o-Phenylene-bridged Cp/amido titanium and zirconium complexes and their polymerization reactivity

Article abstract of DOI:10.1016/j.jorganchem.2007.11.021

o-Phenylene-bridged trimethylcyclopentadienyl/amido titanium complexes [(η⁵-2,3,5-Me₃C₅H)C₆ H₄NR-κN]TiCl₂ (18, R = CH₃; 19, R =CH₂CH₃; 20, R = CH₂C(CH₃)₃; 21, R = CH₂(C₆H₁₁)) and zirconium complexes {[(η⁵-2,3,5-Me₃C₅H)C₆H ₄NR-κN]ZrCl-μCl}₂ (22, R = CH₃; 23, R = CH₂CH₃; 24, R = CH₂C(CH₃)₃; 25, R = CH₂(C₆H₁₁); 26, R = C₆H₁₁; 27, R = CH(CH₂CH₃)₂) are prepared via a key step of the Suzuki-coupling reaction between 2-dihydroxyboryl-3-methyl-2-cyclopenten-1-one (2) and the corresponding bromoaniline compounds. The molecular structures of titanium complexes 18 and 19 and dinuclear zirconium complexes 24 and 26 were confirmed by X-ray crystallography. The Cp(centroid)-Ti-N and Cp(centroid)-Zr-N angles are smaller, respectively, than those observed for the Me₂Si-bridged complex [Me₂Si(η⁵-Me₄C₅) (N^tBu)]TiCl₂ and its Zr-analogue, indicating that the o-phenylene-bridged complexes are more constrained than the Me₂Si-bridged complex. Titanium complex 19 exhibits comparable activity and comonomer incorporation to the CGC ([Me₂Si(η⁵-Me₄C₅) (N^tBu)]TiCl₂) in ethylene/1-octene copolymerization. Complex 19 produces a higher molecular-weight polymer than CGC.

Full text of DOI:10.1016/j.jorganchem.2007.11.021

Available online at www.sciencedirect.com
Journal of Organometallic Chemistry 693 (2008) 457–467
www.elsevier.com/locate/jorganchem
o-Phenylene-bridged Cp/amido titanium and zirconium complexes
and their polymerization reactivity
Sang Hoon Lee a, Chun Ji Wu a, Jina Yoo a, Jung-eun Kwak b,
Hoseop Yun b, Bun Yeoul Lee a,*
a Department of Molecular Science and Technology Ajou University, Suwon 443-749, Republic of Korea
b Energy System Division, Ajou University, Suwon 443-749, Republic of Korea
Received 27 September 2007; received in revised form 13 November 2007; accepted 14 November 2007
Available online 21 November 2007
Abstract
o-Phenylene-bridged trimethylcyclopentadienyl/amido titanium complexes [(g5-2,3,5-Me3C5H)C6H4NR-jN]TiCl2 (18, R = CH3; 19,
R = CH2CH3; 20, R = CH2C(CH3)3; 21, R = CH2(C6H11)) and zirconium complexes {[(g5-2,3,5-Me3C5H)C6H4NR-jN]ZrCl-lCl}2 (22,
R = CH3; 23, R = CH2CH3; 24, R = CH2C(CH3)3; 25, R = CH2(C6H11); 26, R = C6H11; 27, R = CH(CH2CH3)2) are prepared via a key
step of the Suzuki-coupling reaction between 2-dihydroxyboryl-3-methyl-2-cyclopenten-1-one (2) and the corresponding bromoaniline
compounds. The molecular structures of titanium complexes 18 and 19 and dinuclear zirconium complexes 24 and 26 were confirmed
by X-ray crystallography. The Cp(centroid)–Ti–N and Cp(centroid)–Zr–N angles are smaller, respectively, than those observed for
the Me2Si-bridged complex [Me2Si(g5-Me4C5)(NtBu)]TiCl2 and its Zr-analogue, indicating that the o-phenylene-bridged complexes
are more constrained than the Me2Si-bridged complex. Titanium complex 19 exhibits comparable activity and comonomer incorporation
to the CGC ([Me2Si(g5-Me4C5)(NtBu)]TiCl2) in ethylene/1-octene copolymerization. Complex 19 produces a higher molecular-weight
polymer than CGC.
Ó 2007 Elsevier B.V. All rights reserved.
Keywords: Constrained geometry catalyst; Titanium complexes; Cyclopentadienyl; Polymerization
1. Introduction
with other p-donor ligands such as substituted cyclopenta-
dienyls, indenyls, or fluorenyls [5]. Derivatization through
the replacement of the tert-BuN-unit with other amides
or phosphides has been also commonly reported [6].
However, the modification on the bridge-unit by replacing
the Me2Si-bridge to hydrocarbyl-based ones has been rare
and relatively unsuccessful because it requires a different
synthetic route. Erker reported preparation of alkylidene
(R1R2C) bridged complexes, but their activities for ethyl-
ene polymerization are significantly lower than those of
the standard CGC [7,8]. Ethylene-bridged complex,
[(g5-Me4Cp)CH2CH2(NtBu)]TiCl2 was prepared, but it
exhibited a much lower a-olefin incorporation [9].
The Constrained-Geometry Catalyst (CGC), [Me2Si(g5-
Me4C5)(NtBu)]TiCl2 [1] is a typical representative among
the homogeneous Ziegler–Natta catalysts [2,3]. Its acti-
vated complex is thermally stable and provides a high
molecular-weight polymer with a high content of a-olefin
in ethylene/a-olefin copolymerizations, thereby enabling
its use in commercial processes. This catalyst is based on
a ligand design first introduced by Bercaw for scandium
complex [4]. The ligand is prepared by successive attacks
of tetramethylcyclopentadienyl-anion and tert-BuNH-
anion onto Me2SiCl2. A number of its derivatives have
been prepared through the replacement of the Me4C5-unit
Recently, we disclosed a synthetic route for o-phenylene-
bridged complexes Eq. (1). A key step in this novel route is
the Suzuki-coupling reaction between 2-bromoaniline
derivatives and the boronic acids of cyclopentenones
*
Corresponding author. Tel.: +82 31 219 1844; fax: +82 31 219 2394.
E-mail address: bunyeoul@ajou.ac.kr (B.Y. Lee).
0022-328X/$ - see front matter Ó 2007 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2007.11.021

458
S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
(1–2), which can be prepared in a 30 g scale without
column chromatography [10]. The route allows for a num-
ber of complexes, especially through derivatization on the
amide-unit. Among the prepared amido [10], sulfonamido
[11], carboxamido [12], and phosphinoamido complexes
[13], the amido complexes exhibited the best catalytic per-
formance. Contrary to the observation on the Me2Si-
bridged CGC complexes, tert-butyl amido complex 5
exhibited not only a low activity but also a low a-olefin
incorporation, while the secondary hydrocarbyl-based
amido complexes 3 and 4 showed a good activity and good
a-olefin incorporation [10a]. These polymerization results
prompt us to prepare sterically less bulky primary hydro-
carbyl-based amido complexes. The preparation of the
zirconium complexes using the same o-phenylene-bridged
Cp/amide ligand system and their reactivity are another
concern.
O
Me
R
Me
ii)
Me
Br
i)
Me
NH
Me
NH
NH
R
R
R
R
R
6 CH3
7 CH2CH3
8 CH2C(CH3)3
9 CH2(C6H11
14 CH3
10 CH3
15 CH2CH3
11 CH2CH3
16 CH2C(CH3)3
12 CH2C(CH3)3
)
17 CH2(C6H11)
13 CH2(C6H11
)
Me
R
Me
18 CH3
19 CH2CH3
iii)
Me
TiCl2
20 CH2C(CH3)3
N
R
21 CH2(C6H11
)
Scheme 1. aLegend: (i) 2, Na2CO3, Pd(PPh3)4 (1 mol%); (ii) MeLi/(CeCl3–
2LiCl), then HCl (2 N); and (iii) Ti(NMe2)4 then Me2SiCl2.
O
O
Me
Me
B(OH)2
nium complexes which are directly transformed to the
desired dichlorotitanium complexes 18–21 in excellent
yields (overall 72–94%) through the treatment of Me2SiCl2
Me
TiCl2
N
R
Me
R
Me
R'
1
2
R'
1
R
H Me
at room temperature for 6 hours. The H NMR spectra
3 C6H11
4 CH(CH2CH3)2
5 C(CH3)3
indicate that both Me2N-ligands are replaced with the
chloride-ligands, and a Cp–H signal is observed at
6.0 ppm (C6D6). A doublet o-phenylene-H signal is mark-
edly up-filed shifted by the chlorination, and it is observed
at 5.96, 6.03, 6.37, and 6.30 ppm for 18, 19, 20, and 21,
respectively. The corresponding o-phenylene-H signal is
observed at 6.44, 6.45, 6.64, and 6.55 ppm, respectively,
in the 1H NMR spectra of the corresponding bis(dimethyl-
amido)titanium complexes. The two methylene protons on
N–CH2CH3 unit in 19 are diastereotopic to each other, and
Me
R
Me
Me
R
R
Me
O
TiCl2
N
Me
O
Me
R'
TiCl2
TiMe2
S
N
N
P
O
R'
Me
ð1Þ
hence two signals are separately observed at 4.32 and
3
2. Results and discussion
2.1. Synthesis and characterization
4.39 ppm as a doublet quartet (2JHH = 15.2, JHH
=
6.8 Hz). The N–CH2 methylene protons in 21 are also
separately observed at 4.35 and 4.46 ppm as a doublet
(2JHH = 15.6, JHH = 7.6 Hz). Three Cp–CH3 signals are
3
Various N-alkylated anilines containing trimethylcyclo-
pentadienyl-unit at 2-position are prepared (Scheme 1).
