z-3f) in 94% and 5% yields,
respectively. These products were characterized by GC and NMR.
E-3f: 1H NMR (CDCl3): ı 2.33 (s, 6H, Me), 6.31 (d, J = 17 Hz, 1H, =CH),
6.92 (d, J = 17 Hz, 1H, =CH), 7.1–7.5 (m, 4H, C6H4), 7.30 (d, J = 8 Hz,
2H, C6H4), 7.34 (d, J = 8 Hz, 2H, C6H4). Z-3f: 1H NMR (CDCl3): ı
2.33 (overlapped with the signal for E-3f, Me), 5.86 (d, J = 12 Hz,
1H, =CH), 6.65 (d, J = 12 Hz, 1H, =CH), 7.0–7.4 (m, overlapped with
resonance for E-3f, C6H4), 7.85 (d, J = 8 Hz, 2H, C6H4).
4.2.3. 4-Cyanophenylacetylene (2c)
2c (127.3 mg, 1.00 mmol) was treated by 1·(HOPh)0.2
(4.1 mg, 0.0050 mmol) at 100 ◦ C for 2 h to give
(E)-1,4-bis(4-cyanophenyl)but-3-en-1-yne (E-3c) and (Z)-1,4-
bis(4-cyanophenyl)but-3-en-1-yne (Z-3c) in 67% and 3% yields,
respectively. These products were characterized by GC and NMR.
E-3c: 1H NMR (CDCl3): ı 6.49 (d, J = 16 Hz, 1H, =CH), 7.08 (d,
J = 16 Hz, 1H, =CH), 7.50–7.58 (m, 4H, C6H4), 7.61–7.66 (m, 4H,
4.2.7. 2-Methylphenylacetylene (2g)
2g (116.5 mg, 1.00 mmol) was treated by 1·(HOPh)0.5
(4.3 mg, 0.0051 mmol) at 100 ◦ C for 2 h to give (E)-
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1,4-bis(2-methylphenyl)but-3-en-1-yne
(E-3 g)
and
4.3.3. Methyl 2-butynoate (5c)
(Z)-1,4-bis(2-methylphenyl)but-3-en-1-yne (Z-3 g) in 68% and
14% yields, respectively. These products were characterized by GC,
GC–MS and NMR. E-3 g: 1H NMR (CDCl3): ␦ 2.39 (s, 3H, Me), 2.47
(s, 3H, Me), 6.33 (d, J = 16 Hz, 1H, =CH), 7.10-7.23 (m, 6H C6H4), 7.26
(d, J = 16 Hz, 1H, =CH), 7.44 (d, J = 7 Hz, 1H, C6H4), 7.48-7.55 (m, 1H,
C6H4). Z-3 g: 1H NMR (CDCl3): ␦ 2.34 (s, 3H, Me), 2.39 (overlapped
with the signal for E-3 g, Me), 6.00 (d, J = 12 Hz, 1H, =CH), 6.88 (d,
J = 12 Hz, 1H, =CH), 7.1-7.4 (m, overlapped with resonances for
E-3 g, C6H4).
2a (55 ␮L, 0.50 mmol) and 5c (51 ␮L, 0.52 mmol) were treated
by 1·(HOPh)0.5 (8.6 mg, 0.010 mmol) at 100 ◦ C for 3 h to give (E)-
methyl 3-methyl-5-phenylpent-2-en-4-ynoate (E-6c), E-3a and Z-
3a in 28%, 60% and 8% yields, respectively. These products were
characterized by GC, GC–MS and NMR. E-6c: 1H NMR (CDCl3): ␦
2.39 (d, J = 2 Hz, 3H), 3.74 (s, overlapped with resonances for E-6c,
3H), 6.15–6.18 (m, 1H).
