Synthesis of (Z)-1-aryl-2-(germyl)-1-(stannyl)ethenes and the related ethenes, precursors to stereodefined germylethenes, via Pd(dba)2-P(OCH2)3CEt-catalyzed germastannation of acetylenes in THF

Article abstract of DOI:10.1016/S0022-328X(01)00652-0

(Z)-1-Aryl-2-(germyl)-1-(stannyl)ethenes are synthesized in high yields by the addition of tributyl(triethylgermyl)stannane to arylacetylenes catalyzed by a specific combination catalyst, Pd(dba)₂ and 4-ethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane, in tetrahydrofuran. Ethynylthiophene and 2-methyl-3-butyn-2-ol are also subject to the germastannation to afford the respective adducts in high yields. In addition, the J_Sn-H and ¹³C-NMR data for their adducts are presented.

Full text of DOI:10.1016/S0022-328X(01)00652-0

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 622 (2001) 302–308
Note
Synthesis of (Z)-1-aryl-2-(germyl)-1-(stannyl)ethenes and the
related ethenes, precursors to stereodefined germylethenes, via
Pd(dba)2–P(OCH2)3CEt-catalyzed germastannation of acetylenes in
THF
Yoshiya Senda, Yoh-ichi Oguchi, Michihiro Terayama, Taijyu Asai, Taichi Nakano *,
Toshihiko Migita 1
Department of Material Science and Technology, School of High-technology for Human Welfare, Tokai Uni6ersity, 317 Nishino, Numazu,
Shizuoka 410-0395, Japan
Received 6 November 2000; received in revised form 15 December 2000; accepted 21 December 2000
Abstract
(Z)-1-Aryl-2-(germyl)-1-(stannyl)ethenes are synthesized in high yields by the addition of tributyl(triethylgermyl)stannane to
arylacetylenes catalyzed by a specific combination catalyst, Pd(dba)2 and 4-ethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane, in
tetrahydrofuran. Ethynylthiophene and 2-methyl-3-butyn-2-ol are also subject to the germastannation to afford the respective
adducts in high yields. In addition, the JSn–H and 13C-NMR data for their adducts are presented. © 2001 Elsevier Science B.V.
All rights reserved.
Keywords: Germylstannane; Acetylenes; Germastannation; (Z)-Germyl(stannyl)ethenes; Palladium catalysis
1. Introduction
derivatives, because pyridyl(germyl)ethene was reported
to undergo [2+3] cycloaddition with nitrile oxide to
produce (germyl)isoxazolines possessing vasodilating,
antithrombotic and cardioprotective activity [7]. To
synthesize such isoxazolines with a stereodefined struc-
ture, the use of stereodefined germylethene derivatives
is essential. The germastannation of triple bonds can
The bis-silylation [1], bis-germylation [2], silastanna-
tion [3] or bis-stannation [4] of acetylenes forming new
sp2carbon–silicon,
sp2carbon–germanium
or
sp2carbon–tin bonds has been reported. The impor-
tance of their products is the possibility of transforming
them to other new derivatives through the reactions
such as Kosugi Migita-Stille coupling [5]. For example,
the demetallations such as the desilylation of
silylethenes [3f], the destannylation of stannylethenes
[3g] and carbon–carbon formation by the cross cou-
plings using silylethenes [6] or stannylethenes [5] have
been reported. In all these cases, the reaction proceeds
with the retention of the configuration, except for an
example using 6icinal di(silyl)ethenes [6f]. Recently,
much attention has been focused on the germylethene
provide precursors to
a variety of stereodefined
vinylgermane derivatives through the destannylation
[3g] or the Kosugi Migita-Stille coupling [5]. For the
germastannation of acetylenes, Piers et al. [8] previously
reported that addition of tributyl(trimethylgermyl)-
stannane to nonterminal a,b-acetylenic esters in the
presence of Pd(PPh3)4 gave a mixture of 6icinal (ger-
myl)stannylethenes with (E) and (Z)-configurations.
