Synthesis and characterization of titanium and zirconium complexes with silicone-bridged phenoxycyclopentadienyl ligands

Article abstract of DOI:10.1016/j.jorganchem.2007.06.006

Dimethylsilyl(2,3,4,5-tetramethylcyclopentadienyl)(3-tert-butyl-5-methyl-2-phenoxy)titanium dichloride (1a), a useful catalyst precursor for olefin copolymerization, was synthesized at high yield starting from allyl-protected phenolic ligand 3a,which was

Full text of DOI:10.1016/j.jorganchem.2007.06.006

Journal of Organometallic Chemistry 692 (2007) 4059–4066
www.elsevier.com/locate/jorganchem
Synthesis and characterization of titanium and zirconium
complexes with silicone-bridged phenoxycyclopentadienyl ligands
a
a
a
b
Hidenori Hanaoka , Takahiro Hino , Hiroshi Souda , Kazunori Yanagi ,
a,
c,
*
Yoshiaki Oda *, Akio Imai
a
Organic Synthesis Research Laboratory, Sumitomo Chemical Co., Ltd., 1-98, Kasugadenaka 3-chome, Konohana-ku, Osaka 554-8558, Japan
Genomic Science Laboratories, Dainippon Sumitomo Pharma Co., Ltd., 1-98, Kasugadenaka 3-chome, Konohana-ku, Osaka 554-0022, Japan
b
c
Petrochemicals Research Laboratory, Sumitomo Chemical Co., Ltd., Kitasode, Sodegaura, Chiba 299-0295, Japan
Received 3 April 2007; received in revised form 29 May 2007; accepted 5 June 2007
Available online 15 June 2007
Abstract
Dimethylsilyl(2,3,4,5-tetramethylcyclopentadienyl)(3-tert-butyl-5-methyl-2-phenoxy)titanium dichloride (1a), a useful catalyst precur-
sor for olefin copolymerization, was synthesized at high yield starting from allyl-protected phenolic ligand 3a,which was first treated with
2 equiv. of n-BuLi to selectively give the dilithium salt of 3a along with 1-heptene, a coupling product of a protected allyl ether moiety
and butyl anion. Addition of TiCl4 to the resulting dilithium salt of 3a in toluene afforded 1a in 50% isolated yield. This methodology
could be applied to the preparation of related titanium and zirconoium complexes 1b–1d, 8 with silicone-bridged Cp-phenoxy ligands,
whereas the reaction starting from methyl-protected precursor 2a did not produce the zirconium complex 8. Copolymerization of eth-
ylene and 1-hexene with the newly prepared complexes was also investigated.
ꢀ 2007 Elsevier B.V. All rights reserved.
Keywords: Titanium; Silicone-bridged; Phenoxycyclopentadienyl ligand; Deallylation
1. Introduction
copolymer upon activation with activator [3a]. Many olefin
polymerization catalysts with phenoxy moieties have also
been studied [7], and metallocene catalysts with bridged
[4] or non-bridged [8] phenoxy groups have been reported.
Bridged phenoxy complexes, namely ‘‘phenoxy-induced
complex of Sumitomo’’ (PHENICS) catalyst, have a nota-
ble feature in that they show high activities even at elevated
temperatures, producing high molecular weight ethylene-a-
olefin copolymer [4a–e].
Metallocene catalysts of group 4 metals have been
extensively studied for the past two decades and single-site
catalysts have been used to control polyolefin micro-struc-
tures [1]. Bridged monocyclopentadienyl complexes with an
appended heteroatom donor atom such as nitrogen [2,3],
oxygen [4,5], and phosphorous [6] are highly active catalyst
precursors. Bridged cyclopentadienyl amide complexes,
namely ‘‘constrained geometry catalyst’’ (CGC) precur-
sors, produce high molecular weight copolymer with high
comonomer content in ethylene-a-olefin copolymerization
[2a]. Recently, Lee reported that a bridged cyclopentadie-
nyl-anilide complex produced higher molecular weight
R
m
R
m
Cl
Cl
M
A
Cl
Cl
M
A
O
N
*
R'
Corresponding authors.
R'
n
E-mail addresses: oday2@sc.sumitomo-chem.co.jp (Y. Oda), imai@sc.
CGC
PHENICS
sumitomo-chem.co.jp (A. Imai).
0022-328X/$ - see front matter ꢀ 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.06.006

4060
H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
Silicone-bridged PHENICS complex 1a was originally
(Scheme 2), the reaction was conducted below À15 ꢁC.
Treatment of 6 with the lithium or sodium salt of tetram-
ethylcyclopentadienyl anion produced 3a (lithium, 75%
yield; sodium, 86% yield). The sodium tetramethylcyclo-
pentadienilide was prepared using NaH. Since the reacti-
vity of NaH toward tetramethylcyclopentadiene was low,
a catalytic amount (5 mol%) of aniline was added to the
reaction mixture to accelerate the reaction [12]. A sodium
anilide species was assumed likely to play a key role in this
reaction. Other cyclopentadiene derivatives 3b–3d were
prepared in the same manner (3b, 84% yield; 3c, 86% yield;
3d, 83% yield).
