Ring-opening metathesis polymerization using alkenyl sulfides as chain-transfer agents: Efficient route to unsymmetrical poly(norbornene)-based macroinitiators bearing a terminal hydroxy group

Article abstract of DOI:10.1021/ma034653m

Convenient routes to hydroxy-terminated poly(norbornene)s (PNBEs) have been developed. Hydroboration of PNBEs bearing a terminal vinyl group with 9-BBN followed by oxidation with H₂O₂/ NaOH forms of hydroxy-terminated PNBEs in high yields. The parent PNBEs are prepared by ring-opening metathesis polymerization (ROMP) of norbornene using vinylic sulfides as chain-transfer agents (CTAs). On the other hand, ROMP of norbornene using (Z)-1-phenylthio-1-propen-3-ol as a CTA causes one-step synthesis of ω-hydroxy-terminated PNBE, where the molecular weight of polymer depends linearly on the initial feed ratio of CTA to monomer. Similarly, ROMP reactions using (Z)-1-phenylthio-1-propen-3-ols having bromo, amino, and 4-(chloromethyl)benzamido substituents at the para position of the phenyl group as CTAs afford the corresponding α,ω-heterodifunctionalized (heterotelechelic) PNBEs. The resulting PNBEs serve as macroinitiators for anionic ring-opening polymerization (AROP) of εcaprolactone and atom-transfer radical polymerization (ATRP) of styrene, giving AB- and ABC-type block copolymers.

Full text of DOI:10.1021/ma034653m

7020
Macromolecules 2003, 36, 7020-7026
Ring-Opening Metathesis Polymerization Using Alkenyl Sulfides as
Chain-Transfer Agents: Efficient Routes to Unsymmetrical
Poly(norbornene)-Based Macroinitiators Bearing a Terminal Hydroxy
Group
Hir oyu k i Ka ta ya m a ,*,† Yosu k e F u k u se,† Yu k o Nobu to,† Ken su k e Ak a m a tsu ,‡ a n d
F u m iyu k i Oza w a *,†
Department of Applied Chemistry, Graduate School of Engineering, Osaka City University,
Sumiyoshi-ku, Osaka 558-8585, J apan, and Faculty of Science and Engineering, Konan University,
Okamoto, Higashinada-ku, Kobe 658-8501, J apan
Received May 18, 2003; Revised Manuscript Received J uly 16, 2003
ABSTRACT: Convenient routes to hydroxy-terminated poly(norbornene)s (PNBEs) have been developed.
Hydroboration of PNBEs bearing a terminal vinyl group with 9-BBN followed by oxidation with H2O2/
NaOH forms hydroxy-terminated PNBEs in high yields. The parent PNBEs are prepared by ring-opening
metathesis polymerization (ROMP) of norbornene using vinylic sulfides as chain-transfer agents (CTAs).
On the other hand, ROMP of norbornene using (Z)-1-phenylthio-1-propen-3-ol as a CTA causes one-step
synthesis of ω-hydroxy-terminated PNBE, where the molecular weight of polymer depends linearly on
the initial feed ratio of CTA to monomer. Similarly, ROMP reactions using (Z)-1-phenylthio-1-propen-
3-ols having bromo, amino, and 4-(chloromethyl)benzamido substituents at the para position of the phenyl
group as CTAs afford the corresponding R,ω-heterodifunctionalized (heterotelechelic) PNBEs. The resulting
PNBEs serve as macroinitiators for anionic ring-opening polymerization (AROP) of ꢀ-caprolactone and
atom-transfer radical polymerization (ATRP) of styrene, giving AB- and ABC-type block copolymers.
In tr od u ction
CH2dCH- groups at R- and ω-ends, respectively (Scheme
1). Thus, it became feasible to incorporate various
functionalities into the R-end of PNBE by the choice of
R group in vinyl chalcogenides.4b
On the other hand, we found in this study that the
other chain end of PNBE (ω-end) is selectively func-
tionalized for hydroxy group by hydroboration of ω-vinyl
group or by ROMP using (Z)-1-arylthio-1-propen-3-ols
as CTAs. These reactions are applicable to the synthesis
of heterotelechelic polymers bearing two different func-
tional groups at each chain-end, and the resulting
PNBEs serve as macroinitiators for constructing AB-
and ABC-type block copolymers.
Ring-opening metathesis polymerization (ROMP) has
attracted growing interest because of its capability of
producing the polymers that are unable to be prepared
by other polymerization methods.1 In this context,
considerable efforts have been made in recent years for
ROMP approach to end-functionalized polymers,2-4
which are useful intermediates for constructing block
copolymers and polymeric networks. One of the most
efficient ways of incorporating end-functionalities in
ROMP is the use of acyclic olefins bearing functional
groups as chain-transfer agents (CTAs), where two types
of polymers are formed according to the structures of
CTAs. When symmetrically substituted olefins are
employed as CTAs, the resulting polymers have the
same substituents at both chain ends. On the other
hand, the reactions using unsymmetrical CTAs afford
the polymers bearing different substituents at R- and
ω-ends, respectively. Most of the ROMP/CT reactions
reported so far fall into the former class.2,3 This is
probably because the use of symmetrical olefins circum-
vents the regiochemical issue associated with the CT
process, which still remains a principal subject in olefin
metathesis.
Resu lts a n d Discu ssion
Hyd r oxyla tion of Vin yl-Ter m in a ted P oly(n or -
bor n en e)s. Two kinds of PNBEs bearing a vinyl group
at the ω-end (PNBE-1 and -2 in eq 1) were prepared
We recently reported that ROMP/CT reactions in the
latter class are selectively operative using vinyl chal-
cogenides as CTAs.4 For example, polymerization of
norbornene (NBE) in the presence of CH2dCHER (E )
O, S, Se) and a catalytic amount of RuCl2(dCdCHBut)-
(PCy3)2 or RuCl2(dCHEPh)(PCy3)2 (E ) S, Se) affords
poly(norbornene) (PNBE) bearing -CH2dCHER and
for the starting materials by ruthenium-catalyzed ROMP
of norbornene using CH2dCHSPh and CH2dCHSC6H4-
CH2Cl-p as CTAs, respectively. Hydroboration of
PNBE-1 with a 3 mol quantity (based on the ω-vinyl
group) of 9-BBN in THF followed by oxidation using
* Corresponding
author.
E-mail:
katayama@
a-chem.eng.osaka-cu.ac.jp.
† Osaka City University.
‡ Konan University.
10.1021/ma034653m CCC: $25.00 © 2003 American Chemical Society
Published on Web 08/16/2003

Macromolecules, Vol. 36, No. 19, 2003
Ring-Opening Metathesis Polymerization 7021
Sch em e 1. ROMP Usin g Vin yl Ch a lcogen id es a s CTAs
Sch em e 2. ROMP Usin g (Z)-1-Ar ylth io-1-p r op en -3-ols
a s CTAs
F igu r e 1. 1H NMR spectra of (A) PNBE-5 (entry 2 in Table
1) and (B) PCL-b-PNBE-5 (entry 3 in Table 2).
step synthesis of hydroxy-terminated PNBEs with a
wide molecular weight range (Scheme 2).
