New catalytic route to alkynylgermanes

Article abstract of DOI:10.1021/om700528r

Vinyl-trisubstituted germanes react selectively with terminal alkynes in the presence of compounds containing Ru-H and Ru-Ge bonds with formation of functionalized alkynylgermanes. The reaction opens the first transition metal catalytic route for the preparation of this class of organogermanes, which are useful reagents for organic synthesis. The mechanism elucidated by NMR spectroscopic study of stoichiometric reactions shows that this process is a new catalytic activation of an sp-hybridized C-H bond involving the previously discovered activation of the =C-Ge bond.

Full text of DOI:10.1021/om700528r

5188
Organometallics 2007, 26, 5188-5192
New Catalytic Route to Alkynylgermanes†
Bogdan Marciniec,* Hanna Ławicka, and Beata Dudziec
Department of Organometallic Chemistry, Faculty of Chemistry, Adam Mickiewicz UniVersity,
Grunwaldzka 6, 60-780 Poznan, Poland
ReceiVed May 29, 2007
Vinyl-trisubstituted germanes react selectively with terminal alkynes in the presence of compounds
containing Ru-H and Ru-Ge bonds with formation of functionalized alkynylgermanes. The reaction
opens the first transition metal catalytic route for the preparation of this class of organogermanes, which
are useful reagents for organic synthesis. The mechanism elucidated by NMR spectroscopic study of
stoichiometric reactions shows that this process is a new catalytic activation of an sp-hybridized C-H
bond involving the previously discovered activation of the dC-Ge bond.
Scheme 1. Silylative, Borylative, and Germylative Coupling
of Olefin with Vinyl-Substituted Organometallic Compounds
Introduction
Organogermanium compounds have recently been recognized
as useful reagents for organic synthesis.1,2 Unsaturated germanes
are of very low toxicity and therefore can serve as alternatives
to the organotin compounds.3 Functionalized alkynylgermanes,
in particular, have been useful synthons in cross-coupling reac-
tions4a-c as well as in cycloaddition of azides4d-g and synthesis
of other organometallic reagents4h-j and oligosaccharides.4l,m
Germanium-based compounds possessing a π-conjugated system
are also considered (along with the respective silicon com-
pounds) to be potential candidates for electronic devices thanks
to their photo- and electroluminescent properties.5
Alkynylgermanium compounds can be prepared by various
methodologies involving classical stoichiometric organometallic
routes that can be classified into three groups, i.e., the reactions
of organogermanium halides with metal acetylides,6 germylation
of terminal alkynes,7 and modification of preformed alkynylger-
manes8 (for a recent review see ref 9).
In the last two decades we have developed a new type of
transition metal (TM)-catalyzed reaction of vinyl-substituted
organometallic (E) (where E ) Si, Ge, B) compounds with
olefins such as silylative (for review see ref 10), germylative,11
and borylative12 coupling that is complementary to metathesis
and proceeds according to Scheme 1.
The reaction occurs by cleavage of the dC-H bond in an
olefin and the dC-E bond in vinyl-substituted organometallic
compounds.10-13 Very recently we have reported a new catalytic
reaction that also involves coupling of terminal alkynes with
vinylsilicon compounds to form silylacetylenes. This reaction
† Dedicated to Professor Florian Domka on the occasion of his 75th
birthday.
* Corresponding author. Fax: (+48) 61-8291-508. E-mail: marcinb@
(6) (a) Dam, M. A.; Hoogervorst, W. J.; de Kanter, F. J. J.; Bickelhaupt,
F.; Spek, A. L. Organometallics 1998, 17, 1762-1768. (b) Chrostowska,
A.; Metail, V.; Pfister-Guillouzo, G.; Guillemin, J. J. Organomet. Chem.
1998, 570, 175-182. (c) Karlov, S. S.; Shutov, P. L.; Churakov, A. V.;
Lorberth, J.; Zaitseva, G. S. J. Organomet. Chem. 2001, 627, 1-5. (d)
Allasia, S.; Deagostino, A.; Prani, C.; Zavattaro, C.; Venturello, P. Synthesis
2005, 20, 3627-3631.
(7) (a) Lukevics, E.; Arsenian, P.; Belyakov, S.; Pudowa, O. Eur. J.
Inorg. Chem. 2003, 3139-3143. (b) Andreev, A.; Konshin, V. V.;
Vinokurov, N. A.; Komarov, N. V. Russ. Chem. Bull., Int. Ed. 2006, 55,
1430-1432.
(8) Selina, A.; Karlov, S. S.; Gauchenova, E. V.; Churakov, A. V.;
Kuz’mina, L. G.; Howard, J. A. K.; Lorberth, J.; Zaitseva, G. S. Heteroat.