Treatment of 3a under typical deallylation condition
such as catalytic deprotection with palladium complexes
[13] or stoichiometric reaction with trimethylsilyl iodide
[14] did not afford any deprotected compounds but gave
an unidentified mixture presumably due to instability of
the desired product. Accordingly, complex 1a was prepared
by in situ deprotection of 3a using n-BuLi followed by the
reaction with TiCl4. The synthesis of 1a and corresponding
zirconium complex 8 were conducted and results are listed
in Table 1. The protective group of 3a was removed more
easily than that of 2, producing 1a in higher yield (entries 1
and 4). Interestingly, a high molar ratio of n-BuLi contrib-
uted to an increase in the yield of 1a. Thus, treatment of 3
with 2.25 equiv. of n-BuLi in the presence of triethylamine,
enhancing reactivity of lithium reagent, followed by addi-
tion of 1.5 equiv. of TiCl4 produced 1a in 50% isolated
yield (entry 6). Zirconium complex 8 was also obtained in
43% yield by reaction of 3a with zirconium tetrachloride
under the same conditions (entry 7). In contrast, com-
pound 2 did not produce 8 under the tested conditions,
probably because the Lewis acidity of zirconium tetrachlo-
ride was too weak to cleavage of the strong C–O bond of
Ar–OMe (entries 2 and 3) (Scheme 3).
synthesized by reaction of the lithium salt of methyl-pro-
tected compound 2 with titanium tetrachloride, in which
the titanium atom mediated the C–O bond cleavage and
the subsequent formation of the Ti–O bond [4a,4f].
Because the O–Me bond is rather stable [9], this method
has been limited. Our effort was directed to find a more eas-
ily removable protecting group to improve the chemical
yield of 1a [10]. Herein, we report an efficient synthesis of
1a by reaction of a newly introduced allyl-protected precur-
sor 3a with n-BuLi, in situ preparation of the highly reac-
tive dilithium salt of the ligand by deallylation, followed
by subsequent treatment with titanium tetrachloride, and
application of the synthetic method to preparation of
related complexes.
OR
Cl
Cl
Ti
Si
Si
O
2 : R = Me
3a : R = CH2-CH=CH2
1a
2. Results and Discussion
The synthetic pathway to an allyl-protected ligand 3a is
depicted in Scheme 1. 2-Bromo-4-methyl-6-tert-butylphe-
nol 4 was reacted with allyl bromide in the presence of
NaOH to produce allyl ether compound 5 (92% yield).
Treatment of 5 with n-BuLi in toluene at À20 ꢁC followed
by addition of dichlorodimethylsilane gave a chlorosilane
compound 6 (85% yield). Since the lithiated derivative of
5 was thermally too unstable at room temperature and a
Detection of 1-heptene in the reaction mixture suggested
that phenoxy anion was formed by nucleophilic reaction of
n-BuLi at the allyl group of 3a (Scheme 4). The resulting
dilithium salt apparently reacted with titanium tetrachlo-
ride to produce 1a.
dihydrobenzofurane compound
7
was resulted [11]
Compounds 3b–3d could be treated in the same manner
and produced 1b–1d (1b, 36% yield; 1c, 40% yield; 1d, 45%
yield). In these experiments, highly reactive dianion species
were also generated under the reaction conditions. Allyl
precursors are therefore regarded as useful reagents for
the synthesis of silicone-bridged Cp-phenoxy complexes
(Scheme 5).
O
OH
Br
Br
Br
1) n-BuLi
2) Me2SiCl2
< -15 ˚C
NaOH
4
5
A single crystal of 1c suitable for X-ray diffraction study
was grown from toluene at room temperature. Fig. 1 shows
an ORTEP diagram and Table 2 lists selected bond param-
eters. It is of interest that the angle of Ti(1)–O(1)–C(18)
(152.0(2)ꢁ) is smaller than that of the non-bridged
Cp-phenoxy complexes (163.0–173.0ꢁ) [8], indicating the
complex has a larger coordination site suitable for
polymerization of bulky olefin. The angle of Cl(2)–Ti(1)–
Cl(1) (104.55(4)ꢁ) is similar to that of related complexes.
Torsion angles of C(1)–Si(1)–C(12)–C(18) (11.9(3)ꢁ) and
M
O
Si
Cl
3a
M= Li, Na
6
Scheme 1.

H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
4061
O
O
O
Si
Li
Me2SiCl2
n-BuLi
Li
Cl
5
> 0 ˚C
7
Scheme 2.
Table 1
Synthesis of silicone-bridged complexes by the reaction of aryl ether compounds with MCl4a
Entry
Aryl ether
n-BuLi, equiv.
MClb4
Additiveb
Complex
Yield, %c
1
2
3
4
5
6
7
a
2
1.0
1.0
1.0
1.0
2.25
2.25
2.25
TiCl4(1.0)
ZrCl4(1.0)
ZrCl4(1.5)
TiCl4(1.0)
TiCl4(1.5)
TiCl4(1.5)
ZrCl4(1.5)
–
–
1a
8
7
0
0
25
2
2
NEt3(4.5)
–
–
NEt3(4.5)
NEt3(4.5)
8
3a
3a
3a
3a
1a
1a
1a
8
34
50(66)d
43
See Section 3.
b
c
Parentheses indicate equivalence of the substrate.
Isolated yield.
Determined by 1H NMR analysis of crude product.
d
copolymerization upon activation with AliBu3(TIBA) and
[PhNHMe2][B(C6F5)4] (AB) in toluene. The results are
summarized in Table 3. Cp-phenoxy titanium complexes
1a–1d showed efficiently high activity to afford ethylene-
1-hexene high molecular weight copolymer with high
1-hexene content (entries 1–4), whereas zirconium complex
8 showed low activity (entry 5). Complex 1b, which has the
least hindered coordination site, gave copolymer with the
highest 1-hexene content (entry 2). Indene complex 1c
afforded middle molecular weight polymer with moderately
high comonomer content. It should be noted that all Cp-
phenoxy titanium complexes 1a–1d showed higher reactiv-
ity toward 1-hexene than CGC-Ti (entries 1–4 and 6).
