Reaction pathways of zirconocene-catalyzed silylation of alkenes with chlorosilanes

Article abstract of DOI:10.1016/j.tet.2003.08.077

Reaction pathways as well as stereochemistries and stoichiometries of zirconocene-catalyzed silylation of olefins with chlorosilanes in the presence of ⁿBuMgCl were studied and discussed in detail. Rate determining steps were examined by kineti

Full text of DOI:10.1016/j.tet.2003.08.077

Tetrahedron 60 (2004) 1301–1308
Reaction pathways of zirconocene-catalyzed silylation of
alkenes with chlorosilanes
*
Jun Terao, Yingshi Jin, Kazushi Torii and Nobuaki Kambe
Department of Molecular Chemistry and Science and Technology Center for Atoms, Molecules and Ions Control, Osaka University, Suita,
Osaka 565-0871, Japan
Received 4 August 2003; accepted 26 August 2003
Abstract—Reaction pathways as well as stereochemistries and stoichiometries of zirconocene-catalyzed silylation of olefins with
n
chlorosilanes in the presence of BuMgCl were studied and discussed in detail. Rate determining steps were examined by kinetic studies and
labeling experiments.
q 2003 Elsevier Ltd. All rights reserved.
1. Introduction
with chlorosilanes.
Among a variety of reactions that have been developed for
introducing R Si moieties into organic molecules, transition
3
metal catalyzed silylation toward carbon–carbon unsatu-
rated bonds have widely been employed as a straightforward
and useful method of synthesizing organosilicon com-
ð1Þ
ð2Þ
ð3Þ
1
pounds. As for the silylating reagents of such reactions,
2
a
2b
2c
2d
silanes, disilanes, silacyclobutanes or -propanes,
2
e
2f
2g
silyl cyanides, silylgermanes, silylstannanes, silylsele-
f
2
2h–j
nides, and iodosilanes
have been employed. Chloro-
silanes are the most widely used and easily available
silylating reagents in organic synthesis; however, their use
in transition metal catalyzed reactions has been limited. This
is due to the difficulty of the oxidative addition of the Si–Cl
3
bond to low valent metal complexes. We have reported the
first example of transition metal catalyzed silylation of
4
,5
olefins with chlorosilanes by the use of Cp ZrCl . For
2
2
example, styrene reacted with Et SiCl in the presence of
3
n
BuMgCl and a catalytic amount of Cp ZrCl in refluxing
2
2
THF to afford the corresponding alkenylsilane with
complete regio- and stereoselectivities as exemplified by
Eq. 1. Ethylene gave a vinylsilane at 80 8C in good yield
based on the chlorosilane used (Eq. 2). When allylbenzene
was employed, only an E-allylsilane was obtained as a sole
product at room temperature (Eq. 3), whereas alkyl-
substituted olefins such as 1-octene affords a mixture of
allyl- and vinylsilanes. Herein, we wish to reveal the results
obtained in a study performed to shed light on the reaction
pathways of this zirconocene-catalyzed silylation of olefins
2. Results and discussion
2.1. Stereochemistry
In all reactions using arylalkenes only E-isomers of
vinylsilanes were formed. In order to determine whether
the stereochemistry is controlled kinetically or thermo-
dynamically, we carried out a reaction of p-methylstyrene
4
with Et SiCl in the presence of Z-isomer of b-triethylsilyl-
3
styrene 1. As shown in Eq. 4 only E-isomer of b-tri-
ethylsilyl-p-methylstyrene 2 was obtained in 97% yield and
72% of 1 was recovered as a 20:80 mixture of E/Z isomers.
This result clearly indicates that the stereochemistries of
Keywords: Zirconocene; Silylation; Chlorosilanes; Olefins; Grignard
reagents.
*
Corresponding author. Tel.: þ81-6-6879-7388; fax: þ81-6-6879-7390;
e-mail address: kambe@chem.eng.osaka-u.ac.jp
0040–4020/$ - see front matter q 2003 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2003.08.077

1302
J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
products are determined kinetically not by the isomerization
of products.
improved by elongation of the reaction time, the yield
n
increased up to 62% when 0.7 equiv of BuMgCl was
ð4Þ
2
.2. Stoichiometry of Zr-catalyzed silylation reaction
introduced additionally to the reaction mixture. It is known
that Cp ZrCl reacts with 2 equiv. of R-MgX to form
Cp Zr. This evidence along with the results shown in Eq. 6
2
and Figure 1 suggests that the products are formed only in
the presence of Grignard reagents.