Chem. 2004, 15, 43-56.
amu.edu.pl.
(1) For example: (a) Kawashima, T. J. Organomet. Chem. 2000, 611,
256-263. (b) Faller, J. W.; Kultyshev, R. G. Organometallics 2002, 21,
5911-5918. (c) Anod, W.; Itoh, H.; Tsumuraya, T. Organometallics 1989,
8, 2759-2766. (d) Curran, D. P.; Diederichsen, U.; Palovich, M. J. Am.
Chem. Soc. 1997, 119, 4797-4804. (e) Piers, E.; Marais, P. C. J. Org.
Chem. 1990, 55, 3454-3455.
(2) Yorimits, H.; Oshima, K. Inorg. Chem. Commun. 2005, 8, 131-
142.
(3) Aldridge, W. N. In The Organometallic and Coordination Chemistry
of Germanium, Tin and Lead; Harrison, P. G., Gielen, M., Eds.; Freund
Publishing House Ltd.: Tel Aviv, Israel, 1978; pp 101-141.
(4) (a) Faller, J. W.; Kultyshev, R. G.; Parr, J. Tetrahedron Lett. 2003,
44, 451-453. (b) Faller, J. W.; Kultyshev, R. G. Organometallics 2002,
21, 5911-5918. (c) Montel, F.; Beaudegnies, R.; Kessabi, J.; Martin, B.;
Muller, E.; Wendeborn, S.; Jung, P. M. J. Org. Lett. 2006, 8, 1905-1908.
(d) Sauer, J.; Hetzenegger, D. K.; Krauthan, J.; Sichert, H.; Schuster, J.
Eur. J. Org. Chem. 1998, 2885-2896. (e) Piterskaya, Y. L.; Khramchikhin,
A. V.; Stadnichuk, M. D. Russ. J. Gen. Chem. 1996, 66, 1158-1164. (f)
Ma, S.; Negishi, E. J. Org. Chem. 1997, 62, 784-785. (g) Ma, S.; Liu, F.;
Negishi, E. Tetrahedron Lett. 1997, 38, 3829-3832. (h) Wrackmeyer, B.
Coord. Chem. ReV. 1995, 145, 125-156. (i) Wrackmeyer, B.; Klimakina,
E. V.; Bubnov, Y. N. J. Organomet. Chem. 2001, 620, 51-59. (j) David-
Quillot, F.; Marsacq, D.; Balland, A.; Thibonnet, J.; Abarbri, M.; Duchen,
A. Synthesis 2003, 3, 448-454. (k) Rossi, R. A.; Martin, S. E. Coord. Chem.
ReV. 2006, 250, 575-601. (l) Ernst, A.; Schweitzer, W. B.; Vasella, A.
HelV. Chim. Acta 1998, 81, 2157-2189. (m) Ernst, A.; Gobbi, L.; Vasella,
A. Tetrahedron Lett. 1996, 37, 7959-7962.
(9) Fletcher, M. D. Alkynylarsenic, -antimony, -bismuth, -boro, -silicon,
-germanium, and Metal Compounds. In ComprehensiVe Organic Functional
Group Transformations II; Katrytzky, A. R., Taylor, R. J. K., Eds.;
Elsevier: Amsterdam, 2005; Vol. 2, pp 1183-1185 (and references therein).
(10) (a) Marciniec, B.; Pietraszuk, C.; Kownacki, I.; Zaidlewicz, M.
Vinyl- and Arylsilicon, Germanium, and Boron Compounds. In Compre-
hensiVe Organic Functional Group Transformations II; Katrytzky, A. R.,
Taylor, R. J. K., Eds.; Elsevier: Amsterdam, 2005; Vol. 2, pp 941-1024,
and references therein. (b) Marciniec, B. Coord. Chem. ReV. 2005, 249,
2374-2390. (c) Marciniec, B.; Pietraszuk, C. Curr. Org. Chem. 2003, 7,
691-735.
(11) Marciniec, B.; Ławicka, H.; Majchrzak, M.; Kubicki, M.; Kownacki,
I. Chem.-Eur. J. 2006, 12, 244-250.
(12) Marciniec, B.; Jankowska, M.; Pietraszuk, C. Chem. Commun. 2005,
663-665.
(13) Marciniec, B. In Education in AdVanced Chemistry, Vol. X. Organic
and Polymer Synthesis and Catalysis; Marciniec, B., Ed.; Wyd. Poznan´-
skie: Poznan-Wrocław, 2006; pp 141-154.
(5) Ding, L.; Wong. W.; Xiang, H.; Poon, S.; Karasz, F. E. Synth. Met.
2006, 156, 110-116.