N-(primary alkyl)-o-bromoanilines (8–9) are prepared by
reductive amination reaction between o-bromoaniline and
the corresponding aldehydes [14]. The Suzuki-coupling
reaction of 6–9 with 2-dihydroxyboryl-3,4-dimethyl-2-
cyclopenten-1-one (2) affords the corresponding cyclopen-
tenones 10–13 in excellent yields (89–92%). The yields for
the transformation of cyclopentenone compounds 10–13
to trimethylcyclopentadiene compounds 14–17 are signifi-
cantly improved by employing recently reported THF-sol-
uble CeCl3/2LiCl reagent [15]. Thus, the addition of two
equivalents of MeLi in the presence of two equivalents of
THF-soluble CeCl3/2LiCl provides the desired ligands
14–17 in high yields (87–91%). Elimination reaction of
the resulting tertiary alcohol is accomplished during the
aqueous HCl work-up.
observed in the range of 1.6–2.2 ppm as a sharp singlet.
In the H NMR spectrum of 20, the N–CH2 signal and
the two Cp–CH3 signals among the three Cp–CH3 signals
are significantly broadened, which might be attributed to
a slow rotation around the N–CH2 axis in the NMR time
scale.
1
The zirconium dichloride complexes are prepared in
good yields (63–89%) using the same strategy applied for
the preparation of the titanium complexes with Zr(NMe2)4
instead of Ti(NMe2)4 (Scheme 2). Contrary to the observa-
tion in the titanium complexes, a doublet o-phenylene-H
signal is not up-filed shifted by the chlorination, and a
1
single N–CH2 signal is observed, not separated. In the H
NMR spectra of 23, 24, and 25, the N–CH2 signal is
observed at 3.95 ppm as a quartet, at 3.78 ppm as a singlet,
and at 3.78 ppm as a doublet. The ortho-C6H4 signal and
the N–CH signal are very broad at 6.4–6.6 ppm and
3.3–3.5 ppm, respectively, in the 1H NMR spectrum of
26.
Treatment Ti(NMe2)4 to 14–17 at 80 °C for 1 day pro-
vides cleanly the corresponding bis(dimethylamido)tita-

S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
459
14 - 17,
i) Zr(NMe2)4
ii) Me3SiCl
2-(Me3C5H2)-C6H4-NH(C6H11
)
2-(Me3C5H2)-C6H4-NH[CH(CH2CH3)2]
R
Me
R
N
Me
22 CH3
Cl
Zr
Cl
Cl
23 CH2CH3
Me
Zr
Cl
24 CH2C(CH3)3
Me
N
R
25 CH2(C6H11
)
26 C6H11
Me
Me
27 CH(CH2CH3)2
Scheme 2.
2.2. X-ray crystallographic studies
Single crystals of titanium complexes 18 and 19 are
obtained from benzene solution at room temperature
through the slow evaporation of the solvent. The X-ray
crystallographic studies confirm the structures, which are
shown in Figs. 1 and 2, and the selected bond distances
and angles are summarized in Table 1. The Cp(centroid)–
Ti–N angles (105.11° and 104.90° for 18 and 19, respec-
tively) are smaller than that observed for the standard
CGC, [Me2Si(g5-Me4C5)(NtBu)]TiCl2 (107.6°) [16]. All
the o-phenylene-bridged complexes characterized by the
X-ray crystallography have exhibited smaller Cp(cen-
troid)–Ti–N angles than the CGC (104.7° for [2-(g5–
Me3C5H)–C6H4–NC6H11-jN]TiCl2 [10]; 100.91° for
[2-(g5–Me3C5H)–C6H4–NSO2C6H4CH3-j2N, O]TiCl2 [11];
101.36° for [2-(g5-Me3C5H)–C6H4–NC(O)tBu-j2N,O]-
TiCl2 [12]; 103.19° for [2-(g5-Me3C5H)–C6H4–N–PPh2-
j2N,P]TiCl2) [13]. The Cp(centroid)–Ti–N angle has been
used as a qualitative measure for ‘‘constrained geometry”.
The smaller the angle, the more pronounced the ‘‘con-
strained geometry” feature should be. The smaller angles
observed for the o-phenylene-bridged complexes imply that
the o-phenylene-bridge framework provides a more con-
strained feature in the complexes than the Me2Si-bridge
framework. The bridge atoms in the o-phenylene-bridged
complexes are not situated in a severely strained position.
The ipso-carbon (C(9)) is placed almost on the cyclopenta-
dienyl plane (C(centroid)–C(bridgehead)–C(ipso) angle,
170.07° and 170.08° for 18 and 19, respectively). The
Fig. 2. Thermal ellipsoid plot (30% probability level) of 19.
Ti–Cp(centroid) vector is situated almost perpendicularly
to the cyclopentadienyl plane (Ti–Cp(centroid)–C(bridge-
head) angle, 89.11° and 88.83° for 18 and 19, respectively).
On the contrary, the bridging silicon atom in the CGC and
the bridge carbon atom in the C1-bridged Cp/amido com-
plexes are situated severely deviated from the cyclopenta-
dienyl plane. The Cp(centroid)–C(bridgehead)–Si angles
for C5R4SiMe2(N-t-Bu) titanium complexes [16] are
150–154°, and the corresponding Cp(centroid)–C(bridge-
head)–C(bridge) angles for C1-bridged Cp/amido titanium
complexes are 152–156° [8].
The Cp(centroid)–Ti distances are slightly smaller in 18
˚
and 19 (2.001 and 2.002 A, respectively) than that observed
˚
for the standard CGC (2.030 A), while the Ti–N distances
˚
(1.911(3) and 1.919(3) A for 18 and 19, respectively) are
˚
slightly longer than that in CGC (1.907(4) A). The Ti–Cl
distances are also slightly longer than those in CGC. The
Cl–Ti–Cl angles are wider in 18 and 19 (105.16(4)° and
103.97(5)°, respectively) than that observed for the CGC
(102.97(7)°).
Single crystals of zirconium complexes 24 and 26 are
obtained through layer diffusion of pentane onto a benzene
solution at room temperature. The X-ray crystallographic
studies reveal l-chloro dimeric structures, which are shown
in Figs. 3 and 4. The selected bond distances and angles are
tabulated compared with those observed for the titanium
complexes and the zirconium analogue of the standard
CGC, [Me2Si(g5-Me4C5)(NtBu)]ZrCl2 (Table 1). One
Zi–Cl bond distance is normal (2.4414(13) and
˚
2.4314(11) A for 24 and 26, respectively), while the other
Zr–Cl(l) bond distance is long (2.7449(10) and 2.7239(11)
for 24 and 26, respectively). The Cl–Zr–Cl angles are also
deviated from the one observed for the monomeric
Cp/amido zirconium or titanium dichloride complexes.
The formation of l-chloro dinuclear zirconium complexes
Fig. 1. Thermal ellipsoid plot (30% probability level) of 18.

460
S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
Table 1
5
t
5
t
˚
Selected bond distances (A) and angles (°) in 18, 19, 24, 26, [(g -Me4Cp)CH2CH2(N Bu)]TiCl2, and [(g -Me4Cp)CH2CH2(N Bu)]ZrCl2
18
19
CGC–Tia
24
26
CGC–Zrb
2.163
M–Cp(cent)
2.001
2.002
2.030
2.168
2.165
M–C(1) (bridgehead-C)
M–C(2)
M–C(5)
M–C(3)H (peripheral-C)
M–C(4)CH3 (peripheral-C)
M–N
M–Cl(1)
M–Cl(2)
Cp(cent)–M–N
Cl(1)–M–Cl(2)
2.320(3)
2.344(3)
2.330(3)
2.331(3)
2.359(3)
1.911(3)
2.2760(9)
2.2764(10)
105.11
2.313(4)
2.335(4)
2.348(4)
2.329(4)
2.368(4)
1.919(3)
2.2809(13)
2.2816(11)
104.90
2.450(4)
2.454(4)
2.507(4)
2.474(5)
2.517(4)
2.072(3)
2.4414(13)
2.7239(11)
99.79
2.455(4)
2.486(4)
2.478(4)
2.483(4)
2.490(4)
2.058(3)
2.7449(10)
2.4314(11)
99.13
1.907(4)
2.2635(11)
2.052(2)
2.4065(10)
2.4082(10)
102.0
107.6
102.97(7)
105.16(4)
103.97(5)
80.28(4)
73.30
79.40(4) (4)
74.43
104.92(4)
131.22(4)
172.88
88.49
127.8(3)
113.9(3)
117.5(4)
114.8(3)
114.7(4)
130.69
173.40
88.95
129.4(3)
107.4(2)
123.1(3)
114.7(3)
114.4(4)
Cp(cent)–C(1)–C(9)
C(1)–Cp(cent)–M
M–N–C(10)
170.07
89.11
170.08
88.83
127.67(19)
115.2(2)
117.1(3)
112.9(3)
114.4(3)
127.7(2)
113.7(2)
118.7(3)
113.1(3)
114.0(3)
M–N–C(15)
C(10)–N–C(15)
C(1)–C(9)–C(10)
C(9)–C(10)–N
a
[(g5-Me4Cp)CH2CH2(NtBu)]TiCl2, data from Ref. [16].