Treatment of NBE with a 0.2 mol quantity of (Z)-rich
1-phenylthio-1-propen-3-ol ((Z)-5; E/Z ) 8/92) in CH2-
Cl2 in the presence of 1 mol % of RuCl2(dCHSPh)-
4a,6
H2O2/NaOH afforded an ω-hydroxy-terminated polymer
(PNBE-3) in 82% yield. The 1H NMR spectrum exhibited
(PCy3)2
gave a white solid of polymer (PNBE-5) in
93% yield. This reaction was completed in 2 h at room
temperature. The 1H NMR spectrum (Figure 1A) clearly
shows incorporation of a 1:1 ratio of HOCH2CHdCH-
and -CHdCHSPh groups into the PNBE chain. The
HOCH2CHdCH- group exclusively adopted (E)-config-
uration (E/Z > 99/1), whereas the -CHdCHSPh group
was a mixture of (E)- and (Z)-isomers (E/Z ) 57/43). The
molecular weight estimated from peak integration (Mn-
,NMR ) 3800) was in good agreement with the VPO data
(Mn,VPO ) 3900). These observations are consistent with
the PNBE structure bearing HOCH2CHdCH- and
-CHdCHSPh groups at R- and ω-ends, respectively.7
Table 1 lists the results of ROMP/CT of NBE and
exo,exo-5,6-bis(methoxycarbonyl)-7-oxa-2-norbornene
(ONBE) using five kinds of CTAs (5-9). Molecular
weight of PNBE-5 linearly increased as the initial ratio
of (Z)-5 to NBE decreased, and thus suggested high
efficiency of (Z)-5 as a CTA (entries 1-4, Figure 2).
Similarly, (Z)-rich 1-phenylthio-1-propen-3-ols having
bromo, amino, and 4-(chloromethyl)benzamido substit-
uents at the para position of phenyl group (6-8) served
as good CTAs to afford heterotelechelic PNBEs (PNBE-
6-8) with well-controlled molecular weights (entries
5-7). Hydroxy-terminated PONBE was also success-
fully synthesized (entry 8). On the other hand, (E)-5 and
characteristic signals of HOCHa2CHb group at δ 3.65
2
(dt, J ) 6.8, 5.5 Hz, Ha) and 1.61 (dt, J ) 6.8, 6.4 Hz,
Hb) along with the main signals of polymer backbone,
while the signals due to the original ω-vinyl group
disappeared completely. The molecular weight (Mn) and
the molecular weight distribution (Mw/Mn) of PNBE-3
were almost identical with those of PNBE-1 as con-
firmed by 1H NMR and GPC analysis.5 Hence the
selective hydroxylation of terminal vinyl group was
evidenced. PNBE-2 was hydroxylated under the same
reaction conditions to afford an 89% yield of PNBE (4)
bearing 4-(chloromethyl)phenyl and hydroxy groups at
R- and ω-ends, respectively.
R OMP Usin g (Z)-1-Ar ylt h io-1-p r op en -3-ols a s
CTAs. The hydroxylation method described above was
successful also with the vinyl-terminated PNBE-1 with
Mn ) 2800. On the other hand, hydroboration of
PNBE-1 with higher molecular weights (Mn ) 5800,
6500) was incomplete with 3 mol quantities of 9-BBN,
and the reaction using a large excess amount of 9-BBN
(>10 mol quantity) gave a complex mixture of products.
Therefore, we sought other synthetic means of hydoxy-
terminated PNBEs, and as a result, we found that the
use of (Z)-1-arylthio-1-propen-3-ols as CTAs enables one-

7022 Katayama et al.
Macromolecules, Vol. 36, No. 19, 2003
Ta ble 1. ROMP of Nor bor n en e (NBE) a n d exo,exo-5,6-Bis(m eth oxyca r bon yl)-7-oxa -2-n or bor n en e (ONBE) in th e P r esen ce
of Ch a in -Tr a n sfer Agen ts 5-9a
e
f
entry
Mb
CTA (E/Z)c
[M]0/[CTA]0
yield/%d
Mn,NMR
Mn,VPO
Mw/Mn
1
2
3
4
5
6
7
8
NBE
NBE
NBE
NBE
NBE
NBE
NBE
ONBE
NBE
NBE
(Z)-5 (8/92)
(Z)-5 (8/92)
(Z)-5 (8/92)
(Z)-5 (8/92)
(Z)-6 (28/72)
(Z)-7 (<1/99)
(Z)-8 (29/71)
(Z)-5 (8/92)
(E)-5 (>99/1)
(Z)-9 (8/92)
100/50
100/20
100/12
100/10
100/10
100/10
100/20
100/5
82
93
94
90
86
78
66
72
93
98
2500
3800
6000
7100
9500
5500
4300
6100
2800
3900
6000
7000
11 000
5100
2.18
2.37
3.06
2.70
2.92
2.50
2.49
1.59
1.89
2.08
4800
6300
9
10
100/10
100/10
(139000)f
(106900)f
a
All reactions were run at room temperature for 2 h: [M]0 ) 0.10 M, [RuCl2(dCHSPh)(PCy3)2]0 ) 1.0 mM. Solvent: CH2Cl2 (entries
1-5 and 8-10); THF (entries 6 and 7). Monomer. c Determined by 1H NMR. Isolated yield based on the total amount of monomer
b
d
employed and CTA converted. e Measured in CHCl3 at 40 °C. f Determined by GPC based on polystyrene standards.
Sch em e 3. Syn th esis of AB- (A) a n d ABC-typ e (B) Block Cop olym er s
PNBE-5 (Mn,NMR ) 3800, Mw/Mn ) 2.37) with AlEt3 (1
equiv) in toluene at room temperature for 2 h, followed
by with CL (25 equiv) for 24 h afforded PCL-b-PNBE-5
1
in 77% yield (entry 3). The H NMR spectrum is given
in Figure 1B. In addition to the signals arising from the
PNBE-5 part (a-i), the signals assignable to PCL (A-
F) are clearly observed. The ratio of CL to NBE unit in
the block copolymer was estimated to be 0.36. This value
corresponds to the molecular weight (Mn,NMR) of 6300
and is fairly consistent with the reaction stoichiometry
(Mn,theor ) 6700). The GPC analysis of the copolymer
isolated from the reaction system of entry 4 revealed a
clean shift of the monomodal peak profile of PNBE-5 to
a high-molecular-weight region (Figure 3). Further
evidence for the formation of block copolymer was
F igu r e 2. Plot of the Mn,NMR values of poly(norbornene)
obtained by TEM analysis. As seen from Figure 4A,
(PNBE-5) vs the ratio of norbornene to (Z)-1-phenylthio-1-
PCL-b-PNBE-5 exhibited a microphase-separated struc-
propen-3-ol ((Z)-5) (entries 1-4 in Table 1).
ture, characteristic of copolymers having polar and
nonpolar blocks. On the other hand, the development
of PCL spherulites (white region) in PNBE (gray region)
(Z)-9 having a methyl group at the allylic position
exhibited apparently no CTA activity, giving PNBEs
was clearly noted in the polymer blend of PCL and
with high molecular weights (entries 9 and 10).
