Ruthenium-catalyzed addition of terminal alkynes to alkynylstannanes with migration of the stannyl group

Article abstract of DOI:10.1246/bcsj.79.1963

In the presence of a catalytic amount of a ruthenium complex coordinated with PBu₃, alkynylstannanes (R¹C ≡CSnBu₃) were found to accept the addition of terminal alkynes (R²C≡CH) with a 1,2-shift of the stannyl g

Full text of DOI:10.1246/bcsj.79.1963

ꢀ 2006 The Chemical Society of Japan
Bull. Chem. Soc. Jpn. Vol. 79, No. 12, 1963–1976 (2006) 1963
Ruthenium-Catalyzed Addition of Terminal Alkynes to
Alkynylstannanes with Migration of the Stannyl Group
ꢀ1
Eiji Shirakawa, Kouji Nakayama,2 Ryotaro Morita,2 Teruhisa Tsuchimoto,2
Yusuke Kawakami,2 and Toshiaki Matsubara
ꢀ3
1Department of Chemistry, Graduate School of Science, Kyoto University, Sakyo, Kyoto 606-8502
2Graduate School of Materials Science, Japan Advanced Institute of Science and Technology, Nomi, Ishikawa 923-1292
3Center for Quantum Life Sciences and Graduate School of Science, Hiroshima University,
Kagamiyama, Higashi-Hiroshima 739-8530
Received June 8, 2006; E-mail: shirakawa@kuchem.kyoto-u.ac.jp
In the presence of a catalytic amount of a ruthenium complex coordinated with PBu3, alkynylstannanes (R1Cꢁ
CSnBu3) were found to accept the addition of terminal alkynes (R2CꢁCH) with a 1,2-shift of the stannyl group to give
(E)- and (Z)-1-tributylstannylbut-1-en-3-ynes (Bu3SnC(R1)=CHCꢁCR2). Various combinations of substrates having an
aromatic and/or aliphatic substituent can be used, and the stereochemical outcome depends largely on the character of
these substituents. The reaction of aliphatic terminal alkynes proceeds stereoselectively, and substituent R1 on the alky-
nylstannanes determines the configuration: E for R1 = alkyl and Z for R1 = aryl. In contrast, the reaction of arylace-
tylenes gave a mixture of stereoisomers irrespective of the character of substituent R1 on the alkynylstannane. Ruthe-
nium–ꢀ-stannylvinylidene complexes generated from a ruthenium complex and an alkynylstannane with migration of
the stannyl group are likely to be key intermediates, which accept addition of the C–H bond of terminal alkynes to give
the corresponding stannylenynes. DFT calculation clearly shows that the 1,2-shift of the stannyl group on formation of
ruthenium–ꢀ-stannylvinylidene complexes is more facile than the corresponding 1,2-hydrogen shift of the coordinating
terminal alkynes. The effect of the substituents on the stereoselectivity also is discussed based on the calculation.
Easily accessible alkynylmetals, which by themselves react
H
R
H
with various relatively strong electrophiles such as carbonyl
compounds and alkyl halides,1 are known to be effectively
activated by transition-metal catalysts to couple with aryl
and alkenyl halides.2 The collaboration between alkynylmetals
and transition metals enables us also to conduct the transition
metal-catalyzed addition of alkynylmetals to unsaturated
hydrocarbons. We have been disclosing the palladium- or
nickel-catalyzed carbostannylation3 of alkynes,4 1,3-dienes5
and 1,2-dienes,6 which gives synthetically useful alkenyl- and
allylstannanes having various conjugated and non-conjugated
substituents.7 On the contrary, unsaturated hydrocarbons are
reluctant to add to alkynylmetals probably due to the lack of
the method to make alkynylmetals ready to accept addition
of unsaturated hydrocarbons. To the best of our knowledge,
the addition of unsaturated hydrocarbons to alkynylstannanes
has no precedent.
R
H
R
H
cat. Ru
and / or
R
H
2
•
•
1
2
3
R
Ru
H
H
and / or isomers
R
R
H
R
1
R
2
R
H
(Z )-2
4
Ru
H
R
1
H
R
•
Ru
R
H
R
Ru
R
2
R
5
On the other hand, terminal alkynes are known to be activat-
ed by ruthenium complexes to form vinylidene complexes,8
which play important roles in the ruthenium-catalyzed addi-
tion to terminal alkynes.9 The electrophilic ꢁ-carbon atom of
vinylidene complexes reacts with nucleophiles such as water,
amines, alkynes, alkenes, and heteroarenes. Among these,
the dimerization of terminal alkynes giving 1,4-disubstituted
1-buten-3-ynes 2 and/or 1,2,3-butatrienes 3 (Scheme 1) is
one of the most extensively studied reactions,10 the mechanism
of which has been elucidated both experimentally10b,c,e and
theoretically,10e and the proposed catalytic cycle shown in
2
R
7
6
Scheme 1. Ruthenium-catalyzed dimerization of terminal
alkynes.
Scheme 1. Terminal alkyne 1 coordinates to bis(alkynyl)ruthe-
nium(II) complex 4 to form ruthenium–alkyne complex 5, of
which the terminal methyne proton undergoes 1,2-migration
to give vinylidene complex 6. One of the alkynyl groups of
6 shifts from the ruthenium atom to the electrophilic ꢁ-carbon
Published on the web December 13, 2006; doi:10.1246/bcsj.79.1963

1964 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
Table 1. Ruthenium-Catalyzed Addition of Phenylacetylene
to Tributyl(1-octynyl)tin: Effect of SolventsaÞ
H2 (1 atm)
– Ru
R
[{RuCl(η6-p-cymene)}2(µ-Cl)2]
(0.050 mol. amt. of Ru)
PBu3 (0.30 mol. amt.)
Hex
SnBu3
Ph
A
Hex
Bu3Sn
R
Bu3Sn
8a
•
Ru
+
Hex
+
Bu3Sn
R'
50 °C, 5 h
R'
– Ru
H
H
Ph
Bu3Sn
Ph
9a
10a
11a
R
B
Conversion Yield
/%bÞ
Bu3Sn
Entry
Solvent
/%bÞ 10a/11abÞ
Ru
1
2
3
4
5
6
7
8
9
DMSO
DMF
DMA
NMP
THF
Toluene
EtOH
H2O
>99
97
24
17
18
15
13
5
90
76
15
12
9
<1
3
<1
64
67/33
68/32
67/33
67/33
67/33
—
>99/1
—
67/33
R
cat. Pd or Ni
R'
H
SnBu3
R
SnBu3
C
R'
Scheme 2. Addition reactions concerning alkynylstannanes.
atom, giving alkenylruthenium 7. Finally, dimerization prod-
ucts 2 and/or 3 are generated through the reaction of 7 with
another molecule of 1.
DMSO–H2O (3:1)
88
a) The reaction was carried out in a solvent (0.30 mL) at 50 ꢂC
for 5 h using tributyl(1-octynyl)tin (0.40 mmol), phenylacety-
lene (0.60 mmol), [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] (0.050
mol amt. of Ru), and PBu3 (0.30 mol amt.). b) Determined
by 119Sn NMR.
In addition to terminal alkynes, alkynylsilanes are known to
form ruthenium–vinylidene complexes, which have been iso-
lated and characterized by X-ray analysis.11,12 A ꢀ-silylvinyli-
dene complex is considered to be a key intermediate in the cy-
clocarbonylation of 1,10-bis(silylethynyl)ferrocene, where one
of the silyl groups undergoes 1,2-migration.13,14 We have re-
ported the migration of the metal moiety in the ruthenium-cat-
alyzed hydrogenation of alkynylstannanes (Scheme 2, A).15,16
Although we have not clarified the mechanism of the hydroge-
nation, we assumed that the migration of stannyl groups gives
ruthenium–ꢀ-stannylvinylidene complexes,17,18 which accept
the addition of an hydrogen molecule. Consequently, we an-
ticipated that the ꢀ-stannylvinylidene complexes would act
like the ruthenium–vinylidene complexes in the ruthenium-
catalyzed dimerization of terminal alkynes by accepting the
addition of a terminal alkyne, and this turned out to be the
case. Here, we report the addition of terminal alkynes to alky-
nylstannanes with migration of the stannyl group to give 1-
stannyl-1-en-3-yne (Scheme 2, B), where the substrates play
opposite roles to each other compared to the alkynylstannyla-
tion of alkynes (Scheme 2, C). We also report quantum me-
chanical calculations to clarify the reaction mechanism and
determined the activation barrier.
lowered the conversion and the yield after 5 h (Entry 2),
whereas other amides such as N,N-dimethylacetamide (DMA)
and N-methylpyrolidinone (NMP) were much less effective
(Entries 3 and 4). Efficiency of THF, one of the most polar
ethers, was comparable to NMP, and toluene was totally inef-
fective (Entries 5 and 6). On the contrary, protic solvents such
as ethanol and water were less effective in spite of their high
polarity (Entries 7 and 8). It is possible that the insolubility
of the substrates as well as the catalyst in water made it inef-
fective, then we examined a mixed solvent consisting of
DMSO–H2O in a ratio of 3 to 1. The reaction mixture was
homogeneous; however, the yield was ever less (Entry 9).
We ascribe the high efficiency of DMSO to its ability to coor-
dinate to the ruthenium and/or tin atoms. Considering the ster-
ic effect on coordinating ability, the fact that DMF was a better
solvent than more bulky DMA and NMP is understandable. In
any case, the ratio of stereoisomers 10a and 11a was essential-
ly constant.
Next, we examined the effect of ruthenium precursors in the
reaction of 8a with 9a using DMSO as the solvent (Table 2).
In addition to the p-cymene complex, the corresponding ben-
zene complex [{RuCl(ꢃ6-C6H6)}2(ꢂ-Cl)2] gave a comparable
reaction rate and product yield (Entries 1 and 2). Use of
Results and Discussion
Optimization of the Reaction Conditions. We first exam-
ined the reaction of tributyl(1-octynyl)tin (8a) with phenyl-
acetylene (9a). Treatment of 8a and 9a with 0.025 molar
amount of [di-ꢂ-chlorobis{chloro(p-cymene)ruthenium(II)}]
([{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2]) and 0.30 molar amount of
tributylphosphine (PBu3) in DMSO at 50 ꢂC for 5 h gave a
67:33 mixture of (E)-1-phenyl-4-(tributylstannyl)dec-3-en-1-
yne (10a) and (Z)-isomer 11a in 90% yield estimated by
119Sn NMR (Entry 1 of Table 1).19 Dimerization product of
9a was not detected, showing that the alkyne prefers the alky-
nylstannane over another molecule of the alkyne as a coupling
partner.20 The results using different solvents are summarized
in Table 1. For aprotic solvents, the reaction rate as well as the
combined yield of 10a and 11a decreases as the polarity of the
solvent decreases. Thus, use of DMF instead of DMSO slightly
RuCl3 nH2O, which is one of the most readily available ruthe-
ꢃ
nium complexes, gave an acceptable yield of 10a and 11a
(Entry 3). Commercially available [RuH2(CO)(PPh3)3], which
is the best precursor in combination with PBu3 for the hydro-
genation of aliphatic alkynylstannanes with migration of the
stannyl group,15 was much less active (Entry 4). Triphenyl-
phosphine involved in the precursor might lower the catalytic
activity. However, high yields of adducts were obtained in the
reaction of 1-octyne (9b) with 8a catalyzed by this complex at
a higher temperature (80 ꢂC) with a prolonged reaction time
(48 h) (Entries 5 and 6). On the other hand, [{RuCl(ꢃ6-p-cym-
ene)}2(ꢂ-Cl)2] gave low yields (Entries 7 and 8). Here, again