4.3.4. 1-Phenyl-1-propyne (5d)
2a (51.6 mg, 0.51 mmol) and 5d (59.7 mg, 0.51 mmol) were
treated by 1·(HOPh)0.4 (4.2 mg, 0.0050 mmol) at 100 ◦ C for 4 h to
give (E)-3-methyl-1,4-diphenylbut-3-en-1-yne (E-6d), E-3a and Z-
3a in 2%, 78% and 16% yields, respectively. These products were
characterized by GC and NMR. E-6d: 1H NMR (CDCl3): ␦ 2.16 (d,
J = 2 Hz, 3H), 6.93 (s, 1H), the other resonances were obscured
because of significant overlapping with those for 3a.
4.2.8. 1-Octyne (2 h)
2 h (112.6 mg, 1.02 mmol) was treated by 1·(HOPh)0.4 (16.8 mg,
0.020 mmol) at 100 ◦ C for 12 h to give (E)-hexadec-7-en-9-yne
(E-3 h), (Z)-hexadec-7-en-9-yne (Z-3 h) and 9-methylenepentadec-
7-yne (4 h) in 7%, 40% and 11% yields, respectively. These products
were characterized by GC, GC–MS and NMR. E-3 h: 1H NMR (CDCl3):
ı 0.86-0.89 (m, overlapped with resonance for Z-3 h and 4 h, 6H),
1.26-1.44 (m, overlapped with resonance for Z-3 h and 4 h, 16H),
2.22-2.36 (m, overlapped with resonance for Z-3 h and 4 h, 4H),
5.39-5.46 (overlapped with resonance for Z-3 h, 1H, =CH), 6.02
(dt, J = 16, 7 Hz, 1H, =CH). Z-3 h: 1H NMR (CDCl3): ␦ 0.86-0.89 (m,
overlapped with resonance for E-3 h and 4 h, 6H), 1.26-1.44 (m,
overlapped with resonance for E-3 h and 4 h, 16H), 2.22-2.36 (m,
overlapped with resonance for E-3 h and 4 h, 4H), 5.40 (d, J = 11 Hz,
1H, =CH), 5.79 (dt, J = 11, 7 Hz, 1H, =CH). 4 h: 1H NMR (CDCl3): ␦
0.86-0.89 (m, overlapped with resonance for E-3 h and Z-3 h, 6H),
1.26-1.56 (m, overlapped with resonances for E-3 h and Z-3 h, 16H),
2.09 (t, J = 7 Hz, 2H), 2.30 (m, overlapped with resonances for E-3 h
and Z-3 h 2H), 5.10 (d, J = 2 Hz, 1H, =CH), 5.18 (d, J = 2 Hz, 1H, =CH).
In addition to these products, 3 isomers of the trimers of 2 h were
observed by GC–MS analysis [m/z = 303 (M+)], although the detailed
structures of these trimers were not clear by the NMR analysis.
4.3.5. Diphenylacetylene (5e)
2a (51.6 mg, 0.51 mmol) and 5e (89.3 mg, 0.50 mmol) were
treated by 1·(HOPh)0.5 (8.5 mg, 0.010 mmol) at 100 ◦ C for 4 h to
give E-3a and Z-3a in 63% and 10% yields, respectively.
4.4. Dimerization of phenylacetylene (2a) in the presence of PMe3
Complex 1·(HOPh)0.3 (4.2 mg, 0.0051 mmol), 2a (103.1 mg,
1.01 mmol), PMe3 (5.2 ␮L, 0.050 mmol) and toluene (1.0 mL) were
placed in a test tube that was then capped with a screw cap under
nitrogen. The reaction system was stirred at 100 ◦ C for 4 h. Then,
dibenzyl (30.2 mg, 0.17 mmol) was added into the solution as an
internal standard and the products were analyzed by GLC. Conver-
sion of 2a: 5%. Yield of E-3a: 1%.