[(g5-Me4Cp)CH2CH2(NtBu)]ZrCl2, data from Ref. [16].
b
is in contrast with the monomeric structure observed for
the [Me2Si(g5-Me4C5)(NtBu)]ZrCl2. That is, in the mono-
meric structure of [Me2Si(g5-Me4C5)(NtBu)]ZrCl2, the
Cl–Zr–Cl angle (104.92(4)°) is normal, and the two Zr–Cl
˚
distances (2.4065(10) and 2.4082(10) A) are almost the
same [16].
The Cp(centroid)–Zr–N angles (99.79° and 99.13° for 24
and 26, respectively) are smaller than that observed for the
zirconium analogue of the CGC, [Me2Si(g5-Me4C5)-
(NtBu)]ZrCl2 (102.0°) still indicating the more constrained
feature in the o-phenylene bridged complexes than in the
Me2Si-bridged complex. The more opened nature around
the zirconium center in the o-phenylene bridged Cp/amido
complexes, which is inferred from the smaller Cp(cen-
troid)–Zr–N angles, might result in the formation of
l-chloro dinuclear complexes. Similar l-chloro dinuclear
structures were observed for the more constrained C1-
bridged zirconium dichloride complexes [8]. The elements
constituting the chelation are not also situated in a severely
strained position as is observed for the titanium complexes
(Cp(centroid)–C(bridgehead)–C(ipso) angle, 172.88° and
173.40° for 24 and 26, respectively). The sum of bond
angles around the N atoms for both titanium and zirco-
nium complexes, namely, 18, 19, 24, and 26, is very close
to 360°, which is consistent with the sp2-hybridization of
the N atom.
Fig. 3. Thermal ellipsoid plot (30% probability level) of 24.
2.3. Polymerization studies
The newly prepared complexes and 3–4 are tested for
ethylene/1-octene copolymerization after activation with
(Ph3C)[B(C6F5)4] and iBu3Al. The triisobutylaluminum is
added both as a scavenger of the polar impurities and as
Fig. 4. Thermal ellipsoid plot (30% probability level) of 26.

S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
461
Table 2
zophenone ketyl. Me2SiCl2 and Me3SiCl were dried over
CaH2 and transferred under the vacuum to reservoirs.
The NMR spectra were recorded on a Varian Mercury plus
400. Elemental analyses were carried out at the Analytical
Center, Kyunghee University. Mass spectra were obtained
on a Micromass VG Autospec. Gel permeation chromato-
grams (GPC) were obtained at 140 °C in trichlorobenzene
using Waters Model 150-C+GPC and the data were ana-
lyzed using a polystyrene analyzing curve. Compound 2
was prepared according to the procedure and conditions
reported in the literature [10a].
Ethylene/1-octene copolymerization resultsa
Entry
Complex
Yield (g) Activityb [Oct]c Mw
Mw/Mn
1
2
3
4
5
6
7
8
a
18
19
0.29
0.75
0.99
0.27
0.57
0.56
12
30
40
11
23
22
14
16
9
15
11
13
433000 2.6
415000 2.2
226000 2.2
525000 2.4
315000 2.2
514000 2.5
20
21
3
4
22–27
CGCd
negligible
0.97
39
18
192000 2.6
Polymerization conditions: 30 mL toluene solution of 1-octene (0.3 M,
1.0 g), 0.50 lmol Ti, 2.0 lmol [Ph3C][B(C6F5)4], 0.20 mmol Al(iBu)3, 60
psig ethylene, 3 min, initial temperature 70 °C.
3.2. Compound 8
b
Averaged activity in 2 or 3 runs in unit of 106 g/molTi h.
c
c1-Octene content in the copolymer determined by the 1H NMR.
d
[Me2Si(g5-Me4Cp)(NtBu)]TiCl2.
2-Bromoaniline (4.25 g, 24.71 mmol) and trimethylace-
tadehyde (3.19 g, 37.1 mmol) were dissolved in toluene
(60 mL) and molecular sieves (4.0 g) were added. The flask
was sealed with a screw-cap and heated at 100 °C for 2
days. After the molecular sieves were filtered off, all vola-
tiles were removed under vacuum at 60 °C to give a crude
imine compound. The imine compound was dissolved in
degassed methanol (75 mL). After sodium borohydride
(2.80 g, 74.13 mmol) was added slowly under a weak
stream of nitrogen gas, the mixture was stirred at room
temperature for 2 h. Aqueous 1 N KOH (75 mL) was
added, and the product was extracted with methylene chlo-
ride (100 mL ꢀ 2). The combined organic layer was dried
over anhydrous MgSO4 and then the solvent was removed
with a rotary evaporator to give a residue which was puri-
fied by column chromatography on silica gel eluting with
hexane and ethyl acetate (v/v, 10:1). Yellow oil was
an alkylating agent. The polymerization conditions and the
results are summarized in Table 2. Ethylamido titanium
complex 19 and neopentylamido titanium complex 20
exhibit higher activities than secondary-hydrocarbyl amido
titanium complexes 3 and 4, and the activities of 19 and 20
(30 and 40 ꢀ 106 g/molTi h, respectively) are comparable
to that of the standard CGC (39 g/molTi h). The activities
of the methylamido complex 18 and cyclohexylmethylami-
do complex 21 are inferior, and the zirconium complexes
22–27 show a negligible activity under the same conditions.
The 1-octene content in the copolymer is dependent on
the size of the substituent on the nitrogen atom. Primary-
hydrocarbyl amido titanium complexes 18, 19, and 21 are
able to incorporate more 1-octene (14, 16, 15 mol%, respec-
tively) than secondary-hydrocarbyl amido titanium
complexes 3 and 4 (11 and 13 mol%, respectively). The
1-octene incorporation ability of neopentylamido titanium
complex 20 is inferior (9 mol%) even though it is a primary-
hydrocarbyl amido titanium complex. This low 1-octene
incorporation might be attributed to the bulkiness of the
neopentyl group. Ethylamido complex 19, which shows
fairly good activity, can incorporate the highest amount
of 1-octene, but the incorporated amount (16 mol%) is
slightly less than that observed for the polymer obtained
with the standard CGC (18 mol%). The molecular weights
of the polymers obtained with the o-phenylene-bridged
complexes are higher than that of the polymer obtained
with CGC. The molecular weight of the polymer obtained
with 19 (Mw, 415000) is almost two times higher than that
of the polymer obtained with CGC (Mw, 192000). The
molecular weight distributions are narrow in all cases
(Mw/Mn, 2.2–2.6), indicating a single active site.
1
obtained (3.65 g, 65%). IR (neat): 3423 (N–H) cmꢁ1. H
NMR (C6D6): d 0.82 (s, 9H, CH3), 2.61 (d, J = 6.0 Hz,
2H, N–CH2), 4.38 (br s, 1H, NH), 6.40 (t, J = 8.0 Hz,
1H, C6H4), 6.44 (d, J = 8.0 Hz, 1H, C6H4), 7.01
(t, J = 8.0 Hz, 1H, C6H4), 7.37 (dd, J = 7.6, 1.2 Hz, 1H,
C6H4) ppm. 13C{1H} NMR (C6D6): d 27.71, 31.97, 55.54,
110.22, 111.63, 117.64, 128.71, 132.60, 145.82 ppm. HRMS
(EI): m/z calcd ([M]+ C11H16BrN) 241.0466. Found:
241.0470%.
3.3. Compound 9
The compound was synthesized using the same condi-
tions and procedure as those for 8 with cyclohexanecarbox-
aldehyde. It was purified by column chromatography on
silica gel eluting with hexane and ethyl acetate (v/v, 10:1).
Light yellow oil was obtained in 63% yield. IR (neat):
1
3408 (N–H) cmꢁ1. H NMR (C6D6): d 0.72–0.80 (m, 2H,
Cy), 1.02–1.12 (m, 4H, Cy), 1.28–1.33 (m, 1H, Cy), 1.58–
1.65 (m, 4H, Cy), 2.66 (t, J = 6.4 Hz, 2H, N–CH2), 4.34
(br s, 1H, NH), 6.40 (t, J = 8.0 Hz, 1H, C6H4), 6.44 (d,
J = 8.0 Hz, 1H, C6H4), 7.01 (t, J = 8.0 Hz, 1H, C6H4),
7.38 (dd, J = 8.0, 1.6 Hz, 1H, C6H4) ppm. 13C{1H} NMR
(C6D6): d 26.43, 27.04, 31.55, 37.65, 50.57, 110.01,
111.58, 117.60, 128.73, 132.66, 145.56 ppm. HRMS (EI):
m/z calcd ([M]+ C13H13BrN) 267.0623. Found: 267.0620%.
3. Experimental
3.1. General remarks
All manipulations were performed under an inert atmo-
sphere using standard glovebox and Schlenk techniques.