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1965
Table 2. Ruthenium-Catalyzed Addition of Alkynes to Tributyl(1-octynyl)tin: Effect of PrecursorsaÞ
Hex
SnBu3
Ru precursor
(0.050 mol. amt. of Ru)
PBu3 (0.30 mol. amt.)
R
Hex
8a
+
Hex
+
Bu3Sn
5 h
H
R
Bu3Sn
R
9a: R = Ph
9b: R = Hex
10
11
Temp
/ꢂC
Conversion
/%bÞ
Yield
/%bÞ
Entry
Alkyne
Ru Precursor
[{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2]
10/11bÞ
1
2
3
4
Phenylacetylene (9a)
Phenylacetylene (9a)
Phenylacetylene (9a)
Phenylacetylene (9a)
1-Octyne (9b)
1-Octyne (9b)
1-Octyne (9b)
1-Octyne (9b)
50
50
50
50
50
80
50
80
>99
98
99
4
2
>99
86
90
86
77
0
0
85
9
67/33
67/33
68/32
—
[{RuCl(ꢃ6-C6H6)}2(ꢂ-Cl)2]
[RuCl3 nH2O]
[RuH2(CO)(PPh3)3]
[RuH2(CO)(PPh3)3]
ꢃ
5
—
6cÞ
7
[RuH2(CO)(PPh3)3]
[{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2]
17/83
1/>99
1/>99
8
[{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2]
>99
18
a) The reaction was carried out in DMSO (0.30 mL) for 5 h using tributyl(1-octynyl)tin (0.40 mmol), an alkyne (0.60 mmol), a
ruthenium precursor (0.050 mol amt. of Ru), and PBu3 (0.30 mol amt.). b) Determined by 119Sn NMR. c) Reaction time = 48 h.
the ratio of 10a to 11a was not affected by the precursors,
whereas the stereoselectivities in the reaction of 8a with 9b
changed according to the ruthenium precursors.
A sequential reaction consisting of the stannylation of a
terminal alkyne and the ruthenium-catalyzed addition of the al-
kyne to the resulting alkynylstannane is also possible. In other
words, the stannylative dimerization of terminal alkynes was
accomplished by treatment of 1-octyne (9b: 0.40 mmol) and
Bu3SnOMe (0.40 mmol) with [RuH2(CO)(PPh3)3] (20 mmol)
and PBu3 (0.12 mmol) in DMSO at 80 ꢂC for 50 h to give an
18:82 mixture of stannylenynes 10f and 11f in 69% yield
(0.14 mmol) (Eq. 1).
In combination with [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] as a
catalyst precursor, PBu3 was found to be the most effective li-
gand among the ligands we examined. Monodentate ligands
such as PPh3, P(C6F5)3, P(c-Hex)3, Ph2PMe, and PhPMe2 as
well as bidentate ligands such as Ph2P(CH2)nPPh2 (n ¼ 2{4),
Et2P(CH2)3PEt2, and 1,10-bis(diphenylphosphino)ferrocene
gave no adduct, and the conversion was lower than 9% at
50 ꢂC for 5 h. The amount (0.30 mol amt.) of PBu3 is critical:
reduction of the amount lowered the yield considerably and
no adduct was obtained without the ligand.
Scope of the Reaction. A ruthenium complex in combina-
tion with PBu3 as a catalyst was applied to the addition reac-
tion between various alkynylstannanes and terminal alkynes
(Table 3). [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] was found to be
effective for most combinations of alkynylstannanes and al-
kynes, and [RuH2(CO)(PPh3)3] worked well for the reaction
between aliphatic substrates. The trimethylstannyl analogue
of 8a underwent the reaction with 9a in a similar stereoselec-
tivity to 8a (Entries 1 and 2). Acetylenes having a conjugating
aryl or alkenyl group added to 8a, giving mixtures of stereo-
isomers (Entries 3–5), whereas the addition of 3,3-dimeth-
yl-1-butyne to 8a proceeded in a perfect stereoselectivity to
give 10e as the sole product (Entry 6). In contrast, linear ter-
minal alkynes were activated more successfully by [RuH2-
(CO)(PPh3)3] to add to 8a in high yields, though the reaction
gave a mixture of stereoisomers (Entries 7 and 8). Arylethyn-
ylstannanes also accepted the addition of terminal alkynes
(Entries 9–13). The reaction between aromatic substrates pro-
ceeded in a high stereoselectivity to give 11h predominantly
(Entry 9). 1-Octyne added to phenylethynylstannanes having
an electron-donating or -withdrawing group with a perfect ster-
eoselectivity (Entries 11 and 12). A C(sp2)–Br bond, which
can be used for further transformation, on a phenylethynylstan-
nane was tolerated (Entry 13). No addition took place with
internal alkynes such as 4-octyne and 1-phenyl-1-propyne.
Hex
9b (0.40 mmol)
H
[RuH2(CO)(PPh3)3] (20
PBu3 (0.12 mmol)
µ
mol)
+
DMSO, 80 °C, 50 h
Bu3SnOMe
(0.40 mmol)
ð1Þ
Hex
Hex
+
Hex
Bu3Sn
Bu3Sn
Hex
10f
11f
18 : 82
69% (0.14 mmol)
Application of the Addition Products. These addition
products can be transformed to various ꢄ-conjugated com-
pounds having an enyne structure. For example, adduct 11i
derived from tributyl(phenylethynyl)tin and 1-octyne was used
as a nucleophile and converted into various compounds as
shown in Scheme 3. Stannylenyne 11i coupled with 1-iodo-
4-nitrobenzene with an aid of palladium and copper catalysts
to give arylenyne 12 in a high yield with retention of the dou-
ble bond configuration.7b,c Alternatively, stannylenyne 11i was
first converted into more nucleophilic lithioenyne 13, which
reacted with electrophiles such as 1-iodobutane and benzalde-
hyde to give alkylation product 14 and alcohol 15. Enynol 15
further underwent the palladium-catalyzed cyclization fol-
lowed by aromatization to give trisubstituted furan 16.21
Reaction Mechanism. Stannyl groups migrate in the pres-

1966 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
Table 3. Ruthenium-Catalyzed Addition of Terminal Alkynes to AlkynylstannanesaÞ
R1
SnBu3
R2
R1
8
+
cat. Ru
DMSO
R1
Bu3Sn
+
Bu3Sn
H
R2
R2
9
10
11
Temp Time Yield
/ꢂC
119Sn NMRdÞ
Yield/% 10/11
Entry
1
R1
R2
RubÞ
A
/h
/%cÞ
Product(s)
Hex
Bu3Sn
Hex
Hex
Ph
Ph
50
5
85
90
85
67/33
63/37
Hex
10a
11a
Bu3Sn
Hex
Me3Sn
2eÞ
A
A
40
50
9
3
82
83
Hex
10'a
11'a
Me3Sn
OMe
Hex
Bu3Sn
3
Hex
Hex
4-MeOC6H4
4-ClC6H4
88
78
61/39
57/43
10b
11b
Hex
Bu3Sn
OMe
Cl
Hex
Bu3Sn
4
A
50
25
73
10c
11c
Hex
Bu3Sn
Cl
Hex
Bu3Sn
5
6
Hex
Hex
Cyclohexen-1-yl
A
A
50
40
8
57
62
64
64
63/37
Hex
10d
10e
11d
Bu3Sn
Hex
t-Bu
36
>99/1
Bu3Sn
Hex
Hex
Hex
Bu3Sn
7
8
Hex
Hex
Hex
B
B
80
80
48
48
83
76
85
84
17/83
17/83
10f
11f
Bu3Sn
Hex
(CH2
)9CH3
Hex
Bu3Sn
Hex
CH3(CH2)9
10g
11g
9CH3
Bu3Sn
(CH2
)
Bu3Sn
9
10
11
Ph
Ph
Ph
A
A
A
50
50
50
7
9
8
56
50
55
61
52
57
4/96
10h
11h
11i
Bu3Sn
Hex
Hex
1/>99
1/>99
Bu3Sn
Hex
Hex
Hex
Hex
MeO
4-MeOC6H4
4-CF3C6H4
4-BrC6H4
Bu3Sn
C
11j
11k
11l
F3
12
13
Hex
Hex
A
A
50
50
20
16
50
54
54
54
1/>99
1/>99
Bu3Sn
Br
Bu3Sn
a) The reaction was carried out in DMSO (0.3 mL) using an alkynylstannane (0.40 mmol), an alkyne (0.60 mmol for Entries 1–5, 7,
and 8; 0.80 mmol for Entries 9–13; 2.0 mmol for Entry 6), a ruthenium precursor (Ru ¼ 20 mmol), and tributylphosphine
(0.12 mmol). b) A: [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2]; B: [RuH2(CO)(PPh3)3]. c) Isolated yield based on the alkynylstannane.
d) Determined by 119Sn NMR using tetrabutyltin (tetramethyltin for Entry 2) as an internal standard. e) The trimethylstannyl
analogue was used instead of tributyl(1-octynyl)tin (8a).