4.5. Dimerization of phenylacetylene (2a) in the presence of
water or KOH
4.3. Catalytic cross-dimerization of phenylacetylene (2a) with
alkynes by 1
Complex 1·(HOPh)0.4 (4.2 mg, 0.0050 mmol), 2a (102.1 mg,
1.00 mmol), H2O (0.1 mL) and 1,4-dioxane (0.9 mL) were placed in
a test tube that was then capped with a screw cap under nitro-
gen. The reaction system was stirred at 100 ◦ C for 2 h. Then,
dibenzyl (31.4 mg, 0.172 mmol) was added into the solution as an
internal standard and the products were analyzed by GLC. Conver-
sion of 2a: 48%. Yield of E-3a: 45%, Z-3a: 2%. Similarly, complex
1·(HOPh)0.4 (4.2 mg, 0.0050 mmol), 2a (120.0 ␮L, 1.10 mmol), KOH
(2.1 mg, 0.038 mmol) and 1,4-dioxane (1.0 mL) were placed in a
test tube that was then capped with a screw cap under nitrogen.
The reaction system was stirred at 100 ◦ C for 2 h. Then, dibenzyl
(22.1 mg, 0.121 mmol) was added into the solution as an internal
standard and these products were analyzed by GC, GC–MS and
NMR. Conversion of 2a: 77%. Yield of E-3a: 53%, Z-3a: 3%.
4.3.1. Dimethyl acectylenedicarboxylate (DMAD) (5a)
Complex 1·(HOPh)0.4 (8.4 mg, 0.010 mmol) and phenylacetylene
(2a) (51.4 mg, 0.50 mmol), DMAD (5a) (70.9 mg, 0.50 mmol) and
toluene (1.0 ml) were placed in a test tube that was then capped
with a screw cap under nitrogen. The reaction system was stirred
at 100 ◦ C for 3 h. Then, dibenzyl (23 mg, 0.13 mmol) was added
into the solution as an internal standard and these products were
analyzed by GC, GC–MS and NMR. Conversion of 2a: 83%. Yield of
dimethyl 2-(phenylethynyl)maleate (Z-6a): 63%, E-3a: 2%, Z-3a: 3%.
Z-6a: 1H NMR (CDCl3): ␦ 3.79 (s, 3H, CO2Me), 3.92 (s, 3H, CO2Me),
6.34 (s, 1H, CH), 7.33-7.52 (m, 5H, Ph).
4.6. Dimerization of phenylacetylene (2a) in the presence of D2O
4.3.2. Propargyl alcohol (5b)
2a (51.7 mg, 0.51 mmol) and 5b (28.7 mg, 0.51 mmol) were
treated by 1·(HOPh)0.5 (8.4 mg, 0.0099 mmol) at 100 ◦ C for 6 h
to give (E)-5-phenyl-2-penten-4-yn-1-ol (E-6b), 2-Methylene-4-
phenylbut-3-yn-1-ol (7b), E-3a and Z-3a in 40%, 18%, 25%, and
4% yields, respectively. These products were characterized by GC,
GC–MS and NMR. (method B) Similar treatment of 1·(HOPh)0.5
(8.4 mg, 0.0099 mmol) with 2a (51.6 mg, 0.50 mmol) and 5b
(57.0 mg, 1.02 mmol) at 100 ◦ C for 3 h gave E-6b (59%), 7b (11%),
E-3a (6%) and Z-3a (1%). E-6b: 1H NMR (CDCl3): ␦ 4.26 (dd, J = 5,
2 Hz, 2H), 5.96 (dt, J = 16, 2 Hz, 1H, =CH), 6.34 (dt, J = 16, 5 Hz, 1H,
=CH), 7.29-7.32 (m, 3H), 7.41-7.48 (m, 2H). 7b: 1H NMR (CDCl3): ␦
4.21 (br, 2H), 5.57 (d, J = 1 Hz, 1H, =CH2), 5.60 (d, J = 1 Hz, 1H, =CH2),
7.29-7.48 (m, overlapped with resonance for E-6b, 5H).
Complex 1·(HOPh)0.4 (4.2 mg, 0.0050 mmol), 2a (103.0 mg,
1.01 mmol), D2O (0.1 mL) and 1,4-dioxane (0.9 mL) were placed in
a test tube that was then capped with a screw cap under nitrogen.
The reaction system was stirred at 100 ◦ C for 2 h. These products
were characterized by NMR. Yield of E-3a: 40%, Z-3a: 3%. The 3- and
4-positions in E-3a were deuteraed in 60 atom D% and 56 atom D%,
respectively.