Toluene, pentane, THF, and C6D6 were distilled from ben-

462
S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
3.4. Compound 10
obtained (93%). M.p. 73 °C. IR (neat): 3422 (N–H) cmꢁ1
,
1691 (C@O) cmꢁ1 1H NMR (C6D6):
.
d
0.79 (d,
Compound 2 (0.63 g, 4.09 mmol), Na2CO3 (0.65 g,
6.14 mmol), Pd(PPh3)4 (0.14 g, 0.12 mmol), and compound
6 (0.73 g, 3.90 mmol) were added into a Schlenk flask inside
a glovebox. The flask was brought out from the glove box
and degassed DME (23 mL) and degassed water (7.5 mL)
were successively added with a syringe. The mixture was
stirred at 95 °C overnight. After the solution was cooled
to room temperature, it was transferred to a separatory
funnel containing ethyl acetate (25 mL). Water (25 mL)
was added and then the organic phase was collected. The
water phase was extracted with additional ethyl acetate
(10 mL ꢀ 2). The combined organic phase was dried over
anhydrous MgSO4. The solvent was removed with a rotary
evaporator to give a residue which was purified by column
chromatography on silica gel eluting with hexane and ethyl
acetate (v/v, 3:1). A light yellow solid was obtained (0.76 g,
91%). M.p. 88 °C. IR (neat): 3394 (N–H) cmꢁ1, 1690
J = 7.2 Hz, 3H, CH3), 0.91 (s, 9H, CH3), 1.61 (s, 3H,
CH3), 1.84 (dd, J = 18.4, 2.0 Hz, 1H, CH2), 2.20–2.24 (m,
1H, CH), 2.43 (dd, J = 18.0, 6.4 Hz, 1H, CH2), 2.70–2.79
(m, 2H, N–CH2), 4.16 (br s, 1H, NH), 6.71 (d,
J = 8.0 Hz, 1H, C6H4), 6.81 (td, J = 7.2, 1.2 Hz, 1H,
C6H4), 6.99 (dd, J = 7.2, 1.2 Hz, 1H, C6H4), 7.24 (td,
J = 8.0, 1.6 Hz, 1H, C6H4) ppm. 13C{1H} NMR (C6D6):
d 16.14, 19.63, 28.03, 31.84, 37.75, 43.71, 56.10, 111.65,
116.94, 119.07, 129.47, 131.11, 135.24, 139.98, 147.77,
177.18, 205.40 ppm. Anal. Calc. (C13H25NO): C, 79.66;
H, 9.28; N, 5.16. Found: C, 79.62; H, 8.94; N, 5.02%.
3.7. Compound 13
The compound was synthesized using the same condi-
tions and procedure as those for 10 with 9. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 3:1). A light yellow solid was
(C@O) cmꢁ1 1H NMR (C6D6): d 0.73 (d, J = 7.2 Hz,
.
3H, CH3), 1.57 (s, 3H, CH3), 1.82 (dd, J = 18.0, 2.0 Hz,
1H, CH2), 2.15–2.22 (m, 2H, CH), 2.40 (dd, J = 18.4,
6.4 Hz, 1H, CH2), 2.47 (s, 3H, N–CH3), 4.11 (br s, 1H,
NH), 6.64 (d, J = 8.4 Hz, 1H, C6H4), 6.83 (t, J = 8.0 Hz,
1H, C6H4), 6.99 (dd, J = 7.6, 1.6 Hz, 1H, C6H4), 7.26 (td,
J = 8.8, 1.6 Hz, 1H, C6H4) ppm. 13C{1H} NMR (C6D6):
d 16.02, 19.19, 30.84, 37.75, 43.63, 111.04, 117.07, 119.10,
131.03, 140.02, 148.26, 177.19, 205.65 ppm. Anal. Calc.
(C14H17NO): C, 78.10; H, 7.96; N, 6.51. Found: C, 77.83;
H, 8.26; N, 6.45%.
obtained (92%). M.p. 70 °C. IR (neat): 3409 (N–H) cmꢁ1
,
1682 (C@O) cmꢁ1
. d 0.76 (d,
1H NMR (C6D6):
J = 7.2 Hz, 3H, CH3), 0.85–0.93 (m, 2H, Cy), 1.03–1.20
(m, 3H, Cy), 1.46–1.66 (m, 4H, Cy), 1.62 (s, 3H, CH3),
1.77–1.81 (m, 2H, Cy), 1.83 (dd, J = 18.4, 2.0 Hz, 1H,
CH2), 2.17–2.23 (m, 1H, CH), 2.41 (dd, J = 18.4, 6.8 Hz,
1H, CH2), 2.83 (t, J = 6.4 Hz, 2H, N–CH2), 4.26 (br s,
1H, NH), 6.73 (d, J = 8.0 Hz, 1H, C6H4), 6.81 (td,
J = 7.2, 1.2 Hz, 1H, C6H4), 6.99 (dd, J = 7.2, 1.2 Hz, 1H,
C6H4), 7.26 (td, J = 7.2, 1.6 Hz, 1H, C6H4) ppm.
13C{1H} NMR (C6D6): d 16.14, 19.39, 26.53, 27.13,
31.79, 37.77, 38.07, 43.67, 51.18, 111.67, 116.88, 119.02,
129.50, 131.22, 140.16, 147.63, 177.14, 205.52 ppm. Anal.
Calc. (C20H27NO): C, 80.76; H, 9.15; N, 4.71. Found: C,
80.98; H, 8.99; N, 4.82%.
3.5. Compound 11
The compound was synthesized using the same condi-
tions and procedure as those for 10 with 7. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 3:1). A light yellow solid was
3.8. Compound 14
obtained (89%). M.p. 84 °C. IR (neat): 3401 (N–H) cmꢁ1
,
1682 (C@O) cmꢁ1
.
1H NMR (C6D6):
d
0.73 (d,
The CeCl3/2LiCl solution in THF (0.33 M; 17 mL,
5.45 mmol), which was prepared according to the literature
method [15], was added into a Schlenk flask. After the solu-
tion was cooled to ꢁ78 °C, MeLi (3.5 mL, 1.6 M in diethyl
ether, 5.45 mmol) was added with a syringe. The solution
was stirred for 1 h at ꢁ78 °C. Compound 10 (0.59 g,
2.73 mmol) dissolved in THF (1.0 mL) was added with a
syringe. After the mixture was stirred for 2 h at ꢁ78 °C,
it was transferred to a separatory funnel containing ethyl
acetate (10 mL) and water (5 mL). The organic phase was
collected and the water phase was further extracted with
additional ethyl acetate (5 mL ꢀ 2). The combined organic
phase was washed with water (10 mL) and it was shaken
vigorously with aqueous HCl solution (2 N, 5 mL) for
2 min. Aqueous saturated NaHCO3 (10 mL) was added
carefully to neutralize the water phase. The organic phase
was collected and dried over anhydrous MgSO4. The sol-
vent was removed with a rotary evaporator to give a resi-
due which was purified by column chromatography on
J = 6.8 Hz, 3H, CH3), 1.02 (t, J = 6.8 Hz, 3H, CH3), 1.60
(s, 3H, CH3), 1.82 (dd, J = 18.4, 2.4 Hz, 1H, CH2), 2.16–
2.22 (m, 1H, CH), 2.40 (dd, J = 18.4, 7.2 Hz, 1H, CH2),
2.88 (q, J = 6.4 Hz, 2H, N–CH2), 4.11 (br s, 1H, NH),
6.68 (d, J = 8.0 Hz, 1H, C6H4), 6.82 (td, J = 7.2, 1.2 Hz,
1H, C6H4), 7.00 (d, J = 6.4 Hz, 1H, C6H4), 7.25 (td,
J = 7.2, 1.6 Hz, 1H, C6H4) ppm. 13C{1H} NMR (C6D6):
d 15.07, 16.13, 19.25, 37.75, 38.84, 43.63, 111.67, 117.06,
119.05, 129.52, 131.23, 135.14, 147.49, 177.05,
205.60 ppm. Anal. Calc. (C15H19NO): C, 78.56; H, 8.35;
N, 6.11. Found: C, 78.89; H, 8.34; N, 6.37%.
3.6. Compound 12
The compound was synthesized using the same condi-
tions and procedure as those for 10 with 8. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 3:1). A light yellow solid was

S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
463
1
silica gel eluting with hexane and ethyl acetate (v/v, 30:1).
A light yellow solid was obtained (0.53 g, 91%). M.p.
39 °C. H NMR (C6D6): d 1.75 (s, 3H, CH3), 1.84 (s, 3H,
obtained in 87% yield. H NMR (C6D6): d 0.75–0.81 (m,
2H, Cy), 1.03–1.12 (m, 2H, Cy), 1.32–1.37 (m, 2H, Cy)
1.56–1.65 (m, 6H, Cy), 1.80 (s, 3H, CH3), 1.86 (s, 3H,
CH3), 1.90 (s, 3H, CH3), 2.67 (AB, J = 22.8 Hz, 1H,
CH2), 2.77 (AB, J = 22.8 Hz, 1H, CH2), 2.77–2.85 (m,
2H, N–CH2), 3.94 (br s, 1H, NH), 6.73 (d, J = 8.0 Hz,
1H, C6H4), 6.85 (t, J = 7.2 Hz, 1H, C6H4), 7.14 (d,
J = 7.2 Hz, 1H, C6H4), 7.28 (t, J = 7.2 Hz, 1H, C6H4)
ppm, 13C{1H} NMR (C6D6): d 12.09, 13.85, 14.67, 26.43,
27.09, 31.64, 38.01, 49.09, 51.00, 110.44, 116.69, 122.96,
128.68, 130.34, 133.34, 136.41, 136.41, 137.03, 140.92,
146.85 ppm. HRMS (EI): m/z calcd ([M]+ C21H29N)
295.2300. Found: 295.2300%.
1
CH3), 1.88 (s, 3H, CH3), 2.40 (d, 3H, N–CH3), 2.67 (AB,
J = 22.8 Hz, 1H, CH2), 2.75 (AB, J = 22.8 Hz, 1H, CH2),
3.65 (br d, J = 4.4 Hz, 1H, NH), 6.60 (d, J = 8.0 Hz, 1H,
C6H4), 6.84 (td, J = 7.2, 1.2 Hz, 1H, C6H4), 7.11 (dd,
J = 7.2, 1.2 Hz, 1H, C6H4), 7.27 (td, J = 8.0, 1.6 Hz, 1H,
C6H4) ppm, 13C{1H} NMR (C6D6): d 12.00, 13.85, 14.55,
30.55, 49.06, 109.66, 116.82, 122.86, 128.71, 130.14,
133.15, 136.43, 136.97, 140.78, 147.47 ppm. Anal. Calc.