2
2
6
In this silylation of olefins, vinylic hydrogen is replaced by a
silyl group. In order to reveal the exact mass balance of this
reaction, we carried out a reaction of styrene-d with
2
n
Et SiCl (2 equiv) and OctMgCl (1.5 equiv) in the presence
3
of 5 mol% of ‘Cp Zr’ generated in situ from Cp ZrCl and
2
2
2
n
6
BuMgCl. Refluxing the solution for 40 min followed by
quenching with 0.1 N HClaq gave nearly equal amounts of
monodeuterated vinylsilane 3 (deuterium content .98%)
and octane 4 containing a deuterium at the terminal carbon
(
deuterium content .95%) (Eq. 5). This result shows that
one of the deuterium atoms at the b-carbon of styrene-d2
was transferred to the a-carbon of the octyl group of the
Grignard reagent provably via b-elimination from dialkyl-
zirconocene intermediate 5 (vide infra). The mechanism of
b-hydrogen elimination of dialkylzirconocene complexes
has been examined and a unique pathway involving direct
transfer of a b-hydrogen of one of the alkyl substituents on
Zr to an a-carbon of another alkyl group, not via a
ð6Þ
This phenomenon can more clearly be confirmed by the
following control experiments. A reaction of allylbenzene
with Et SiCl in the presence of a stoichiometric amount of
7
hydrozirconocene intermediate, has been proposed.
3
ð5Þ
Present silylation reaction provides good yields of products
based on the limiting substrates, either on olefins (Eqs. 1 and
Cp Zr, generated in situ by the reaction of Cp ZrCl with
2
2
2
n
2 equiv. of BuMgCl, gave no silylated products, such as 6
or 7, even after quenching the resulting mixture with HClaq
(Eq. 7). On the other hand, a similar reaction in the presence
3
) or on chlorosilanes (Eq. 2); however, we encounter an
interesting phenomenon when a limited amount of Grignard
reagents was employed. When Cp ZrCl was treated with
n
n
of 1 equiv. of BuMgCl (i.e., total amount of BuMgCl used
is 3 equiv.) afforded 6 in 72% yield (Eq. 8). A reaction of
Cp Zr with styrene (5 equiv.) and Et SiCl under THF reflux
2
2
n
2.3 equiv. of BuMgCl in the presence of 5 equiv. each of
allylbenzene and Et SiCl, the corresponding allylsilane 6
3
2
3
was obtained only in 16% yield based on Cp ZrCl used in
2
condition for 1 h did not afford any silylated products.
However, 65% yield of the corresponding vinylsilane was
2
2
0 min (Eq. 6 and Figure 1). Although the yield of 6 was not

J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
1303
obtained when a similar reaction was carried out in the
n
presence of 1 equiv. of BuMgCl.
ð7Þ
ð8Þ
Figure 1.
an equilibrium process which is biased toward 8, path B may
not be contradicted by the results of Eqs. 6–8.
In order to reveal which path is more likely, we examined
whether b-Si elimination process from 10 to 8 can take place
rapidlyunderthepresentreactionconditions. Sinceitisknown
that internal arylalkenes react with Cp ZrHCl to give
2
1
0
benzylzirconocene complex predominantly, we stirred a
THF solution of b-trimethylsilylstyrene and Cp ZrHCl at
0 8C for 3 h and quenched the products with D O. NMR
2
.3. Reaction pathways
2
5
2
Taking into account these results mentioned above and the
evidence that zirconocene–ethylene complex reacts with
measurements showed that the resulting mixture contained
unreacted b-trimethylsilylstyrene (48% recovered), 19% of
saturated silane 13 having a deuterium atom at the benzylic
position (56% ofdeuterium content), 13% of styrene, and 15%
of ethylbenzene (Eq. 9). It is likely that incorporation of
deuterium in 13 arises from the reaction of 14 with
8
EtMgBr givingrise to zirconate complex, we propose that the
present reaction proceeds via zirconate complex 9 that reacts
0
with R SiCl to give dialkylzirconocene 11, which then
3
undergoes b-elimination to afford 12 (Scheme 1, path A).