PNBE (Figure 4B).
Syn th esis of Block Cop olym er s. The end-function-
The synthesis of an ABC triblock copolymer was
also successful (Scheme 3B). Thus, heating a mixture
of styrene, PNBE-8 (Mn,NMR ) 4300, Mw/Mn ) 2.49),
CuCl, and 1,1,4,7,10,10-hexamethyltriethylenetetra-
mine (HMTETA) in a 100:1:2:6 ratio in diphenyl ether
at 130 °C for 22 h led to atom-transfer radical polym-
erization (ATRP) of styrene at the R-end of PNBE-8 to
alized PNBEs thus prepared were tested as macroini-
tiators. At first, monofunctionalized PNBE-5 was sub-
jected to anionic ring-opening polymerization (AROP)
of ꢀ-caprolactone (CL) to give an AB-type diblock
copolymer (Scheme 3A). The results for the synthesis
of PCL-b-PNBE-5 with a variety of unit ratios are
summarized in Table 2. For example, treatment of

Macromolecules, Vol. 36, No. 19, 2003
Ring-Opening Metathesis Polymerization 7023
Ta ble 2. AROP of E-Ca p r ola cton e (CL) Usin g Hyd r oxy-Ter m in a ted P oly(n or bor n en e)s (P NBE-5) a s Ma cr oin itia tor sa
PNBE-5 Mn,NMR
(Mw/Mn)
PCL/PNBEe
(unit ratio)
c
d
entry
[CL]0/[PNBE-5]0
yield/%b
Mn,theor
Mn,NMR
Mw/Mn
1
2
3
4
5
7500 (3.18)
5200 (2.87)
3800 (2.37)
3800 (2.37)
2800 (2.27)
15
25
25
100
100
92
86
77
88
88
9200
8100
6700
15 200
16 500
9000
7700
6300
13 600
16 100
2.66
2.40
1.73
2.04
1.40
14/86
29/71
36/64
69/31
81/19
a
c
All reactions were run in toluene at room temperature. b Isolated yield based on total mass of PNBE-5 and CL. Mn,theor ) Mn,NMR(PNBE-
5) + MW(CL) × (molar ratio). Determined by GPC based on polystyrene standards. e Determined by 1H NMR.
d
approach to hydroxy-terminated polymers have been
studied to a considerable extent owing to the significant
utility of product polymers, all of them are related to
the reactions using symmetrically substituted acyclic
olefins X(CH2)nCHdCH(CH2)nX (X ) AcO, TBDMSO,
9-BBN, etc.) as CTAs.2 Accordingly, the resulting poly-
mers inevitably have hydroxy groups at both chain ends.
Furthermore, since the CTAs so far employed have
“masked” hydroxy groups such as OAc and 9-BBN in
most cases,8 deprotection or chemical transformation of
terminal groups into hydroxy groups has been needed
to obtain desirable hydroxy-terminated polymers. On
the other hand, in the present ROMP/CT reactions using
(Z)-1-arylthio-1-propen-3-ols as CTAs, it is unnecessary
to protect the hydroxy group prior to polymerization.
Moreover, since the resulting polymers have hydroxy
group only at one chain end, the other chain end may
be applied to other functionalities. Clearly, the present
ROMP/CT system is a hitherto unknown type, and its
applicability has been demonstrated in the synthesis of
AB and ABC block copolymers (Scheme 3).
F igu r e 3. GPC curves for PNBE-5 (entry 2 in Table 1) and
PCL-b-PNBE-5 (entry 4 in Table 2).
Exp er im en ta l Section
Gen er a l Exp er im en ta l P r oced u r es a n d Ma ter ia ls. All
manipulations were performed under a nitrogen atmosphere
using conventional Schlenk techniques. Nitrogen gas was
purified by passing successively through the columns of an
activated copper catalyst (BASF, R3-11) and P2O5 (Merck,
SICAPENT). NMR spectra were recorded on a Varian Mercury
300 (1H NMR, 300.11 MHz; 13C NMR, 75.46 MHz) spectrom-
eter. Chemical shifts are reported in δ (ppm), referenced to
the 1H (of residual protons) and 13C signals of deuterated
solvents. Mass spectra were measured with a Shimadzu QP-
5000 GC-mass spectrometer (EI, 70 eV). GLC analysis was
performed on a Shimadzu GC-14B instrument equipped with
an FID detector and a capillary column (CBP-1, 25 m × 0.25
mm). Flash column chromatography was performed using
Merck silica gel 60 (230-400 mesh). Gel permeation chroma-
tography (GPC) was carried out on a J ASCO GPC assembly
consisting of a model PU-980 pump, a model RI-1530 refractive
index detector, and three GPC gel columns (Shodex KF-801,
KF-803L, KF-805L). Polystyrene standards were used for
calibration, and THF was used as the mobile phase with a flow
rate of 1.0 mL/min. Vapor pressure osmometry (VPO) was
carried out on a Knauer K-7000 osmometer in chloroform at
40 °C using sucrose octaacetate for calibration. Transmission
electron microscopy (TEM) observations were performed with
Hitachi 7100TE, operating at 100 kV.
Dichloromethane and THF were dried over CaH2 and
sodium benzophenone ketyl, respectively. These solvents were
distilled and stored over activated molecular sieves (MS4A)
under a nitrogen atmosphere. Norbornene was distilled from
sodium prior to use. ꢀ-Caprolactone and styrene were distilled
from CaH2 prior to use. Thiocarbene complex RuCl2(dCHSPh)-
(PCy3)2 was prepared from [RuCl2(p-cymene)]2, PCy3, and Cl2-
CHSPh according to the literature.4a exo,exo-5,6-Bis(meth-
oxycarbonyl)-7-oxa-2-norbornene,9 phenyl vinyl sulfide,10 p-
bromophenyl disulfide,11 (Z)-1-phenylthio-1-propen-3-ol ((Z)-
5),12 (E)-1-phenylthio-1-propen-3-ol ((E)-5),13 and (Z)-1-phe-
nylthio-1-buten-3-ol ((Z)-9)14 were synthesized according to the
F igu r e 4. TEM profiles of (A) PCL-b-PNBE-5 (Mn,NMR ) 6300)
and (B) polymer blend of PCL (Mn,NMR ) 3900) and PNBE
(Mn,NMR ) 3800) in a 35:65 ratio. The sample films were cast
from toluene solutions and dyed with OsO4. The white and
gray regions represent PCL and PNBE, respectively.
give PNBE-8-b-PSt in 76% yield (Mn,NMR ) 12 700, Mw/
Mn ) 2.70). The resulting polymer reacted with a 100
M quantity of CL under AROP conditions similar to
those in the reaction in Scheme 3A, affording PCL-b-
PNBE-8-b-PSt in 81% yield (Mn,NMR ) 21 800, Mw/Mn
) 2.63). Similarly, heterotelechelic PNBE-4 served as
a bifunctional macroinitiator for constructing ABC-type
block copolymer. To our knowledge, this is the first
example of the synthesis of an ABC triblock copolymer
by the combination of olefin metathesis, radical, and
anionic polymerization processes.