Mitchell et al. investigated the addition of the (ger-
myl)stannane to terminal alkynes including pheny-
lacetylene catalyzed by Pd(PPh3)4 and reported that the
reaction formed 6icinal (germyl)stannylethenes with the
Z-configuration [9]. However the product yields did not
exceed 50%.
* Corresponding author.
E-mail address: naka1214@wing.ncc.u-tokai.ac.jp (T. Nakano).
1 Retired, March 31, 1997.
0022-328X/01/$ - see front matter © 2001 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(01)00652-0

Y. Senda et al. / Journal of Organometallic Chemistry 622 (2001) 302–308
303
Table 1
Influence of catalysts and reaction conditions in Scheme 1 a
b
Run
Catalyst
Ligand
Solvent
Reaction time (h)
Yield (%) c
1
2
3
4
5
6
7
8
Pd(PPh3)4
Pd(dba)2
Pd(dba)2
Pd(dba)2
Pd(dba)2
RhCl(PPh3)3
RuCl2(PPh3)3
PdCl2(PPh3)2
PtCl2(PPh3)2
Pd(dba)2
–
–
–
–
–
–
–
–
–
19
48
48
48
96
48
48
40
48
48
48
48
48
5
0
2
0
0
d
P(o-tol)3
P(OPh)3
P(OEt)3
–
–
–
–
d
d
0
0
THF
–
–
THF
THF
PhH
Trace
0
27
32
91
0
9
d
10
11 e
12
13
PPh3
PPh3
Pd(dba)2
Pd(dba)2
Pd(dba)2
P(OCH2)3CEt d
P(OCH2)3CEt d
a A 1 mmol:2 mmol:0.01 mmol mixture of 1, phenylacetylene and the catalyst was introduced into a glass ampoule and degassed through several
freeze-evacuate-thaw cycles prior to sealing under vacuum. The mixture was then stirred at 80°C.
b One ml of the solvent was used.
c GLC yields based on the 1 used.
d Amounts of the ligand were 0.02 mmol.
e Amounts of the palladium and the ligand were 0.05 and 0.1 mmol, respectively.
germylethene derivatives and related (Z)-(germyl)-
stannylethenes by the reaction shown in Scheme 1.
2. Results and discussion
The Pd(PPh3)4-catalyzed addition of 1 to pheny-
lacetylene was carried out at 80°C for 19 h in a sealed
glass ampoule tube. However, the reaction produced
(Z) - 1 - (tributylstannyl) - 2 - (triethylgermyl) - 1 - phenyl-
ethene (2a) in only 5% (entry 1 in Table 1). These
Scheme 1.
results suggest that the reactivity of 1 is much lower
than that of the tributyl(trimethylgermyl)stannane pre-
viously used by Mitchell et al. The reaction conditions
are almost the same as those reported by Mitchell et al.
[9] except for the reaction time and the use of 1.
Promising results were obtained using Pd(dba)2 with
two equivalents of triphenylphosphine without or with
THF as the solvent. The catalyst showed a slightly
better activity for producing the product 2a in 27% and
32% yield, respectively (entries 10 and 11). Much better
results were obtained using a combination catalyst of
Pd(dba)2 and the phosphite ligand, 4-ethyl-1-phospha-
2,6,7-trioxabicyclo[2.2.2]octane, L. The catalyst system
most effectively accelerated the reaction, especially in
THF, to realize the highest product yield (91%, entry
12) of the adduct 2a. Other catalysts such as Pd(dba)2,
As mentioned above, in view of the importance for
the (Z)-(germyl)stannylethenes as key compounds to
synthesize stereodefined germylethene derivatives, we
examined the addition of tributyl(triethylgermyl)-
stannane 1 to phenylacetylene in the presence of a
transition metal complex catalyst and found that a
specific palladium combination catalyst, Pd(dba)2–
P(OCH2)3CEt (dba=dibenzylideneacetone, P(OCH2)3-
CEt=4 - ethyl - 1 - phospha - 2,6,7 - trioxabicyclo[2.2.2]-
octane2), very effectively accelerated the germastanna-
tion in tetrahydrofuran (THF) to afford (Z)-2-(germyl)-
1-phenyl-1-(stannyl)ethenes in a high-isolated yield. We
now report an alternative synthesis of (Z)-1-aryl-2-(ger-
myl)-1-(stannyl)ethenes as precursors to a variety of
Pd(dba)2–2P(o-tol)3
(o-tol=o-tolyl),
Pd(dba)2–
2P(OPh)3, Pd(dba)2–2P(OEt)3, RhCl(PPh3)3, RuCl2-
(PPh3)3, PdCl2(PPh3)2, and PtCl2(PPh3)2 were all inef-
fective (entries 2–9). Here, the use of THF is essential
in the present germastannation. No reaction occurred
when an aromatic solvent such as benzene was used
(entry 13).