(C15H19N): C, 84.46; H, 8.98; N, 6.57. Found: C, 84.60;
H, 8.74; N, 6.38%.
3.9. Compound 15
3.12. Complex 18
The compound was synthesized using the same condi-
tions and procedure as those for 14 with 11. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 30:1). Light yellow oil was
obtained in 87% yield. 1H NMR (C6D6): d 0.87 (t,
J = 7.2 Hz, 3H, CH3), 1.78 (s, 3 H, CH3), 1.87 (s, 6H,
CH3), 2.67 (AB, J = 22.8 Hz, 1H, CH2), 2.76 (AB,
J = 22.4 Hz, 1H, CH2), 3.71 (br s, 1H, NH), 6.66 (d,
J = 8.0 Hz, 1H, C6H4), 6.84 (td, J = 7.2, 1.2 Hz, 1H,
C6H4), 7.12 (dd, J = 7.6, 1.6 Hz, 1H, C6H4), 7.26 (td,
J = 8.0, 1.2 Hz, 1H, C6H4) ppm, 13C{1H} NMR (C6D6):
d 12.05, 13.85, 14.62, 15.04, 38.47, 49.04, 110.27, 116.79,
122.88, 128.67, 130.36, 133.31, 136.32, 136.87, 140.82,
146.48 ppm. HRMS (EI): m/z calcd ([M]+ C16H21N)
227.1674. Found: 227.1674%.
Compound 14 (0.238 g, 1.12 mmol), Ti(NMe2)4
(0.250 g, 1.12 mmol), and toluene (5 mL) were added into
a Schlenk flask. The solution was stirred for 1 day at
80 °C. Removal of the solvent gave red oil. The 1H
NMR datum for the intermediate bis(dimethylamido)tita-
nium complex (C6D6): d 1.78 (s, 3H, CH3), 1.85 (s, 3H,
CH3), 1.86 (s, 3H, CH3), 2.89 (s, 6H, N–CH3), 3.23 (s,
6H, N–CH3), 3.45 (s, 3H, N–CH3), 5.76 (s, 1H, Cp–H),
6.44 (d, J = 8.0 Hz, 1H, C6H4), 6.94 (td, J = 7.2, 1.2 Hz,
1H, C6H4), 7.22 (dd, J = 7.2, 1.6 Hz, 1H, C6H4), 7.32 (td,
J = 8.0, 1.6 Hz, 1H, C6H4) ppm. The resulting bis(dimeth-
ylamido)titanium complex was dissolved in toluene (5 mL)
and Me2SiCl2 (0.432 g, 3.35 mmol) was added. After the
solution was stirred 6 h at room temperature, all volatiles
were removed under vacuum to give a dark red solid which
was triturated in pentane (0.35 g, 94%). The analytical data
1
3.10. Compound 16
for 18: H NMR (C6D6): d 1.64 (s, 3H, CH3), 1.74 (s, 3H,
CH3), 2.06 (s, 3H, CH3), 3.66 (s, 3H, N–CH3), 5.96 (d,
J = 8.0 Hz, 1H, C6H4), 5.99 (s, 1H, Cp–H), 6.95 (t,
J = 7.2 Hz, 1H, C6H4), 7.03 (dd, J = 7.2, 1.6 Hz, 1H,
C6H4), 7.12 (t, J = 8.0 Hz, 1H, C6H4) ppm. 13C{1H}
NMR (C6D6): d 12.66, 14.87, 14.99, 40.11, 108.63,
117.96, 123.50, 128.29, 129.28, 130.85, 131.63, 143.20,
143.68, 144.16, 167.06 ppm. Anal. Calc. (C15H17Cl2NTi):
C: 54.58; H, 5.19; N, 4.24. Found: C, 54.42; H, 5.32; N,
4.05%.
The compound was synthesized using the same condi-
tions and procedure as those for 14 with 12. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 30:1). Yellow oil was obtained
1
in 91% yield. H NMR (C6D6): d 0.82 (s, 9H, CH3), 1.78
(s, 3H, CH3), 1.85 (s, 3H, CH3), 1.88 (s, 3H, CH3), 2.68
(AB, J = 22.8 Hz, 1H, CH2), 2.75 (AB, J = 22.8 Hz, 1H,
CH2), 2.73–2.81 (m, 2H, N–CH2), 3.93 (br t, J = 4.8 Hz,
1H, NH), 6.72 (d, J = 8.0 Hz, 1H, C6H4), 6.85 (td,
J = 7.2, 1.2 Hz, 1H, C6H4), 7.14 (dd, J = 7.2, 1.6 Hz, 1H,
C6H4), 7.28 (td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm,
13C{1H} NMR (C6D6): d 12.07, 13.82, 14.67, 27.80,
32.12, 49.05, 55.91, 110.28, 116.65, 122.90, 128.65,
130.18, 133.37, 136.26, 137.07, 140.82, 147.12 ppm. HRMS
(EI): m/z calcd ([M]+ C19H27N) 269.2143. Found:
269.2144%.
3.13. Complex 19
It was synthesized using the same conditions and proce-
dure as those for 18 with 15. It was purified by trituration
1
in pentane. Overall yield from 15 was 90%. The H NMR
datum for the intermediate bis(dimethylamido)titanium
complex (C6D6): d 1.02 (t, J = 7.2 Hz, 3H, CH3), 1.74 (s,
3H, CH3), 1.84 (s, 3H, CH3), 1.91 (s, 3H, CH3), 2.88 (s,
6H, N–CH3), 3.12 (s, 6H, N–CH3), 3.85 (dq, J = 13.6,
6.8 Hz, 1H, N–CH2), 4.08 (dq, J = 13.6, 6.8 Hz 1H,
N–CH2), 5.72 (s, 1H, Cp–H), 6.46 (d, J = 8.0 Hz, 1H,
C6H4), 6.91 (t, J = 8.0 Hz, 1H, C6H4), 7.24 (dd, J = 7.2,
1.6 Hz, 1H, C6H4), 7.28 (td, J = 8.0, 1.6 Hz, 1H, C6H4)
3.11. Compound 17
The compound was synthesized using the same condi-
tions and procedure as those for 14 with 13. It was purified
by column chromatography on silica gel eluting with hex-
ane and ethyl acetate (v/v, 30:1). Light yellow oil was
1
ppm. The analytical data for 19: H NMR (C6D6): d 1.10

464
S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
(t, J = 6.8 Hz, 3H, CH3), 1.64 (s, 3H, CH3), 1.74 (s, 3H,
CH3), 2.07 (s, 3H, CH3), 4.32 (dq, J = 15.2, 6.8 Hz, 1H,
N–CH2), 4.39 (dq, J = 15.2, 16.8 Hz, 1H, N–CH2), 6.01
(s, 1H, Cp–H), 6.03 (d, J = 8.8 Hz, 1H, C6H4), 6.94 (t,
J = 7.2 Hz, 1H, C6H4), 7.04 (dd, J = 7.2, 1.2 Hz, 1H,
C6H4), 7.10 (td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm.
13C{1H} NMR (C6D6): d 11.56, 12.65, 14.91, 15.03,
45.45, 109.11, 118.00, 123.28, 128.61, 129.16, 131.35,
131.63, 143.05, 143.52, 143.96, 165.28 ppm. Anal. Calc.
(C16H19Cl2NTi): C, 55.85; H, 5.57; N, 4.07. Found: C,
55.98; H, 5.69; N, 3.82%.
13C{1H} NMR (C6D6): d 12.76, 14.97, 15.14, 26.79,
32.06, 32.11, 39.12, 57.74, 110.10, 118.57, 123.18, 128.63,
129.92, 130.78, 132.04, 142.49, 143.40, 143.81,
166.11 ppm. Anal. Calc. (C21H27Cl2NTi): C, 61.19; H,
6.60; N, 3.40. Found: C, 61.35; H, 6.76; N, 3.28%.