Con clu sion
We have described a new efficient route to PNBEs
bearing a terminal hydroxy group. Although ROMP/CT

7024 Katayama et al.
Macromolecules, Vol. 36, No. 19, 2003
literature. All other chemicals were obtained from commercial
suppliers and used without further purification.
Mn ) 1.56; PNBE-2, Mn,NMR ) 1700, Mw/Mn ) 1.70). The 1H
NMR data of PNBE-1 were identical with those previously
P r ep a r a tion of p-Br om op h en yl Vin yl Su lfid e. Ethylene
gas was gently bubbled into a solution of p-bromophenyl
disulfide (11.61 g, 30.87 mmol) in CH2Cl2 (44 mL). A solution
of bromine (5.7 g, 36 mmol) in CH2Cl2 (10 mL) was slowly
added over 40 min at room temperature. Ethylene gas was
added continuously until the color of the bromine disappeared.
DBU (10 g, 66 mmol) was added at room temperature, and
the reaction mixture was refluxed for 48 h. The reaction
mixture was cooled to room temperature and then quenched
with 1.0 M aqueous ammonia (10 mL). The organic layer was
separated, washed with water, and dried over anhydrous
MgSO4. After the drying agent was filtered off, the solution
was concentrated to dryness to give an orange oil. The crude
product was purified by flash column chromatography with
hexane as eluent to give the title compound as a pale yellow
reported.4c
PNBE-2:
1H NMR (CDCl3): δ 7.32-7.25 (m, Hj,k), 6.10 (d, J ) 15.0
Hz, (E)-Hi), 6.09 (dd, J ) 9.0, 0.7 Hz, (Z)-Hi), 6.01 (dd, J )
15.0, 7.1 Hz, (E)-Hh), 5.85 (apparent t, J ) 9.0 Hz, (Z)-Hh),
5.80 (ddd, J ) 17.6, 10.0, 7.3 Hz, (E)-Hc), 5.39-5.28 (m, Hg of
trans-polymer), 5.24-5.16 (m, Hg of cis-polymer), 4.96 (ddd, J
) 17.6, 2.0, 1.3 Hz, Ha), 4.86 (ddd, J ) 10.0, 2.0, 1.1 Hz, Hb),
4.56 (s, Hl), 2.85-2.69 (m, Hd of cis-polymer), 2.56-2.36 (m,
Hd of trans-polymer), 2.05-1.70 (m, He,f), 1.45-1.26 (m, He),
1.12-0.97 (m, Hf).
1
oil (9.55 g, 72% yield). H NMR (CDCl3): δ 7.47-7.42 (m, 2H,
C6H4), 7.26-7.21 (m, 2H, C6H4), 6.54 (dd, J ) 16.7, 9.5 Hz,
1H, CHdCH2), 5.40 (d, J ) 9.5 Hz, 1H, CHdCH2), 5.37 (d, J
) 16.7 Hz, 1H, CHdCH2). 13C{1H} NMR (CDCl3): δ 133.5,
132.2, 131.8 (each s, C6H4), 131.0 (s, CHdCH2), 121.1 (s, C6H4),
116.5 (s, CHdCH2). MS, m/z (rel intensity, %): 216 (M++1,
39), 214 (M+-1, 38), 169 (11), 136 (11), 135 (100), 134 (39),
109 (20), 108 (30), 91 (58), 82 (10), 76 (10), 69 (20), 67 (33).
Anal. Calcd for C8H7BrS: C, 44.67; H, 3.28. Found: C, 44.52;
H, 3.19.
Hyd r oxyla tion of P NBE-1 a n d -2. A typical procedure is
as follows. To a solution of PNBE-1 (513 mg, 0.395 mmol) in
THF (3.3 mL) was added a 0.5 M solution of 9-BBN (2.3 mL,
1.1 mmol). The mixture was stirred at room temperature for
2 h. To the resulting solution were successively added 6 M
aqueous NaOH (1.0 mL, 6.0 mmol) and 30% aqueous H2O2
(0.92 mL, 8.1 mmol). The organic layer was separated, and
the aqueous layer was extracted with CH2Cl2 (20 mL × 4).
The combined organic layer was dried over anhydrous MgSO4,
filtered, and evaporated. The oily residue was redissolved in
CH2Cl2, and the solution was poured into a vigorously stirred
MeOH to give a white precipitate of PNBE-3 which was
collected by filtration, washed with methanol, and dried under
P r ep a r a tion of p-(Hyd r oxym eth yl)p h en yl Vin yl Su l-
fid e. A mixture of p-bromophenyl vinyl sulfide (4.93 g, 22.9
mmol), magnesium (0.55 g, 23 mmol), 1,2-dibromoethane (20
µL), and THF (15 mL) was stirred at 40 °C for 1 h. To the
resulting yellow solution was added paraformaldehyde (0.69
g, 23 mmol) at room temperature. The reaction mixture was
stirred at 50 °C for 3 h and then quenched with saturated
aqueous NH4Cl (15 mL). The organic layer was separated, and
the aqueous layer was extracted with ether (100 mL × 2). The
combined organic layer was washed with water and dried over
anhydrous MgSO4. After the drying agent was filtered off, the
solution was evaporated to give a yellow liquid. The crude
product was purified by flash column chromatography with
hexane:AcOEt (4:1) as eluent to give the title compound as a
colorless oil (1.34 g, 35% yield). 1H NMR (CDCl3): δ 7.40-
7.30 (m, 4H, C6H4), 6.52 (dd, J ) 16.7, 9.7 Hz, 1H, CHdCH2),
5.36 (d, J ) 9.7 Hz, 1H, CHdCH2), 5.34 (d, J ) 16.7 Hz, 1H,
CHdCH2), 4.67 (d, J ) 5.5 Hz, 2H, CH2OH), 1.92 (t, J ) 5.5
Hz, 1H, CH2OH). 13C{1H} NMR (CDCl3): 139.9, 133.4 (each
s, C6H4), 131.7 (s, CHdCH2), 130.7, 127.7 (each s, C6H4), 115.5
(s, CHdCH2), 64.7 (s, CH2OH). MS, m/z (rel intensity, %): 166
(M+, 64), 147 (12), 135 (100), 109 (13), 105 (15), 91 (26), 79
(35), 77 (46), 69 (11), 65 (14), 59 (41), 51 (30). Anal. Calcd for
C9H10OS: C, 65.02; H, 6.06. Found; C, 64.88; H, 5.96.