However, an alternative pathway that involves direct reaction
of neutral olefin complexes 8 with chlorosilanes to give 10
may not be ruled out since a neutral zirconocene–ethylene
complex Cp Zr(CH vCH ) reacts with chlorosilanes in the
D O. Although the formation of styrene and ethylbenzene
2
suggests that b-silyl elimination from 14 proceeds under these
conditions, this can not be a rapid process since 14 remained
under the conditions of Eq. 9 as suggested by formation of 13.
These results would rule out a possibility of the formation of
10 from 8 in the present reaction.
2
2
2
presence of Me P to form the corresponding b-silylalkylzir-
3
9
conocene complex. If 10 is formed in only a small amount by
ð9Þ
Scheme 1.

1304
J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
A plausible catalytic cycle is shown in Scheme 2. Zirconate
complex 17, formed by the reaction of zirconocene-olefin
n
complex 16 with BuMgCl, reacts with chlorosilanes to give
dialkylzirconocene complex 18 which undergoes b-hydro-
gen elimination with removal of one of the b-hydrogen to
afford a vinylsilane or allylsilane.
In all of the present silylation reactions examined, a small
amount of R SiH was formed along with the desired
3
silylation product. Since it is known that Cp TiCl
2
2
1
1
catalyzes the reduction of R SiCl to R SiH in the
3
3
i
n
presence of PrMgBr and that Cp Zr Bu catalyzes the
2
2
1
2
addition of R SiH to olefins, there may still remain a
3
possibility of an alternative pathway involving hydro-
silylation process. So we then performed a reaction of
allylbenzene with Me SiCl in the presence of Et SiH.
3
3
The result that only a trimethylsilylated product 20 was
obtained in 86% yield along with 76% recovery of
Et SiH would suggest that R SiH is not involved in this
3
3
catalytic cycle. When a similar reaction was carried out
using styrene, Pr SiCl, and Et SiH, only tripropylsilylated
vinylsilane was obtained in 76% yield and 97% of Et SiH
3
3
3
was recovered unreacted.
Scheme 2.
ð10Þ
2
.4. Rate determining steps
yield of the product obeys pseudo first-order kinetics
21
2
5
(
k¼3.9£10 min ) on the concentration of styrene.
To investigate the rate determining step of silylation of
styrene with chlorosilanes, we ran the reaction employing
different concentrations of substrates in THF at 50 8C for
5
Interesting to note, change of the concentration of Et SiCl
These results suggest that the rate determining step is the
ligand exchange process to regenerate zirconocene-styrene
complex 21 from 24. It was also surprising that decreasing
n
min and quenched with H O (Eq. 11 and Fig. 2).
the concentration of BuMgCl increased the reaction rate.
This unexpected phenomenon can be explained by assum-
2
3
did not affect the product yield indicating that Et SiCl is not
3
involved either in the rate determining step or in the
preceding equilibrium processes. On the other hand, the
ing an equilibrium between 24 and 26. High concentration
n
of BuMgCl shifted the equilibrium toward 26 resulting in
retardation of the ligand exchange. In fact, when a reaction
n
SiCl, (b) styrene, and (c) BuMgCl. The dotted line shows a representative concentration of the
Figure 2. Plots of yields of 25 against concentration of (a) Et
standard conditions of this silylation.
3

J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
1305
mixture was quenched with D O after the reaction, a
2
2.5. Mechanisms of C–Si bond forming step
dideuterated silane 27 was obtained, probably by the reaction
of 26 with D O, in almost the same amount of zirconocene
catalyst employed (Fig. 2).