2 P(OCH2)3CEt; 4-ethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]octane.
For use of the specific ligand in the Pd-catalyzed addition of Si–Si
bonds and Ge–Ge bonds to acetylenes in benzene solvent, see: (the
former) [1f]; (the latter) [2a,b].

304
Y. Senda et al. / Journal of Organometallic Chemistry 622 (2001) 302–308
Table 3
JSn–H for (Z)-Ar(Bu3Sn)CꢀCH(GeEt3)a
Run
Product
Substituent (X)
3J117Sn–H
3J119Sn–H
1
2
3
4
5
6
7
8
2a
2b
2c
2d
2e
2f
H
m-Cl
p-Cl
p-F
m-CF3
p-CN
p-NO2
3,4-(OMe)2
161.2
156.0
157.2
159.2
154.8
151.2
150.0
162.4
168.4
163.2
164.8
166.4
162.0
158.4
156.8
169.6
Fig. 1. Reported JSn–H in three different types of vinylstannanes.
The NMR coupling constants (JSn–H) for the respec-
tive tin-117 and 119 with vinyl proton for adduct 2a
were 161.2 and 168.4 Hz, respectively, being typical for
the structures with tin and hydrogen in trans-disposi-
2g
2h
3
tion [3b,3e,3f,4b,9]. The coupling constants of JSn–
a Average of three measurements in CDCl3 is shown in Hz.
3
2
H(trans), JSn–H(cis), and JSn–H(geminal) for the tri-
substituted or di-substituted stannylethene derivatives
have been reported [3b,3e,3f,4b,9] and are summarized
in Fig. 1.
Next, the present catalyst system was applied to the
reaction with a series of arylacetylenes. Respective (Z)-
1-aryl-1-(tributylstannyl)-2-(triethylgermyl)ethenes were
successfully synthesized in satisfactory yields, as shown
3
in Table 2. The observed magnitudes of JSn–H for their
products are summarized in Table 3.
Scheme 2.
By reference to the magnitudes of the reported JSn–H
shown in Fig. 1, the configurations for 2b through 2h
were determined as the (Z)-structure, in which a stan-
nyl group is connected with the sp2 carbon bearing an
aryl group.
The germastannation of 2-ethynylthiophene also gave
(Z)-1-(tributylstannyl)-2-(triethylgermyl)-1-(2-thienyl)-
ethene 2i in the isolated yield of 83% (Scheme 2). The
reaction in Scheme 3 showed that the hydroxy func-
tional group was tolerated during the reaction. Thus,
2-methyl-3-butyn-2-ol was effectively subject to the ger-
mastannation to produce (Z)-3-(tributylstannyl)-4-(tri-
ethylgermyl)-2-methyl-3-buten-2-ol (2j) in 85% yield.
The coupling constants, 3JSn–H, of 2j (179.0 and 187.7
Hz) possessing the electron-donating group (1-hydroxy-
Scheme 3.
1-methylethyl group) on tin-bearing vinyl carbon were
reasonably the smallest among adducts obtained in this
study.