Desired copolymer would be obtained using 1a–1d when
an appropriate catalyst was chosen, because fine structural
tuning of the catalyst controls molecular weight and como-
nomer content of resulting copolymer in wide range. To
confirm the efficiency of newly prepared complexes, larger
scale polymerization using 1c was carried out in a 300 mL
autoclave at 40 ꢁC. The polymerization gave similarly high
Cl
Cl
1) n-BuLi
2) MCl4
M
Si
O
or
2
3a
toluene
1a : M = Ti
8 : M = Zr
Scheme 3.
Ti(1)–O(1)–C(18)–C(12) (7.3(5)ꢁ) indicate the complex has
a slightly twisted structure. As the bridging group is
expected to be flexible in solution, the structure could
change appropriately to uptake bulky a-olefin during
copolymerization.
Newly prepared complexes 1b–1d, 8 along with 1a and
CGC-Ti[(tert-BuNSiMe2C5Me4)TiCl2] were used as cata-
lyst precursors for preliminary study of ethylene-1-hexene
-
n-Bu
H
Si
O
TiCl4
Li
Si
1a
O
-2LiCl
-
Li
n-Bu
3a
+
Scheme 4.

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H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
molecular weight copolymer (Mw = 293,000; number of
Cp'
O
Cl
Cl
short chain branch = 23 per 1000 C) with high activity
Ti
Si
O
(223.8 · 106 g mol(cat)À1 hÀ1).
1) n-BuLi (2.25 equiv.)
2) TiCl4 (1.5 equiv.)
Si
In conclusion, silicone-bridged cyclopentadienyl phen-
oxy titanium and zirconium complexes were synthesized
by reaction of metal tetrachloride and the dilithium salt
of the ligands, prepared by in situ deprotection of allyl
ether precursors. More detailed catalytic study of these
complexes for olefin polymerization will be described
elsewhere.
Cp'
toluene
3b : Cp' = C5H5
3c : Cp' = 1-Indenyl
3d : Cp' = 3-tert-Butyl-C5H4
1b : Cp'= C5H4
1c : Cp' = 1-Indenyl
1d : Cp' = 3-tert-Butyl-C5H3
Scheme 5.
3. Experimental
3.1. General
All manipulations of air- and moisture-sensitive com-
pounds were performed under dry nitrogen using a Braun
drybox or standard Schlenk line technique. Solvents were
purchased from Kanto Chemicals Co., Ltd. (anhydrous
grade) and stored in a drybox over molecular sieves. Tolu-
ene-d8 was stored similarly. 2-Bromo-6-tert-butyl-4-meth-
ylphenol (4) was prepared according to a previously
reported method [4a]. 1H NMR (270 MHz) and 13C
NMR (68 MHz) were measured using a JEOL EX270 spec-
trometer. Mass spectra were recorded using a JEOL
AX-505W. Elemental analyses were performed using an
ELEMENTAR element analyzer at Sumika Chemical
Analysis Service Ltd. All melting points were measured
in sealed tubes under nitrogen atmosphere and were not
corrected. Gel permeation chromatographic analyses were
performed at 160 ꢁC using a Symyx RapidsGPCꢂ,
equipped with three PLgel 10MICRO METER MIXED-
B columns, and a Tosoh HLC-8121GPC/HT, equipped
with a TSKgel GMHHR-H(S)HT. GPC columns were cal-
ibrated against commercially available polystyrene stan-
dards (Polymer Laboratories).
Fig. 1. ORTEP drawing of the molecular structure of 1c. All hydrogen
atoms are omitted for clarity. Key atoms are labeled.
3.2. 2-(Allyloxy)-1-bromo-3-tert-butyl-5-methylbenzene (5)
Table 2
A mixture of 4 (19.45 g, 80 mmol) and allylbromide
(10.65 g, 88 mmol) in acetone (240 mL) was added to 20%
NaOH (17.60 g, 88 mmol) dropwise at 25 ꢁC. After the reac-
tion mixture was stirred for 3 h, the aqueous layer was neu-
tralized by addition of 5% H2SO4. After removal of
acetone, the residue was extracted with toluene (200 mL).