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1967
nism of the ruthenium-catalyzed dimerization of terminal
alkynes has been elucidated by ab initio molecular orbital
analysis,10e which shows that the catalytic cycle consists of
4-I–C6H4–NO2 (0.66 mol. amt.)
[Pd(PPh3)4] (0.066 mol. amt.)
CuI (0.50 mol. amt.)
Ph
Ph
SnBu3
DMF, 50 °C, 4 h
84%
the formation of vinylidene complex (RCꢁC)2Ru= =C(H)R
Hex
Hex
ꢃ
NO2
through coordination of a terminal alkyne on Ru(CꢁCR)2
(Step 1), 1,2-shift of an alkynyl group from Ru to the ꢁ-carbon
to give RCꢁCRuC(CꢁCR)=C(H)R (Step 2), and formation of
the dimerization product accompanied by regeneration of
Ru(CꢁCR)2 (Step 3) (vide supra, Scheme 1).
11i
12
BuLi (equimol. amt.)
THF, –78 °C, 3 h
Ph
Ph
Bu
BuI (equimol. amt.)
The entire catalytic cycle of the dimerization of terminal
alkynes (Scheme 1) was followed by the density functional
method (B3LYP) using the model complex [Ru(PH3)2(Cꢁ
CH)2] and substrate HCꢁCH. The energy surface of the cata-
lytic cycle calculated at the B3LYP/BSII//B3LYP/BSII level
is displayed in Fig. 1. The catalytic cycle of the dimerization
of acetylene mainly consists of Steps 1–3 mentioned above.
The geometries of the intermediates and the transition states
as well as the feature of the potential energy surface for Step 1
were similar to those calculated previously at the MP2 level
for the [RuCl2(PH3)2]/HCꢁCH system.10e Here, it should be
noted that the reaction from 5m to 7m has a small energy bar-
rier indicating that the migration of the methyne proton of
acetylene to the alkenyl carbon is very facile. Intermediate
6m is quite stable in energy, though the ruthenium atom has
a high oxidation state (IV) due to oxidative addition of the
acetylene C–H bond. The hydrido in 6m would migrate as a
proton to the alkenyl carbon to form stable CꢁC ꢄ-coordinate
complex 7m, where the oxidation state of the Ru atom again
becomes II. The transition states between 5m and 6m as well
as between 6m and 7m were not determined because the ener-
gy surface between 5m and 7m is very flat.
Li
0 °C, 3 h
80%
Hex
Hex
13
14
PhCHO (equimol. amt.)
0 °C, 3 h
91%
Ph
PdI2 (0.050 mol. amt.)
KI (0.10 mol. amt.)
Ph
Ph
Ph
DMA, 50 °C, 24 h
CH3(CH2)6
16
O
HO
15
81%
Hex
Scheme 3. Transformation of addition product 11i.
ent reaction in a similar manner to the migration in the hy-
drogenation of alkynylstannanes.15 Furthermore, ruthenium
complexes have a tendency to form vinylidene complexes
Ru= =C(X)R upon reaction with X–CꢁC–R such as terminal
ꢃ
alkynes (X ¼ H) and alkynylsilanes (X ¼ SiMe3) with migra-
tion of X.10,11,22 These phenomena convince us that the pres-
ent reaction proceeds through ruthenium–ꢀ-stannylvinylidene
complexes, Ru= =C(SnBu3)R, which react with terminal
alkynes in the same manner as Ru= =C(H)R do in the ruthe-
ꢃ
ꢃ
nium-catalyzed dimerization of alkynes. Thus, the only differ-
ence between the catalytic cycles of these two ruthenium-cat-
alyzed reactions should be the alkynic substrate transformed
to the vinylidene complexes: alkynylstannanes for the present
addition vs terminal alkynes for the dimerization. The mecha-
We focused on the vinylidene formation (Step 1), which has
a large barrier (80.8 kJ molꢄ1), with acetylene as a starting
material and examined Paths A and B shown in Fig. 2 using
Me3SnCꢁCMe instead of acetylene as a substrate. Vinylidene
intermediate 3m0 is finally formed in both Paths A and B, where
Energy (kJ/mol)
Ru
P
+
P
53.6
TS1m
0.0
–27.2
1m
2m
–87.9
–130.5
TS2m
–166.1
–171.5
3m
–200.8
6m
5m
–213.4
4m
1m
–272.4
+
7m
Step 1
Step 2
Step 3
Reaction Coordinate
Fig. 1. B3LYP/BSII-optimized equilibrium (1m–7m) and transition state (TS1m–TS2m) structures, and the potential energy sur-
face of the full catalytic cycle at the B3LYP/BSII level.

1968 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
∆E =
17.6 kJ/mol
–21.3
–38.9
2m'aI
TS1m'aI
Path A
∆E =
9.6 kJ/mol
–41.4
2m'aII
–31.8 TS1m'aII
Ru
Sn
P
P
3m'
+
0.0
1m'
∆E =
–82.4
176.6 kJ/mol
–66.5
2m'bI
TS1m'bI
110.0
Path B
∆E =
178.7 kJ/mol
118.0
–60.7
TS1m'bII
2m'bII
Fig. 2. B3LYP/BSII-optimized equilibrium and transition state structures of Paths A and B with Me3SnCꢁCMe for Step 1, and
their relative energies (kJ molꢄ1) at the B3LYP/BSII level.
the migrating group is Me3Sn in Path A and Me in Path B.
Each path has two possible directions: the migrating group is
far away from ethynyl ligands in a transition state and comes
close to the ethynyl ligands in the other transition state. Inter-
mediate 2m0 is Sn–C-ꢅ-complex in Path A while it is CꢁC-
ꢄ-complex in Path B. The energetics of Paths A and B were
compared at the B3LYP/BSII level. The energy barriers of
Path A are much smaller than those of Path B, which indicates
that the former is energetically much more favorable than the
latter. This trend is understandable because the positively
charged Sn atom23 of Me3SnCꢁCMe stabilizes the transition
state interacting with the ꢄ-electrons of the CꢁC bond. The mi-
grating Sn atom also interacts with the ꢄ-electrons of the CꢁC
bond of one of the ethynyl ligands in TS1m0aII to further sta-
bilize the transition state. As a result, TS1m0aII is 10.5
kJ molꢄ1 more stable than TS1m0aI. This also contributes to
low energy barrier of 9.6 kJ molꢄ1 for the step from 2m0aII
to TS1m0aII, which is 8.0 kJ molꢄ1 smaller than that from
2m0aI to TS1m0aI. Therefore, the large energy barrier (80.8
kJ molꢄ1) of Step 1 in Fig. 1 would be lowered to 9.6 kJ molꢄ1
by replacement of the terminal methyne proton by a stannyl
group, and the catalytic reaction would be controlled in Step 2.
Stereoselectivities in the Addition Reaction. Depending
on substituent R2 on acetylene, the stereochemical outcome in
use of [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] as a catalyst precursor
can be divided into two patterns: the addition proceeded ster-
eoselectively for R2 = alkyl (Types A and B in Scheme 4:
Entries 6 and 10–13 of Table 3), whereas mixtures of stereo-
isomers were produced when R2 = aryl or alkenyl (Type C
in Scheme 4: Entries 1–5 and 9 of Table 3). The reaction pro-
ceeded in a perfect selectivity over 10 with Type A, where
substrates 8 and 9 which only have alkyl substituents (R1
and R2). When we pay attention to the geometric structures in-
volved in the catalytic cycle, we can easily notice that the ster-
eoselectivity of the reaction is determined in the transition
state TS2m in Step 2, where the stereoselectivity is likely to
be governed primarily by steric factors. The catalytic cycles
leading to the stereoisomeric products 10 and 11 can be thus

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1969
R2
R1
Bu3Sn
cat.
[{RuCl(η6-p-cymene)}2(µ-Cl)2]
R1
SnBu3
H
R2
+
R1
Bu3Sn
+
8
9
R2
10
11
Type
R1
R2
A
B
C
alkyl
aryl
alkyl
alkyl
>99/1
1/>99
alkyl, aryl
aryl, alkenyl
a mixture of stereoisomers
Scheme 4. Stereochemical outcome in use of [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] as a catalyst precursor.
R1
SnBu3
H
Ru
R1
H
SnBu3
R2
R2
2
R2
10
4
11
R1
SnBu3
8
R1 SnBu3
R1
SnBu3
R1
SnBu3
H
H
Ru
Ru
Ru
R2
R2
R2
R2
R2
R2
R2
(Z)-17
2
(E)-17
5'
H
R2
R2
H
9
9
R1 SnBu3
R1
SnBu3
R1
SnBu3
•
Ru
Ru
Ru
R2
R2
R2
R2
R2
R2
(Z)-7'
6'
(E)-7'
Scheme 5. Possible catalytic cycles of the addition of terminal alkynes to alkynylstannanes.
drawn as shown in Scheme 5. We compared the stability be-
the migrating alkynyl groups expels the phenyl ring out of the
plane in transition state 19 for (E)-isomer 10, reducing the res-
onance stabilization. In fact, from calculations (Fig. 4), the
energy of transition stꢂate 18 is lowest when the dihedral angle
tween the transition states that produce the Z and E products
for Types A–C (Fig. 3). A lower energy was found for the
transition state that produces (E)-product 10 in each case.
The calculations showed that the steric contact between the
substituents of alkynyl and vinylidene ligands controls the ster-
eoselectivity. The computational results agree with the exper-
imentals for Type A, though there was a discrepancy between
the results for Types B and C, suggesting the possibility that
the conjugating substituents such as phenyl and alkenyl groups
make other factors more important in determining the stereo-
chemistry. The reaction of Type B combination of the sub-
strates proceeds in a stereoselectivity opposite to that with
Type A, giving (Z)-isomers 11 exclusively. A possible explan-
ation of the stereochemical preference is as follows (Scheme 6
exemplified with PhCꢁCSnBu3). The ꢀ-phenyl group derived
from PhCꢁCSnBu3 may conjugatedly stabilize transition state
18 leading to (Z)-isomers 11, lying in the plane constructed by
the ruthenium atom, the vinylidene moiety and the two alkynyl
groups. In contrast, the steric repulsion between the phenyl and
= C1–C2–C3–C4 is 0 , whereas the phenyl group is largely
À
rotated out of the C3–C4–C5 plane due to steric repulsion in
transition state 19 which has a minimum energy when the
dihedral angle = C1–C2–C3–C4 is 45ꢂ. Thus, transition state
À
18 compared to 19 is likely to be stabilized by the resonance,
which is stronger than the steric repulsion between the stannyl
and the migrating alkynyl groups.
In contrast to the reaction with Types A and B giving a
single isomer, mixtures of stereoisomers were produced in
the addition of aryl- and alkenylacetylenes to alkynylstannanes
(Type C). From the fact that the reaction of 8a and 9a, the
combination of which represents Type C, under various condi-
tions gave mixtures of 10a and 11a in a constant ratio (67:33),
and that use of the trimethylstannyl analogue instead of 8a
hardly affected the selectivity, an equilibrium must be present
somewhere in the catalytic cycle. Because, upon the exposure

1970 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
Type A
Type B
Type C
t-Bu
Ph
Me
Sn
Sn
Sn
Ru
Ru
P
Ph
Ru
Me
Me
P
P
P
P
P
Z
Z
Z
t-Bu
Ph
Me
C
C
C
C
H
C
H
C
SnMe3
Me
SnMe3
Ph
SnMe3
Me
0.0
0.0
0.0
0.0
0.0
0.0
C C
C C
C
C
H
E
E
E
Me
t-Bu
Ph
C
C
C
C
Ph
C
H
C
Me
Me
-19.7
-21.8
-11.3
-13.8
-14.6
-14.2
C
C
C C
C C
SnMe3
H
SnMe3
SnMe3
H
Fig. 3. B3LYP/BSI-optimized structures of the transition states in Step 2 with the various substituents, and their relative energies
(kJ molꢄ1) at the B3LYP/BSI (plain) and B3LYP/BSII (italic) levels. For each case, the Z and E products are formed through the
transition states in the upper and lower sides, respectively.
R2
R2
H
Ru
•
Ru
SnBu3
SnBu3
SnBu3
R2
R2
R2
R2
18
(E)-7'
11
•
Ru
SnBu3
R2
R2
R2
6'
R2
Ru
•
Ru
SnBu3
SnBu3
H
SnBu3
R2
R2
19
(Z)-7'
10
Scheme 6. Stereochemical course with type B combination of substrates.
of 11a to the reaction mixture of the ruthenium catalyst, 8a and
p-methoxyphenylacetylene in DMSO,24 11a did not change
and was recovered quantitatively, the equilibrium between ad-
dition products 10a and 11a can be excluded. Thus, the equi-
librium is likely to exist between alkenylruthenium (Z)- and
(E)-70 (Scheme 5).25,26 A possible explanation should be as
follows. For the isomerization to take place, the double bond
of alkenylruthenium complexes 70 have to show some single
bond character. As shown in Scheme 7 exemplified by the re-
action of 8a with 9a, the flow of the electrons on the phenyl
group into the enyne moiety in (Z)- or (E)-70a makes the dou-
ble bond into a single bond to give 1,2,3-butatrienylruthenium
20 or 21, respectively, which has a carbanion stabilized by the
stannyl group.27 The resulting single bond between the carbon
atom coordinated to the ruthenium atom and that attached to
the stannyl group rotates to give isomer 21 or 20, which re-
spectively isomerizes to (E)- or (Z)-70a.28 The ruthenium atom
may play a role to stabilize the positive charge generated on
the benzene ring by donating its own electrons through the
triene moiety to form carbene complex 200.29,30