P r ep a r a tion of p-(Ch lor om eth yl)p h en yl Vin yl Su lfid e.
A colorless solution of p-(hydroxymethyl)phenyl vinyl sulfide
(0.94 g, 5.7 mmol) and PPh3 (1.92 g, 7.32 mmol) in CCl4 (5.6
mL) was stirred at 60 °C for 1 h. The resulting white
suspension was evaporated, and the residue was purified by
flash column chromatography with hexane as eluent to give
the title compound as a colorless oil (0.31 g, 29% yield). 1H
NMR (CDCl3): 7.39-7.33 (m, 4H, C6H4), 6.54 (dd, J ) 16.7,
9.5 Hz, 1H, CHdCH2), 5.41 (d, J ) 16.7 Hz, 1H, CHdCH2),
5.41 (d, J ) 9.5 Hz, 1H, CHdCH2), 4.57 (s, 2H, CH2Cl). 13C-
{1H} NMR (CDCl3): 136.2, 135.0 (each s, C6H4), 131.1 (s, CHd
CH2), 130.2, 129.3 (each s, C6H4), 116.6 (s, CHdCH2), 45.7 (s,
CH2Cl). MS, m/z (rel intensity, %): 186 (M++2, 14), 184 (M+,
37), 149 (100), 134 (20), 121 (13), 105 (33), 89 (11), 77 (14), 74
(15), 63 (13). Anal. Calcd for C9H9ClS: C, 58.53; H, 4.91.
Found: C, 58.38; H, 4.93.
1
vacuum (410 mg, 82% yield). The H NMR and GPC analysis
of PNBE-3 revealed its molecular weight and molecular weight
distribution to be 1300 and 1.58, respectively. PNBE-2 was
similarly hydroxylated to afford PNBE-4 (Mn,NMR ) 1800, Mw/
Mn ) 1.78) in 89% yield.
PNBE-3:
1H NMR (CDCl3): δ 7.35-7.27, 7.22-7.15 (each m, Ph), 6.11
(dd, J ) 15.0, 0.7 Hz, (E)-Hh), 6.11 (dd, J ) 9.2, 0.9 Hz, (Z)-
Hh), 5.98 (dd, J ) 15.0, 7.7 Hz, (E)-Hg), 5.79 (apparent triplet,
J ) 9.2 Hz, (Z)-Hg), 5.39-5.29 (m, Hf of trans-polymer), 5.22-
5.19 (m, Hf of cis-polymer), 3.65 (dt, J ) 6.8, 5.5 Hz, Ha), 2.86-
2.71 (m, Hc of cis-polymer), 2.52-2.32 (m, Hc of trans-polymer),
1.99-1.70 (m, Hd,e), 1.61 (dt, J ) 6.8, 6.4 Hz, Hb), 1.44-1.23
(m, Hd), 1.11-0.97 (m, He).
PNBE-4:
1H NMR (CDCl3): δ 7.32-7.25 (m, Hi,j), 6.10 (d, J ) 15.0
Hz, (E)-Hh), 6.09 (dd, J ) 9.0, 0.7 Hz, (Z)-Hh), 6.01 (dd, J )
15.0, 7.1 Hz, (E)-Hg), 5.85 (apparent t, J ) 9.0 Hz, (Z)-Hg),
5.39-5.28 (m, Hf of trans-polymer), 5.24-5.16 (m, Hf of cis-
polymer), 4.56 (s, Hk), 3.65 (dt, J ) 6.5, 4.0 Hz, Ha), 2.85-
2.69 (m, Hc of cis-polymer), 2.56-2.36 (m, Hc of trans-polymer),
2.05-1.70 (m, Hd,e), 1.61 (dt, J ) 6.8, 6.5 Hz, Hb), 1.45-1.26
(m, Hd), 1.12-0.97 (m, He).
ROMP of Nor bor n en e Usin g Vin ylic Su lfid es a s CTAs.
Syn th esis of P NBE-1 a n d -2. PNBE-1 was synthesized from
norbornene (720 mg, 7.64 mmol), phenyl vinyl sulfide (84 mg,
0.62 mmol), and RuCl2(dCHSPh)(PCy3)2 (128 mg, 150 µmol)
according to the reported procedure.4a Similarly, PNBE-2 was
synthesized using p-(chloromethyl)phenyl vinyl sulfide in place
of phenyl vinyl sulfide. These compounds were characterized
P r ep a r a tion of 1-(p-Br om op h en ylth io)-1-p r op en -3-ol
(6). The following procedure was based on the synthesis of (Z)-
1-phenylthio-1-propen-3-ol ((Z)-5) reported by Owen et al.12 To
a
mixture of propargyl alcohol (7.11 g, 127 mmol) and
powdered KOH (238 mg, 4.24 mmol) was slowly added p-
bromothiophenol (20.1 g, 106 mmol) at 125 °C. The resulting
1
by H NMR and GPC analysis (PNBE-1, Mn,NMR ) 1300, Mw/

Macromolecules, Vol. 36, No. 19, 2003
Ring-Opening Metathesis Polymerization 7025
dark brown solution was stirred at 125 °C for 3 h. The solution
was diluted with ethyl acetate, washed with aqueous NaOH
and water, and dried over magnesium sulfate. After the drying
agent was filtered off, the filtrate was evaporated. The residual
brown liquid was purified by distillation under reduced pres-
sure (115-120 °C at 0.14 mmHg) and then by flash column
chromatography over silica gel eluted with hexane/ether (2/
1). Evaporation of the eluate afforded 6 as a white solid (9.81
g, 38% yield). 1H NMR (CDCl3): δ 7.46-7.41, 7.25-7.18 (each
m, 4H, C6H4), 6.41 (dt, J ) 15.0, 1.5 Hz, 0.28H, (E)-CHdCHS),
6.30 (dt, J ) 9.5, 1.3 Hz, 0.72H, (Z)-CHdCHS), 6.00 (dt, J )
9.5, 6.2 Hz, 0.72H, (Z)-CHdCHS), 5.99 (dt, J ) 15.0, 5.7 Hz,
0.28H, (E)-CHdCHS), 4.36 (dd, J ) 6.2, 1.3 Hz, 1.44H, (Z)-
CH2), 4.22 (dd, J ) 5.7, 1.5 Hz, 0.56H, (E)-CH2), 1.60 (br, 1H,
OH). MS, m/z (rel intensity, %): 246 (M+, 20), 244 (20), 207
(25), 190 (79), 188 (74), 109 (91), 108 (42), 69 (26), 65 (20), 57
(56), 55 (23), 51 (20), 50 (37), 44 (100). Anal. Calcd for C9H9-
BrOS: C, 44.10; H, 3.70. Found: C, 44.23; H 3.61.