The organic layer was washed with saturated aqueous NaCl,
then dried. Evaporation of the solvent followed by distilla-
tion (bp 74–75 ꢁC, 0.08 Torr) gave 5 as a colorless oil
(20.84 g, 92% yield). 1H NMR (CDCl3) d 1.38 (s, 9H,
t-Bu), 2.27 (s, 3H, Me), 4.57 (dt, 2H, J = 5, 2 Hz,
OCH2CH@CH2), 5.29 (dq, 1H, J = 11, 2 Hz, OCH2CH
@CH2), 5.49 (dq, 1H, J = 17, 2 Hz, OCH2CH@CH2), 6.13
(ddt, 1H, J = 17, 11, 5 Hz, OCH2CH@CH2), 7.07 (d, 1H,
J = 2 Hz, Ar-H), 7.25 (d, 1H, J = 2 Hz, Ar-H); 13C{1H}
NMR (CDCl3) d 21.1 (Ar-CH3), 31.3 (Ar-CMe3), 35.9 (Ar-
CMe3), 73.8, 117.5, 118.4, 127.9, 132.6, 133.9, 134.6, 145.2,
153.2. HRMS: m/z calcd 282.0619, found 282.0614.
˚
Selected bond lengths (A) and angles (ꢁ) for 1c
˚
Bond lengths (A)
Ti(1)–Cl(1)
Ti(1)–O(1)
Ti(1)–C(2)
Ti(1)–C(4)
2.253(1)
1.772(2)
2.328(4)
2.453(3)
Ti(1)–Cl(2)
Ti(1)–C(1)
Ti(1)–C(3)
Ti(1)–C(9)
2.252(1)
2.266(3)
2.407(4)
2.344(3)
Bond angles (ꢁ)
Cl(2)–Ti(1)–Cl(1)
C(1)–Ti(1)–Cl(1)
C(3)–Ti(1)–Cl(1)
C(9)–Ti(1)–Cl(1)
C(1)–Ti(1)–Cl(2)
C(3)–Ti(1)–Cl(2)
C(9)–Ti(1)–Cl(2)
C(2)–Ti(1)–O(1)
C(4)–Ti(1)–O(1)
Ti(1)–O(1)–C(18)
104.55(4) O(1)–Ti(1)–Cl(1)
107.12(9) C(2)–Ti(1)–Cl(1)
100.5(1)
142.51(9) O(1)–Ti(1)–Cl(2)
143.12(9) C(2)–Ti(1)–Cl(2)
96.81(9)
99.38(7)
86.5(1)
C(4)–Ti(1)–Cl(1)
134.41(9)
104.55(7)
130.5(1)
85.11(8)
88.51(9)
146.0(1)
90.22(9)
114.8(1)
C(4)–Ti(1)–Cl(2)
107.92(8) C(1)–Ti(1)–O(1)
121.3(1)
121.5(1)
152.0(2)
C(3)–Ti(1)–O(1)
C(9)–Ti(1)–O(1)
Ti(1)–C(1)–Si(1)
Torsion angles (ꢁ)
C(1)–Si(1)–C(12)–C(18) 11.9(3)
Ti(1)–O(1)–C(18)–C(12) 7.3(5)

H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
4063
Table 3
Copolymerization of ethylene and 1-hexene catalyzed by 1a–1d and 8 upon activation with TIBA/ABa
Entry
Complex
Activityb
Mwc
Mw/Mcn
1-Hexene contentd
1
2
3
4
5
6
a
1a
1b
61.6
5.8
52.2
47.0
3.2
635,000
104,000
265,000
106,000
n.d.e
2.2
1.7
1.9
2.2
n.d.e
4.5
18
35
20
18
n.d.e
15
1c
1d
8
CGC-Ti
66.5
682,000
Conditions: toluene; 5 mL, 1-hexene; 60 lL, ethylene; 0.6 MPa, complex; 0.1 lmol, TIBA; 40 lmol, AB; 0.3 lmol, temperature; 40 ꢁC.
In kg mmol(cat)À1 hÀ1
b
c
.
Determined by GPC against polystyrene standards.
Number of methyl branches per 1000 carbon determined by FT-IR.
Not determined.
d
e
3.3. [2-(Allyloxy)-3-tert-butyl-5-methylphenyl]
(chloro)dimethylsilane (6)
yield). 1H NMR (CDCl3) d 0.13 (s, 6H, SiMe2), 1.42 (s, 9H,
t-Bu), 1.69 (s, 6H, C5HMe4), 1.79 (s, 6H, C5HMe4), 2.28 (s,
3H, Ar-Me), 3.42 (s, 1H, C5HMe4), 4.40 (dt, 2H, J = 2,
2 Hz, OCH2CH@CH2), 5.28 (dq, 1H, J = 11, 2 Hz,
OCH2CH@CH2), 5.54 (dq, 1H, J = 17, 2 Hz, OCH2CH
@CH2), 5.99 (ddt, 1H, J = 17, 11, 2 Hz, OCH2CH@CH2),
7.03 (d, 1H, J = 2 Hz, Ar-H), 7.17 (d, 1H, J = 2 Hz, Ar-H);
13C{1H} NMR (CDCl3) d À2.4 (SiMe2), 11.1, 14.0, 21.1
(Ar-CH3), 31.2 (Ar-CMe3), 35.2 (Ar-CMe3), 75.9, 116.0,
130.0, 132.1, 132.6, 133.4, 133.7, 133.9, 134.7,
135.8, 141.9, 161.3. HRMS: m/z calcd 382.2692, found
382.2686.
To a mixture of 5 (19.82 g, 70 mmol) and toluene
(200 mL), 1.60 M hexane solution of n-BuLi (57 mL,
91 mmol) was added at À78 ꢁC, and then the mixture
was allowed to warm to À20 ꢁC. After lithiation was com-
pleted, the mixture was transferred to a toluene (140 mL)
solution of dichlorodimethylsilane (27.10 g, 210 mmol).
The mixture was allowed to warm to room temperature
and stirred for 5 h. After removal of inorganic materials
by filtration, the solvent was evaporated. Distillation
(129 ꢁC, 0.1 Torr) gave 6 as a colorless oil (17.67 g, 85%
1
yield). H NMR (CDCl3) d 0.72 (s, 6H, SiMe2), 1.39 (s,
3.4.2. Method B
9H, t-Bu), 2.32 (s, 3H, Me), 4.42 (dt, 2H, J = 4, 2 Hz,
OCH2CH@CH2), 5.28 (dq, 1H, J = 11, 2 Hz, OCH2CH
@CH2), 5.52 (dq, 1H, J = 17, 2 Hz, OCH2CH@CH2),
6.03 (ddt, 1H, J = 17, 11, 5 Hz, OCH2CH@CH2), 7.27 (d,
1H, J = 2 Hz, Ar-H), 7.25 (d, 1H, J = 2 Hz, Ar-H);
13C{1H} NMR (CDCl3) d 3.8 (SiMe2), 21.1 (Ar-CH3),
31.3 (Ar-CMe3), 35.2 (Ar-CMe3), 76.4, 116.3, 129.8,
131.9, 132.9, 133.5, 134.6, 142.2, 161.0. HRMS: m/z calcd
296.1363, found 296.1363.
To a THF (400 mL) solution of 1,2,3,4-tetramethyl-1,3-
cyclopentadiene (8.25 g, 67.5 mmol), 1.60 M hexane solu-
tion of n-BuLi (50 mmol) was added at À10 ꢁC. The
mixture was allowed to warm to 20 ꢁC and then stirred
for 3 h. THF (20 mL) solution of 6 (14.85 g, 50 mmol)
was added to the mixture at À10 ꢁC. The resulting mixture
was allowed to warm to 20 ꢁC, then stirred for 20 h. The
same work-up as for Method A gave 3a (14.35 g, 75%
yield).