10.1021/om700528r CCC: $37.00 © 2007 American Chemical Society
Publication on Web 09/01/2007

New Catalytic Route to Alkynylgermanes
Organometallics, Vol. 26, No. 21, 2007 5189
Table 1. Catalytic Transformation of Terminal Alkynes with
Vinylgermanes: Reaction Catalyzed by Ruthenium
Complexes I-Va
Scheme 2. Germylative Coupling of Terminal Alkynes with
Vinyl-Substituted Germanes
no.
1
GeR′3
GeEt3
R
catalyst
yield [%] (TOF [h-1])
88,d 70g (56 h-1
opens a new catalytic route for the activation of sp-hybridized
C-H bonds.14 Moreover, we have found that this mode of
reactivity, which is well known for vinylsilicon compounds,
seems to be more general and is also exhibited by vinylger-
manes.11 In this paper, therefore, we report a new catalytic
transformation of vinyl-trisubstituted germanes of the general
formula CH2dCHGeR3 (where GeR3 is GeEt3 and GePhMe2)
with selected alkynes, which by analogy can be called germyl-
ation (germylative coupling) of alkynes by vinylgermanes.15
I
)
2
3
4
5
6
7
8
9
I
47f (20 h-1
)
II
III
IV
V
I
80
54
50
26
99b
37
0
t-Bu
Cy
Ph
I
I
10
I
0
Results and Discussion
11
12
13
14
15
16
17
n-C5H11
SiEt3
Si(i-Pr)3
Si(t-Bu)Me2
SiMe2Ph
GeEt3
I
I
I
I
I
I
I
69, 57g (38 h-1
)
The reaction of germylative coupling, which proceeds in the
presence of complexes containing [Ru]-H and/or [Ru]-Ge
bonds such as [RuHCl(CO)(PCy3)2] (I), [RuHCl(CO)(Pi-Pr3)2]
(II), [RuHCl(CO)(PPh3)3] (III), [Ru(GeEt3)Cl(CO)(PPh3)2] (IV),
and [RuH(CO)(MeCN)2(PCy3)2]+[BF4]- (V), leads (under
optimum conditions) to the formation of germyl-substituted
derivatives with evolution of ethylene (see Scheme 2).
To our knowledge it is the first direct TM-catalyzed process
for the preparation of alkynyl germanes. The reaction was
examined in an open system in toluene at 110 °C under a gentle
stream of argon. Only for the volatile tert-butylacetylene was
the process conducted in a closed system. Germylation of alkyne
required a little more time than the silylation of alkynes and
required more catalyst (2%) than used in silylation (1%) (Table
1).14a While alkyl, cycloalkyl, silyl, and germyl ethynes reacted
efficiently in this process, the germylation of phenylacetylene
(as had been formed in the reaction with vinylsilanes14a) did
not occur.
Since the equimolar reaction of vinylgermanes with alkynes
yielded some enyne byproducts as a result of the alkyne
dimerization, a 2- to 3-fold excess of vinylgermane is necessary
to prevent this reaction.
The turnover frequency parameters (TOF) were calculated
for selected reactions and are comparable to those found for
silylation (see Table 1). Reaction products were characterized
by GC and GC-MS methods and identified by 1H and 13C NMR
spectroscopy.
81, 54,e 75g (36 h-1
74, 48,e 68g
50
)
47, 45g
94,c 90g (58 h-1
90,c 83g (59 h-1
)
)
GeMe2Ph
GeEt3
a Reaction conditions unless stated otherwise: open system, toluene (0.5
M), t ) 48 h, T ) 110 °C, [Ru]:[CH2dCHGeR3]:[CHtCR] ) 2 × 10-2
:
3:1. Closed system, t ) 24 h, T ) 100 °C. c t ) 24h [Ru]:[CH2dCHGeR3]:
b
[CHtCGeEt3] ) 2 × 10-2:2:1. t ) 24h.
[Ru]:[CH2dCHGeR3]:
d
e
[CHtCR] ) 2 × 10-2:2:1, accompanied by traces of alkyne dimerization
product. [Ru]:[CH2dCHGeR3]:[CHtCR] ) 10-2:3:1. Isolated yield. The
product yields were determined by GC. Initial TOF measured after 0.5 h
of reaction and expressed by moles of alkyne per mole of [Ru] per hour.
f
g
ruthenium complex VI [Ru(Cl)(CO)(PPh3)2(CHdCHPh)], and
no [Ru]-H was detected. The characteristic feature of this
reaction followed by GC-MS analysis is an almost quantitative
conversion of phenylacetylene, leading to a high excess of the
primary product (Et3GeCCH) over secondary products of
phenylacetylene hydrogenation (styrene) and dimerization (enyne)
(see the ratio of products in brackets in Scheme 3, path (1)).