In Table 4 are shown selected NMR data for all
adducts 2a–2j. In a series of 1-aryl-2-germyl-1-stan-
Table 2
Reaction time and product yields in the reaction of 1 with arylacetylenes a
Run
Time (h)
Conversion of 1
Substituent (X)
Product number
Yield (%) b
1 c
2
3
4
5
6
7
8
9
19
50
30
19
40
30
40
40
35
98
98
94
91
95
94
88
96
98
H
H
m-Cl
p-Cl
p-F
m-CF3
p-CN
p-NO2
3,4-(OMe)2
2a
2a
2b
2c
2d
2e
2f
91 d
85
88
78
75
83
76
91
78
2g
2h
a A THF (5 ml) solution of 1 mmol:3–4 mmol:0.05 mmol:0.1 mmol of 1, arylacetylene, Pd(dba)2 and phosphite L was stirred at 80°C.
b Isolated yields after column chromatography (see Section 3) unless otherwise stated. The chromatography produced a spectroscopically
(1H-NMR) pure product.
c See footnote ‘a’ in the Table 1.
d GLC yield based on the 1 used.

Y. Senda et al. / Journal of Organometallic Chemistry 622 (2001) 302–308
305
Table 4
lene to the palladium, although we can not entirely
exclude the possibility of the initial addition of a
germylstannane to the palladium complex as the pri-
mary event.3 Hence, we propose the mechanism shown
in Fig. 2.
Selected NMR data for (Z)-R(Bu3Sn)C=CH(GeEt3)
Run Product Substituent (R)
l(ꢀCH) a l(C1) b l(C2) b
1
2
3
4
5
2a
2b
2c
2d
2e
2f
C6H5
m-ClC6H4
p-ClC6H4
6.63
6.63
6.62
6.61
6.67
6.65
6.69
6.63
6.93
6.42
165.5
164.2
164.3
164.4
164.3
164.2
164.0
164.9
155.1
175.1
151.8
153.6
150.3
147.9
152.4
156.6
158.9
148.2
154.5
135.7
In conclusion, the present method provided a high-
yield synthesis of (Z)-1-aryl-2-(germyl)-1-(stannyl)-
p-FC6H4
ethenes,
(Z)-2-(germyl)-1-(stannyl)-1-(thienyl)ethenes
m-CF3C6H4
p-CNC6H4
p-NO2C6H4
3,4-(OMe)2C6H3
2-thienyl
6
and (Z)-2-(germyl)-1-{1-hydroxy-1-(substituted)alkyl}-
1-(stannyl)ethenes, which can be used as starting mate-
rials for a variety of germylethene derivatives.
7
8
9
2g
2h
2i
10
2j
C(CH3)OHCH3
a NMR was measured in chloroform-d and chemical shifts refer-
3. Experimental
enced to TMS in ppm
b C1 is the tin-bearing vinyl carbon, while C2 bears germanium.
Both are shown with reference to TMS.
3.1. Measurements
GLC analyses were performed using an Ohkura
Model 103 instrument equipped with a thermal conduc-
tivity detector and a stainless column packed with 20%
or 10% Silicone KF-96/Celite 545 SK (60–80 mesh, 2
m×3 mm). The IR spectra were measured using a
JASCO A-102 spectrophotometer. Mass spectra were
obtained using a JEOL JMSAX-500 spectrometer with
1
the DA7000 data system. H-NMR spectra and 13C-
NMR spectra were recorded at 400 MHz and 100
MHz, respectively, on a Varian UNITY-400 spectrome-
ter in chloroform-d using tetramethylsilane (TMS) as
the internal standard. Splitting patterns are designated
as s (singlet), d (doublet), t (triplet), q (quartet), sep
(septet) and m (multiplet).
Fig. 2. A possible mechanism for the formation of (Z)-2-(germyl)-1-
(stannyl)ethenes.
3.2. Materials
nylethenes, the chemical shifts of the germanium-bear-
ing vinyl carbon (C2 in the Table 4) were affected by
the electronic effects of the substituent on the aromatic
ring. In constrast, C1 was not subject to such a large
change. Similar propensities are seen in the NMR data
for vicinal (stannyl)silylethenes [3e].