3.4. [2-(Allyloxy)-3-tert-butyl-5-methylphenyl](dimethyl)
(2,3,4,5-tetramethylcyclopenta-2,4-dien-1-yl)silane (3a)
3.5. Dimethylsilyl(2,3,4,5-tetramethylcyclopentadienyl)
(3-tert-butyl-5-methyl-2-phenoxy)-titanium dichloride (1a)
3.4.1. Method A
To a toluene (20 mL) solution of triethylamine (2.27 g,
22.6 mmol) and 3a (1.91 g, 5 mmol), 1.60 M hexane solu-
tion of n-BuLi (7.0 mL, 11.3 mmol) was added at À78 ꢁC.
The mixture was allowed to warm to 20 ꢁC, then stirred
for 3 h. To the mixture cooled at À78 ꢁC a toluene
(5 mL) solution of TiCl4 (0.82 mL, 7.5 mmol) was added
dropwise. The resulting mixture was warmed to room tem-
perature and then stirred for 1 h. Thereafter, the mixture
was heated to 90 ꢁC and stirred for a further 3 h. After
cooling to room temperature, insoluble materials were fil-
tered out. Removal of the solvent followed by recrystalliza-
tion from hexane/toluene gave 1a as a red solid (1.15 g,
50% yield). Mp: 228–230 ꢁC (dec). 1H NMR (C7D8) d
0.41 (s, 6H, SiMe2), 1.53 (s, 9H, t-Bu), 1.95 (s, 6H,
C5Me4), 2.02 (s, 6H, C5Me4), 2.25 (s, 3H, Ar-Me), 7.12
To a mixture of THF (80 mL) and 60% NaH (2.50 g,
62.5 mmol), aniline (0.23 g, 2.5 mmol) was added at room
temperature, and the mixture was then stirred for 30 min.
1,2,3,4-Tetramethyl-1,3-cyclopentadiene
(6.42 g,
52.5
mmol) was dropwise added to the mixture to 50 ꢁC. The
mixture was then stirred until evolution of hydrogen
ceased. A toluene (10 mL) solution of 6 (14.85 g, 50 mmol)
was added dropwise to the mixture cooled at 10 ꢁC. The
resulting mixture was allowed to warm to 20 ꢁC, then stir-
red for 1 h. After the mixture was poured into water, the
separated organic layer was washed with saturated aqueous
NaCl and then dried over Na2SO4. Removal of the solvent
followed by short column chromatography over silica (hex-
ane/EtOAc, 20:1) gave 3a as a pale yellow oil (16.45 g, 86%

4064
H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
(m, 1H, Ar-H), 7.19 (m, 1H, Ar-H); 13C{1H} NMR (C7D8)
d 0.0 (SiMe2), 12.8, 14.8, 21.3 (Ar-Me), 30.2 (Ar-CMe3),
35.2 (Ar-CMe3), 117.7, 129.6, 129.9, 132.3, 133.8, 136.7,
138.6, 139.9, 166.8. Anal. Calc. for C22H32Cl2OSiTi: C,
57.52; H, 7.02. Found C, 57.30; H, 7.00%.
168.5. Anal. Calc. for C18H24Cl2OSiTi: C, 53.61; H, 6.00.
Found C, 53.50; H, 6.00%.
3.9. [2-(Allyloxy)-3-tert-butyl-5-methylphenyl](inden-1-yl)
(dimethyl)silane (3c)
3.6. Dimethylsilyl(2,3,4,5-tetramethylcyclopentadienyl)
(3-tert-butyl-5-methyl-2-phenoxy)-zirconium dichloride (8)
In a similar manner as for 3a, reaction of 6 with indene
gave 3c (Method B) (86% yield). H NMR (CDCl3) d 0.01
1
(s, 3H, SiMe2), 0.12 (s, 3H, SiMe2), 1.43 (s, 9H, t-Bu), 2.30
(s, 3H, Ar-Me), 4.05 (br, 1H, Ind-H), 4.41 (dt, 2H, J = 2,
2 Hz, OCH2CH@CH2), 5.27 (dq, 1H, J = 11, 2 Hz,
OCH2CH@CH2), 5.54 (dq, 1H, J = 17, 2 Hz, OCH2-
CH@CH2), 6.40 (ddt, 1H, J = 17, 11, 2 Hz, OCH2CH
@CH2), 6.56 (dd, 1H, J = 5, 2 Hz, Ar-H), 6.88 (dd, 1H,
J = 5, 1 Hz, Ar-H), 7.02–7.26 (m, 5H, Ar-H), 7.43 (d,
1H, J = 7 Hz, Ar-H); 13C{1H} NMR (CDCl3) d À3.2
(SiMe), À3.0 (SiMe), 21.1 (Ar-Me), 31.2 (Ar-CMe3), 35.2
(Ar-CMe3), 76.4, 116.1, 120.8, 123.0, 123.5, 124.8, 129.2,
130.6, 131.6, 132.5, 133.6, 134.9, 136.4, 142.1, 144.5,
145.3, 161.4. EI-MS: m/z 376 (M+), 261, 205.