3.16. Complex 22
Compound 14 (0.097 g, 0.46 mmol), Zr(NMe2)4 (0.134 g,
0.50 mmol) and toluene (2.5 mL) were added into a Schlenk
flask. The solution was stirred for 1 day at 80 °C. Removal
1
of the solvent gave red oil. The H NMR datum for the
3.14. Complex 20
intermediate bis(dimethylamido)titanium complex (C6D6):
d 1.82 (s, 3H, CH3), 1.88 (s, 3H, CH3), 1.90 (s, 3H, CH3),
2.79 (s, 6H, N–CH3), 3.02 (s, 6H, N–CH3), 3.18 (s, 3H,
N–CH3), 5.73 (s, 1H, Cp–H), 6.45 (d, J = 8.0 Hz, 1H,
C6H4), 6.90 (td, J = 7.2, 0.8 Hz, 1H, C6H4), 7.21 (dd,
J = 7.2, 1.6 Hz, 1H, C6H4), 7.32 (td, J = 8.0, 1.6 Hz, 1H,
C6H4) ppm. The resulting bis(dimethylamido)titanium
complex was dissolved in toluene (2.5 mL) and Me3SiCl
(0.300 g, 2.76 mmol) was added. After the solution was stir-
red 6 hours at room temperature, all volatiles were removed
under vacuum to give a yellow solid which was triturated in
benzene (0.13 g, 77%). The analytical data for 22: 1H NMR
(CDCl3): d 1.91 (s, 3H, CH3), 1.98 (s, 3H, CH3), 2.34 (s, 3H,
CH3), 3.42 (s, 3H, N–CH3), 6.19 (s, 1H, Cp–H), 6.54 (t,
J = 8.0 Hz, 1H, C6H4), 7.03 (t, J = 7.2 Hz, 1H, C6H4),
7.25 (dd, J = 7.2, 1.2 Hz, 1H, C6H4), 7.32(t, J = 8.0 Hz,
1H, C6H4) ppm. 13C{1H} NMR (CDCl3): d 12.32, 14.17,
14.26, 34.79, 109.92, 114.06, 120.55, 127.77, 127.35,
127.51, 128.34, 128.99, 129.94, 136.69, 136.98, 139.74,
165.13 ppm. Anal. Calc. (C15H17Cl2NZr): C: 48.24; H,
4.59; N, 3.75. Found: C, 48.03; H, 4.70; N, 3.84%.
It was synthesized using the same conditions and proce-
dure as those for 18 with 16. It was purified by recrystalli-
zation in pentane at ꢁ30 °C. Overall yield from 16 was
72%. The 1H NMR datum for the intermediate bis(dimeth-
ylamido)titanium complex (C6D6): d 0.97 (s, 9H, CH3),
1.64 (br s, 3H, CH3), 1.93 (s, 3H, CH3), 2.03 (br s, 3H,
CH3), 3.13 (s, 12H, N–CH3), 3.81 (d, J = 14.4 Hz, 1H,
CH2), 3.96 (d, J = 14.4 Hz, 1H, CH2), 5.74 (s, 1H,
Cp–H), 6.64 (d, J = 8.0 Hz, 1H, C6H4), 6.83 (td, J = 7.2,
1.2 Hz, 1H, C6H4), 7.21 (d, J = 7.2 Hz, 1H, C6H4), 7.22
(td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm. The analytical data
1
for 20: H NMR (C6D6): d 1.08 (s, 9H, CH3), 1.75 (br s,
6H, CH3), 2.07 (s, 3H, CH3), 3.65 (s, 1H, N–CH2), 5.32
(s, 1H, N–CH2), 6.03 (s, 1H, Cp–H), 6.37 (d, J = 8.8 Hz,
1H, C6H4), 6.92 (t, J = 7.2 Hz, 1H, C6H4), 7.03 (dd,
J = 7.2, 1.6 Hz, 1H, C6H4), 7.11 (td, J = 8.0, 1.6 Hz, 1H,
C6H4) ppm. 13C{1H} NMR (C6D6): d 12.90, 15.00, 31.43,
36.67, 61.24, 110.65, 119.08, 123.16, 128.55, 130.15,
141.92, 166.64 ppm. Anal. Calc. (C19H25Cl2NTi): C,
59.09; H, 6.53; N, 3.63. Found: C, 58.97; H, 6.59; N, 3.75%.
3.17. Complex 23
3.15. Complex 21
It was synthesized using the same conditions and proce-
It was synthesized using the same conditions and proce-
dure as those for 22 with 15. It was purified by recrystalli-
zation in CHCl3. Overall yield from 15 was 64%. The H
1
dure as those for 18 with 17. It was purified by trituration
1
in pentane. Overall yield from 17 was 84%. The H NMR
NMR datum for the intermediate bis(dimethylamido)tita-
nium complex (C6D6): d 1.12 (t, J = 7.2 Hz, 3H, CH3),
1.81 (s, 3H, CH3), 1.88 (s, 3H, CH3), 1.92 (s, 3H, CH3),
2.78 (s, 6H, N–CH3), 3.00 (s, 6H, N–CH3), 3.61–3.75 (m,
2H, N–CH2), 5.71 (s, 1H, Cp–H), 6.49 (d, J = 8.0 Hz,
1H, C6H4), 6.87 (t, J = 7.2 Hz, 1H, C6H4), 7.22 (dd,
J = 7.2, 1.6 Hz, 1H, C6H4), 7.28 (td, J = 8.0, 1.6 Hz, 1H,
C6H4) ppm. The analytical data for 23: 1H NMR (CDCl3):
d 1.35 (t, J = 6.8 Hz, 3H, CH3), 1.91 (s, 3H, CH3), 1.97 (s,
3H, CH3), 2.34 (s, 3H, CH3), 3.95 (q, J = 6.4 Hz, 2H,
N–CH2), 6.21 (s, 1H, Cp–H), 6.54 (d, J = 8.0 Hz, 1H,
C6H4), 7.00 (td, J = 7.2, 1.2 Hz, 1H, C6H4), 7.25 (dd,
J = 7.2, 1.2 Hz, 1H, C6H4), 7.34 (td, J = 7.2, 1.2 Hz, 1H,
C6H4) ppm. 13C{1H} NMR (CDCl3): d 11.94, 12.21,
13.99, 14.34, 40.89, 110.63, 113.57, 119.86, 125.19,
127.51, 127.87, 128.03, 128.63, 136.43, 138.69,
163.62 ppm. Anal. Calc. (C16H19Cl2NZr): C, 49.60; H,
4.94; N, 3.62. Found: C, 49.57; H, 4.73; N, 3.75%.
datum for the intermediate bis(dimethylamido)titanium
complex (C6D6): d 0.85–1.02 (m, 2H, Cy), 1.12–1.21 (m,
4H, Cy), 1.61–1.73 (m, 5H, Cy), 1.70 (s, 3H, CH3), 1.91
(s, 3H, CH3), 1.93 (s, 3H, CH3), 3.13 (s, 6H, N–CH3),
3.16 (s, 6H, N–CH3), 3.76 (dd, J = 14.0, 7.6 Hz, 1H,
N–CH2), 3.95 (dd, J = 14.0, 7.6 Hz, 1H, N–CH2), 5.74 (s,
1H, Cp–H), 6.55 (d, J = 8.0 Hz, 1H, C6H4), 6.92 (t,
J = 8.0 Hz, 1H, C6H4), 7.24 (dd, J = 7.2, 1.6 Hz, 1H,
C6H4), 7.29 (td, J = 7.2, 1.2 Hz, 1H, C6H4) ppm. The ana-
1
lytical data for 21: H NMR (C6D6): d 1.02–1.07 (m, 2H,
Cy), 1.22–1.30 (m, 4H, Cy), 1.50–1.53 (m, 1H, Cy), 1.61
(br d, J = 6.0 Hz, 4H, Cy), 1.69 (s, 3H, CH3), 1.81 (s,
3H, CH3), 2.08 (s, 3H, CH3), 4.35 (dd, J = 15.6, 7.6 Hz,
1H, N–CH2), 4.46 (dd, J = 15.6, 7.6 Hz, 1H, N–CH2),
6.01 (s, 1H, Cp–H), 6.30 (d, J = 8.0 Hz, 1H, C6H4), 6.93
(t, J = 7.2 Hz, 1H, C6H4), 7.04 (dd, J = 7.2, 1.6 Hz, 1H,
C6H4), 7.12 (td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm.

S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
465
3.18. Complex 24
datum for the intermediate bis(dimethylamido)titanium
complex (C6D6): d 1.16–1.22 (m, 2H, Cy), 1.32–1.14 (m,
4H, Cy), 1.66–1.69 (m, 2H, Cy), 1.79–1.83 (m, 2H, Cy),
1.84 (s, 3H, CH3), 1.91 (s, 3H, CH3), 1.99 (s, 3H, CH3),
2.78 (s, 6H, N–CH3), 2.88 (s, 6H, N–CH3), 3.66 (br s,
1H, N–CH2), 5.68 (s, 1H, Cp–H), 6.77 (br d, J = 8.0 Hz,
1H, C6H4), 6.87 (t, J = 7.2 Hz, 1H, C6H4), 7.21 (dd,
J = 7.2, 1.6 Hz, 1H, C6H4), 7.28 (t, J = 8.0 Hz, 1H,
It was synthesized using the same conditions and proce-
dure as those for 22 with 16. It was purified by trituration
in pentane. Overall yield from 16 was 88%. The H NMR
1
datum for the intermediate bis(dimethylamido)titanium
complex (C6D6): d 0.98 (s, 9H, CH3), 1.74 (s, 3H, CH3),
1.95 (s, 3H, CH3), 2.02 (s, 3H, CH3), 2.69 (s, 6H,
N–CH3), 2.93 (s, 6H, N–CH3), 3.50 (d, J = 15.2 Hz, 1H,
N–CH2), 3.69 (d, J = 14.4 Hz, 1H, N–CH2), 5.73 (s, 1 H,
Cp–H), 6.70 (d, J = 8.0 Hz, 1H, C6H4), 6.81 (td, J = 7.2,
0.8 Hz, 1H, C6H4), 7.21 (dd, J = 7.2, 1.6 Hz, 1H, C6H4),
7.23 (td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm. The analytical
1
C6H4) ppm. The analytical data for 26: H NMR (C6D6):
d 1.14 (br s, 4H, Cy), 1.45 (br s, 2H, Cy), 1.66–1.69 (m,
2H, Cy), 1.72 (s, 3H, CH3), 1.85 (s, 3H, CH3), 2.22–2.04
(m, 2H, Cy), 2.07 (s, 3H, CH3), 5.90 (s, 1H, Cp–H), 6.51
(br s, 1H, C6H4), 6.92 (t, J = 7.2 Hz, 1H, C6H4), 7.06
(dd, J = 7.2, 1.2 Hz, 1H, C6H4), 7.18 (t, J = 8.0 Hz, 1H,
C6H4) ppm. 13C{1H} NMR (C6D6): d 11.54, 13.78, 13.85,
25.87, 26.47, 32.15, 57.33, 111.88, 114.56, 120.77, 129.11,
129.29, 136.23, 136.34, 137.99, 162.08 ppm. Anal. Calc.