We further examined the present catalyst system for
other alkynols such as 2-propyn-1-ol, 5-hexyn-1-ol and
4-pentyn-2-ol. However, the germastannation did not
occur, apart from that of 4-pentyn-2-ol, which gave a
17% yield of the expected (Z)-adduct. Nonterminal
alkynes such as 2-butyn-1,4-diol and terminal acetyle-
nes such as 1-hexyne, (trimethylsilyl)phenylethyne, and
(dimethylphenylsilyl)phenylethyne also did not enter
into the germastannation. Further study is needed for
these acetylenes.
Aimed at better understanding the reaction mecha-
nism, the reaction of Pd(dba)2 with 1 in THF in the
presence of ligand L was examined at 80°C for 40 h
under argon. However, the attempt left 1 unchanged,
and demonstrated that a germyl(stannyl)palladium was
not formed under these conditions. Therefore, the first
step for this reaction may be coordination of an acety-
Arylacetylenes and thienylacetylene were prepared by
the Sonogashira reaction [11]. Aryl halides and 2-
methyl-3-butyn-2-ol were purchased from Tokyo Kasei
Kogyo Co. and used without purification. Pd(dba)2
[12], RhCl(PPh3)3 [13], RuCl2(PPh3)3 [14] and PtCl2-
(PPh3)2 [15] were prepared according to the literature
procedures.
triphenylphosphine, triphenylphosphite, trieth-ylphos-
phite, 4-ethyl-1-phospha-2,6,7-trioxabicyclo[2.2.2]-
Tetrakis(triphenylphosphine)palladium,
octane L and silica gel (Wako gel C-300) were pur-
chased from Wako Chemical. Co. Tributyl(tri-
ethylgermyl)stannane was prepared by reference to the
synthesis of tributyl(trimethylsilyl)stannane [16]. Ben-
zene and toluene were distilled from LiAlH4 and stored
over molecular sieves. THF was distilled from sodium
benzophenone ketyl prior the use.
3 (a) For the addition of a Pd–Sn bond to acetylenes, see: [4d]. (b)
For the addition of a Pd–Si bond to an acetylene, see: [10a]. (c) For
the addition of a Pt–Si bond to an acetylene, see: [10b]. (d) For the
formation of a Pt–Ge bond from a digermane and Platinum com-
plex, see: [10c].

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Y. Senda et al. / Journal of Organometallic Chemistry 622 (2001) 302–308
3
3.3. Synthesis
2H), 6.62 (s, 1H, JSn–H=157.2 (for 117Sn), 164.8 (for
119Sn) Hz), 1.4 (m, 6H), 1.27 (sep, 6H, J=7.6 Hz), 1.07
(t, 9H, J=7.8 Hz), 0.88 (m, 21H) ppm. 13C-NMR
(CDCl3) l 164.3, 150.3, 147.5, 131.1, 127.9, 127.4, 29.0,
27.4, 13.6, 11.6, 9.1, 5.6 ppm. IR (neat) 3065, 2950,
3.3.1. A typical example for the germastannation of the
acetylenes: (Z)-1-(tributylstannyl)-2-(triethylgermyl)-1-
phenylethene (2a)
A THF (5 ml) solution of phenylacetylene (0.451 g,
4.4 mmol), 1 (0.456 g, 1.01 mmol), Pd(dba)2 (0.0281 g,
0.049 mmol), and phosphite L (0.0167 g, 0.103 mmol)
was stirred at 80°C under argon. After 50 h, the GLC
analysis of the resulting mixture disclosed that 98% of 1
was consumed. The mixture was concentrated under
vacuum and then added to the concentrate a hexane–
ether (1/1) mixed solution. The resulting solution was
passed through a short silica gel column with hexane–
ether (1/1) to remove tarry compounds. Purification by
column chromatography eluted with hexane then gave
spectroscopically pure 2a as a colorless oil (0.477 g,
2925, 2860, 1480, 1460, 1090, 1010, 815, 690, 645 cm−1
.
LRMS (EI) 588 [M]+, 559 [M–C2H5]+, 531 [M–
C4H9]+, 477 [M–C6H4Cl]+. HRMS (EI) Calc. for
C26H47ClGeSn: 588.1600. Found: 588.1588.