As discussed above carbon–silicon bond forming process is
rapid and is not the rate determining step of this silylation
reaction. Adopting the intermediary of the ate complex 33,
2
ð11Þ
We next examined the rate determining step of the
silylation reaction of allylbenzene by the similar pro-
cedures (Eq. 12 and Fig. 3). The rate of allylsilane
we would like to propose three possible mechanisms for this
process as shown in Scheme 3. Mechanism A involves
electrophilic outside attack of R SiCl to the coordinated olefin
3
formation is independent on the concentration of Et SiCl
3
to give a silylzirconation product 34. Mechanism B affords 35
via s-metathesis and mechanism C involves oxidative
addition of R SiCl to 33 affording a Zr(IV) intermediate and
n
as in the case of styrene and also on that of BuMgCl.
However, the rate surprisingly decreased when the
concentration of allylbenzene increased in the region of
3
subsequent insertion. In mechanism A, Si and Zr were
introducedatvinylic carbons from the opposite sides ofolefins
and, contrary to this, addition proceeds in syn fashion in
mechanisms B and C. In order to determine the stereochem-
istry of this C–Si bond forming process, we prepared p-
methylstyrenes having one deuterium atom at trans- or cis-
position on the b-carbon (36 and 37, respectively) and
subjected them to the present silylation reaction.
.
0.2 M. With these observations, we would like to
propose that the rate determining step is the b-
elimination process since the reaction rate was not
affected by the concentrations of any substrates in the
region of [allylbenzene] ,0.2 M. Higher concentration of
allylbenzene (.0.2 M) would retard the reaction probably
by converting 28 to zirconacyclopentane 32 which is a
resting stage of the catalyst. GC and GC-MS analyses of
the resulting mixture after quenching with aqueous HCl
suggested the formation of a dimerized product of
allylbenzene arising by hydrolysis from 32 in ca. 40%
As mentioned above, only E-vinyl silanes were formed from
styrenes by kinetic control. If b-elimination of dialkylzir-
conocene complexes proceeds intramolecularly via direct H
shift from the b-carbon of an alkyl group on Zr to the b-carbon
based on Cp Zr employed (Fig. 3).
2
ð12Þ

1306
J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
n
SiCl, (b) allylbenzene, and (c) BuMgCl. The dotted line shows a representative concentration of
Figure 3. Plots of yields of 6 against concentration of (a) Et
the standard conditions of this silylation.
3
7
of the other as demonstrated by Negishi et al., the
stereochemistry of this step should be cis. So it was expected
thatDandHcontentsattheb-carbonoftheproductreflectsthe
stereochemistry of this process. Unfortunately, both 36 and
These results also show another important feature of this
reaction. It has been reported that the first isotope effect
on b-hydrogen elimination of dialkylzirconocene com-
plexes is nearly 6. However, no isotope effect was
observed in the reactions of Eq. 13. This evidence
indicates that C–Si bond forming process is irreversible
under the conditions employed or b-Si elimination, if
1
4
37 gave similar mixtures of products with nearly 1:1 ratio of
d - and d -vinylsilanes as shown in Eq. 13 and we could not
0
1
determine the stereochemistry of this process; however, these
experiments provide useful information about relative rates
proceeds,
elimination.
is much slower than the b-hydrogen
1
3
of C–Si bond formation, cis-trans isomerization, and
ligand exchange process as shown below.
It was confirmed by NMR and GC-Mass analyses that
vinylsilanes having more than one deuterium were not
formed and the deuterium was attached only to the b-carbon
3. Conclusion
Zr-catalyzed silylation of olefins with chlorosilanes have
been examined in detail focusing on the reaction pathway
and mechanisms of this reaction. Important results
obtained are (i) it is likely that this reaction proceeds
via zirconocene–olefin ate complexes, (ii) the rate
determining step of this catalytic cycle is ligand exchange
process in the case of styrene and is b-hydrogen
elimination step in the case of allylbenzene, (iii) the
C–Si bond forming process is irreversible and faster than
olefin exchange reaction on Zr, and (iv) cis-trans
isomerization of coordinated olefins proceeds rapidly on
(
the carbon bearing a silyl group). The E/Z ratios of the
recovered p-methylstyrene-d , were 82:18 from 36 and
1
1
1:89 from 37 indicating that cis-trans isomerization of
starting olefin proceeds only to a small extent. These results
suggest; (1) cis-trans isomerization takes place rapidly on
Zr metal, (2) this isomerization reaction is much faster than
the competing silylation process leading the products, and
(
3) this silylation process proceeds faster than olefin
exchange reaction on Zr, i.e., most of the coordinated olefin
molecules go to the products without dissociation from Zr.