4.7. Kinetic study
In the volumetric flask 2a (550 ␮L, 5.05 mmol) and dibenzyl
(149.5 mg, 0.820 mmol) were diluted with toluene to prepare a pre-
cise dilution of 2a (5.00 mL, 1.01 M). The toluene solution (1.0 mL)
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9
was added to 1·(HOPh)0.4 (4.2 mg, 0.0050 mmol) and a magnetic stir
bar in a test tube by using a volumetric pipette. Then a screw cap
was put on the test tube under nitrogen. The reaction system was
stirred at 100 ◦ C. The time course of the reaction was monitored by
GLC.
[12] (a) by Sc, Y, La K.H. den Haan, Y. Wielstra, J.H. Teuben, Organometallics 6
(1987) 2053–2060;
(b) R. Duchateau, C.T. van Wee, J.H. Teuben, Organometallics 15 (1996)
2291–2302;
(c) H.J. Heeres, J.H. Tauben, Organometallics 10 (1991) 1980–1986.
[13] by Ti complex: G.V. Oshovsky, B. Hessen, J.N.H. Reek, B. de Bruin,
Organometallics 30 (2011) 6067–6070.
Following experiments were also carried out in the similar way.
[1] = 2.5 mM: 1·(HOPh)0.4 (2.1 mg, 0.0025 mmol), a toluene solu-
tion of 2a (1.00 mL, 1.01 M, 1.01 mol) and dibenzyl (0.143 mmol).
[1] = 7.6 mM: 1·(HOPh)0.4 (6.4 mg, 0.0076 mmol), a toluene solu-
tion of 2a (1.00 mL, 1.01 M, 1.01 mmol) and dibenzyl (0.164 mmol),
[1] = 10.0 mM: 1·(HOPh)0.4 (8.4 mg, 0.010 mmol), a toluene solu-
tion of 2a (1.00 mL, 1.01 M, 1.01 mmol) and dibenzyl (0.164 mmol),
[1] = 15.0 mM: 1·(HOPh)0.4 (12.6 mg, 0.0150 mmol), a toluene solu-
tion of 2a (1.00 mL, 1.01 M, 1.01 mmol) and dibenzyl (0.164 mmol).
[14] (a) by Ru complex: K. Melis, D.D. Vos, P. Jacobs, F. Verpoort, J. Organomet.
Chem. 671 (2003) 131–136;
(b) K. Melis, T. Opstal, F. Verpoort, Eur. J. Org. Chem. (2002) 3779–3784.
[15] (Z)-1,4-disubstituted enyne by Ru complex: M. Echavarren, J. López, A. Santos,
J. Montoya, J. Organomet. Chem. 414 (1991) 393–400.
[16] (a) by Ru complexes: L. Dahlensburg, K.-M. Frosin, S. Kerstan, D. Werner, J.
Organomet. Chem. 407 (1991) 115–124;
(b) C. Gemel, G. Kickelbick, R. Schmid, K. Kirchner, J. Chem. Soc. Dalton Trans.
(1997) 2113–2118;
(c) M.A.J. Tenorio, M.J. Tenorio, M.C. Puerta, P. Valerga, Organometallics 19
(2000) 1333–1342;
(d) A. Coniglio, M. Bassetti, S.E. García-Garrído, J. Gimeno, Adv. Synth. Catal.
354 (2012) 148–158;
(e) L.D. Field, A.M. Magill, T.K. Shearer, S.J. Dalgarno, M.M. Bhadbhade, Eur. J.
Inorg. Chem. (2011) 3503–3510.
Acknowledgments
[17] by Fe complex: O. Rivada-Wheelaghan, S. Chakraborty, L.J.W. Shimon, Y.
Ben-David, D. Milstein, Angew. Chem. Int. Ed. 55 (2016) 6942–6945.
[18] (a) by Ru complexes: C. Bianchini, M. Peruzzini, F. Zanobini, P. Frediani, A.