3.4.3. (Z)-1-(tributylstannyl)-2-(triethylgermyl)-
1-(p-fluorophenyl)ethene (2d)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2d was obtained as a colorless oil (0.429 g,
1
75% yield). H-NMR (CDCl3) l 6.93 (d, 4H, J=7.2
3
Hz), 6.61 (s, 1H, JSn–H=159.2 (for 117Sn), 166.4 (for
1
85% yield based on the 1 used). H-NMR (CDCl3) l
119Sn) Hz), 1.39 (m, 6H), 1.26 (sep, 6H, J=7.2 Hz),
1.07 (t, 9H, J=7.8 Hz), 0.87 (m, 21H) ppm. 13C-NMR
7.24 (m, 2H), 7.13 (m, 2H), 6.98 (m, 1H), 6.63 (s, 1H,
3JSn–H=161.2 (for 117Sn), 168.4 (for 119Sn) Hz), 1.4 (m,
6H), 1.26 (sep, 6H, J=7.2 Hz), 1.07 (t, 9H, J=7.6
Hz), 0.87 (m, 21H) ppm. 13C-NMR (CDCl3) l 165.5,
151.8, 146.5, 127.9, 126.0, 125.3, 29.1, 27.4, 13.6, 11.6,
9.2, 5.6 ppm. IR (neat) 3050, 2950, 2910, 2860, 1480,
1460, 700 cm−1. LRMS (EI) 554 [M]+, 525 [M–
C2H5]+, 497 [M–C4H9]+, 468 [M–C2H5–C4H9]+, 393
[M–C6H15Ge]+, 293 [M–C12H27Sn]+. HRMS (EI)
Calc. for C26H48GeSn: 554.1991. Found: 554.1994.
1
(CDCl3) l 164.4, 161.1 (d, JCF=242 Hz), 147.9, 147.1,
127.4, 114.6 (d, JCF=20.5 Hz), 29.0, 27.4, 13.6, 11.6,
2
9.1, 5.6 ppm. IR (neat) 3030, 2950, 2925, 2860, 1595,
1495, 1460, 1365, 1225, 1150, 1010, 825, 725, 690 cm−1
.
LRMS (EI) 572 [M]+, 543 [M–C2H5]+, 515 [M–
C4H9]+, 281 [M–C12H27Sn]+. HRMS (EI) Calc. for
C26H47FGeSn: 572.1869. Found: 572.1890.
3.4.4. (Z)-1-(tributylstannyl)-2-(triethylgermyl)-
1-(m-trifluoromethylphenyl)ethene (2e)
3.4. Isolation and spectral data for other new
germyl(stannyl)ethenes (2b)–(2j)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2e was obtained as a colorless oil (0.534 g,
1
3.4.1. (Z)-1-(tributylstannyl)-1-(m-chlorophenyl)-
2-(triethylgermyl)ethene (2b)
83% yield). H-NMR (CDCl3) l 7.40 (m, 2H), 7.21 (m,
1H), 7.15 (m, 1H), 6.67 (s, 1H, 3JSn–H=154.8 (for
117Sn), 162.0 (for 119Sn) Hz), 1.39 (m, 6H), 1.25 (sep,
6H, J=7.2 Hz), 1.08 (t, 9H, J=8 Hz), 0.88 (m, 21H)
ppm. 13C-NMR (CDCl3) l 164.3, 152.4, 148.5, 130.1 (q,
A reaction similar to that for the synthesis of 2a was
carried out. Purification of the resulting mixture by
column chromatography eluted with hexane gave spec-
troscopically pure 2b as a colorless oil (0.527 g, 88%
1
2JCF=31 Hz), 129.3, 128.3, 124.3 (q, JCF=270 Hz),
1
yield). H-NMR (CDCl3) l 7.17 (m, 1H), 7.11 (m, 1H),
122.8, 122.0, 29.0, 27.3, 13.5, 11.6, 9.1, 5.6 ppm.
IR(neat) 3050, 2950, 2920, 2860, 1455, 1160, 1130,
1070, 700 cm−1. LRMS (EI) 622 [M]+, 593 [M–
C2H5]+, 565 [M–C4H9]+. HRMS (EI) Calc. for
C27H47F3GeSn: 622.1864. Found: 622.1819.