P r ep a r a tion of 1-(p-Am in op h en ylth io)-1-p r op en -3-ol
(7). This compound was synthesized by a procedure similar
to that described for 6 using propargyl alcohol (2.68 g, 47.8
mmol), KOH (107 mg, 1.91 mmol), and p-aminothiophenol
(5.00 g, 39.9 mmol), to give a yellow oil (770 mg, 16% yield).
1H NMR (THF-d8): δ 7.09-7.05, 6.55-6.50 (each m, 4H, C6H4),
6.05 (dt, J ) 9.7, 1.5 Hz, 1H, (Z)-CHdCHS), 5.63 (dt, J )
9.7, 5.9 Hz, 1H, (Z)-CHdCHS), 4.68 (br, 2H, NH2), 4.14 (ddd,
J ) 6.2, 5.9, 1.5 Hz, 2H, CH2), 3.76 (t, J ) 6.2 Hz, 1H, OH).
MS, m/z (rel intensity, %): 181 (M+, 77), 150 (7), 125 (65), 93
(100), 80 (38), 65 (22). Anal. Calcd for C9H11NOS: C, 59.64;
H, 6.12; N 7.73. Found: C, 60.01; H, 6.17; N, 7.31.
P r ep a r a tion of 4-Ch lor om eth yl-N-[4-(3-h yd r oxyp r o-
p en ylth io)p h en yl]ben za m id e (8). A solution of 4-chlorom-
ethylbenzoyl chloride (2.60 g, 14.0 mmol) in CH2Cl2 (16 mL)
was added dropwise at 0 °C to a solution of 7 (E/Z ) <1/99;
2.54 g, 14.0 mmol) and pyridine (4.1 g, 52 mmol) in CH2Cl2
(18 mL). The mixture was stirred at room temperature for 2
h. The resulting yellow suspension was diluted with ethyl
acetate, washed with water and brine, and dried over mag-
nesium sulfate. After the drying agent was filtered off, the
filtrate was evaporated to give a yellow solid, which was
purified by flash column chromatography over silica gel eluted
with hexane/THF (1/2). Evaporation of the eluate afforded 8
as a white solid (2.63 g, 57% yield). 1H NMR (THF-d8): δ 9.46
(br, 1H, NHCO), 7.93, 7.78, 7.52, 7.32 (each d, J ) 6.6 Hz, 8H,
C6H4), 6.41 (dt, J ) 14.8, 1.6 Hz, 0.29H, (E)-CHdCHS), 6.25
(dt, J ) 9.5, 1.5 Hz, 0.71H, (Z)-CHdCHS), 5.88 (dt, J ) 14.8,
5.0 Hz, 0.29H, (E)-CHdCHS), 5.87 (dt, J ) 9.5, 6.0 Hz, 0.71H,
(Z)-CHdCHS), 4.70 (s, 2H, CH2Cl), 4.21 (d, J ) 6.0 Hz, 1.42H,
(Z)-CH2OH), 4.06 (d, J ) 5.0 Hz, 0.58H, (E)-CH2OH), 3.92 (br,
1H, OH). Anal. Calcd for C17H16ClNO2S: C, 61.16; H, 4.83; N,
4.20. Found: C, 60.89; H, 4.87; N, 4.11.
A Typ ica l P r oced u r e for ROMP Usin g (Z)-1-Ar ylth io-
1-p r op en -3-ols a s CTAs (En tr y 2 in Ta ble 1). To a solution
of norbornene (123 mg, 1.30 mmol), (Z)-5 (E/Z ) 8/92; 44 mg,
0.26 mmol), and decane (19 mg; internal standard for GLC
analysis) in CH2Cl2 (13 mL) was added solid RuCl2(dCHSPh)-
(PCy3)2 (11 mg, 13 mmol) at room temperature. The mixture
was stirred for 2 h. The GLC analysis of the resulting solution
revealed a complete consumption of norbornene and 10%
conversion of (Z)-5. The solution was concentrated to ca. 2 mL
and then slowly added to a vigorously stirred MeOH (ca. 30
mL). A white solid of poly(norbornene) (PNBE-5) thus pre-
cipitated was collected by suction filtration, washed with
MeOH repeatedly, and dried under vacuum (119 mg, 93%
yield). All the reactions listed in Table 1 were similarly carried
out.
(dd, J ) 15.0, 7.5 Hz, (E)-Hh), 5.79 (apparent t, J ) 9.2 Hz,
(Z)-Hh), 5.68 (dd, J ) 15.4, 6.4 Hz, Hc), 5.60 (dt, J ) 15.4, 5.3
Hz, Hb), 5.40-5.29 (m, Hg of trans-polymer), 5.24-5.16 (m, Hg
of cis-polymer), 4.09 (apparent t, J ) 5.3 Hz, Ha), 2.85-2.69
(m, Hd of cis-polymer), 2.56-2.36 (m, Hd of trans-polymer),
1.94-1.70 (m, He,f), 1.45-1.26 (m, He), 1.12-0.97 (m, Hf).
PNBE-6:
1H NMR (CDCl3): δ 7.42-7.40, 7.20-7.17 (each m, Hj,k), 6.06
(d, J ) 15.8 Hz, (E)-Hi), 6.04 (d, J ) 8.6 Hz, (Z)-Hi), 5.99 (dd,
J ) 15.8, 7.2 Hz, (E)-Hh), 5.83 (apparent t, J ) 8.6 Hz, (Z)-
Hh), 5.68 (dd, J ) 15.6, 6.8 Hz, Hc), 5.60 (dt, J ) 15.6, 5.0 Hz,
Hb), 5.39-5.28 (m, Hg of trans-polymer), 5.24-5.16 (m, Hg of
cis-polymer), 4.09 (d, J ) 5.0 Hz, Ha), 2.85-2.70 (m, Hd of cis-
polymer), 2.54-2.34 (m, Hd of trans-polymer), 1.90-1.72 (m,
He,f), 1.45-1.26 (m, He), 1.11-0.97 (m, Hf).
PNBE-7:
1H NMR (THF-d8): δ 7.07-7.04, 6.54-6.51 (each m, Hj,k),
6.00 (d, J ) 15.2 Hz, (E)-Hi), 5.95 (d, J ) 9.3 Hz, (Z)-Hi), 5.61
(dd, J ) 15.2, 6.8 Hz, (E)-Hh), 5.57-5.46 (m, (Z)-Hh and Hb,c),
5.41-5.30 (m, Hg of trans-polymer), 5.22-5.15 (m, Hg of cis-
polymer), 4.65 (br, NH2), 3.91 (dd, J ) 5.3, 4.4 Hz, Ha), 3.82
(br, OH), 2.90-2.74 (m, Hd of cis-polymer), 2.54-2.34 (m, Hd
of trans-polymer), 1.88-1.68 (m, He,f), 1.46-1.28 (m, He), 1.12-
0.97 (m, Hf).