The respective spectrum is identical to those presented in our
previous communication.14a The corresponding reactions of IV
with ethynyltriethylsilane and ethynyltriethylgermane at low
temperatures allowed the detection of a [Ru]-H complex, as
confirmed by the appearance of a doublet of triplets at -6.63
ppm (JH-P ) 105.2 Hz, JH-P ) 24.3 Hz). They compose
vinylenesilylene and vinylenegermyleneruthenium analogues
VII [RuCl(CO)(PPh3)2(CHdCHSiEt3)] and vinylenegermyle-
neruthenium VIII [RuCl(CO)(PPh3)2(CHdCHGeEt3)] at room
temperature, respectively (see Figures 1 and 2). Both complexes
were isolated, and the evidence for such a ruthenium-vinylene
structure comes from the 1H NMR spectra, in which two
In order to provide evidence for the insertion of alkyne into
the Ru-Ge bond, the [Ru(GeEt3)Cl(CO)(PPh3)2] (catalyst IV)
equimolar reactions were carried out with some alkyness
ethynyltriethylsilane, ethynyltriethylgermane, and phenyl-
acetylenesto yield the respective main insertion products
1
(identified by GC-MS and H NMR spectroscopy) and ruthe-
doublets of triplets of vinylene signals appear at 8.84 (JH-H
)
nium complexes formed according to Scheme 3.
13.0 Hz) and 5.70 (JH-H ) 13.0 Hz) (for triethylsilylvinylene)
and 8.52 (JH-H ) 12.6 Hz) and 5.80 (JH-H ) 12.6 Hz) (for
triethylgermylvinylene). It is worth emphasizing that similarly
to the catalytic transformation of terminal alkynes with vi-
nylgermanes versus vinylsilanes, the stoichiometric reaction (3)
takes twice as long as reaction (2), and therefore the GC-MS
analysis showed much less unreacted ethynyltriethylgermane
than the respective ethynyltriethylsilane.
The NMR spectra were measured at various temperatures
during the reactions, between -20 and +60 °C (at 10 °C
intervals of temperature) and showed significant differences in
the reaction of IV with the substituted acetylenes studied. The
reaction with phenylacetylene occurs in the same manner as
that previously found in the case of the [Ru]-Si complex,14a
i.e., forming immediately even at -20 °C vinylenephenylene-
(14) (a) Marciniec, B.; Dudziec, B.; Kownacki, I. Angew. Chem., Int.
Ed. 2006, 45, 8180-8184. (b) Marciniec, B.; Dudziec, B.; Szubert, K. Polish
Patent Appl. P 380 422, 2006.
(15) Marciniec, B.; Ławicka, H. B. Dudziec Polish Patent Appl. P 382
237, 2007.
The [Ru]-H complex is apparently a product of acetylene
insertion into complex IV (followed by the elimination of the
substituted ethyne compound) in three experiments (similarly
to the insertion of acetylene into the [Ru]-Si bond14a and to

5190 Organometallics, Vol. 26, No. 21, 2007
Scheme 3. Reaction of Equimolar Amounts of IV with Acetylenes
Marciniec et al.
the insertion of olefins into the [Ru]-Ge11 and [Ru]-Si10
bonds). However, in the absence of vinylgermane this complex
is active in the hydrogenation of acetylenes as well as its
respective dimerization and co-dimerization with styrene as a
result of the well-known reactions catalyzed by ruthenium
complexes.16
Vinylene complexes of ruthenium VI-VIII were isolated,
and their structures were confirmed by 1H NMR and by
comparison with those previously reported.14a,17,18
Contrary to the stoichiometric experiments (under catalytic
conditions (100-110 °C)), vinylgermane, particularly if added
in excess, reacted preferentially with the ruthenium hydride
complex according to a well-documented process to yield the
[Ru]-Ge complex and ethylene,11 which explains the catalytic
activity of both [Ru]-H and [Ru]-Ge systems in the germyl-
ative coupling of alkynes. Apparently, similarly to silylative
coupling of acetylenes14a in the case of phenylacetylene, its
reaction with the [Ru]-H occurs more rapidly than with the
[Ru]-Ge complex, giving vinylene complex VI, and germyl-
ation of phenylacetylene is not observed under the conditions
studied.
The results of the above experiments on germylation of
acetylenes and their previously reported silylation allow us to
propose a unified mechanism for the reaction of vinyl-substituted
germanium and silicon compounds with selected substituted
acetylenes (see Scheme 4).
The mechanistic scheme involves an insertion of alkynes into
the [Ru]-E (E ) Ge, Si) bond followed by â-H elimination to
give substituted ethynes and subsequently the well-documented
insertion of vinylgermanium (vinylsilicon) compounds into the
[Ru]-H bond followed by â-E (E ) Ge, Si) elimination of
ethylene. Dissociation of phosphine is postulated to generate
the active Ru catalysts.