3
6.96 (m, 1H), 6.84 (m, 1H), 6.63 (s, 1H, JSn–H=156.0
(for 117Sn), 163.2 (for 119Sn) Hz), 1.4 (m, 6H), 1.26 (sep,
6H, J=7.2 Hz), 1.07 (t, 9H, J=7.8 Hz), 0.88 (m, 21H)
ppm. 13C-NMR (CDCl3) l 164.2, 153.6, 147.8, 133.7,
129.0, 126.1, 125.3, 124.3, 29.0, 27.3, 13.6, 11.6, 9.1, 5.5
ppm. IR (neat) 3050, 2950, 2925, 2870, 1585, 1460,
1070, 1020, 875, 840, 790, 740, 690 cm−1. LRMS (EI)
588 [M]+, 559 [M–C2H5]+, 531 [M–C4H9]+, 477 [M–
C6H4Cl]+. HRMS (EI) Calc. for C26H47ClGeSn:
588.1600. Found: 588.1558.
3.4.5. (Z)-1-(tributylstannyl)-1-(p-cyanophenyl)-
2-(triethylgermyl))ethene (2f)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2f was obtained as a colorless oil (0.436 g,
1
76% yield). H-NMR (CDCl3) l 7.54 (m, 2H), 7.04 (m,
3
3.4.2. (Z)-1-(tributylstannyl)-1-(p-chlorophenyl)-
2-(triethylgermyl)ethene (2c)
2H), 6.65 (s, 1H, JSn–H=151.2 (for 117Sn), 158.4 (for
119Sn) Hz), 1.39 (m, 6H), 1.26 (sep, 6H, J=7.2 Hz),
1.08 (t, 9H, J=7.8 Hz), 0.88 (m, 21H) ppm. 13C-NMR
(CDCl3) l 164.2, 156.6, 149.2, 131.8, 126.7, 119.3,
108.7, 28.9, 27.3, 13.5, 11.6, 9.1, 5.5 ppm. IR (neat)
3050, 2945, 2920, 2865, 2225, 1595, 1490, 1460, 1020,
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2c was obtained as a colorless oil (0.430 g,
1
78% yield). H-NMR (CDCl3) l 7.22 (m, 2H), 6.9 (m,

Y. Senda et al. / Journal of Organometallic Chemistry 622 (2001) 302–308
307
825, 690, 675 cm−1. LRMS (EI) 579 [M]+, 550 [M–
3.4.9. (Z)-3-(tributylstannyl)-4-(triethylgermyl)-
2-methyl-3-buten-2-ol (2j)
C2H5]+, 522 [M–C4H9]+, 493 [M–C2H5–C4H9]+, 418
[M–C6H15Ge]+. HRMS (EI) Calc. for C27H47NGeSn:
579.1942. Found: 579.1989.
The reaction was carried out with a procedure similar
to the synthesis of 2a. Purification of the resulting
mixture by column chromatography eluted with
dichloromethane spectroscopically gave pure 2j as a
3.4.6. (Z)-1-(tributylstannyl)-2-(triethylgermyl)-1-
(p-nitrophenyl)ethene (2g)
1
colorless oil (0.461 g, 85% yield). H-NMR (CDCl3) l
3
6.42 (s, 1H, JSn–H=179.0 (for 117Sn), 187.7 (for 119Sn)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2g was obtained as a colorless oil (0.580 g,
Hz), 1.51 (s, 1H), 1.47 (m, 6H), 1.33 (sep, 6H, J=7.2
Hz), 2.39 (s, 6H), 1.03 (t, 9H, J=7.8 Hz), 0.88 (m,
21H) ppm. 13C-NMR (CDCl3) l 175.1, 135.7, 78.0,
30.6, 29.3, 27.6, 13.7, 12.6, 9.1, 5.9 ppm. IR (neat) 3600,
3450, 2950, 2920, 2865, 1460, 1375, 1260, 1100, 1020,
835, 710 cm−1. LRMS (EI) 536 [M]+, 518 [M–H2O]+,
1
91% yield). H-MR (CDCl3) l 8.13 (m, 2H), 7.08 (m,
3
2H), 6.69 (s, 1H, JSn–H=150.0 (for 117Sn), 156.8 (for
119Sn) Hz), 1.40 (m, 6H), 1.26 (sep, 6H, J=7.2 Hz),
1.08 (t, 9H, J=8 Hz), 0.89 (m, 21H) ppm. 13C-NMR
(CDCl3) l 164.0, 158.9, 149.7, 145.6, 126.6, 123.4, 29.0,
27.3, 13.5, 11.7, 9.1, 5.5 ppm. IR (neat) 3020, 2950,
2920, 2860, 1585, 1515, 1455, 1340, 1105, 1015, 860,
840, 720 cm−1. LRMS (EI) 599 [M]+, 570 [M–C2H5]+,
477
[M–C3H7O]+.