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1971
Bu3SnC(R1)=CHCꢁCR2 with all the substituent patterns,
i.e., R1/R2 = alkyl/alkyl, alkyl/aryl, aryl/alkyl, and aryl/
aryl, which are otherwise hardly accessible even with the
palladium- or nickel-catalyzed alkynylstannylation of alkynes
giving the same SnC=CCꢁC framework. Some examples of
synthetic application of the addition products are shown in
Scheme 3, though the versatility of this type of stannylenynes
has already been demonstrated extensively by transformation
of alkynylstannylation products prepared under palladium or
nickel catalysis.7 The reaction mechanism is revealed by the
density functional method (B3LYP). The DFT calculation
clarified that 1,2-shift of the stannyl group leading to the for-
mation of ruthenium–ꢀ-stannylvinylidene complex is facile
with energy barrier of only 9.6 kJ molꢄ1, which is much lower
than that (80.8 kJ molꢄ1) of the 1,2-hydrogen shift in the cor-
responding ruthenium–terminal alkyne complex. The stereose-
lectivity is largely affected by substituents on alkynylstannanes
(R1) and terminal alkynes (R2): (E)-stannylenyne for (R1/
R2 =) alkyl/alkyl; (Z)-stannylenyne for aryl/alkyl; a mixture
of the stereoisomers for alkyl/aryl and aryl/aryl. The compu-
tational results reasonably explain the formation of (E)-stan-
nylenyne for combination of R1/R2 = alkyl/alkyl, where ster-
ic effect compared with electronic effect should be dominant.
On the other hand, introduction of conjugating substituents
such as phenyl and alkenyl group into the substrates caused
some discrepancy between the theoretical and experimental re-
sults. However, considering the resonance effect, the stereose-
lectivity in such cases also should be rationally understood.
Not only this new reaction itself should be beneficial for
organic synthesis, but also the finding of ruthenium–ꢀ-stannyl-
vinylidene complexes will lead to new reactions giving struc-
turally diverse organostannanes.
12.0
10.0
8.0
5
3
4
1
2
2
5
1
3
4
19
18
6.0
4.0
2.0
0.0
0
40
80
120
160
Dihedral angle ∠C1–C2–C3–C4 (degree)
Fig. 4. Energy change of transition state TS2m with the
Me, Ph, and SnH3 substituents by the rotation of the Ph
substituent around the C2–C3 axis at the B3LYP/BSI lev-
el. The geometry at each point was optimized fixing the
dihedral angle = C1–C2–C3–C4 and the Ru–C4–C5 trian-
gle. : The Ph group is on the side of the migrating alky-
nyl group. : The Ph group is on the side of the Ru atom.
À
Conclusion
In conclusion, we have demonstrated that the addition of
terminal alkynes to alkynylstannanes with migration of the
stannyl group is effectively catalyzed by a ruthenium–PBu3
complex. The reaction is applicable to various aromatic/
aliphatic alkynylstannanes/alkynes, giving (E)- and (Z)-
Hex
SnBu3
•
Ru
Ph
–
Ph
6'a
Hex
SnBu3
Ru
Hex
Ru
SnBu3
Hex
SnBu3
+
Ru
Ph
Ph
Ph
Ph
Ph
20'
Ph
(Z)-7'a
(E)-7'a
–
–
Hex
SnBu3
Ru
Bu3Sn
Hex
Ru
•
•
•
•
Ph
Ph
+
+
20
21
Hex
SnBu3
Hex
H
SnBu3
H
Ph
Ph
10a
11a
Scheme 7. A possible equilibrium between alkenylruthenium complexes (Z)- and (E)-70a.

1972 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
100a could not be separated from 110a, only the NMR data that can
be distinguished from the mixture are described. 1H NMR (300
MHz, CDCl3): ꢆ 0.26 (s, 9H), 2.52 (t, J ¼ 7:2 Hz, 2H), 6.50 (s,
1H). 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ24:7. Anal. Calcd
for C19H28Sn: C, 60.83; H, 7.52%. Found as a mixture of 100a
and 110a: C, 61.09; H, 7.61%.
Experimental
General Remarks. All manipulations of oxygen- and mois-
ture-sensitive materials were conducted with a standard Schlenk
technique under a nitrogen atmosphere. Nuclear magnetic reso-
nance spectra were taken on a Varian Gemini 2000 (1H, 300 MHz;
13C, 75 MHz) or a Varian UNITY 500 plus (13C, 126 MHz; 119Sn,
186 MHz) spectrometer using tetramethylsilane (1H and 13C) as an
internal standard and tetrabutyltin or tetramethyltin (119Sn) as an
internal or external standard. The preparative medium-pressure
liquid chromatography was performed with YAMAZEN chroma-
tography system equipped with an activated aluminum oxide
using hexane as an eluent. Preparative recycling gel permeation
chromatography was performed with JAI LC-908 equipped with
JAIGEL-1H and -2H using chloroform as an eluent. Elemental
analyses were carried out with a Vario EL III machine. High-
resolution mass spectra were obtained with a Bruker Bio APEX
70e spectrometer. Unless otherwise noted, reagents were commer-
cially available and used without further purification. Anhydrous
DMSO was purchased from Aldrich Chemical Co. and used as
received.
(Z)-1-Phenyl-4-(trimethylstannyl)dec-3-en-1-yne (110a): An
1
orange oil, H NMR (300 MHz, CDCl3): ꢆ 0.28 (s, 9H), 0.89 (t,
J ¼ 6:8 Hz, 3H), 1.20–1.43 (m, 8H), 2.35 (td, J ¼ 7:1, 0.3 Hz,
2H), 6.26 (t, J ¼ 1:5 Hz, 1H), 7.26–7.34 (m, 3H), 7.37–7.43 (m,
2H). 13C NMR (75 MHz, CDCl3): ꢆ ꢄ8:8, 14.0, 22.5, 28.8, 29.6,
31.6, 40.7, 88.8, 90.3, 119.0, 123.8, 127.9, 128.4, 131.3, 165.4.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ44:5. Anal. Calcd for
C19H28Sn: C, 60.83; H, 7.52%. Found: C, 60.75; H, 7.63%.
(E)-1-(4-Methoxyphenyl)-4-(tributylstannyl)dec-3-en-1-yne
(10b): As 10b could not be separated from 11b, only the NMR
data that can be distinguished from the mixture are described.
1H NMR (300 MHz, CDCl3): ꢆ 2.47 (t, J ¼ 7:7 Hz, 2H), 3.82 (s,
3H), 6.45 (s, 1H). 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ39:2.
Anal. Calcd for C29H48OSn: C, 65.55; H, 9.10%. Found as a mix-
ture of 10b and 11b: C, 65.41; H, 9.23%.
Ruthenium-Catalyzed Addition of Terminal Alkynes to Al-
kynylstannanes with Migration of the Stannyl Group. A Gen-
eral Procedure. An alkyne (0.60, 0.80, or 2.0 mmol) was added
to a solution of an alkynylstannane (0.40 mmol), a ruthenium pre-
cursor {[{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2] (6.1 mg, 0.010 mmol) or
[RuH2(CO)(PPh3)3] (18.4 mg, 0.0200 mmol)} and tributylphos-
phine (30 mL, 0.12 mmol) in DMSO (0.30 mL). The mixture was
stirred at the temperature specified in Table 3. After the time
specified in Table 3, the resulting solution was treated with water
(5 mL) and extracted with diethyl ether (20 mL ꢅ 3). The com-
bined organic layer was washed with brine (10 mL), and dried
over anhydrous magnesium sulfate. Evaporation of the solvent
followed by purification with medium-pressure liquid chromatog-
raphy on aluminum oxide using hexane as an eluent gave stan-
nylenynes 10 and/or 11. Further separation was performed with
recycling gel permeation chromatography, though some of (E)-
isomers 10 are too unstable to be isolated under the conditions
of the chromatography. Consequently, elemental analyses of some
products were done as mixtures of 10 and 11 in addition as pure
11. The results are summarized in Table 3.
(E)-1-Phenyl-4-(tributylstannyl)dec-3-en-1-yne (10a): An
orange oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.90 (t, J ¼ 7:2 Hz,
12H), 1.05–1.14 (m, 6H), 1.22–1.44 (m, 14H), 1.51–1.65 (m, 6H),
2.51 (td, J ¼ 8:1, 1.2 Hz, 2H), 6.51 (s, 1H), 7.19 (t, J ¼ 7:3 Hz,
1H), 7.31 (t, J ¼ 7:7 Hz, 2H), 7.41 (d, J ¼ 7:4 Hz, 2H). 13C NMR
(75 MHz, CDCl3): ꢆ 10.7, 13.5, 14.0, 22.5, 27.3, 28.9, 29.0, 29.5,
31.7, 38.7, 107.9, 127.0, 127.4, 128.5, 134.7, 138.1, 163.0, 167.5.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ38:1. Anal. Calcd for
C28H46Sn: C, 67.08; H, 9.25%. Found as a mixture of 10a and
11a: C, 67.19; H, 9.32%.
(Z)-1-(4-Methoxyphenyl)-4-(tributylstannyl)dec-3-en-1-yne
(11b): A yellow oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.87 (t,
J ¼ 7:5 Hz, 12H), 1.00–1.08 (m, 6H), 1.20–1.42 (m, 14H), 1.47–
1.60 (m, 6H), 2.31 (t, J ¼ 6:6 Hz, 2H), 3.81 (s, 3H), 6.29 (s, 1H),
6.84 (d, J ¼ 9:0 Hz, 2H), 7.33 (d, J ¼ 9:0 Hz, 2H). 13C NMR (75
MHz, CDCl3): ꢆ 10.1, 13.6, 14.0, 22.5, 27.3, 28.9, 29.2, 29.7,
31.7, 41.1, 55.2, 88.2, 89.2, 114.0, 116.2, 119.3, 132.7, 159.3,
164.5. 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ50:6. Anal. Calcd
for C29H48OSn: C, 65.55; H, 9.10%. Found: C, 65.19; H, 9.10%.
(E)-1-(4-Chlorophenyl)-4-(tributylstannyl)dec-3-en-1-yne
(10c): As 10c could not be separated from 11c, only the NMR
data that can be distinguished from the mixture are described.
1H NMR (300 MHz, CDCl3): ꢆ 2.50 (t, J ¼ 8:1 Hz, 2H), 6.44 (s,
1H). 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ38:9. Anal. Calcd
for C28H45ClSn: C, 62.76; H, 8.47%. Found as a mixture of 10c
and 11c: C, 62.51; H, 8.50%.
(Z)-1-(4-Chlorophenyl)-4-(tributylstannyl)dec-3-en-1-yne
(11c): An orange oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.86 (t, J ¼
7:4 Hz, 12H), 0.99–1.08 (m, 6H), 1.20–1.41 (m, 14H), 1.46–1.60
(m, 6H), 2.32 (t, J ¼ 6:6 Hz, 2H), 6.26 (s, 1H), 7.27 (d, J ¼ 8:7
Hz, 2H), 7.32 (d, J ¼ 8:7 Hz, 2H): 13C NMR (75 MHz, CDCl3)
ꢆ 10.1, 13.5, 13.7, 22.5, 27.3, 28.9, 29.1, 29.6, 31.7, 41.2, 87.1,
91.6, 118.8, 122.5, 128.7, 132.5, 133.8, 166.5. 119Sn{1H} NMR
(186 MHz, CDCl3): ꢆ ꢄ49:9. HRMS (EI): Calcd for C24H36ClSn
½M ꢄ Buꢆþ, 479.15257; Found, 479.15397. Anal. Calcd for
C28H45ClSn: C, 62.76; H, 8.47%. Found: C, 63.06; H, 8.59%.
(E)-1-(1-Cyclohexenyl)-4-(tributylstannyl)dec-3-en-1-yne
(10d): As 10d could not be separated from 11d, only the NMR
data that can be distinguished from the mixture are described.
1H NMR (300 MHz, CDCl3): ꢆ 2.40 (t, J ¼ 7:4 Hz, 2H), 5.79–
5.86 (m, 1H), 6.19 (s, 1H). 119Sn{1H} NMR (186 MHz, CDCl3):
ꢆ ꢄ39:2. Anal. Calcd for C28H50Sn: C, 66.54; H, 9.97%. Found
as a mixture of 10d and 11d: C, 66.48; H, 9.96%.
(Z)-1-Phenyl-4-(tributylstannyl)dec-3-en-1-yne (11a): An
orange oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.87 (t, J ¼ 7:2 Hz,
12H), 1.05–1.10 (m, 6H), 1.20–1.42 (m, 14H), 1.46–1.64 (m, 6H),
2.32 (t, J ¼ 6:7 Hz, 2H), 6.29 (s, 1H), 7.22–7.36 (m, 3H), 7.37–
7.44 (m, 2H). 13C NMR (75 MHz, CDCl3): ꢆ 10.1, 13.6, 14.0,
22.5, 27.3, 28.9, 29.2, 29.7, 31.7, 41.2, 88.3, 90.6, 119.1, 124.0,
127.8, 128.3, 131.3, 165.7. 119Sn{1H} NMR (186 MHz, CDCl3):
ꢆ ꢄ49:7. HRMS (EI): Calcd for C24H37Sn ½M ꢄ Buꢆþ, 445.19154;
Found, 445.19290. Anal. Calcd for C28H46Sn: C, 67.08; H, 9.25%.
Found: C, 66.73; H, 9.29%.
(Z)-1-(1-Cyclohexenyl)-4-(tributylstannyl)dec-3-en-1-yne
(11d): An orange oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.88 (t,
J ¼ 7:2 Hz, 12H), 0.95–1.05 (m, 6H), 1.18–1.40 (m, 14H), 1.44–
1.70 (m, 10H), 2.06–2.16 (m, 4H), 2.26 (t, J ¼ 6:5 Hz, 2H), 6.00–
6.06 (m, 1H), 6.17 (s, 1H). 13C NMR (75 MHz, CDCl3): ꢆ 10.0,
13.6, 14.0, 21.5, 22.3, 22.5, 25.6, 27.4, 28.8, 29.10, 29.15, 29.7,
31.7, 41.0, 87.8, 90.3, 119.4, 121.1, 134.1, 163.6. 119Sn{1H} NMR
(186 MHz, CDCl3): ꢆ ꢄ51:3. Anal. Calcd for C28H50Sn: C, 66.54;
(E)-1-Phenyl-4-(trimethylstannyl)dec-3-en-1-yne (100a): As