A
1.60 M hexane solution of n-BuLi (7.0 mL,
11.3 mmol) was added to a toluene (20 mL) solution of tri-
ethylamine (2.27 g, 22.6 mmol) and 3a (1.91 g, 5.0 mmol)
cooled at À78 ꢁC. The reaction mixture was gradually
warmed to room temperature, then stirred for further
3 h. After the reaction mixture was again cooled to
À78 ꢁC, a suspension of toluene (20 mL) and ZrCl4
(1.73 g, 7.5 mmol) was added dropwise. The resulting mix-
ture was allowed to warm to room temperature and then
stirred for 3 h. Insoluble materials were filtrated off, the fil-
trate was concentrated, and recrystallization from hexane/
1
toluene gave 8 as a yellow solid (1.07 g, 43% yield). H
NMR (CD2Cl2) d 0.54 (s, 6H, SiMe2), 1.37 (s, 9H, t-Bu),
2.10 (s, 6H, C5Me4), 2.23 (s, 6H, C5Me4), 2.32 (s, 3H,
Ar-Me), 7.11–7.18 (m, 2H, Ar-H); 13C{1H} NMR
(CD2Cl2) d À0.3 (SiMe2), 11.5, 13.4, 20.4, 29.5, 34.3,
116.5, 129.0, 131.8, 132.9, 134.2, 135.9, 136.9, 139.0,
161.2. HRMS: m/z calcd 500.0646, found 500.0645.
3.10. Dimethylsilyl(inden-1-yl)(3-tert-butyl-5-methyl-2-
phenoxy)-titanium dichloride (1c)
Compound 1c was prepared in a similar manner as for
1a, but without triethylamine. 40% yield. Mp: 178–180 ꢁC
(dec). 1H NMR (C7D8) d 0.43 (s, 3H, SiMe2), 0.50 (s,
3H, SiMe2), 1.37 (s, 9H, t-Bu), 2.27 (s, 3H, Ar-Me),
6.60–6.71 (m, 2H, Ar-H), 6.73 (dt, 1H, J = 2, 4 Hz, Ar-
H), 6.92 (ddd, 1H, J = 8, 7, 1 Hz, Ar-H), 7.12 (dq, 1H,
J = 8, 1 Hz, Ar-H), 7.19 (ddd, 1H, J = 7, 2, 1 Hz, Ar-H),
7.52 (dt, 1H, J = 9, 1 Hz, Ar-H); 13C{1H} NMR (C7D8)
d À2.0 (SiMe), À1.8 (SiMe), 21.3 (Ar-Me), 30.1 (Ar-
CMe3), 35.0 (Ar-CMe3), 113.4, 117.6, 125.0, 126.7, 128.1,
128.6, 128.7, 129.8, 131.9, 133.1, 134.3, 135.5, 136.9,
140.4, 168.1. Anal. Calc. for C22H26Cl2OSiTi: C, 58.29;
H, 5.78. Found C, 57.90; H, 5.80%.
3.7. [2-(Allyloxy)-3-tert-butyl-5-methylphenyl]
(cyclopentadienyl)(dimethyl) silane (3b)
In a similar manner as described for preparation of 3a,
reaction of 6 with sodium cyclopentadienylide gave 3b as
a pale yellow oil (84% yield after short column chromatog-
1
raphy over silica (hexane)). H NMR (CDCl3) d 0.19 (s,
6H, SiMe2), 1.45 (s, 9H, t-Bu), 2.36 (s, 3H, Ar-Me), 3.11
(s, 1H, SiC5H5), 4.43 (m, 2H, OCH2CH@CH2), 5.31 (m,
1H, OCH2CH@CH2), 5.57 (m, 1H, OCH2CH@CH2),
6.07 (m, 1H, OCH2CH@CH2), 6.40–6.70 (m, 4H, SiC5H5),
7.16–7.22 (m, 2H, Ar-H); 13C{1H} NMR (CDCl3, major
isomer) d À2.7 (SiMe2), 21.1 (Ar-CH3), 31.2 (Ar-CMe3),
35.2 (Ar-CMe3), 76.4, 116.1, 130.5, 132.1, 132.4, 133.6,
134.4, 135.1, 136.0, 138.2, 142.1, 161.3. HRMS: m/z calcd
326.2066, found 326.2073.
3.11. [2-(Allyloxy)-3-tert-butyl-5-methylphenyl]
(3-tert-butylcyclopentadienyl)(dimethyl)silane (3d)
In a similar manner as for 3a, reaction of 6 with tert-
butylcyclopentadiene gave 3d (Method B) (83% yield). H
1
NMR (CDCl3) d 0.10 (s, 3H, SiMe2), 0.17 (s, 3H, SiMe2),
1.17 (s, 9H, t-Bu), 1.40 (s, 9H, t-Bu), 2.31 (s, 3H, Ar-
Me), 3.70 (br, 1H, Cp-H), 4.18–4.41 (m, 2H,
OCH2CH@CH2), 5.13–5.40 (m, 1H, OCH2CH@CH2),
5.42–5.58 (m, 1H, OCH2CH@CH2), 5.95–6.20 (m, 2H,
OCH2CH@CH2 and Cp-H), 6.38–6.42 (m, 1H, Cp-H),
6.60–6.65 (m, 1H, Cp-H), 7.08–7.22 (m, 2H, Ar-H);
13C{1H} NMR (CDCl3, major isomer) d À2.9 (SiMe),
À2.5 (SiMe), 21.1 (Ar-CH3), 30.4 (CMe3), 31.2 (CMe3),
32.2 (CMe3), 35.2 (CMe3), 76.3, 116.1, 124.1, 130.4,
130.6, 132.3, 132.4, 133.7, 134.1, 134.4, 134.5, 142.0,
143.1, 161.3. HRMS: m/z calcd 382.26919, found
382.26430.