This general mechanism is proved by the stoichiometric
studies of the insertion of vinylsilicon10 and vinylgermanium11
compounds into the [Ru]-H bond as well as the above-
described insertion of acetylenes into [Ru]-Ge and, as previ-
ously reported, also into [Ru]-Si bonds.14a
Experimental Section
1
General Methods. H NMR (300 MHz), 13C NMR (75 MHz),
and DEPT spectra were recorded on a Varian XL 300 MHz
spectrometer in CDCl3 (or C6D5CD3) solution. Chemical shifts are
reported in δ (ppm) with reference to the residue portion solvent
(CH3Cl) peak for 1H and 13C. Gas chromatographic (GC) analyses
were performed on a Varian 3300 with a DB-5 fused silica capillary
column (30 m × 0.15 mm) and TCD. Mass spectra of the monomers
and products were obtained by GC-MS analysis (Varian Saturn
2100T, equipped with a BD-5 capillary column (30 m) and an ion
trap detector). Thin-layer chromatography (TLC) was made on
plates coated with 250 µm thick silica gel (Aldrich and Merck),
and column chromatography was conducted with silica gel 60 (70-
230 mesh, Fluka). Toluene and pentane were dried by distillation
from sodium hydride; similarly hexane was distilled from calcium
hydride under argon. All liquid substrates were also dried and
(16) (a) Bruneau, C. In Topics in Organometallic Chemistry Vol. 11,
Ruthenium Catalysts and Fine Chemistry; Bruneau, C., Dixneuf, P. H., Eds.;
Springer-Verlag: Berlin, 2004; pp 138-141, and references therein. (b)
Slugovc, C.; Mereiter, K.; Zobetz, E.; Schmidt, R.; Kirchner, K. Organo-
metallics 1996, 15, 5275-5277. (c) Bianchini, C.; Peruzzini, M.; Zanobini,
F.; Frediani, P.; Albinati, A. J. Am. Chem. Soc. 1991, 113, 5453-5454. (d)
Bianchini, C.; Frediani, P.; Masi, D.; Peruzzini, M.; Zanobini, F. Organo-
metallics 1994, 13, 4616-4632. (e) Yi, Ch. S.; Liu, N. Organometallics
1996, 15, 3968-3971. (f) Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.;
Satoh, T.; Satoh, J. Y. J. Am. Chem. Soc. 1991, 113, 9604-9610. (g)
Wakatsuki, Y.; Yamazaki, H.; Kumegawa, N.; Johar, P. S. Bull. Chem.
Soc. Jpn 1993, 66, 987-989.
(17) Torres, M. R.; Vegas, A.; Santos, A. J. Organomet. Chem. 1986,
309, 169-177.
(18) Maddock, S. M.; Rickard, C. E. F.; Roper, W. P.; Wright, L. J.
Organometallics 1996, 15, 1793-1803.

New Catalytic Route to Alkynylgermanes
Organometallics, Vol. 26, No. 21, 2007 5191
Figure 2. Temperature dependence of the 1H NMR spectra in the
reaction of IV with HCtCGeEt3.
Scheme 4. Mechanism of Coupling of Alkynes with
Vinyl-Substituted Organometallic Compounds
Figure 1. Temperature dependence of the 1H NMR spectra in the
reaction of IV with HCtCSiEt3.
degassed by bulb-to-bulb distillation. All the reactions were carried
out under dry argon.
Materials. The chemicals were obtained from the following
sources: toluene, dodecane, pentane, and hexane were purchased
from Fluka; CDCl3 and C6D5CD3 from Dr Glaser A.G. Basel.
Triethylbromogermane and phenyldimethylbromogermane were
purchased from GELEST. The substituted acetylenes were bought
from Aldrich. CH2dCHGeEt3 and CH2dCHGeMe2Ph were pre-
pared according to literature procedures.11 The ruthenium complexes
[RuHCl(CO)(PCy3)2] (I), [RuHCl(CO)(Pi-Pr3)2] (II), [RuHCl(CO)-
(PPh3)3] (III), [Ru(GeEt3)Cl(CO)(PPh3)2] (IV), and [RuH(CO)-
(MeCN)2(PCy3)2]+[BF4]- (V) were prepared according to literature
procedures.11,19 Toluene and pentane were dried by distillation from
sodium hydride; similarly hexane was distilled from calcium hydride
under argon. All liquid substrates were also dried and degassed by
bulb-to-bulb distillation. All the reactions were carried out under
dry argon.