ð13Þ

J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
1307
C H DSi 219.1570, found 219.1547. The deuterium
1
4 21
content was determined by a comparison of its mass
spectrum with that of the corresponding non-deuterated
triethyl(2-phenylethenyl)silane.
4.1.2. Octane-1-d (4) (deuterium content >95%). The
deuterium content of octane-1-d (4) was determined
similarly by mass spectroscopy. The evidence that only a
terminal carbon shows a triplet peak at d 13.9 (t, J¼19 Hz)
1
3
in the C NMR spectrum (100 MHz, CDCl ) indicates that
3
a deuterium is incorporated at the terminal carbon.
4.1.3. (E)-1-Phenyl-3-(triethylsilyl)prop-1-ene (6). To a
mixture of allylbenzene (382.9 mg, 3.24 mmol), Et SiCl
3
(
(
1
487.9 mg, 3.24 mmol) and a catalytic amount of Cp ZrCl
2 2
n
34.0 mg, 0.12 mmol) was added BuMgCl (0.90 M in THF,
.7 mL, 1.49 mmol) at 20 8C under nitrogen. After stirring
the solution for 30 min at 20 8C, a small portion of reaction
mixture was treated with 1 N HCl , followed by the same
aq
workup as mentioned above gave 6 in 16% GC yield. To a
n
remaining reaction mixture was added BuMgCl (0.90 M in
THF, 0.5 mL, 0.45 mmol) at 20 8C under nitrogen.
Additional stirring the solution for 90 min at 20 8C, 6 was
obtained in 62% GC yield. Purification by silica gel column
chromatography with hexane as the eluent afforded 80 mg
Scheme 3.
(
53%) of 6. IR (NaCl) 2952, 2910, 2874, 2360, 960, 728,
2
1 1
692 cm ; H NMR (400 MHz, CDCl ) d 7.23 7.30 (m,
3
4
H), 7.11–7.16 (m, 1H), 6.24 (m, 2H), 1.69 (m, 2H), 0.95 (t,
1
Zr and is faster than the C–Si bond forming process. In
this reaction the olefinic carbon acts as a nucleophilic
center toward chlorosilanes. This unique reactivity may
arise from strong back donation from zirconium to olefins
and this effect would be enhanced by complexation to
form ate complexes.
3
J¼8.0 Hz, 9H), 0.56 (q, J¼8.0 Hz, 6H);
C NMR
100 MHz, CDCl ) d 138.4, 128.3, 128.0, 127.9, 126.0,
(
3
1
25.3, 19.0, 7.6, 3.5; MS (EI) m/z (relative intensity, %) 232
þ
C H Si 232.1647, found 232.1634. Anal. calcd: C, 77.51;
H, 10.41. Found: C, 77.36; H, 10.61.
(M , 32), 115 (100), 87 (91), 59 (28). HRMS calcd for
15 24
4.1.4. (E)-1-Phenyl-3-(trimethylsilyl)prop-1-ene (20). To
a mixture of allylbenzene (138.8 mg, 1.17 mmol), Me SiCl
4
. Experimental
.1. (E)-Triethyl(2-phenylethenyl-1-d)silane (3)
Ethenyl-2,2-d2-benzene was prepared in 87% yield from
3
(319 mg, 2.94 mmol), Et SiH (341 mg, 2.94 mmol) and a
catalytic amount of Cp
3
4
2
ZrCl (34.2 mg, 0.12 mmol) was
2
n
added BuMgCl (0.90 M in THF, 3.90 mL, 3.51 mmol) at
20 8C under nitrogen. Stirring the solution for 3 h at 20 8C,
1 N HClaq was added to the solution at 0 8C, and the mixture
1
5
PhCHO and CD I following a reported procedure. A THF
3
solution of Cp Zr was prepared by the addition of 2 equiv.