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1973
H, 9.97%. Found: C, 66.53; H, 9.87%.
13.6, 14.0, 19.7, 22.5, 27.3, 28.6, 28.7, 29.0, 31.4, 81.5, 92.7,
122.1, 126.2, 126.5, 128.2, 146.4, 160.2. 119Sn{1H} NMR (186
MHz, CDCl3): ꢆ ꢄ45:4. HRMS (EI): Calcd for C24H37Sn ½M ꢄ
Buꢆþ, 445.19154; Found, 445.19242. Anal. Calcd for C28H46Sn:
C, 67.08; H, 9.25%. Found: C, 67.21; H, 9.40%.
(E)-2,2-Dimethyl-6-(tributylstannyl)dodec-5-en-3-yne (10e):
A yellow oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.89 (t, J ¼ 7:2
Hz, 12H), 0.95–1.04 (m, 6H), 1.12 (s, 9H), 1.22–1.40 (m, 8H),
1.43–1.60 (m, 12H), 2.37 (td, J ¼ 7:5, 1.1 Hz, 2H), 5.66 (s, 1H).
13C NMR (75 MHz, CDCl3): ꢆ 10.3, 13.6, 14.0, 22.5, 27.3,
28.9, 29.5, 29.9, 31.7, 35.3, 38.2, 120.2, 126.2, 162.7, 167.0.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ40:3. Anal. Calcd for
C26H50Sn: C, 64.87; H, 10.47%. Found: C, 64.51; H, 10.37%.
(E)-7-(Tributylstannyl)hexadec-7-en-9-yne (10f): An orange
oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.76–1.04 (m, 21H), 1.18–1.60
(m, 28H), 2.35 (td, J ¼ 6:6, 2.1 Hz, 2H), 2.51 (t, J ¼ 6:9, 2H),
5.57–5.63 (m, 1H). 13C NMR (126 MHz, CDCl3): ꢆ 9.8, 13.6,
14.0, 14.1, 19.6, 22.57, 22.64, 27.4, 28.6, 29.0, 29.1, 29.2, 29.7,
31.4, 31.8, 36.6, 78.0, 93.6, 118.3, 162.0. 119Sn{1H} NMR (186
MHz, CDCl3): ꢆ ꢄ37:5. Anal. Calcd for C28H54Sn: C, 66.01; H,
10.68%. Found: C, 65.88; H, 10.92%.
(Z)-1-(4-Methoxyphenyl)-1-(tributylstannyl)dec-1-en-3-yne
1
(11j): An orange oil, H NMR (300 MHz, CDCl3): ꢆ 0.82–0.94
(m, 12H), 0.99–1.07 (m, 6H), 1.22–1.62 (m, 20H), 2.35 (td, J ¼
6:9, 2.4 Hz, 2H), 3.80 (s, 3H), 6.23 (t, J ¼ 2:4 Hz, 1H), 6.82 (dt,
J ¼ 8:7, 2.3 Hz, 2H), 7.00 (dt, J ¼ 8:7, 2.3 Hz, 2H). 13C NMR
(126 MHz, CDCl3): ꢆ 11.0, 13.6, 14.0, 19.8, 22.6, 27.3, 28.78,
28.81, 29.1, 31.4, 55.3, 81.7, 92.3, 113.7, 121.0, 127.6, 132.7,
139.0, 158.4. 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ44:9. Anal.
Calcd for C29H48OSn: C, 65.55; H, 9.10%. Found: C, 65.57; H,
9.01%.
(Z)-1-(Tributylstannyl)-1-[4-(trifluoromethyl)phenyl]dec-1-
1
en-3-yne (11k): An orange oil, H NMR (300 MHz, CDCl3): ꢆ
(Z)-7-(Tributylstannyl)hexadec-7-en-9-yne (11f): An orange
oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.84–0.93 (m, 15H), 0.94–1.02
(m, 6H), 1.20–1.58 (m, 28H), 2.22 (t, J ¼ 6:9 Hz, 2H), 2.28 (td,
J ¼ 6:9, 2.2 Hz, 2H), 6.02–6.06 (m, 1H). 13C NMR (126 MHz,
CDCl3): ꢆ 10.2, 13.7, 14.01, 14.04, 19.7, 22.5, 22.6, 27.5, 28.8,
28.9, 29.0, 29.3, 29.9, 31.4, 31.8, 40.8, 81.4, 89.2, 119.5, 161.9.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ50:5. Anal. Calcd for
C28H54Sn: C, 66.01; H, 10.68%. Found: C, 66.04; H, 10.46%.
(E)-7-(Tributylstannyl)icos-7-en-9-yne (10g): An orange oil,
1H NMR (300 MHz, CDCl3): ꢆ 0.82–0.96 (m, 21H), 1.18–1.66
(m, 36H), 2.35 (td, J ¼ 7:2, 2.1 Hz, 2H), 2.51 (t, J ¼ 7:2 Hz, 2H),
5.57–5.64 (m, 1H). 13C NMR (126 MHz, CDCl3): ꢆ 10.3, 13.8,
14.1, 14.2, 19.8, 22.7, 22.8, 27.6, 29.0, 29.1, 29.2, 29.3, 29.36,
29.42, 29.6, 29.7, 30.0, 31.9, 32.0, 40.9, 78.1, 93.7, 118.3,
162.1. 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ37:6. Anal. Calcd
for C32H62Sn: C, 67.96; H, 11.05%. Found: C, 67.91; H, 11.30%.
(Z)-7-(Tributylstannyl)icos-7-en-9-yne (11g): An orange oil,
1H NMR (300 MHz, CDCl3): ꢆ 0.84–0.93 (m, 15H), 0.94–1.02
(m, 6H), 1.18–1.58 (m, 36H), 2.22 (t, J ¼ 7:0 Hz, 2H), 2.29 (td,
J ¼ 7:0, 1.8 Hz, 2H), 6.01–6.06 (m, 1H). 13C NMR (126 MHz,
CDCl3): ꢆ 10.2, 13.7, 14.0, 14.1, 19.7, 22.6, 22.7, 27.5, 28.9,
29.0, 29.1, 29.2, 29.26, 29.32, 29.5, 29.6, 29.9, 31.8, 31.9, 40.8,
81.4, 89.3, 119.5, 161.8. 119Sn{1H} NMR (186 MHz, CDCl3): ꢆ
ꢄ50:7. Anal. Calcd for C32H62Sn: C, 67.96; H, 11.05%. Found:
C, 67.88; H, 10.82%.
0.80–0.96 (m, 12H), 1.08–1.17 (m, 6H), 1.18–1.64 (m, 20H),
2.37 (td, J ¼ 7:2, 2.1 Hz, 2H), 6.27 (t, J ¼ 2:1 Hz, 1H), 7.12 (d,
J ¼ 8:4 Hz, 2H), 7.52 (d, J ¼ 8:4 Hz, 2H). 13C NMR (126 MHz,
CDCl3): ꢆ 11.0, 13.6, 14.0, 19.8, 22.6, 27.3, 28.7, 28.8, 29.1,
1
31.4, 81.3, 93.8, 123.6, 124.4 (q, JC{F ¼ 271 Hz), 125.1 (q,
2
3JC{F ¼ 3:9 Hz), 126.6, 128.2 (q, JC{F ¼ 32:7 Hz), 150.3, 158.8.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ41:6. Anal. Calcd for
C28H45F3Sn: C, 61.17; H, 7.97%. Found: C, 61.08; H, 7.99%.
(Z)-1-(4-Bromophenyl)-1-(tributylstannyl)dec-1-en-3-yne
1
(11l): An orange oil, H NMR (300 MHz, CDCl3): ꢆ 0.83–0.93
(m, 12H), 0.99–1.07 (m, 6H), 1.20–1.62 (m, 20H), 2.35 (td,
J ¼ 7:2, 2.1 Hz, 2H), 6.23 (t, J ¼ 2:1 Hz, 1H), 6.82 (dt, J ¼ 8:4,
4.5 Hz, 2H), 7.39 (dt, J ¼ 8:4, 4.5 Hz, 2H). 13C NMR (126 MHz,
CDCl3): ꢆ 11.0, 13.6, 14.0, 19.8, 22.5, 27.3, 28.7, 28.8, 29.1,
31.4, 81.4, 93.3, 120.0, 122.7, 128.1, 131.2, 145.4, 158.8.
119Sn{1H} NMR (186 MHz, CDCl3): ꢆ ꢄ43:5. Anal. Calcd for
C28H45BrSn: C, 57.96; H, 7.82%. Found: C, 57.70; H, 8.02%.
The Sequential Reaction Consisting of the Stannylation of
1-Octyne with Tributyltin Methoxide Followed by the Ruthe-
nium-Catalyzed Addition. A solution of 1-octyne (44.1 mg,
0.400 mmol), RuH2(CO)(PPh3)3 (18.4 mg, 0.0200 mmol), tributyl-
phosphine (30 mL, 0.12 mmol), and Bu3SnOMe (128.4 mg, 0.4000
mmol) in DMSO (0.30 mL) was degassed by three freeze–thaw
cycles. After the solution was stirred at 80 ꢂC for 50 h, water
(10 mL) was added and the resulting mixture was extracted with
diethyl ether (20 mL ꢅ 3). The combined organic layer was wash-
ed with brine (10 mL), and dried over anhydrous magnesium
sulfate. Evaporation of the solvent followed by purification with
recycling gel permeation chromatography gave an 18:82 ratio of
10f and 11f (70.4 mg, 69%) as a pale yellow oil.
(E)-1,4-Diphenyl-1-(tributylstannyl)but-1-en-3-yne (10h):
A yellow oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.87 (t, J ¼ 7:2
Hz, 9H), 0.94–1.02 (m, 6H), 1.29 (sext, J ¼ 7:3 Hz, 6H), 1.41–
1.58 (m, 6H), 6.08 (s, 1H), 7.18–7.39 (m, 10H). 119Sn{1H} NMR
(186 MHz, CDCl3): ꢆ ꢄ31:2.
(Z)-1,4-Diphenyl-1-(tributylstannyl)but-1-en-3-yne (11h):
The Palladium-Catalyzed Coupling Reaction of (Z)-1-Phen-
yl-1-(tributylstannyl)dec-1-en-3-yne (11i) with 1-Iodo-4-nitro-
benzene. A solution of 11i (50.1 mg, 0.0999 mmol), 1-iodo-4-
nitrobenzene (37.4 mg, 0.150 mmol), [Pd(PPh3)4] (11.6 mg, 0.0100
mmol), and CuI (14.3 mg, 0.0751 mmol) in DMF (1.0 mL) was de-
gassed by three freeze–thaw cycles. After the solution was stirred
at 50 ꢂC for 4 h, water (10 mL) was added, and the resulting mix-
ture was extracted with diethyl ether (20 mL ꢅ 3). The combined
organic layer was washed with brine (10 mL) and dried over anhy-
drous magnesium sulfate. Evaporation of the solvent followed by
purification with recycling gel permeation chromatography gave
(Z)-1-(4-nitrophenyl)-1-phenyldec-1-en-3-yne (12: 28.8 mg, 84%)
1
A yellow oil, H NMR (300 MHz, CDCl3): ꢆ 0.83 (t, J ¼ 7:2 Hz,
9H), 1.06–1.15 (m, 6H), 1.27 (sext, J ¼ 7:3 Hz, 6H), 1.45–1.58
(m, 6H), 6.51 (s, 1H), 7.06–7.14 (m, 2H), 7.17–7.26 (m, 1H),
7.27–7.39 (m, 5H), 7.40–7.53 (m, 2H). 13C NMR (75 MHz,
CDCl3): ꢆ 11.0, 13.5, 27.2, 29.0, 90.6, 91.3, 121.5, 123.7, 126.46,
126.53, 128.2, 128.3, 128.4, 131.4, 146.3, 163.1. 119Sn{1H} NMR
(186 MHz, CDCl3): ꢆ ꢄ43:4. HRMS (EI): Calcd for C24H29Sn
½M ꢄ Buꢆþ, 437.12898; Found, 437.12906. Anal. Calcd for
C28H38Sn: C, 68.17; H, 7.76%. Found: C, 68.05; H, 7.82%.
(Z)-1-Phenyl-1-(tributylstannyl)dec-1-en-3-yne (11i):
A
yellow oil, 1H NMR (300 MHz, CDCl3): ꢆ 0.82–0.94 (m, 12H),
0.99–1.07 (m, 6H), 1.20–1.64 (m, 20H), 2.36 (td, J ¼ 7:2, 2.1 Hz,
2H), 6.26 (t, J ¼ 2:1 Hz, 1H), 7.00–7.08 (m, 2H), 7.13–7.21 (m,
1H), 7.22–7.32 (m, 2H). 13C NMR (75 MHz, CDCl3): ꢆ 10.8,
1
as a pale yellow oil. H NMR (300 MHz, CDCl3): ꢆ 0.87 (t, J ¼
6:9 Hz, 3H), 1.20–1.50 (m, 8H), 2.28 (td, J ¼ 6:9, 2.1 Hz, 2H),
6.14 (t, J ¼ 2:1 Hz, 1H), 7.30–7.43 (m, 5H), 7.64 (dt, J ¼ 9:0,