Albinati, J. Am. Chem. Soc. 113 (1991) 5453–5454;
A part of work was financially supported by Japan Science and
Technology Agency (JST), ACT-C and JSPS Grant-in-Aid for Scientific
Research on Innovative Areas “3D Active-Site Science” 26105003.
(b) T. Rappert, A. Yamamoto, Orgnaometallics 13 (1994) 4984–4993;
(c) C. Bianchini, P. Frediani, D. Masi, M. Peruzzini, F. Zanobini, Organometallics
13 (1994) 4616–4632;
Appendix A. Supplementary data
(d) C.S. Yi, N. Liu, Organometallics 15 (1996) 3968–3971;
(e) H. Katayama, M. Nakayama, T. Nakano, C. Wada, K. Akamatsu, F. Ozawa,
Macromolecules 37 (2004) 13–17;
(f) R.U. Kirss, R.D. Ernst, A.M. Arif, J. Organomet. Chem. 689 (2004) 419–428;
(g) X. Chen, P. Xue, H.H.Y. Sung, I.D. Williams, M. Peruzzini, C. Bianchini, G. Jia,
Organometallics 24 (2005) 4330–4332.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.molcata.2016.08.
027.
[19] by Os complex: M.A. Esteruelas, L.A. Oro, N. Ruiz, Organometallics 13 (1994)
1507–1509.
References
[20] mechanism B by a dinuclear Zr complex: R.H. Platel, L.L. Schafer, Chem.
Commun. 48 (2012) 10609–10611.
[21] (a) mecahnism C by dinuclear Ru complexes: J.-P. Qu, D. Masui, Y. Ishii, M.
Hidai, Chem. Lett. (1998) 1003–1004;
(b) Y. Nishibayashi, M. Yamanashi, I. Wakiji, M. Hidai, Angew. Chem. Int. Ed.
39 (2000) 2909–2911.
[22] 2,4-disubstituted enyne Y. Gao, R.J. Puddephatt, Inorg. Chim. Acta 350 (2003)
101–106.
[23] M. Nishiura, Z. Hou, Y. Wakatsuki, T. Yamaki, T. Miyamoto, J. Am. Chem. Soc.
125 (2003) 1184–1185.
[24] W.-X. Zhang, M. Nishiura, Z. Hou, Angew. Chem. Int. Ed. 47 (2008) 9700–9703.
[25] H. Matsuzaka, Y. Takagi, Y. Ishii, M. Nishio, M. Hidai, Organometallics 14
(1995) 2153–2155.
[1] B.M. Trost, Angew. Chem. Int. Ed. Engl. 34 (1995) 259–281.
[2] (a) C. Bruneau, P.H. Dixneuf, Acc Chem. Res. 32 (1999) 311–323;
(b) M. Nishiura, Z. Hou, J. Mol. Catal. A 213 (2004) 101–106;
(c) Y. Wakatsuki, Z. Hou, M. Tokunaga, Chem. Rec. 3 (2005) 144–157;
(d) E. Buestelo, P. H. Dixneuf: G. Dyker (Ed.), Handbook of C-H
Transformations, vol. 1, Wiley-VCH, Weinheim, (2005), pp. 62–72;
(e) B.M. Trost, A. McClory, Chem. Asian J. 3 (2008) 164–194;
(f) S.E. García-Garrído, B.M. Trost, C.-J. Li (Eds.), Catalytic Dimerization of
Alkyes. Modern Alkyne Chemistry: Catalytic and Atom-Economic
Transformations, Wiley-VCH, Weinheim, 2015, pp. 299–334;
(g) R. Drozdzak, B. Allaert, N. Ledoux, I. Dragutan, V.F. Valerian, Coord. Chem.
Rev. 249 (2005) 3055–3074.
[26] S. Kiyota, T. Kobori, H. Soeta, Y. Ichikawa, N. Komine, S. Komiya, M. Hirano,
Polyhedron (2016) http://dx.doi.org/10.1016/j.poly.2016.04.006.