3.8. Dimethylsilyl(cyclopentadienyl)(3-tert-butyl-5-methyl-
2-phenoxy)-titanium dichloride (1b)
Compound 1b was prepared in a similar manner as 1a
(36% yield). Mp: 179–182 ꢁC (dec). 1H NMR (C7D8) d
0.27 (s, 6H, SiMe2), 1.57 (s, 9H, t-Bu), 2.22 (s, 3H,
Ar-Me), 6.06 (t, 2H, J = 2 Hz, SiC5H4), 6.62 (t, 2H,
J = 2 Hz, SiC5H4), 7.08(d, 1H, J = 2 Hz, Ar-H), 7.21 (d,
1H, J = 2 Hz, Ar-H); 13C{1H} NMR (C7D8) d À2.1
(SiMe2), 21.2 (Ar-Me), 30.5 (Ar-CMe3), 35.2 (Ar-CMe3),
121.5, 125.8, 126.5, 129.9, 133.1, 134.4, 136.6, 137.5,

H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
4065
3.12. Dimethylsilyl(3-tert-butylcyclopentadienyl)(3-tert-
butyl-5-methyl-2-phenoxy)-titanium dichloride (1d)
3.14. Polymerization of ethylene with 1-hexene catalyzed by
1a–1d and 8 in 20 mL autoclave
Compound 1d was prepared in a similar manner as for
1a. 45% yield. Mp: 170–172 ꢁC (dec). H NMR (C7D8), d
A pre-weighed glass vial insert and disposable stirring
paddle were fitted to each reaction vessel of the reactor.
The reactor was then closed, and 0.25 M triisobutylalumin-
ium (160 lL), 1-hexene (60 lL) and toluene were injected
into each reaction vessel through a valve. The total volume
of reaction mixture was adjusted with toluene to 5 mL. The
temperature was then set to the reaction temperature, the
stirring speed was set to 800 rpm, and the mixture was pres-
surized to 0.6 MPa. Toluene solution of Cp-phenoxy com-
plex (0.1 lmol, 1 mM toluene solution) was added followed
by toluene solution of AB (0.3 lmol, 1 mM toluene solu-
tion). Ethylene pressure in the cell and the temperature set-
ting were maintained by computer control until the end of
the polymerization experiment. The polymerization
reactions were allowed to continue for 20 min unless con-
sumption of ethylene reached pre-set levels. After polymer-
ization reaction, the temperature was allowed to drop to
room temperature and the ethylene pressure in the cell
was slowly vented. The glass vial insert was then removed
from the pressure cell and the volatile components were
removed using a centrifuge vacuum evaporator to give
polymer product.
1
0.32 (s, 3H, SiMe2), 0.38 (s, 3H, SiMe2), 1.34 (s, 9H,
t-Bu), 1.57 (s, 9H, t-Bu), 2.23 (s, 3H, Ar-Me), 5.74 (dd,
1H, J = 3, 2 Hz, Cp-H), 6.74 (t, 1H, J = 2 Hz, Cp-H),
6.78 (dd, 1H, J = 3, 2 Hz, Cp-H), 7.10 (m, 1H, Ar-H),
7.20 (m, 1H, Ar-H). 13C NMR (C7D8) d À2.0 (SiMe),
À1.9 (SiMe), 21.2 (Ar-CH3), 30.4 (CMe3), 31.1 (CMe3),
33.9 (CMe3), 35.2 (CMe3), 121.7, 124.3, 125.5, 125.8,
129.9, 133.2, 134.3, 136.6, 154.4, 169.0. Anal. Calc. for
C25H39Cl2OSiTi(1e Æ 0.5C6H14): C, 59.76; H, 7.82. Found
C, 60.06; H, 7.50%.
3.13. Crystallographic analysis of 1c
A red block crystal of 1c was mounted on glass, and
intensity data were then collected using
a Rigaku
RAXIS-RAPID Imaging Plate diffractometer with graph-
ite monochromated CuKa radiation. The structure was
solved using a direct method (SIR92 [15]) and refined by
the full-matrix least-squares methods. Crystal data and
details of refinement are summarized in Table 4. The final
discrepancy indices were R (I > 3r(I)) = 0.029 and Rw
(I > 3r(I)) = 0.035. All calculations were performed using
the CrystalStructure crystallographic software package
(Rigaku/MSC).
3.15. Polymerization of ethylene and 1-hexene catalyzed by
1c in 300 mL autoclave
An autoclave with an inner volume of 300 mL was dried
under vacuum and purged with nitrogen. Toluene
(150 mL) and 1-hexene (1.5 mL) were introduced into the
vessel, which was then heated to 40 ꢁC. After ethylene
was introduced (0.6 MPa), triisobutylaluminum (0.60
mmol, 1.0 M toluene solution) was added. Subsequently,
1c (1.0 lmol, 1 mM toluene solution) and TB (6.0 lmol,
6 mM toluene solution) were added. Polymerization was
performed at 40 ꢁC for 5 min, and then the reaction was
then quenched by addition of methanol (5 mL). The reac-
tion mixture was then poured into acidic methanol
(500 mL with 1 mL of 5% HCl). The polymer was collected
by filtration, washed with methanol, and then dried in a
high vacuum oven at 80 ꢁC for 2 h to constant weight.
Table 4
Crystal data and data collection parameters for 1c
Empirical formula
Formula weight
Crystal dimensions (mm)
Crystal system
C22H26Cl2OSiTi
453.34
0.1 · 0.2 · 0.2
Monoclinic
127.40
Detector position (mm)
Pixel size (mm)
0.100
˚
a (A)
10.073(2)
10.114(2)
22.788(5)
95.54(1)
2310.9(8)
P21/c (#14)
4
˚
b (A)
˚
c (A)
b (ꢁ)
3
˚
V (A )
Space group
Z value
Dcalc (g/cm3)
Diffractometer
Radiation
Appendix A. Supplementary data
1.303
Rigaku RAXIS-RAPID
CuKa (l = 1.54187 A)
Graphite, monochromated
143.6
Supplementary data associated with this article can be
found, in the online version, at doi:10.1016/j.jorganchem.