HRMS
(EI)
Calc.
for
C23H50OGeSn: 536.2095. Found: 536.2064.
3.5. The reaction of Pd(dba)2–2P(OCH2)3CEt with
(Et3Ge)SnBu3 at 80°C in THF
542
[M–C4H9]+.
HRMS
(EI)
Calc.
for
C26H47NO2GeSn: 599.1841. Found: 599.1821.
A THF (1 ml) solution of Pd(dba)2 (0.0577 g, 0.1
mmol), and P(OCH2)3CEt (0.0331 g, 0.204 mmol) was
stirred at r.t. under argon. After 5 min, the dark violet
solution turned yellow. Addition of 1 (0.0429 g, 0.109
mmol) to the mixture turned to clear yellow–green. The
mixture was then stirred at 80°C under argon. After 40
h, no color change was observed and the GLC analysis
of the resulting mixture showed that no 1 was con-
sumed. In addition, the NMR analysis of the concen-
trate of the mixture showed the sample to be a simple
mixture of Pd(dba)2, L, and 1.
3.4.7. (Z)-1-(tributylstannyl)-2-(triethylgermyl)-
1-(3,4-dimethoxyphenyl))ethene (2h)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2h was obtained as a colorless oil (0.478 g,
1
78% yield). H-NMR (CDCl3) l 6.73 (m, 1H), 6.63 (s,
1H, 3JSn–H=162.4 (for 117Sn), 169.6 (for 119Sn) Hz),
6.56 (m, 2H), 3.88 (s, 3H), 3.87 (s, 3H), 1.42 (m, 6H),
1.27 (sep, 6H, J=7.2 Hz), 1.08 (t, 9H, J=7.8 Hz), 0.88
(m, 21H) ppm. 13C-NMR (CDCl3) l 164.9, 148.2,
147.0, 145.8, 144.9, 118.0, 110.9, 109.7, 55.9, 55.7, 29.1,
27.4, 13.6, 11.6, 9.1, 5.6 ppm. IR (neat) 3040, 2940,
Acknowledgements
2920, 2865, 1505, 1460, 1260, 1030, 815, 785, 700 cm−1
.
LRMS (EI) 614 [M]+, 557 [M–C4H9]+, 453 [M–
C6H15Ge]+, 323 [M–C12H27Sn]+. HRMS (EI) Calc. for
C28H52O2GeSn: 614.2201. Found: 614.2225.
Partial financial support from the Shizuoka Shougou
Kenkyu Kikoh Foundation of Japan is gratefully ac-
knowledged by one of the authors (T.N.). The authors
are indebted to Ms. Fumiyo O-ikawa (Tokai Univer-
sity) for the mass measurements, especially the high
resolution ones on the (Z)-2-(germyl)-1-(stannyl)-1-
(substituted)ethenes.
3.4.8. (Z)-1-(tributylstannyl)-2-(triethylgermyl)-1-
(2-thienyl)ethene (2i)
The reaction and purification were carried out with a
procedure similar to the synthesis of 2b. Spectroscopi-
cally pure 2i was obtained as a colorless oil (0.470 g,
1
References
83% yield). H-NMR (CDCl3) l 7.06 (m, 1H), 6.93 (s,
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560.1554. Found: 560.1540.
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