2
was again warmed to 20 8C. A saturated aqueous NH
solution (50 mL) was added, and the product was extracted
with ether (50 mL), dried over MgSO , and evaporated to
give 20 (86% NMR yield) along with recovery of Et SiH
4
Cl
n
of BuMgCl (0.9 M in THF, 0.22 ml, 0.20 mmol) to
Cp ZrCl (29 mg, 0.10 mmol) at 278 8C followed by
2
2
4
stirring for 1 h at the temperature. Into this solution were
added Ethenyl-2,2-d2-benzene (212 mg, 2.0 mmol), Et SiCl
3
(89% GC yield). Purification by silica gel column
chromatography with hexane as the eluent afforded
172 mg (78%) of 20. IR (NaCl) 3023, 2954, 1248, 1148,
3
n
(
603 mg, 4.0 mmol) and OctMgCl (1.0 M in THF, 3.0 ml,
3
addition of benzaldehyde in order to trap the remaining
.0 mmol) and the mixture was refluxed for 40 min. The
961, 862, 740, 693 cm2 ; H NMR (400 MHz, CDCl
1
1
) d
7.23–7.31 (m, 4H), 7.11–7.17 (m, 1H), 6.21–6.26 (m, 2H),
3
n
OctMgCl and subsequent quenching with 0.1 N HClaq
afforded monodeuterated products 3 (91% NMR yield) and
1
3
1.65 (m, 2H), 0.03 (s, 9H); C NMR (100 MHz, CDCl ) d
3
4
(89% GC yield).
138.3, 128.3, 128.1, 127.7, 126.1, 125.4, 24.1, 21.6. HRMS
calcd for C H Si 190.1178, found 190.1174. Anal. calcd:
C, 75.72; H, 9.53. Found: C, 75.59; H, 9.60.
1
2 18
Compound 3. (Deuterium content .98%), purified by
HPLC. IR (NaCl) 2953, 2909, 2874, 1494, 1015, 722,
6
99 cm2
1
;
1
H NMR (400 MHz, CDCl ) d 7.43 (d,
3
J¼7.1 Hz, 2H), 7.32 (t, J¼7.5 Hz, 2H), 7.24 (t, J¼5.4 Hz,
Acknowledgements
1
H), 6.88 (s, J¼2.4 Hz, 1H), 0.98 (t, J¼7.8 Hz, 9H), 0.65 (q,
1
3
J¼7.9 Hz, 6H); C NMR (100 MHz, CDCl ) d 144.5,
This research was supported financially in part by a grant
from the Asahi Glass Foundation, Handai Frontier Research
Center and the Ministry of Education, Culture, Sports,
Science and Technology of Japan.
3
1
MS (EI) m/z (relative intensity, %) 219 (M , 19), 191 (24),
38.2, 128.3, 127.6, 126.1, 125.3 (t, J¼20.7 Hz,), 7.5, 3.6;
þ
90 (100), 162 (64), 134 (31), 132 (25). HRMS calcd for
1

1308
J. Terao et al. / Tetrahedron 60 (2004) 1301–1308
References and notes
Watabe, H.; Terao, J.; Kambe, N. Org. Lett. 2001, 3,
733–1735. (d) Terao, J.; Oda, A.; Ikumi, A.; Nakamura,
1
1
. (a) In The Chemistry of Organic Silicon Compounds; Patai, S.,
Rappoport, Z., Eds.; Wiley: Chichester, 1989. (b) In The
Chemistry of Organic Silicon Compounds Volume 2; Patai, S.,
Rappoport, Z., Eds.; Wiley: Chichester, 1998. (c) Hiyama, T.;
Kusumoto, T. Comprehensive Organic Synthesis; Fleming, I.,
Ed.; Pergamon: Oxford, 1991; Vol. 8, pp 763–792.
A.; Kuniyasu, H.; Kambe, N. Angew. Chem., Int. Ed. Engl.
2003, 42, 3412–3414.
6. Negishi, E.; Cederbaum, F. E.; Takahashi, T. Tetrahedron
Lett. 1986, 27, 2829–2832.
7. Negishi, E.; Swanson, D. R.; Takahashi, T. J. Chem. Soc.,
Chem. Commun. 1990, 1254–1255.