2007.06.006.
˚
2hmax (ꢁ)
Number of reflections measured
Total: 27,638
Unique: 4229 (Rint = 0.023)
Direct methods (SIR92)
References
Structure solution
Refinement
Full-matrix least-squares on F
2428
0.029
0.035
1.008
[1] (a) H.H. Brintzinger, D. Fischer, R. Mulhaupt, B. Rieger, R.M.
¨
Number of observations (I > 3r(I))
Residuals: R (I > 3r(I))
Residuals: Rw (I > 3r(I))
Goodness of fit indicator
Waymouth, Angew. Chem. Int., Ed. Engl. 34 (1995) 1143;
(b) A.L. McKnight, R.M. Waymouth, Chem. Rev. 98 (1998) 2587;
(c) G.W. Coates, Chem. Rev. 100 (2000) 1223;
(d) U. Siemeling, Chem. Rev. 100 (2000) 1495.

4066
H. Hanaoka et al. / Journal of Organometallic Chemistry 692 (2007) 4059–4066
[2] (a) J.C. Stevens, F.J. Timmers, D.R. Wilson, G.F. Schmit, P.N.
Nickas, R.K. Rosen, G.W. Knight, S.Y. Lai, (Dow) Eur. Pat. Appl.
EP 416815, 1991;
(h) Y. Zhang, J. Wang, Y. Mu, Z. Shi, C. Lu, Y. Zhang, L. Qiao,
¨
S. Feng, Organometallics 22 (2003) 3877;
(i) Y.X. Chen, P.-F. Fu, C.L. Stern, T.J. Marks, Organometallics
16 (1997) 5958.
(b) J.A.M. Canich, G.G. Hlatky, H.W. Turner, (Exxon) PCT Appl.
WO 92/00333, 1992;
(c) A.K. Hughes, A. Meetsma, J.H. Teuben, Organometallics 12
(1993) 1936;
[5] (a) E.E.C.G. Gielens, J.Y. Tiesnitsch, B. Hessen, J.H. Teuben,
Organometallics 17 (1998) 1652;
´
(b) G. Trouve, D.A. Laske, A. Meetsma, J.H. Teuben, J. Organomet.
(d) K.E. du Plooy, U. Moll, S. Wocadol, W. Massa, J. Okuda,
Organometallics 14 (1995) 3129;
(e) J.T. Park, S.C. Yoon, B.-J. Bae, W.S. Seo, I.-H. Suh, T.K. Han,
J.R. Park, Organometallics 19 (2000) 1269.
Chem. 511 (1996) 255;
(c) S.D.R. Christie, K.W. Man, R.J. Whitby, A.M.Z. Slawin,
Organometallics 18 (1999) 348.
[6] (a) S. Bredeau, G. Altenhoff, K. Kunz, S. Do¨ring, S. Grimme, G.
Kehr, G. Erker, Organometallics 23 (2004) 1836;
(b) K. Kunz, G. Erker, S. Do¨ring, R. Fro¨hlich, G. Kehr, J. Am.
Chem. Soc. 123 (2001) 6181.
[7] Y. Suzuki, H. Terao, T. Fujita, Bull. Chem. Soc. Jpn. 76 (2003) 1493.
[8] (a) K. Nomura, K. Oya, T. Komatsu, Y. Imanishi, Macromolecules
33 (2000) 3187;
(b) K. Nomura, N. Naga, M. Miki, K. Yanagi, Macromolecules 31
(1998) 7588.
[9] M. Nabika, T. Miyatake, Kobunshi Ronbunshu 59 (2002) 382.
[10] H. Hanaoka, Y. Imamoto, T. Hino, Y. Oda, J. Organomet. Chem.
691 (2006) 4968.
[3] (a) D.J. Cho, C.J. Wu, S. Sujith, W.-S. Han, S.O. Kang, B.Y. Lee,
Organometallics 25 (2006) 2133;
(b) C.J. Wu, S.H. Lee, H. Yun, B.Y. Lee, J. Organomet. Chem. 691
(2006) 5626.
[4] (a) H. Katayama, M. Nabika, A. Imai, A. Miyashita, T. Watanabe,
H. Johohji, Y. Oda, H. Hanaoka, (Sumitomo) PCT Appl. WO 97/
03992, 1997;
(b) A. Imai, A. Ogawa, T. Takei, T. Nishiyama, H. Johoji,
MetCon2000, 2000;
(c) A. Imai, H. Katayama, M. Nabika, T. Watanabe, MetCon2001,
2001;
(d) A. Imai, H. Johoji, H. Hozumi, T. Nishiyama, MetCon2002, 2002;
(e) T. Miyatake, in: The 15th International Symposium on Olefin
Methathesis and Related Chemistry, Kyoto, July 31–August 1, 2003;
(f) A. Rau, S. Schmitz, G. Luft, J. Organomet. Chem. 608 (2000)
71;
[11] P.R. Hamann, J.E. Toth, P.L. Fuchs, J. Org. Chem. 49 (1984) 3865.
[12] Y. Oda, K. Yamauchi, H. Hanaoka, H. Souda, (Sumitomo) Eur. Pat.
Appl. EP 963990, 1999.
[13] H. Hey, H.-J. Arpe, Angew. Chem., Int. Ed. 12 (1973) 928.
[14] M.V. Bhatt, S.S. El-Morey, Synthesis (1982) 1048.
[15] A. Altomare, M.C. Burla, M. Camalli, G.L. Cascarano, C. Giaco-
vazzo, A. Guagliardi, G. Polidori, J. Appl. Cryst. 27 (1994) 435.
(g) Y. Zhang, Y. Mu, C. Lu, G. Li, J. Xu, Y. Zhang, D. Zhu, S.
¨
Feng, Organometallics 23 (2004) 540;