5320
N. Suzuki et al. / Journal of Organometallic Chemistry 692 (2007) 5317–5321
(
1.0 M) was purchased from Aldrich. Benzaldehyde and
in vacuo leaving a pale yellow oil. The product was purified
by column chromatography (silica gel, hexane/
EtOAc = 95/5). Yield 48% isolated. The products were
identified according to the literature [20,21].
propionaldehyde was purchased form Kanto Chemical
Co., Inc. and distilled. Ammonium salts were purchased
and used without further purification. Triethylammonium
tetraphenylborate was prepared according to the literature
[
19]. Complex 1 was prepared by the method reported in
3
[
.6. Reaction of 1 with aldehydes in the presence of
NEt H][BPh ] (preparation of 4a)
our previous paper [2].
3
4
3
.2. Protonolysis of 1 with hydrochloric acid
The reaction was conducted similarly to the above
described using triethylammonium tetraphenylborate
and 1,2-dichloroethane. For isolation of the product, com-
plex 1 (683.1 mg, 2.5 mmol), benzaldehyde (239 mg,
To a solution of 1 (54.6 mg, 0.2 mmol) and toluene (20.2
lL, 0.19 mmol) in THF-d (0.4 mL) was added conc.HCl
8
(
33 lL, ca. 0.4 mmol) dropwise at r.t. The pale yellow mix-
2
2
.25 mmol), triethylammonium tetraphenylborate (1.05 g,
.5 mmol) and 12 mL of 1,2-dichloroethane was used. To
1
ture was immediately observed by H NMR spectroscopy.
The formation of 2-butyne and 1,2-butadiene in 29% and
the reaction mixture was added 1 N HCl and extracted
5
5%, respectively, was detected. Yields were determined
based on toluene as internal standard. Deuterolysis was
conducted in a similar manner using DCl/D O (20%). Deu-
with chloroform, dried over MgSO and purified by col-
4
umn chromatography (silica gel, hexane/EtOAc = 95/5).
Yield was determined by gas chromatography (80%). The
product was identified based on the reported spectroscopic
data [22].
2
1
3
terium incorporation was estimated by C NMR spectros-
copy. 2-Butyne: H NMR (THF-d ): d 1.60 (s, 6H).
1
13
C
8
NMR (THF-d ): d 2.96 (96% D), 74.57. 1,2-butadiene:
8
1
H NMR (THF-d ): d 1.52–1.57 (m, 3H), 4.49–4.55 (m,
H), 4.92–5.04 (m, 1H). C NMR (THF-d ): d 13.62
8
1
3
Acknowledgement
2
8
(
97% D), 74.02, 84.57 (96% D), 209.82.
This work was financially supported by the Ministry of
Education, Culture, Sports, Science, and Technology of Ja-
pan (Grant-in-Aid for Scientific Research, C: No.
3
.3. Protonolysis of 1 with anhydrous hydrogen chloride
18550065).
The reaction was carried out similarly to described
above using HCl in Et O (1.0 M, 0.4 mL, 0.4 mmol). Yields
2
of 2-butyne and 1,2-butadiene were 3% and 83%,
respectively.
References
[
[
1] N. Suzuki, M. Nishiura, Y. Wakatsuki, Science 295 (2002) 660.
2] N. Suzuki, N. Aihara, H. Takahara, T. Watanabe, M. Iwasaki, M.
Saburi, D. Hashizume, T. Chihara, J. Am. Chem. Soc. 126 (2004) 60.
3] D. Hashizume, N. Suzuki, T. Chihara, Chem. Commun. (2006) 1233.
4] N. Suzuki, T. Watanabe, T. Hirose, T. Chihara, Chem. Lett. 33
(2004) 1488.
3
.4. Observation of intermediate 2 in protonolysis
[
[
Complex 1 (136.6 mg, 0.5 mmol) was dissolved in THF
(
2.5 mL) and to this solution HCl in Et O (1.0 M,
2
0
.15 mL, 0.15 mmol) was added dropwise at 0 °C. Observa-
[5] V.V. Burlakov, P. Arndt, W. Baumann, A. Spannenberg, U.
Rosenthal, P. Parameswaran, E.D. Jemmis, Chem. Commun. (2004)
1
tion by H NMR spectroscopy indicated the formation of 2
in 71% based on HCl. Then volatiles were removed in vacuo
and the yellow residue was dissolved in THF-d . 2: H
NMR (THF-d ): d 1.99 (t, J = 2.8 Hz, 3H), 2.75 (q,
J = 2.8 Hz, 2H), 5.86 (s, 10H). C NMR (THF-d ): d
9
2
074.
[
6] N. Suzuki, T. Watanabe, H. Yoshida, M. Iwasaki, M. Saburi, M.
Tezuka, T. Hirose, D. Hashizume, T. Chihara, J. Organomet. Chem.
691 (2006) 1175.
1
8
8
1
3
[7] N. Suzuki, T. Watanabe, M. Iwasaki, T. Chihara, Organometallics
4 (2005) 2065.
8
2
.06 (CH ), 42.92 (CH ), 97.98 (q), 102.91 (q), 111.57 (Cp).
3 2
[8] M.A. Bach, V.V. Burlakov, P. Arndt, W. Baumann, A. Spannenberg,
U. Rosenthal, Organometallics 24 (2005) 3047.
3.5. Reaction of 1 with aldehydes in the presence of proton
source (preparation of 3)
[9] M.A. Bach, T. Beweries, V.V. Burlakov, P. Arndt, W. Baumann, A.
Spannenberg, U. Rosenthal, W. Bonrath, Organometallics 24 (2005)
5
916.
[
[
10] T. Beweries, M.A. Bach, V.V. Burlakov, P. Arndt, W. Baumann, A.
Spannenberg, U. Rosenthal, Organometallics 26 (2007) 241.
11] (a) U. Rosenthal, V.V. Burlakov, M.A. Bach, T. Beweries, Chem.
Soc. Rev. 36 (2007) 719;
Typically, to a solution of 1 (27.3 mg, 0.1 mmol) in THF
1 mL) were added benzaldehyde (10.6 mg, 0.1 mmol) and
(
triethylamine hydrochloride (13.8 mg, 0.1 mmol) at r.t.
After stirring at 50 °C for 1 h, 1 N HCl was added to
quench the reaction. Yield was determined by gas chroma-
tography. To isolate the product, complex 1 was prepared
in situ using 10 mmol of Cp ZrCl , and the reaction was
(
b) M.A. Bach, T. Beweries, V.V. Burlakov, P. Arndt, W. Baumann,
[
[
12] Although we tried a same reaction on the trimethylsilyl-substituted 1-
zirconacylopent-3-yne, only 1,4-trimethylsilyl-2-butyne was observed
in the solution and no intermediate was detected.
13] T. Takahashi, K. Aoyagi, R. Hara, N. Suzuki, Chem. Lett. (1992)
1693.
2
2
conducted in a similar manner. After dil.HCl was added,
the mixture was extracted with ether and the organic layer
was dried with MgSO , then volatiles were removed
4