Synthesis of Ethynyltriethylgermane [Et3GetCH]. In a
Schlenk tube equipped with magnetic stirrer 2.89 g (12.06 mmol)
of bromotriethylgermane and 60 mL of dried and deoxidized THF
were placed under argon, then 29 mL of the CHtCMgBr (1.0 mol/
L) THF solution was added dropwise. The reaction mixture was
kept for 24 h at 45 °C while stirring the contents with a magnetic
stirrer. After this time the reaction mixture was washed with water
and diethyl ether three times and dried over CaCl2. The ethynyl-
triethylgermane was purified by distillation (bp 115 °C, yield 82%).
Analytic data: 1H NMR (CDCl3; δ (ppm)): 0.88 (q, 6H, GeCH2-
CH3, JH-H ) 8.1 Hz), 1.09 (t, 9H, GeCH2CH3, JH-H ) 8.1 Hz),
2.28 (s, 1H, CH). 13C NMR (CDCl3; δ (ppm)): 5.67 (GeCH2CH3),
8.96 (GeCH2CH3), 87.67 (Ge-CtCH), 93.11 (Ge-CtCH). MS
(EI) [m/z (%)]: 157 (M+• - CH2CH3, 100), 129 (89), 113 (3), 99
(43), 89 (11), 73 (7). This type of compound is known from the
literature.20 However, the method used is analogous to the one
described in the case of vinyltriethylgermane.11
Reaction of Equimolar Amounts of [Ru(GeEt3)Cl(CO)-
(PPh3)2] with Acetylenes. In a typical test, the ruthenium catalyst
[Ru(GeEt3)Cl(CO)(PPh3)2] was dissolved in [D8]toluene and placed
in an NMR ampule under argon. The ampule was cooled in liquid
(19) (a) Yi, C. S.; Lee, D. W.; Chen, Y. Organometallics 1999, 18, 2043.
(b) Levison, J. J.; Robinson, S. D. J. Chem. Soc. A 1970, 2947-2954. (c)
Yi, C. S.; He, Z. Organometallics 2001, 20, 3641-3643.
(20) (a) Eastmond; R.; Walton, D. R. M. Tetrahedron 1972, 28, 4591-
4599. (b) Marerolles Bull. Soc. Chim. Fr. 1960, 859.

5192 Organometallics, Vol. 26, No. 21, 2007
Marciniec et al.
nitrogen, then acetylene was added (at the molar ratio [Ru]:
[acetylene] ) 1:1.2). After that, the ampule was inserted into a
Brucker Ultra Shield spectrometer (600 MHz) and slowly heated.
The spectra were recorded at various temperatures between -20
and +60 °C with 10 °C gradation of temperature.
215 (42), 201 (60), 185 (19), 171 (44), 143 (17), 129 (18), 101
(24), 87 (13), 73 (24), 59 (19). Anal. Calcd (%) for C17H36GeSi:
C 59.84, H 10.63. Found: C 59.75, H 10.49. Isolated yield: 68%.
1-(tert-Butyldimethylsilyl)-2-(triethylgermyl)ethyne. 1H NMR
(CDCl3; δ (ppm)): 0.17 (s, CH3((CH3)3C)SiCt); 0.96 (s, CH3-
((CH3)3C)SiCt); 0.86 (q, 6H, GeCH2CH3, JH-H ) 8,1 Hz), 1.12
(t, 9H, GeCH2CH3, JH-H ) 8,1 Hz). 13C NMR (CDCl3; δ (ppm)):
-4.54 (CH3((CH3)3C)SiCt), 5.85 (GeCH2CH3), 9.25 (GeCH2CH3),
16.62 (CH3((CH3)3C)SiCt), 26.13 (CH3((CH3)3C)SiCt), 112.12,
114.40 (SiCtCGe). MS (EI) [m/z (%)]: 271 (M+• - CH2CH3, 99),
243 (100), 215 (69), 188 (31), 188 (31), 173 (7), 157 (33), 143 (4),
131 (13), 111(14), 87 (10), 73 (31), 57 (11). Anal. Calcd (%) for
C14H30GeSi: C 56.22, H 10.11. Found: C 56.39, H 9.89. Isolated
yield: 45%.
Representative Procedure for Synthesis of [Et3Ge-CtC-
R]. In a typical experiment, the ruthenium catalyst [RuHCl(CO)-
(PCy3)2)] (2 mol %) was dissolved in toluene and placed in a glass
ampule under argon. The reagents and decane as internal standard
(5% by volume all components), vinyltriethylgermane, and the
acetylene (usually used in the molar ratio [Ru]:[CH2dCHGeEt3]:
[CHtCR] ) 2 × 10-2:3:1 or 2 × 10-2:1:2) were added.