1974 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
2.1 Hz, 2H), 8.22 (dt, J ¼ 9:0, 2.1 Hz, 2H). 13C NMR (126 MHz,
CDCl3): ꢆ 14.0, 19.8, 22.5, 28.4, 28.5, 31.3, 79.1, 97.5, 110.5,
123.1, 123.6, 127.7, 128.5, 128.6, 129.8, 130.9, 140.4, 146.4.
HRMS (EI): Calcd for C22H23NO2 [M]þ, 333.17275; Found,
333.17335.
and 11. Hydrolysis of 10 and/or 11. To a solution of 10
and/or 11 (0.15 mmol) in THF (10 mL) was added a 6 M HCl
aqueous solution (120 mL, 0.72 mmol), and the mixture was stirred
at room temperature for 1 h. The resulting solution was treated
with a saturated NaHCO3 aqueous solution (5 mL) and extracted
with diethyl ether (10 mL ꢅ 3). The organic layer was dried over
anhydrous magnesium sulfate, and evaporation of the solvent
followed by purification by recycling gel permeation chromatog-
raphy gave 1000 and/or 1100 as a colorless oil. Yields are listed
in Table 4.
Alkylation of (Z)-1-Phenyl-1-(tributylstannyl)dec-1-en-3-
yne (11i). To a solution of 11i (50.1 mg, 0.0999 mmol) in THF
(1.0 mL) was added BuLi (1.58 M in hexane, 63 mL, 0.10 mmol)
at ꢄ78 ꢂC and the resulting solution was stirred at ꢄ78 ꢂC for
3 h. To this was added 1-iodobutane (18.4 mg, 0.100 mmol), and
the solution was stirred at 0 ꢂC for 3 h. Water (5 mL) was added,
and the resulting mixture was extracted with diethyl ether
(10 mL ꢅ 3). The combined organic layer was washed with brine
(10 mL) and dried over anhydrous magnesium sulfate. Evapora-
tion of the solvent followed by purification by column chromatog-
raphy on silica gel (hexane) gave (Z)-5-phenyltetradec-5-en-7-yne
(14: 21.5 mg, 80%) as a pale yellow oil. 1H NMR (300 MHz,
CDCl3): ꢆ 0.86–0.94 (m, 6H), 1.22–1.64 (m, 12H), 2.41 (td,
J ¼ 6:9, 2.1 Hz, 2H), 2.78 (t, J ¼ 7:5 Hz, 2H), 5.76 (t, J ¼ 2:1 Hz,
1H), 7.24–7.40 (m, 5H). 13C NMR (126 MHz, CDCl3): ꢆ 13.9,
14.0, 19.8, 22.6, 27.2, 28.6, 29.0, 30.6, 31.4, 31.9, 79.0, 95.8,
107.5, 126.0, 127.5, 128.3, 140.8, 152.2. HRMS (EI): Calcd for
C20H28 [M]þ, 268.21896; Found, 268.21949.
R2
R1
Bu3Sn
H
R1
Bu3Sn
and / or
R2
H
10
11
R2
ð2Þ
R1
H
H
6 M HCl
THF, r.t., 1 h
R1
and / or
R2
H
H
10"
11"
Hydroxymethylation of (Z)-1-Phenyl-1-(tributylstannyl)-
dec-1-en-3-yne (11i). To a solution of 11i (50.1 mg, 0.0999
mmol) in THF (1.0 mL) was added BuLi (1.58 M in hexane,
63 mL, 0.10 mmol) at ꢄ78 ꢂC and the resulting solution was stirred
at ꢄ78 ꢂC for 3 h. To this was added benzaldehyde (10.6 mg,
0.0999 mmol) and the solution was stirred at 0 ꢂC for 3 h. Water
(5 mL) was added, and the resulting mixture was extracted with
diethyl ether (10 mL ꢅ 3). The combined organic layer was wash-
ed with brine (10 mL) and dried over anhydrous magnesium sul-
fate. Evaporation of the solvent followed by purification by col-
umn chromatography on silica gel (hexane:ethyl acetate = 10:1)
gave (Z)-1,2-diphenylundec-2-en-4-yn-1-ol (15: 29.0 mg, 91%)
(Z)-1-Phenyldec-3-en-1-yne (1000a):
1H NMR (300 MHz,
CDCl3): ꢆ 0.90 (t, J ¼ 6:9 Hz, 3H), 1.20–1.60 (m, 8H), 2.32
(tdd, J ¼ 7:5, 7.5, 1.5 Hz, 2H), 5.79 (dt, J ¼ 7:5, 7.5 Hz, 1H),
6.37 (d, J ¼ 7:5 Hz, 1H), 7.20–7.42 (m, 5H).
(E)-1-Phenyldec-3-en-1-yne (1100a):
1H NMR (300 MHz,
CDCl3): ꢆ 0.90 (t, J ¼ 6:9 Hz, 3H), 1.20–1.50 (m, 8H), 2.16
(tdd, J ¼ 7:2, 7.2, 1.5 Hz, 2H), 5.69 (dt, J ¼ 15:9, 1.5 Hz, 1H),
6.25 (dt, J ¼ 15:9, 7.2 Hz, 1H), 7.26–7.44 (m, 5H).
(Z)-2,2-Dimethyldodec-5-en-3-yne (1000e):
1H NMR (300
MHz, CDCl3): ꢆ 0.89 (t, J ¼ 6:8 Hz, 3H), 1.10 (s, 9H) 1.20–
1.55 (m, 8H), 2.20 (dt, J ¼ 8:7, 6.0 Hz, 2H), 5.46 (d, J ¼ 6:8
Hz, 1H), 5.48 (q, J ¼ 6:8 Hz, 1H).
1
as a pale yellow oil. H NMR (300 MHz, CDCl3): ꢆ 0.87 (t, J ¼
(E)-1-Phenyldec-1-en-3-yne (1100i):
1H NMR (300 MHz,
6:9 Hz, 3H), 1.21–1.44 (m, 6H), 1.47–1.60 (m, 2H), 2.38 (td,
J ¼ 6:9, 2.4 Hz, 2H), 2.58 (d, J ¼ 6:9 Hz, 1H), 5.95 (t, J ¼ 2:4 Hz,
1H), 6.29 (d, J ¼ 6:9 Hz, 1H), 7.20–7.28 (m, 6H), 7.29–7.37 (m,
2H), 7.46–7.52 (m, 2H). 13C NMR (126 MHz, CDCl3): ꢆ 14.0,
19.8, 22.5, 28.60, 28.65, 31.3, 73.8, 77.7, 98.3, 110.5, 125.8,
127.1, 127.5, 128.0, 128.2, 128.3, 138.2, 142.2, 152.8. HRMS
(EI): Calcd for C23H26O [M]þ, 318.19823; Found, 318.19931.
Cycloisomerization of (Z)-1,2-Diphenylundec-2-en-4-yn-1-ol
(15). A solution of 15 (31.8 mg, 0.0999 mmol), PdI2 (1.8 mg,
0.0050 mmol), and KI (1.7 mg, 0.010 mmol) in DMA (1.0 mL)
was degassed by three freeze–thaw cycles. After the solution
was stirred at 50 ꢂC for 24 h, water (10 mL) was added and the re-
sulting mixture was extracted with diethyl ether (20 mL ꢅ 3). The
combined organic layer was washed with brine (10 mL) and dried
over anhydrous magnesium sulfate. Evaporation of the solvent
followed by purification by column chromatography on silica
gel (hexane:ethyl acetate = 100:1) gave 2,3-diphenyl-5-heptynyl-
furan (16: 25.8 mg, 81%) as a pale yellow oil. 1H NMR (300 MHz,
CDCl3): ꢆ 0.90 (t, J ¼ 6:8 Hz, 3H), 1.22–1.48 (m, 8H), 1.73
(quint, J ¼ 7:5 Hz, 2H), 2.70 (t, J ¼ 7:7 Hz, 2H), 6.16 (s, 1H),
7.16–7.38 (m, 6H), 7.38–7.44 (m, 2H), 7.48–7.54 (m, 2H).
13C NMR (126 MHz, CDCl3): ꢆ 14.1, 22.7, 28.0, 28.1, 29.1, 29.2,
31.8, 109.3, 123.0, 126.0, 126.9, 127.0, 128.3, 128.5, 128.6, 131.6,
134.9, 146.6, 155.8. HRMS (EI): Calcd for C23H26O [M]þ,
318.19823; Found, 318.19697.
CDCl3): ꢆ 0.90 (t, J ¼ 6:9 Hz, 3H), 1.25–1.60 (m, 8H), 2.36 (td,
J ¼ 7:5, 2.4 Hz, 2H), 6.16 (dt, J ¼ 16:2, 2.4 Hz, 1H), 6.86 (d,
J ¼ 16:2 Hz, 1H), 7.26–7.38 (m, 5H).
3
Table 4 summarizes JSn{H values31 and chemical shifts
(
119Sn NMR) of addition products 10 and 11 as well as 3JH{H val-
ues of their hydrolyzed products 1000 and 1100, all of which should
contribute the determination of the stereochemistry of the addition
reaction.
Computational Details. The density functional calculations
were performed by the density functional method using the
Gaussian98 program.32 All the geometry optimizations and energy
calculations of the equilibrium and the transition state structures
were performed at the B3LYP level33 using two basis sets, BSI
and BSII. LANL2DZ was used for all the atoms, H, C, P, Ru,
ꢀꢀ
and Sn in BSI. In BSII, 6-31G was used for the H, C, and P
atoms of the model substrates, HCꢁCH and Me3SnCꢁCMe, ex-
cept for the Me substituents of the SnMe3, and of the model ligand
PH3. For the Me substituents on the SnMe3, 6-31G was used. For
ꢀ
Ru, the triple ꢇ valence basis functions augmented by an addition-
al single set of f orbitals with the exponents of 1.235,34 and the
effective core potential (ECP) determined by Hay–Wadt35 to re-
place the core electrons except for the 16 electrons in the valence
shell, and for Sn, the (3s,3p)/[2s,2p] basis functions with a polar-
ization function, i.e., 5d with the exponents of 0.18336 and the
Hay–Wadt ECP37 to replace the 46 core electrons except for the
valence electrons were used. The equilibrium structures and tran-
Determination of Configuration of Addition Products 10