PNBE-8:
1H NMR (CDCl3): δ 7.87 (d, J ) 8.1 Hz, Hl), 7.59 (d, J )
8.4 Hz, Hk), 7.52 (d, J ) 8.1 Hz, Hm), 7.33 (d, J ) 8.4 Hz, Hj),
6.09 (d, J ) 14.8 Hz, (E)-Hi), 6.08 (d, J ) 9.0 Hz, (Z)-Hi), 5.93
(dd, J ) 14.8, 7.7 Hz, (E)-Hh), 5.77 (apparent t, J ) 9.0 Hz,
(Z)-Hh), 5.68 (dd, J ) 15.4, 6.8 Hz, Hc), 5.60 (dt, J ) 15.4, 5.1
Hz, Hb), 5.39-5.28 (m, Hg of trans-polymer), 5.24-5.16 (m, Hg
of cis-polymer), 4.64 (s, Hn), 4.09 (d, J ) 5.1 Hz, Ha), 2.85-
2.70 (m, Hd of cis-polymer), 2.56-2.34 (m, Hd of trans-polymer),
1.90-1.71 (m, He,f), 1.45-1.26 (m, He), 1.11-0.97 (m, Hf). The
amido proton signal was obscure due to broadening.
PONBE-5:
1H NMR (CDCl3): δ 7.37-7.22 (m, Ph), 6.57 (dd, J ) 14.7,
3.8 Hz, (E)-Hh), 6.46 (dd, J ) 9.5, 3.8 Hz, (Z)-Hh), 5.88 (br s,
Hf of trans-polymer), 5.76 (dd, J ) 14.7, 7.0 Hz, (E)-Hg), 5.66-
5.52 (m, Hf of cis-polymer), 5.06 (br s, Hd of cis-polymer), 4.69
(br s, Hd of trans-polymer), 4.15 (br s, Ha), 3.68 (s, CO2Me),
3.08 (s, He). The signals of Hb,c were obscure.
PNBE-5:
A Typ ica l P r oced u r e for An ion ic Rin g-Op en in g P o-
lym er iza tion of E-Ca p r ola cton e (CL) Usin g P NBE-5 a s a
Ma cr oin itia tor (En tr y 3 in Ta ble 2). To a solution of
PNBE-5 (100 mg, 26.3 mmol) in toluene (2.0 mL) was added
a 0.93 M solution of AlEt3 in toluene (30 mL, 28 mmol) at room
temperature. The mixture was stirred for 2 h, during which
evolution of ethane gas was observed. Then, a stock solution
1H NMR (CDCl3): δ 7.35-7.29, 7.22-7.15 (each m, Ph), 6.10
(d, J ) 15.0 Hz, (E)-Hi), 6.09 (dd, J ) 9.0, 0.7 Hz, (Z)-Hi), 5.98

7026 Katayama et al.
Macromolecules, Vol. 36, No. 19, 2003
of CL in toluene (1.9 M, 0.35 mL, 0.67 mmol) and decane (10
mg; internal standard for GLC analysis) were added, and the
mixture was stirred at room temperature for 24 h. GLC
analysis of the resulting solution revealed a complete con-
sumption of CL. The viscous mixture thus obtained was
quenched by adding aqueous HCl (0.1 M, 0.8 mL), and then
poured into cold MeOH (ca. 50 mL) with stirring. A white solid
of block copolymer PCL-b-PNBE-5 thus precipitated was
collected by suction filtration, washed with MeOH, and dried
under vacuum (136 mg, 77% yield). All the reactions listed in
Table 2 were similarly carried out.
Ack n ow led gm en t. This work was supported by a
Grand-in-Aid for Scientific Research from the Ministry
of Education, Culture, Sports, Science, and Technology,
J apan.
Refer en ces a n d Notes
(1) (a) Buchmeiser, M. R. Chem. Rev. 2000, 100, 1565-1604. (b)
Trnka, T. M.; Grubbs, R. H. Acc. Chem. Res. 2001, 34, 18-
29. (c) Schrock, R. R. Acc. Chem. Res. 1990, 23, 158-165. (d)
Olefin Metathesis and Metathesis Polymerization; Ivin, K. J .;
Mol, J . C., Eds.; Academic Press: San Diego, CA, 1997. (e)
Metathesis Polymerization of Olefins and Polymerization of
Alkynes; Imamoglu, Y., Ed.; Kluwer: Dordrecht, The Neth-
erlands, 1998.
PCL-b-PNBE-5:
(2) (a) Bielawski, C. W.; Scherman, O. A.; Grubbs, R. H. Polymer
2001, 42, 4939-4945. (b) Bielawski, C. W.; Benitez, D.;
Morita, T.; Grubbs, R. H. Macromolecules 2001, 34, 8610-
8618. (c) Gibson, V. C.; Okada, T. Macromolecules 2000, 33,
655-656. (d) Hillmyer, M. A.; Grubbs, R. H. Macromolecules
1995, 28, 8662-8667. (e) Chung, T. C.; Chasmawala, M.
Macromolecules 1992, 25, 5137-5144. (f) Cramail, H.; Fon-
tanille, M.; Soum, A. J . Mol. Catal. 1991, 65, 193-203. (g)
Cramail, H.; Fontanille, M.; Soum, A. Makromol. Chem.,
Macromol. Symp. 1991, 42/ 43, 282-292.
(3) Owen, R. M.; Gestwicki, J . E.; Young, T.; Kiessling, L. L. Org.
Lett. 2002, 4, 2293-2296. (b) Maughon, B. R.; Morita, T.;
Bielawski, C. W.; Grubbs, R. H. Macromolecules 2000, 33,
1929-1935. (c) Morita, T.; Maughon, B. R.; Bielawski, C. W.;
Grubbs, R. H. Macromolecules 2000, 33, 6621-6623. (d)
Bielawski, C. W.; Morita, T.; Grubbs, R. H. Macromolecules
2000, 33, 678-680. (e) Nomura, K.; Takahashi, S.; Imanishi,
Y. Polymer 2000, 41, 4345-4350. (f) Coca, S.; Paik, H.-J .;
Matyjaszewski, K. Macromolecules 1997, 30, 6513-6516. (g)
France, M. B.; Grubbs, R. H.; McGrath, D. V.; Paciello, R. A.
Macromolecules 1993, 26, 4742-4747.
(4) (a) Katayama, H.; Nagao, M.; Ozawa, F. Organometallics
2003, 22, 586-593. (b) Katayama, H.; Yonezawa, F. Nagao,
M.; Ozawa, F. Macromolecules 2002, 35, 1133-1136. (c)
Katayama, H.; Urushima, H.; Ozawa, F. J . Organomet. Chem.