Subsequently, the ampule was heated to 100 or 110 °C and
maintained at that temperature for 24-48 h. The progress of the
reaction was monitored by GC and GC-MS. The final products
were separated from the residues of the catalyst and reactants by
purification on an SiO2 column (modified with 15% of Et3N when
needed) with hexane as eluent. All products of catalytic transforma-
tion of terminal alkynes with vinylgermanes were oily liquids.
Analytic Data: 1-(tert-Butyl)-2-(triethylgermyl)ethyne. 1H
NMR (CDCl3; δ (ppm)): 0.81 (q, 6H, GeCH2CH3, JH-H ) 8,1
Hz), 1.15 (t, 9H, GeCH2CH3, JH-H ) 8,1 Hz), 1.22 (s, 9H, (CH3)3C),
13C NMR (CDCl3; δ (ppm)): 5.81 (GeCH2CH3), 9.20 (GeCH2CH3),
29.01 ((CH3)3C); 30.82 ((CH3)3C), 83.5 (Ge-CtC), 108.74 (Ge-
CtC). MS (EI) [m/z (%)]: 226 ([M + H]+• - CH3, 1), 213 (M+•
- CH2CH3, 100), 184 (9), 157 (29), 139 (6), 129 (5), 113 (9), 101
(8), 79 (4), 68 (4), 53 (3). Anal. Calcd (%) for C12H24Ge: C 59.81,
H 10.04. Found: C 59.90, H 10.11. Isolated yield: 80%.
1-(Phenyldimethylsilyl)-2-(triethylgermyl)ethyne. 1H NMR
(CDCl3; δ (ppm)): 0.41 (s, 6H, SiCH3), 0.86 (q, 6H, GeCH2CH3,
JH-H ) 8,1 Hz), 0.92 (t, 9H, GeCH2CH3, JH-H ) 8,1 Hz), 7.36-
7.69 (m, 5H, CH). 13C NMR (CDCl3; δ (ppm)): -0.37 (SiCH3),
5.85 (GeCH2CH3), 9.08 (GeCH2CH3), 111.58 (Ge-CtC), 113.88
(Si-CtC), 127.65 (CH), 129.11 (CH), 133.62 (CH), 137.37 (ci-
C6H5). MS (EI) [m/z (%)]: 319 (M+, 3), 291 (M+• - CH2CH3,
100), 263 (65), 235 (22), 171 (3), 159 (12), 145 (13), 105 (8), 89
(4), 75 (8), 53 (4). Anal. Calcd (%) for C16H26GeSi: C 60.22, H
8.21. Found: C 60.04, H 8.29. Isolated yield: 45%.
1
1-(Triethylgermylethynyl)-1-trimethylsiloxycyclohexane. H
NMR (CDCl3; δ (ppm)): 0.19 (s, 9H, SiCH3), 0.85 (q, 6H, GeCH2-
CH3, JH-H ) 8,1 Hz), 1.09 (t, 9H, GeCH2CH3, JH-H ) 8,1 Hz),
1.47-1.85 (m, 10H, CH2). 13C NMR (CDCl3; δ (ppm)): 2.13
(SiCH3), 5.64 (GeCH2CH3), 8.99 (GeCH2CH3), 23.36 (CH2), 25.34
(CH2), 41.55 (CH2), 70.45 (ci-C6H10), 87.17 (Ge-CtC), 110.35
(Ge-CtC). MS (EI) [m/z (%)]: 328 (M+• - CH2CH3, 79), 311
(42), 300 (38), 271 (43), 224 (9), 209 (26), 196 (39), 181 (46), 161
(24), 147 (22), 133 (21), 117 (23), 101 (19), 74 (100), 60 (10), 48
(39). Anal. Calcd (%) for C17H34GeOSi: C 57.49, H 9.65. Found:
C 57.56, H 9.60. Isolated yield: 70%.
1,2-Bis(triethylgermyl)ethyne. 1H NMR (CDCl3; δ (ppm)):
0.84 (q, 12H, GeCH2CH3, JH-H ) 8,1 Hz), 1.10 (t, 18H,
GeCH2CH3, JH-H ) 8,1 Hz). 13C NMR (CDCl3; δ (ppm)): 4.65
(SiCH2CH3), 5.98 (GeCH2CH3), 9.07 (GeCH2CH3), 110.75 (Ge-
CtC-Ge). MS (EI) [m/z (%)]: 315 (M+• - CH2CH3, 100), 287
(51), 258 (30), 231 (16), 199 (9), 171 (14), 157 (6), 129 (10), 101
(11), 75 (5). Anal. Calcd (%) for C14H30Ge2: C 48.93, H 8.80.
Found: C 48.89, H 8.77. Isolated yield: 90%.