[27] (a) G. Goddard, H.M. Herzog, M.T. Reetz, Tetrahedron 58 (2002) 7847–7850;
(b) T.D. Kim, T.J. McNeesem, A.L. Rheingold, Inorg. Chem. 27 (1988)
2554–2555;
[3] (a) by Re complex: A. Kawata, Y. Kuninobu, K. Takai, Chem. Lett. 38 (2009)
836–837;
(b) W. Baratta, W.A. Herrmann, P. Rigo, J. Schwarz, J. Organomet. Chem.
593–594 (2000) 489–493.
[4] In the following classifications of the (E)- and (Z)-enynes, we focused on the
dominant product of the phenylacetylene dimers as best as possible because
the same catalytic system sometimes produces different regio- and
stereoisomers depending on the substrates.
(c) R.O. Gould, C.L. Jones, T.A. Stephenson, D.A. Tocher, J. Organomet. Chem.
264 (1984) 365–378;
(d) T.V. Ashworth, M.J. Nolte, E. Singleton, J. Chem. Soc., Chem. Commun.
(1977) 936–937;
(e) R.A. Jones, G. Wilkinson, A.M.R. Galas, M.B. Hurshouse, K.M. Abudul Malik,
J. Chem. Soc. Dalton Trans. (1980) 1771–1778.
[5] (a) (E)-1,4-disubstituted enynes by Rh complexes: M. Schäfer, J. Wolf, H.
Werner, Organometallics 23 (2004) 5713–5728;
(b) W. Weng, C. Guo, R. C¸ elenligil-C¸ etin, B.M. Foxman, O.V. Ozerov, Chem.
Commun. (2006) 197–199;
(c) C.J. Pell, O.V. Ozerov, ACS Catal. 4 (2014) 3470–3480;
(d) A.M. Geer, A. Julián, J.A. López, M.A. Ciriano, C. Tejel, Chem. Eur. J. 20
(2014) 2732–2736.
[28] H. Katayama, F. Ozawa, Coord. Chem. Rev. 248 (2004) 1703–1715.
[29] (a) M. Akita, H. Yasuda, A. Nakamura, Bull Chem. Soc. J. 57 (1984) 480–487;
(b) J. Wang, M. Kapon, J.C. Berhet, M. Ephritikhine, M.S. Eisen, Inorg. Chim.
Acta 334 (2002) 183–192;
(c) H. Katayama, H. Yari, M. Tanaka, F. Ozawa, Chem. Commun. (2005)
4336–4338;
(d) W. Weng, C. Guo, R. Celenligil-Cetin, B.M. Foxman, O.V. Ozerov, Chem.
Commun. (2006) 197–199;
(e) T. Katagiri, H. Tsurugi, T. Satoh, M. Miura, Chem. Commun. (2008)
3405–3407;
(f) N. Tsukada, S. Ninomiya, Y. Aoyama, Y. Inoue, Org. Lett. 9 (2007)
2919–2921.
[6] by Ir complex: K. Ogata, A. Tokyota, J. Organomet. Chem. 692 (2007)
4139–4146.
[7] (a) 2,4-disubstituted enynes by Rh complex: W.T. Boese, A.S. Goldman,
Organometallics 10 (1991) 782–786;
(b) K. Mochizuki, K. Sakai, T. Kochi, F. Kakiuchi, Synthesis 45 (2013)
2088-2092;
(c) G. Kleinhans, G. Guisado-Barrios, D.C. Liles, G. Bertrand, D.I. Bezuidenhout,
Chem. Commun. 52 (2016) 3504–3507.
[30] H. Werner, F. Kukla, P. Steinert, Eur. J. Inorg. Chem. (2002) 1377–1389.
[32] A.W. Kaplan, R.G. Bergman, Organometallics 16 (1997) 1106–1108.
[33] (a) Pioneering kinetic studies for alkyne dimerizations: by a mononuclear Ir
complex: R. Ghosh, X. Zhang, P. Achord, T.J. Emge, K. Krogh-Jespersen, A.S.