E. Shirakawa et al.
Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006) 1975
Table 4. Selected Data of 10, 11, and Their Hydrolyzed Products
Hydrolysis
Yield/% 3JH{H/Hz
1000 1100 1000 1100
78 85 7.4 15.9
80 15.9
86 7.4 15.9
Chemical shift
3JSn{H (Hz) 119Sn NMR (ppm)
Product(s) 10 11 10 11
10a, 11a
20.1 58.1 ꢄ38:1
Entry
1
R1
R2
Substrate(s)
Hex
Ph
Ph
ꢄ49:7 10a + 11a (67:33)
11a
2
3
4
5
6
7
8
9
10
11
12
13
Hex
Hex
Hex
Hex
Hex
Hex
Hex
Ph
100a, 110a 20.7 60.6 ꢄ24:7
10b, 11b 20.0 59.1 ꢄ39:2
ꢄ44:5 100a + 110a (63:37) 75
4-MeO-C6H4
4-Cl-C6H4
ꢄ50:6
ꢄ49:9
ꢄ51:3
10c, 11c
19.2 57.1 ꢄ38:9
Cyclohexen-1-yl 10d, 11d 21.6 60.3 ꢄ39:2
t-Bu
Hex
10e
10f, 11f
10g, 11g
21.7
—
ꢄ40:3
—
10e
71
6.8
29.6 60.0 ꢄ37:5
29.4 61.2 ꢄ37:6
ꢄ50:5
ꢄ50:7
ꢄ43:4
CH3(CH2)9
Ph
Hex
10h, 11h 26.1 54.5 ꢄ31:2
Ph
11i
11j
11k
11l
—
—
—
—
57.3
54.8
51.5
52.5
—
—
—
—
ꢄ45:4 11i
ꢄ44:9
79
16.2
4-MeO-C6H4 Hex
4-CF3-C6H4 Hex
4-Br-C6H4
ꢄ41:6
Hex
ꢄ43:5
R2
R2
3JSn–H
R1
3JH–H
R1
R1
Bu3Sn
R1
H
H
H
Bu3Sn
H
H
H
R2
R2
3JSn–H
10
3JH–H
10"
11
11"
sitions states were fully optimized without any symmetry restric-
tions and identified by the number of imaginary frequencies calcu-
lated from the analytical Hessian matrix. The reaction coordinates
were followed from the transition state to the reactant and the
product by the intrinsic reaction coordinate (IRC) technique.38
J. Am. Chem. Soc. 1999, 121, 10221. d) H. Yoshida, E. Shirakawa,
T. Kurahashi, Y. Nakao, T. Hiyama, Organometallics 2000, 19,
5671. e) H. Yoshida, E. Shirakawa, Y. Nakao, Y. Honda, T.
Hiyama, Bull. Chem. Soc. Jpn. 2001, 74, 637.
5
E. Shirakawa, Y. Nakao, H. Yoshida, T. Hiyama, J. Am.
Chem. Soc. 2000, 122, 9030.
a) E. Shirakawa, Y. Nakao, T. Tsuchimoto, T. Hiyama,
6
We thank Professor Kouichi Ohe (Kyoto University) and
Professor Fumitoshi Kakiuchi (Keio University) for helpful
discussions. This work has been supported financially by
Grant-in-Aids for Scientific Research (No. 17550100) from
the Ministry of Education, Culture, Sports, Science and Tech-
nology. We thank Daicel Chemical Industries for financial
support.
Chem. Commun. 2002, 1962. b) Y. Nakao, E. Shirakawa, T.
Tsuchimoto, T. Hiyama, J. Organomet. Chem. 2004, 689, 3701.
Furthermore, the nickel-catalyzed tandem alkynylstannylation
of alkynes and 1,2-dienes also has recently been disclosed. c) E.
Shirakawa, Y. Yamamoto, Y. Nakao, S. Oda, T. Tsuchimoto, T.
Hiyama, Angew. Chem., Int. Ed. 2004, 43, 3448.
7
For an account of transformation of carbostannylation
products of alkynes and 1,2-dienes, see: a) E. Shirakawa, T.
Hiyama, J. Organomet. Chem. 2002, 653, 114. For reviews of
the transformation of organostannanes, see: b) V. Farina, V.
Krishnamurthy, W. J. Scott, Org. React. 1997, 50, 1. c) K.
Fugami, M. Kosugi, Top. Curr. Chem. 2002, 219, 87. d) A. G.
Davies, Organotin Chemistry, 2nd ed., Wiley-VCH, Weinheim,
2004.
Supporting Information
Cartesian coordinates of computationally optimized structures.
This material is available free of charge on the web at http://
www.csj.jp/journals/bcsj/.
References
1
L. Brandsma, Preparative Acetylene Chemistry, 2nd ed.,
Elsevier, Amsterdam, 1988, Chap. 3, pp. 39–77.
For recent reviews, see: a) E. Negishi, C. Xu, in Handbook
8
For reviews of metal–vinylidene complexes including
ruthenium–vinylidene complexes, see: a) M. I. Bruce, Chem.
Rev. 1991, 91, 197. b) C. Bruneau, P. H. Dixneuf, Acc. Chem.
Res. 1999, 32, 311. c) F. E. McDonald, Chem. Eur. J. 1999, 5,
3103. d) M. C. Puerta, P. Valerga, Coord. Chem. Rev. 1999,
193–195, 977. e) C. Bruneau, P. H. Dixneuf, Angew. Chem., Int.
Ed. 2006, 45, 2176.
2
of Organopalladium Chemistry for Organic Synthesis, ed. by
E. Negishi, Wiley-Interscience, New York, 2002, pp. 531–549.
b) E. Negishi, L. Anastasia, Chem. Rev. 2003, 103, 1979.
3
nylation of alkynes and dienes, see: E. Shirakawa, T. Hiyama,
For an account of the transition metal-catalyzed carbostan-
9
For recent reviews on ruthenium-catalyzed reactions, see:
Bull. Chem. Soc. Jpn. 2002, 75, 1435.
a) E. Shirakawa, H. Yoshida, T. Kurahashi, Y. Nakao, T.
Hiyama, J. Am. Chem. Soc. 1998, 120, 2975. b) E. Shirakawa,
H. Yoshida, Y. Nakao, T. Hiyama, J. Am. Chem. Soc. 1999,
121, 4290. c) E. Shirakawa, K. Yamasaki, H. Yoshida, T. Hiyama,
a) T. Naota, H. Takaya, S.-I. Murahashi, Chem. Rev. 1998, 98,
2599. b) B. M. Trost, F. D. Toste, A. B. Pinkerton, Chem. Rev.
2001, 101, 2067. c) C. Fischmeister, C. Bruneau, P. H. Dixneuf,
in Ruthenium in Organic Synthesis, ed. by S.-I. Murahashi,
Wiley-VCH, Weinheim, 2004, Chap. 8, pp. 189–217.
4