(C15H17Cl2NZr): C, 54.40; H, 5.71; N, 3.17. Found: C,
54.67; H, 5.76; N, 3.22%.
1
data for 24: H NMR (CDCl3): d 1.01 (s, 9H, CH3), 1.80
(s, 3H, CH3), 1.87 (s, 3H, CH3), 2.26 (s, 3H, CH3), 3.78
(s, 2H, N–CH2), 6.21 (s, 1H, Cp–H), 6.50 (d, J = 8.0 Hz,
1H, C6H4), 6.87 (td, J = 7.2, 0.8 Hz, 1H, C6H4), 7.12 (dd,
J = 7.2, 1.2 Hz, 1H, C6H4), 7.18 (td, J = 7.2, 1.2 Hz, 1H,
C6H4) ppm. 13C{1H} NMR (CDCl3): d 11.65, 13.76,
13.78, 30.72, 36.02, 38.44, 38.44, 48.54, 56.43, 112.26,
113.67, 120.46, 126.40, 126.46, 128.23, 128.87, 136.51,
137.09, 163.83 ppm. Anal. Calc. (C19H25Cl2NZr): C,
53.13; H, 5.87; N, 3.26. Found: C, 53.24; H, 5.60; N, 3.45%.
3.21. Complex 27
It was synthesized using the same conditions and
procedure as those for 22 with 2-(Me3C5H2)–C6H4–
NH[CH(CH2CH3)2]. It was purified by trituration in
pentane. Overall yield from 2-(Me3C5H2)–C6H4–NH-
3.19. Complex 25
1
It was synthesized using the same conditions and proce-
[CH(CH2CH3)2] was 63%. The H NMR datum for the
dure as those for 22 with 17. It was purified by trituration
in pentane. Overall yield from 17 was 84%. The H NMR
intermediate bis(dimethylamido)titanium complex (C6D6):
d 0.82–1.02 (m, 6H, pentyl-CH3), 1.81 (s, 3H, CH3), 1.92
(s, 6H, CH3), 1.95 (br s, 3H, CH3), 2.78 (br s, 4H, pen-
tyl-CH3), 2.98 (s, 12H, N–CH3), 3.57 (br s, 1H, N–CH2),
5.75 (s, 1H, Cp–H), 6.68 (d, J = 8.0 Hz, 1H, C6H4), 6.82
(t, J = 7.6 Hz, 1H, C6H4), 7.17 (br s, 2H, C6H4) ppm.
1
datum for the intermediate bis(dimethylamido)titanium
complex (C6D6): d 0.77–0.96 (m, 2H, Cy), 1.06–1.22 (m,
3H, Cy), 1.61–1.74 (m, 6H, Cy), 1.78 (s, 3H, CH3), 1.94
(s, 3H, CH3), 1.95 (s, 3H, CH3), 2.75 (s, 6H, N–CH3),
2.99 (s, 6H, N–CH3), 3.51 (dd, J = 14.4, 8.0 Hz, 1H,
N–CH2), 3.62 (dd, J = 14.4, 5.6 Hz, 1H, N–CH2), 5.73 (s,
1H, Cp–H), 6.59 (d, J = 8.0 Hz, 1H, C6H4), 6.87 (t,
J = 7.2 Hz, 1H, C6H4), 7.24 (dd, J = 7.2, 1.6 Hz, 1H,
C6H4), 7.30 (td, J = 8.0, 1.6 Hz, 1H, C6H4) ppm. The ana-
1
The analytical data for 27: H NMR (C6D6): d 0.94 (t,
J = 7.6 Hz, 3H, pentyl-CH3), 0.96 (t, J = 7.6 Hz, 3H, pen-
tyl-CH3), 1.69 (s, 3H, CH3), 1.81 (s, 6H, CH3), 1.80–1.86
(m, 4H, pentyl-CH2), 2.03 (s, 3H, CH3), 4.25 (quin,
J = 7.2 Hz, 1H, N–CH), 5.86 (s, 1H, Cp–H), 6.50 (d, J =
8.0 Hz, 1H, C6H4), 6.88 (t, J = 7.2 Hz, 1H, C6H4), 7.06
(d, J = 7.2 Hz, 1H, C6H4), 7.08 (t, J = 8.0 Hz, 1H, C6H4)
ppm. 13C{1H} NMR (C6D6): d 11.39, 12.38, 12.41, 13.51,
13.60, 27.25, 27.30, 59.83, 113.08, 113.51, 120.95, 126.08,
128.84, 129.59, 136.21, 136.19, 137.93, 162.04 ppm. Anal.
Calc. (C19H25Cl2NZr): C, 53.13; H, 5.87; N, 3.26. Found:
C, 52.92; H, 5.93; N, 3.50%.
1
lytical data for 25: H NMR (C6D6): d 1.01–1.18 (m, 4H,
Cy), 1.51–1.68 (m, 6H, Cy), 1.72 (s, 3H, CH3), 1.83 (s,
3H, CH3), 1.99–2.04 (m, 1H, Cy), 2.04 (s, 3H, CH3), 3.78
(d, J = 6.8 Hz, 2H, N–CH2), 5.84 (s, 1H, Cp–H), 6.41 (d,
J = 8.0 Hz, 1H, C6H4), 6.91 (t, J = 7.2 Hz, 1H, C6H4),
7.07 (dd, J = 7.2, 1.2 Hz, 1H, C6H4), 7.18 (td, J = 8.0,
1.2 Hz, 1H, C6H4) ppm. 13C{1H} NMR (C6D6): d 11.61,
13.69, 13.78, 26.64, 26.80, 32.04, 32.10, 38.05, 53.17,
111.99, 113.57, 120.99, 126.15, 127.58, 128.53, 129.16,
129.24, 136.68, 136.72, 138.20, 164.16 ppm. Anal. Calc.
(C21H27Cl2NZr): C, 55.36; H, 5.97; N, 3.07. Found: C,
55.27; H, 5.89; N, 3.19%.
3.22. Polymerization
In a glove box, 30 mL of toluene solution of 1-octene
(1.0 g, 0.30 M) was added to a dried 60 mL glass reactor.
The reactor was assembled and brought out from the
glovebox. The reactor was then heated to 70 °C by a man-
tle. After an activated catalyst, which was prepared by
mixing the complex (0.50 lmol), [C(C6H5)3]+[B(C6F5)4]ꢁ
(2.0 lmol), and (iBu)3Al (0.20 mmol) for 5 min, was added
with a syringe, the ethylene gas (60 psig) was fed immedi-
ately. After polymerization was conducted for 3 min, the
3.20. Complex 26
It was synthesized using the same conditions and proce-
dure as those for 22 with 2-(Me3C5H2)–C6H4– NH(C6H11).
It was purified by trituration in pentane. Overall yield from
1
2-(Me3C5H2)–C6H4– NH(C6H11) was 89%. The H NMR

466
S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
Table 3
Crystallographic parameters of 18, 19, 24, and 26
18
19
24
26
Formula
Fw
C15H17Cl2NTi
330.08
C16H19Cl2NTi
344.11
C19H25Cl2NZr
429.54
C20H24Cl2NZr
440.56
Size (mm3)
0.5 ꢀ 0.4 ꢀ 0.3
7.3913(10)
25.769(3)
7.8466(9)
90
98.092(4)
90
1479.7(3)
Monoclinic
P21=a
1.482
4
0.924
14372
3359 [0.0591]
172
0.0423
0.0977
1.090
0.4 ꢀ 0.3 ꢀ 0.3
7.7969(6)
16.1013(10)
25.1753(16)
90
0.5 ꢀ 0.4 ꢀ 0.4
16.4245(8)
7.4451(5)
17.6997(9)
90
117.9866(12)
90
1911.26(18)
Monoclinic
P21=n
1.493
4
0.854
17206
4331 [0.0628]
214
0.0598
0.1418
1.113
0.4 ꢀ 0.3 ꢀ 0.3
˚
a (A)
9.9199(8)
˚
b (A)
10.8132(8)
10.8662(8)
105.185(2)
100.255(2)
113.116(2)
981.40(13)
Triclinic
˚
c (A)
a (°)
b (°)
c (°)
90
90
3
˚
V (A )
3160.5(4)
Orthorhombic
Pbca
1.446
8
0.869
26253
3597 [0.1163]
187
0.0700
Crystal system
Space group
Dcalc (g cmꢁ1
ꢀ
P1
)
1.491
2
0.834
4429
4429 [0.0474]
247
0.0552
0.1469
1.078
Z
l (mmꢁ1
)
No. of data collected
No. of unique data [R(int)]
No. of variables
R (%)
Rw (%)
Goodness-of-fit
a
0.1649
1.055
Data collected at 150(2) K with Mo Ka radiation (k(Ka) = 0.7107 A), R(F) = RkFoj ꢁ jFck/RjFoj with Fo > 2.0r(I), Rw = [R[w(Fo ꢁ Fc2)2]/R[w(Fo)2]2]1/2
2
˚
with Fo > 2.0r(I).