Goldman, J. Am. Chem. Soc. 129 (2007) 853–866;
[8] (a) by Fe complexes: G.C. Midya, S. Paladhi, K. Dhara, J. Dash, Chem. Commum.
47 (2011) 6698–6700;
(b) G.C. Midya, B. Parasar, K. Dhara, J. Dash, Org. Biomol. Chem. 12 (2014)
1812–1822.
[9] (a) by Ru complexes: C. Slugovc, K. Meriter, E. Zobetz, R. Schmid, K. Kirchner,
Organometallics 15 (1996) 5275–5277;
(b) C.S. Yi, N. Liu, Organometallics 16 (1997) 3910–3913;
(c) M. Bassetti, S. Marini, F. Tortorella, V. Cadierno, J. Diez, M.P. Gamasa, J.
Gimeno, J. Organomet. Chem. 593–594 (2000) 292–298.
[10] by Pd complex: M. Rubina, V. Gevorgyan, J. Am. Chem. Soc. 123 (2001)
11107–11108.
(b) by mononuclear Ru complex: M. Bassetti, S. Marini, J. Díaz, M.P. Gamasa, J.
Gimeno, Y. Rodíguez- Álvarez, S. García-Granda, Organometallics 21 (2002)
4815–4822;
(c) M. Daniels, R.U. Kirss, J. Organomet. Chem. 692 (2007) 1716–1725;
(d) by a mononuclear Th complex: A.K. Dash, I. Gourevich, J.Q. Wang, M.
Kapon, M.S. Eisen, Organometallics 20 (2001) 5084–5104;
(e) by mononuclear Y and La complexes S. Ge, A. Meetsma, B. Hessen,
Organometallics 28 (2009) 719–726.
[11] by Th complex: A. Haskel, J.Q. Wang, T. Straub, T.G. Neyroud, M.S. Eisen, J. Am.
Chem. Soc. 121 (1999) 3025–3034.
Please cite this article in press as: S. Kiyota, et al., J. Mol. Catal. A: Chem. (2016), http://dx.doi.org/10.1016/j.molcata.2016.08.027

G Model
MOLCAA-10014; No. of Pages10
ARTICLE IN PRESS
S. Kiyota et al. / Journal of Molecular Catalysis A: Chemical xxx (2016) xxx–xxx
10
[34] Y. Toda, K. Sonogashira, N. Hagihara, Synthesis 11 (1977) 777–778.
[35] O.V. Zatolochnaya, E.G. Gordeev, C. Jahier, V.P. Ananikov, V. Gevorgyan, Chem.
Eur. J. 20 (2014) 9578–9588.
[40] J. Ito, M. Kitase, H. Nishiyama, Organometallics 26 (2007) 6412–6417.
[41] R. Takeuchi, K. Tanabe, S. Tanaka, J. Org. Chem. 65 (2000) 1558–1561.
[42] H.-D. Xu, R.-W. Zhang, X. Li, S. Huang, W. Tang, W. Hu, Org. Lett. 15 (2013)
840–843.
[43] H. Nakatsuji, K. Ueno, T. Misaki, Y. Tanabe, Org. Lett. 10 (2008) 2131–2134.
[44] B.D. Mokar, R.-S. Liu, Chem. Commun. 50 (2014) 8966–8969.
[36] C.-C. Lee, Y.-C. Lin, Y.-H. Liu, Y. Wang, Organometallics 24 (2005) 136–143.
˙
[37] B.Ö. Öztürk, S. Karabulut, Y. Appl. Catal. Imamog˘lu, A. 433–434 (2012)
214–222.
[38] S.R. Dubbaka, M. Kienle, H. Mayr, P. Knochel, Angew. Chem. Int. Ed. 46 (2007)
9093–9096.
[39] T. Hatakeyama, Y. Yoshimoto, T. Gabriel, M. Nakamura, Org. Lett. 10 (2008)
5341–5344.
Please cite this article in press as: S. Kiyota, et al., J. Mol. Catal. A: Chem. (2016), http://dx.doi.org/10.1016/j.molcata.2016.08.027