1976 Bull. Chem. Soc. Jpn. Vol. 79, No. 12 (2006)
Addition of 1-Alkynes to Alkynylstannanes
10 a) H. Yamazaki, J. Chem. Soc., Chem. Commun. 1976,
841. b) C. Bianchini, M. Peruzzini, F. Zanobini, P. Frediani, A.
Albinati, J. Am. Chem. Soc. 1991, 113, 5453. c) Y. Wakatsuki,
H. Yamazaki, N. Kumegawa, T. Satoh, J. Y. Satoh, J. Am. Chem.
Soc. 1991, 113, 9604. d) Y. Wakatsuki, H. Yamazaki, N.
Kumegawa, P. S. Johar, Bull. Chem. Soc. Jpn. 1993, 66, 987.
e) Y. Wakatsuki, N. Koga, H. Yamazaki, K. Morokuma, J. Am.
Chem. Soc. 1994, 116, 8105. f) C. S. Yi, N. Liu, Organometallics
1996, 15, 3968.
11 a) H. Katayama, F. Ozawa, Organometallics 1998, 17,
5190. b) H. Katayama, C. Wada, K. Taniguchi, F. Ozawa, Orga-
nometallics 2002, 21, 3285.
12 For rhodium–ꢀ-silylvinylidene complexes, see: D.
Schneider, H. Werner, Angew. Chem., Int. Ed. Engl. 1991, 30,
700.
librium, we excluded its participation from the succeeding discus-
sion because of its intrinsic short lifetime suggested by the DFT
calculation (Fig. 1, 5m).
26 As the stereoselectivities should depend not only on the
ratio of (E)- and (Z)-70 but also on their reactivities, the result that
the ratio of 10a and 11a is hardly affected by the ligands, ruthe-
nium precursors and solvents was unexpected.
27 Considering that tin and silicon atoms belong to the same
group in the periodic table, trialkylstannyl groups should have the
potential to stabilize ꢁ-carbanion in a similar manner to trialkyl-
silyl groups. For an example of the ꢁ-carbanion stabilizing ability
of silyl groups, see: D. M. Wetzel, J. I. Brauman, J. Am. Chem.
Soc. 1988, 110, 8333.
28 According to the calculation shown in Fig. 1, 70 should be
ꢃ3-butenynyl complexes rather than alkenylruthenium complexes.
The ruthenium–ꢃ3-butenynyl structure might contribute to convert
the double bond into the single bond. This type of a ruthenium–
ꢃ3-butenynyl complex was isolated as an intermediate of the
ruthenium-catalyzed dimerization of terminal alkynes and was
characterized by X-ray analysis. See Ref. 10b.
29 For an example of the transformation of alkenylruthenium
complexes to ruthenium–carbene complexes, see: N. Chatani, H.
Inoue, T. Ikeda, S. Murai, J. Org. Chem. 2000, 65, 4913.
30 In use of [RuH2(CO)(PPh3)3] as a catalyst precursor,
mixtures of stereoisomers are obtained even with Type A combi-
nation, which lacks a conjugating group on the terminal alkyne
(Entries 7 and 8 in Table 3). There is some possibility that the
ruthenium complexes generated from this precursor, compared
with those derived from [{RuCl(ꢃ6-p-cymene)}2(ꢂ-Cl)2], have
stronger tendency to form carbene complexes like 200, where
the isomerization takes place through the rotation of the C(ꢁ)–
C(ꢀ) single bond.
13 K. Onitsuka, H. Katayama, K. Sonogashira, F. Ozawa,
J. Chem. Soc., Chem. Commun. 1995, 2267.
14 For the rhodium-catalyzed reactions that are considered
to proceed through rhodium–ꢀ-silylvinylidene complexes, see:
a) J. W. Dankwardt, Tetrahedron Lett. 2001, 42, 5809. b) M.
Murakami, M. Ubukata, Y. Ito, Chem. Lett. 2002, 294. c) M.
Murakami, S. Hori, J. Am. Chem. Soc. 2003, 125, 4720. d) T.
Miura, H. Murata, K. Kiyota, H. Kusama, N. Iwasawa, J. Mol.
Catal. A: Chem. 2004, 213, 59.
15 E. Shirakawa, R. Morita, T. Tsuchimoto, Y. Kawakami,
J. Am. Chem. Soc. 2004, 126, 13614.
16 Organoboron compounds reportedly add to alkynylmetals
including alkynylstannanes with 1,2-migration of the metal moie-
ty. For a review, see: B. Wrackmeyer, Coord. Chem. Rev. 1995,
145, 125.
17 Rhodium–ꢀ-vinylidene complexes are known to be pro-
duced by the reaction of [RhCl(i-Pr3P)2]n with R–CꢁC–SnPh3
through 1,2-shift of the stannyl group. M. Baum, N. Mahr, H.
Werner, Chem. Ber. 1994, 127, 1877.
31 The coupling constant between the tin atom and the trans-
olefinic proton (3JSn{H) in alkenylstannanes are reported to be
larger than that between cis-3JSn{H. A. J. Leusink, H. S. Budding,
J. W. Marsman, J. Organomet. Chem. 1967, 9, 285.
18 Alkynes substituted by a heteroatom such as sulfur and se-
lenium at the terminal carbon undergo 1,2-shift upon reaction with
ruthenium complexes to give the corresponding ꢀ-heteroatom-
substituted vinylidene complexes. For an example of sulfur, see:
a) D. C. Miller, R. J. Angelici, Organometallics 1990, 10, 89.
Selenium: b) A. F. Hill, A. G. Hulkes, A. J. P. White, D. J.
Williams, Organometallics 2000, 19, 371.
32 M. J. Frisch, G. W. Trucks, H. B. Schlegel, G. E.
Scuseria, M. A. Robb, J. R. Cheeseman, V. G. Zakrzewski, J. A.
Montgomery, Jr., R. E. Stratmann, J. C. Burant, S. Dapprich, J. M.
Millam, A. D. Daniels, K. N. Kudin, M. C. Strain, O. Farkas,
J. Tomasi, V. Barone, M. Cossi, R. Cammi, B. Mennucci, C.
Pomelli, C. Adamo, S. Clifford, J. Ochterski, G. A. Petersson,
P. Y. Ayala, Q. Cui, K. Morokuma, D. K. Malick, A. D. Rabuck,
K. Raghavachari, J. B. Foresman, J. Cioslowski, J. V. Ortiz, B. B.
Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R.
Gomperts, R. L. Martin, D. J. Fox, T. Keith, M. A. Al-Laham,
C. Y. Peng, A. Nanayakkara, C. Gonzalez, M. Challacombe,
P. M. W. Gill, B. G. Johnson, W. Chen, M. W. Wong,
J. L. Andres, M. Head-Gordon, E. S. Replogle, J. A. Pople,
Gaussian 98, Gaussian, Inc., Pittsburgh, PA, 1998.
3
19 Configuration of 10a and 11a was determined by JSn{H
value between the tin atom and the olefinic proton of 10a and
3
11a in addition to JH{H value between the olefinic protons of
the hydrolyzed products of 10a and 11a. For details, see Experi-
mental.
20 The reaction of 9a under the same conditions but in the
absence of 8a gave a mixture of (E)- and (Z)-1,4-diphenylbut-1-
en-3-yne in addition to (E)- and (Z)-1,4-diphenylbuta-1,2,3-triene
(45:45:5:5) in 10% yield.
21 B. Gabriele, G. Salerno, E. Lauria, J. Org. Chem. 1999, 64,
7687.
33 a) C. Lee, W. Yang, R. G. Parr, Phys. Rev. B 1988, 37, 785.
b) A. D. Becke, J. Chem. Phys. 1993, 98, 5648.
22 Alkynyl iodides are known to form tungsten–vinylidene
complexes, which undergo electrocyclization. T. Miura, N.
Iwasawa, J. Am. Chem. Soc. 2002, 124, 518.
23 T. Matsubara, K. Hirao, Organometallics 2002, 21, 4482.
24 The addition of p-methoxyphenylacetylene to 8a took
place in a similar manner to Entry 3 of Table 3, giving a 56:44
mixture of 10b and 11b in 85% yield.
34 A. W. Ehlers, M. Bohme, S. Dapprich, A. Gobbi, A.
¨
Hollwarth, V. Jonas, K. F. Kohler, R. Stegmann, A. Veldkamp,
¨
¨
G. Frenking, Chem. Phys. Lett. 1993, 208, 111.
35 P. J. Hay, W. R. Wadt, J. Chem. Phys. 1985, 82, 299.
36 S. Huzinaga, Physical Sciences Data 16, Gaussian Basis
Sets for Molecular Calculations, Elsevier, Amsterdam, 1984.
37 W. R. Wadt, P. J. Hay, J. Chem. Phys. 1985, 82, 284.
38 K. Fukui, S. Kato, H. Fujimoto, J. Am. Chem. Soc. 1975,
97, 1.
25 Although alkenylruthenium intermediates 17 in Scheme 5
also should be candidates that are responsible for such an equi-