2000, 606, 16-25.
(5) The Mn,NMR values and the [monomer]/[CTA] ratios incorpo-
rated into hydroxy-terminated PNBEs (3-7) were deter-
mined by peak integration of the 1H NMR spectra. The
signals of the hydroxy-bonded methylene protons (δ 3.65 or
3.91-4.15) and the vinylene group protons of the main chain
(ca. δ 5.3 for trans, 5.2 for cis) are well-separated from the
other signals, providing a principal basis of estimating the
values. It has been also confirmed that signal intensities of
the other signals are consistent with the compositions.
1H NMR (CDCl3): δ 7.32-7.28, 7.21-7.15 (each m, Ph), 6.11
(dd, J ) 15.0, 0.7 Hz, (E)-Hi), 6.10 (dd, J ) 8.7, 0.9 Hz, (Z)-
Hi), 5.97 (dd, J ) 15.0, 7.7 Hz, (E)-Hh), 5.78 (apparent t, J )
8.7 Hz, (Z)-Hn), 5.74 (dd, J ) 15.0, 7.7 Hz, Hc), 5.51 (dt, J )
15.0, 6.7 Hz, Hb), 5.39-5.28 (m, Hg of trans-polymer), 5.24-
5.16 (m, Hg of cis-polymer), 4.50 (d, J ) 6.7 Hz, Ha), 4.06 (t, J
) 6.6 Hz, HF), 3.65 (dt, J ) 6.2, 5.1 Hz, HA), 2.85-2.70 (m, Hd
of cis-polymer), 2.54-2.34 (m, Hd of trans-polymer), 2.31 (t, J
) 7.3 Hz, HE), 1.90-1.56 (m, HB,D,e,f), 1.45-1.26 (m, HC,e), 1.10-
0.97 (m, Hf).
Syn th esis of ABC-Typ e Tr iblock Cop olym er P CL-b-
P NBE-8-b-P St. (i) Atom -Tr a n sfer Ra d ica l P olym er iza -
tion of Styr en e (St) Usin g P NBE-8 a s a Ma cr oin itia tor .
A mixture of PNBE-8 (184 mg, 42.8 mmol), styrene (444 mg,
4.26 mmol), CuCl (8.4 mg, 85 mmol), 1,1,4,7,10,10-hexameth-
yltriethylenetetramine (59 mg, 0.26 mmol), and diphenyl ether
(0.85 mL) was degassed by three freeze-pump-thaw cycles,
and then heated at 130 °C for 22 h. The resulting viscous
mixture was slowly added to vigorously stirred MeOH (ca. 30
mL) to give a white precipitate of diblock copolymer PNBE-
8-b-PSt, which was collected by suction filtration, washed with
MeOH, and dried under vacuum (477 mg, 76% yield). GLC
analysis of the filtrate indicated ca. 20% recovery of styrene.
The molecular weight of PNBE-8-b-PSt estimated by 1H NMR
was in good agreement with the theoretical value (Mn,NMR
)
12 700, Mn,theor ) 12 600). The GPC measurement showed a
monomodal peak profile (Mn,GPC ) 20 700, Mw/Mn ) 2.70).
(ii) An ion ic Rin g-Op en in g P olym er iza tion of CL Usin g
P NBE-8-b-P St a s a Ma cr oin itia tor . According to the pro-
cedure for the synthesis of PCL-b-PNBE-5, PNBE-8-b-PSt (102
mg, 8.0 mmol) was reacted with AlEt3 (24 mmol) and CL (92
mg, 0.80 mmol) in toluene at room temperature. After the
reaction was stirred for 22 h, a complete conversion of CL was
confirmed by GLC analysis of the reaction solution. Quenching
with aqueous HCl followed by reprecipitation from MeOH
afforded a white solid of triblock copolymer PCL-b-PNBE-8-
b-PSt (157 mg, 81% yield). The molecular weight was esti-
mated by 1H NMR to be 21 800; the value was fairly consistent
with the theoretical value (Mn,theor ) 24 100). The GPC data
are as follows: Mn,GPC ) 30 700, PDI ) 2.63. The GPC analysis
of the copolymer revealed a clean shift of the monomodal peak
profile of PNBE-8-b-PSt to a high-molecular-weight region,
indicating a clean formation of the triblock copolymers.
PCL-b-PNBE-8-b-PSt:
(6) (a) Katayama, H.; Urushima, H.; Nishioka, T.; Wada, C.;
Nagao, M.; Ozawa, F. Angew. Chem., Int. Ed. 2000, 39, 4513-
4515. (b) Louie, J .; Grubbs, R. H. Organometallics 2002, 21,
2153-2164.
(7) The regioselective formation of R,ω-heterotelechelic PNBE-5
was consistent with the following stoichiometric observation.
Thus, the treatment of (Z)-5 with RuCl2(dCHPh)(PCy3)2 as
a model of propagating alkylidene complex at room temper-
ature caused the cross-metathesis, giving quantitative yields
of thiocarbene complex RuCl2(dCHSPh)(PCy3)2 and cinnamyl
alcohol in perfect regioselectivity. Therefore, it is convincing
that the highly selective ROMP/CT process similarly to
Scheme 1 is operative for the reaction system with (Z)-5 as
well.
(8) Grubbs and co-workers reported that unprotected cis-2-
butene-1,4-diol serves as a CTA for ROMP of cyclooctadiene
catalyzed by benzylideneruthenium bearing a diaminocar-
bene ligand.2a
(9) Mu¨hlebach, A.; Bernhard, P.; Bu¨hler, N.; Karlen, T.; Ludi,
A. J . Mol. Catal. 1994, 90, 143-156.
(10) Reno, D. S.; Pariza, R. J . Org. Synth. 1996, 74, 124-129.
(11) Fagerburg, D. R.; van Sickle, D. E. J . Appl. Polym. Sci. 1994,
51, 989-997.
(12) Behzadi, A.; Owen, L. N. J . Chem. Soc., Perkin Trans. 1 1974,
25-29.
(13) Ogawa, A.; Ikeda, T.; Kimura, K.; Hirao, T. J . Am. Chem.
Soc. 1999, 121, 5108-5114.
(14) Schmid, G. United States Patent 4,816,581.
1H NMR (CDCl3): δ 7.30-6.88, 6.75-6.30 (each m, HX-Z),
5.39-5.28 (m, Ha of trans-polymer), 5.24-5.16 (m, Ha of cis-
polymer), 4.06 (t, J ) 6.6 Hz, HA), 2.85-2.70 (m, Hb of cis-
polymer), 2.54-2.28 (m, Hb of trans-polymer), 2.31 (t, J ) 7.3
Hz, HE), 2.10-1.61 (m, HB,D,d,c,V), 1.60-1.25 (m, HC,c,W), 1.10-
0.97 (m, Hd). The signals due to terminal and linking groups
were obscure.
MA034653M