2
. (a) Marciniec, B. In Applied Homogeneous Catalysis with
Organometallic Compounds; 2nd ed. Cornils, B., Herrmann,
W. A., Eds.; Wiley-VCH: Weinheim, 2002; pp 491–512. (b)
Horn, K. A. Chem. Rev. 1995, 95, 1317–1350. (c) Saso, H.;
Ando, W. Chem. Lett. 1988, 1567–1570. (d) Sakurai, H.; Imai,
T. Chem. Lett. 1975, 891–894. (e) Chatani, N.; Hanafusa, T.
J. Chem. Soc., Chem. Commun. 1985, 838–839. (f) Ogawa,
A.; Kuniyasu, H.; Takeba, M.; Ikeda, T.; Sonoda, N.; Hirao, T.
J. Organomet. Chem. 1998, 564, 1–4. (g) Hada, M.; Tanaka,
Y.; Ito, M.; Murakami, M.; Amii, H.; Ito, Y.; Nakatsuji, H.
J. Am. Chem. Soc. 1994, 116, 8754–8765, and references
therein. (h) Yamashita, H.; Kobayashi, T.; Hayashi, T.;
Tanaka, M. Chem. Lett. 1991, 761–762. (i) Chatani, N.;
Amishiro, N.; Murai, S. J. Am. Chem. Soc. 1991, 113,
8. Takahashi, T.; Suzuki, N.; Kageyama, M.; Nitto, Y.; Saburi,
M.; Negishi, E. Chem. Lett. 1991, 1579–1582.
9
. (a) Ura, Y.; Hara, R.; Takahashi, T. Chem. Lett. 1998,
95–196. (b) Ura, Y.; Hara, R.; Takahashi, T. J. Organomet.
Chem. 2000, 611, 299–303.
1
1
0. Gibson, T. Organometallics 1987, 6, 918–922.
1. Corriu, R. J. P.; Meunier, B. J. Organomet. Chem. 1974, 65,
1
1
87–194.
1
2. (a) Takahashi, T.; Hasegawa, H.; Suzuki, N.; Saburi, M.;
Rousset, C. J.; Fanwick, P. E.; Negishi, E. J. Am. Chem. Soc.
1
991, 113, 8564–8566. (b) Kesti, M. R.; Abdulrahman, M.;
Waymouth, R. M. J. Organomet. Chem. 1991, 417, C12–C15.
c) Corey, J. Y.; Zhu, X.-H. Organometallics 1992, 11,
(
6
72–683. (d) Kesti, M. R.; Waymouth, R. M. Organometallics
992, 11, 1095–1103.
7
778–7780. (j) Chatani, N.; Amishiro, N.; Morii, T.;
1
Yamashita, T.; Murai, S. J. Org. Chem. 1995, 60, 1834–1840.
. The oxidative addition of chlorosilanes into late transition
metals were sluggish due to the strong Si–Cl bond energy, see:
Yamashita, H.; Tanaka, M.; Goto, M. Organometallics 1997,
1
3. Zirconocene-catalyzed cis-trans isomerization of olefins has
been studied by Negishi et al., and it is revealed that the
isomerization obeys the second order kinetics on concentration
of zirconocene catalyst and scrambling of vinylic hydrogens
does not take place Negishi, E.; Choueiri, D.; Nguyen, T.;
Swanson, D. R. J. Am. Chem. Soc. 1994, 116, 9751–9752.
4. Negishi, E.; Nguyen, T.; Maye, J. P.; Choueiri, D.; Suzuki, N.;
Takahashi, T. Chem. Lett. 1992, 2367–2370.
3
16, 4696–4704, and references therein.
4
5
. Terao, J.; Torii, K.; Saito, K.; Kambe, N.; Baba, A.; Sonoda,
N. Angew. Chem., Int. Ed. Engl. 1998, 37, 2653–2656.
1
1
. For other transition metal catalyzed silylation using chlor-
osilanes, see: (a) Terao, J.; Kambe, N.; Sonoda, N.
Tetrahedron Lett. 1998, 39, 9697–9698. (b) Nii, S.; Terao,
J.; Kambe, N. J. Org. Chem. 2000, 65, 5291–5297. (c)
5. Fischetti, W.; Heck, R. F. J. Organomet. Chem. 1985, 293,
3
91–405.