ethylene gas was vented. Acetone was added to the reactor
to give white precipitates which were collected by filtration,
and then they were dried under vacuum at 60 °C. The
1-octene contents were calculated by the analysis of the
1H NMR spectra of the copolymers. In the 1H NMR spec-
tra, the methyl (CH3) signal (0.93–1.02 ppm) is well iso-
lated from the methine (CH) and methylene (CH2)
signals (1.30–1.50 ppm), and the 1-octene content can be
calculated from the integration values of the two regions
by the equation of [1-octene] (mol%) = [(B/3)]/{(B/3) +
[A ꢁ (B/3) ꢀ 13]/4}, where A is the integration value of
1.6–1.2 ppm region and B is the integration value of
1.0–0.85 ppm region. The integration values were rather
sensitively changeable depending on the conditions of the
instrument shimming, signal phase, or integration phase.
However, cutting with seizers and weighing the two signals
after printing the spectrum on a paper in the 0.5–2.0 ppm
region gave consistently invariable values. The copolymer
Acknowledgement
This work was supported by the Korea Research Foun-
dation Grant funded by the Korean Government
(MOEHRD, Basic Research Promotion Fund) (KRF-
2007-314-C00190).
Appendix A. Supplementary material
CCDC 661641, 661642, 661643, 661644 contain the sup-
plementary crystallographic data for this paper. These data
can be obtained free of charge from The Cambridge Crys-
tallographic Data Centre via www.ccdc.cam.ac.uk/
data_request/cif. Supplementary data associated with this
article can be found, in the online version, at
doi:10.1016/j.jorganchem.2007.11.021.
References
1
(5 mg) was dissolved in C6D6, and the H NMR spectra
[1] (a) A.L. McKnight, R.M. Waymouth, Chem. Rev. 98 (1998) 2587;
(b) V.C. Gibson, S.K. Spitzmesser, Chem. Rev. 103 (2003) 283;
(c) A. Motta, I.L. Fragala, T.J. Marks, J. Am. Chem. Soc. 129 (2007)
7327.
were recorded at 80 °C.
3.23. X-ray crystallography
[2] Review: (a) R. Kempe, Chem. Eur. J. 13 (2007) 2764;
(b) H.G. Alt, Dalton Trans. (2005) 3271;
Crystals of 18, 19, 24, and 26 coated with grease (Apie-
zon N) were mounted onto a thin glass fiber with epoxy
glue and placed in a cold nitrogen stream at 150(2) K on
Rigaku single crystal X-ray diffractometer. The structures
were solved by direct methods (SHELXL-97) and refined
against all F2 data (SHELXL-97). All non-hydrogen atoms
were refined with anisotropic thermal parameters. The
hydrogen atoms were treated as idealized contributions.
The crystal data and refinement results are summarized
in Table 3.
(c) K. Nomura, J. Liu, S. Padmanabhan, B. Kitiyanan, J. Mol.
Catal. A: Chem. 267 (2007) 1;
(d) Z. Hou, Y. Luo, X. Li, J. Organomet. Chem. 691 (2006) 3114.
[3] Recent progress: (a) D.J. Arriola, E.M. Carnahan, P.D. Hustad,
R.L. Kuhlman, T.T. Wenzell, Science 312 (2006) 714;
(b) C. Alonso-Moreno, S.J. Lancaster, C. Zuccaccia, A. Macchioni,
M. Bochmann, J. Am. Chem. Soc. 129 (2007) 9282;
(c) S.B. Amin, T.J. Marks, J. Am. Chem. Soc. 129 (2007) 2938;
(d) T.A. Manz, K. Phomphrai, G. Medvedev, B.B. Krishnamurthy,
S. Sharma, J. Haq, K.A. Novstrup, K.T. Thomson, W.N. Delgass,
J.M. Caruthers, M.M. Abu-Omar, J. Am. Chem. Soc. 127 (2005) 3776;

S.H. Lee et al. / Journal of Organometallic Chemistry 693 (2008) 457–467
467
(e) J. Zhang, Y.-J. Lin, G.-X. Jin, Organometallics 26 (2007) 4042;
(f) P.M. Gurubasavaraj, H.W. Roesky, P.M.V. Sharma, R.B. Oswald,
V. Dolle, R. Herbst-Irmer, A. Pal, Organometallics 26 (2007) 3346.
[4] P.J. Shapiro, E. Bunel, W.P. Schaefer, J.E. Bercaw, Organometallics
9 (1990) 867.
[5] (a) D.J. Arriola, M. Bokota, R.E. Campbell Jr., J. Klosin, R.E.
LaPointe, O.D. Redwine, R.B. Shankar, F.J. Timmers, K.A.
Abboud, J. Am. Chem. Soc. 129 (2007) 7065;
(b) K. Kunz, G. Erker, S. Doring, R. Frohlich, G. Kehr, J. Am.
Chem. Soc. 123 (2001) 6181;
(c) K. Kunz, G. Erker, S. Doring, S. Bredeau, G. Kehr, R. Frohlich,
Organometallics 21 (2002) 1031.
[8] T.H. Kim, Y.C. Won, B.Y. Lee, D.M. Shin, Y.K. Chung, Eur. J.
Inorg. Chem. (2004) 1522.
[9] D. van Leusen, D.J. Beetstra, B. Hessen, J.H. Teuben, Organome-
tallics 19 (2000) 4084, and references therein.
(b) C. Ramos, P. Royo, M. Lanfranchi, M.A. Pellinghelli, A.
Tiripicchio, Organometallics 26 (2007) 445;
[10] (a) D.J. Cho, C.J. Wu, S. S, W.-S. Han, S.O. Kang, B.Y. Lee,
Organometallics 25 (2006) 2133;
(c) K. Nishii, H. Hagihara, T. Ikeda, M. Akita, T. Shiono, J.
Organomet. Chem. 691 (2006) 193;
(b) S.H. Lee, C.J. Wu, U.G. Joung, B.Y. Lee, J. Park, Dalton Trans.
(2007) 4608.
(d) L.J. Irwin, S.A. Miller, J. Am. Chem. Soc. 127 (2005) 9972;
(e) C. Grandini, I. Camurati, S. Guidotti, N. Mascellani, L. Resconi,
I.E. Nifant’ev, I.A. Kashulin, P.V. Ivchenko, P. Mercandelli, A.
Ironi, Organometallics 23 (2004) 344;
(f) C. De Rosa, F. Auriemma, O. Ruiz de Ballesteros, L. Resconi, A.
Fait, E. Ciaccia, I. Camurati, J. Am. Chem. Soc. 125 (2003) 10913;
(g) J. Klosin, W.J. Kruper Jr., P.N. Nickias, G.R. Roof, P. De
Waele, K.A. Abboud, Organometallics 20 (2001) 2663;
[11] D.J. Cho, C.J. Wu, T. Bok, E.J. Lee, C.H. Lee, W.-S. Han, S.O.
Kang, B.Y. Lee, Dalton Trans. (2006) 4056.
[12] U.G. Joung, C.J. Wu, S.H. Lee, C.H. Lee, E.J. Lee, W.-S. Han, S.O.
Kang, B.Y. Lee, Organometallics 25 (2006) 5122.
[13] C.J. Wu, S.H. Lee, H. Yun, B.Y. Lee, J. Organomet. Chem. 691
(2006) 5626.
[14] (a) A. Kessler, C.M. Coleman, P. Charoenying, D.F. O’Shea, J. Org.
Chem. 69 (2004) 7836;
(h) F.G. Sernetz, R. Mulhaupt, F. Amor, J. Polym. Sci., Part A:
¨
Polym. Chem. 35 (1997) 1571.
(b) A.F. Abdel-Magid, K.G. Carson, B.D. Harris, C.A. Maryanoff,
R. Shah, J. Org. Chem. 61 (1996) 3849.
[6] (a) G. Altenhoff, S. Bredeau, G. Erker, G. Kehr, O. Kataeva, R.
Frohlich, Organometallics 21 (2002) 4084;
[15] A. Krasovskiy, F. Kopp, P. Knochel, Angew. Chem., Int. Ed. 45
(2006) 497.
(b) J.A.M. Canich (Exxon), U.S. Patent 5026798 (1991);
(c) J.A.M. Canich (Exxon), U.S. Patent 5504169 (1996).
[7] (a) C. Wang, G. Erker, G. Kehr, K. Wedeking, R. Frohlich,
Organometallics 24 (2005) 4760;
[16] D.W. Carpenetti, L. Kloppenburg, J.T. Kupec, J.L. Petersen,
Organometallics 15 (1996) 1572.