1-(Phenyldimethylgermyl)-2-(triethylgermyl)ethyne. 1H NMR
(CDCl3; δ (ppm)): 0.56 (s, 6H, GeCH3), 0.89 (q, 6H, GeCH2CH3,
JH-H ) 8.1 Hz), 1.11 (t, 9H, GeCH2CH3, JH-H ) 8.1 Hz), 7.35-
7.62 (m, 5H, CH). 13C NMR (CDCl3; δ (ppm)): -0.50 (GeCH3),
5.91 (GeCH2CH3), 9.09 (GeCH2CH3), 110.86, 111.31 (Ge-CtC),
(Ge-CtC), 127.95 (CH), 129.66 (CH), 132.98 (CH), 139.18 (ci-
C6H5). MS (EI) [m/z (%)]: 335 (M+• - CH2CH3, 100), 307 (33),
277 (17), 245 (2), 175 (10), 151 (10), 132 (3), 89 (8), 75 (4), 51
(6). Anal. Calcd (%) for C16H26Ge2: C 52.84, H 7.21. Found: C
52.93, H 7.27. Isolated yield: 83%.
1-(Cyclohexyl)-2-(triethylgermyl)ethyne. 1H NMR (CDCl3; δ
(ppm)): 0.83 (q, 6H, GeCH2CH3, JH-H ) 8.1 Hz), 1.11 (t, 9H,
GeCH2CH3, JH-H ) 8.1 Hz), 1.2-2.6 (m, 11H, C6H11). 13C NMR
(CDCl3; δ (ppm)): 5.75 (GeCH2CH3), 9.20 (GeCH2CH3), 24.8-
32.6 (C6H11), 82.6 (Ge-CtC), 107.7 (Ge-CtC). MS (EI) [m/z
(%)]: 238 ([M + H]+• - CH2CH3, 100), 211 (38), 181 (23), 153
(6), 125 (7), 105 (11), 79 (17), 55 (4). Anal. Calcd (%) for C14H26-
Ge: C 62.98, H 9.82. Found: C 61.85, H 9.99. Isolated yield: 34%.
1-(n-Pentyl)-2-(triethylgermyl)ethyne. 1H NMR (CDCl3; δ
(ppm)): 0.80-2.2 (m, 26H, CH2, CH3). 13C NMR (CDCl3; δ
(ppm)): 5.88 (GeCH2CH3), 9.05 (GeCH2CH3), 19.94 (CH2), 22.25
(CH2), 22.65 (CH2), 28.76 (CH2), 30.99 (CH3), 88.77 (Ge-CtC),
107.74 (Ge-CtC). MS (EI) [m/z (%)]: 227 (M+• - CH2CH3, 100),
199 (64), 171 (19), 139 (6), 127 (5), 113 (11), 95 (31), 77 (5), 67
(8), 55 (2). Anal. Calcd (%) for C13H26Ge: C 61.23, H 10.28.
Found: C 61.12, H 10.19. Isolated yield: 57%.
1
1-(Triethylsilyl)-2-(triethylgermyl)ethyne. H NMR (CDCl3;
δ (ppm)): 0.59 (q, 6H, SiCH2CH3), 0.84 (q, 6H, GeCH2CH3, JH-H
) 8,1 Hz), 1.01 (t, 9H, SiCH2CH3), 1.10 (t, 9H, GeCH2CH3, JH-H
) 8,1 Hz). 13C NMR (CDCl3; δ (ppm)): 4.65 (SiCH2CH3), 5.90
(GeCH2CH3), 7.59 (SiCH2CH3), 9.07 (GeCH2CH3), 111.17 (Ge-
CtC), 112.56 (Si-CtC). MS (EI) [m/z (%)]: 271 (M+• - CH2-
CH3, 100), 244 (16), 215 (9), 185 (9), 157 (13), 127 (8), 103 (3),
83 (2), 60 (5). Anal. Calcd (%) for C14H30GeSi: C 56.22, H 10.11.
Found: C 56.32, H 9.99. Isolated yield: 75%.
1-(Triisopropylsilyl)-2-(triethylgermyl)ethyne. 1H NMR (CDCl3;
δ (ppm)): 0.84 (q, 6H, GeCH2CH3, JH-H ) 8.1 Hz), 1.03-1.13
(m, 30H, CH, CH2, CH3). 13C NMR (CDCl3; δ (ppm)): 5.97
(GeCH2CH3), 9.14 (GeCH2CH3), 11.27 (CH), 18.70 (SiCH(CH3)2),
109.80 (Ge-CtC), 112.97 (Si-CtC). MS (EI) [m/z (%)]: 313
(M+• - CH2CH3, 14), 299 (80), 271 (100), 243 (68), 229 (65),
Acknowledgment. This work was supported by the Ministry
of Science and Higher Education (Poland) (grant PBZ-KBN
118/T09/17).
OM700528R