The catalytic isomerization of terminal carbon-carbon double bonds in liquid crystalline polyesters at hydrosilation with 1-(1′-arylethoxy)-1,1, 3,3-tetramethyl disiloxanes

Article abstract of DOI:10.1080/10426500600605814

In the present article, we report on the synthesis and investigation of the hydrosilylation of liquid crystalline compounds with terminal carbon-carbon double bonds in aliphatic tails mediated by complexes of rhodium (I) and platinum (II). New liquid crystalline compounds based on terephthaloyl-bis-4- oxybenzoate with terminal carbon-carbon double bonds in aliphatic tails were synthesized. The introduction in aliphatic tails of polar and light polarizible fragments lead to a decrease of mesomorphogenic ability-resulting compounds. The hydrosilylation of liquid crystalline compounds with terminal carbon-carbon double bonds in aliphatic tails with 1-(1′-arylethoxy)-1,1,3,3-tetramethyl disiloxanes mediated by complexes of rhodium (I) and platinum (II) was investigated. The main process in these conditions was the isomerization of olefin fragments. Copyright Taylor & Francis Group, LLC.

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The Catalytic Isomerization
of Terminal Carbon–Carbon
Double Bonds in Liquid
Crystalline Polyesters
at Hydrosilation with 1-
(1′-Arylethoxy)-1,1,3,3-
Tetramethyl Disiloxanes
Vjacheslav V. Zuev a & Dimitry A. de Vekki b
a Institute of Macromolecular Compounds of the
Russian Academy of Sciences, Sankt Petersburg,
Russian Federation
b Department of Organic Chemistry, Sankt
Petersburg State Institute of Technology (Technical
University), Sankt Petersburg, Russian Federation
Version of record first published: 21 Sep 2006.
To cite this article: Vjacheslav V. Zuev & Dimitry A. de Vekki (2006): The Catalytic
Isomerization of Terminal Carbon–Carbon Double Bonds in Liquid Crystalline Polyesters
at Hydrosilation with 1-(1′-Arylethoxy)-1,1,3,3-Tetramethyl Disiloxanes, Phosphorus,
Sulfur, and Silicon and the Related Elements, 181:9, 2063-2078
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Phosphorus, Sulfur, and Silicon, 181:2063–2078, 2006
Copyright © Taylor & Francis Group, LLC
ISSN: 1042-6507 print / 1563-5325 online
DOI: 10.1080/10426500600605814
The Catalytic Isomerization of Terminal Carbon–Carbon
Double Bonds in Liquid Crystalline Polyesters at
Hydrosilation with 1-(1’-Arylethoxy)-1,1,3,3-Tetramethyl
Disiloxanes
Vjacheslav V. Zuev
Institute of Macromolecular Compounds of the Russian Academy
of Sciences, Sankt Petersburg, Russian Federation
Dimitry A. de Vekki
Department of Organic Chemistry, Sankt Petersburg State Institute
of Technology (Technical University), Sankt Petersburg,
Russian Federation
In the present article, we report on the synthesis and investigation of the hydrosily-
lation of liquid crystalline compounds with terminal carbon–carbon double bonds
in aliphatic tails mediated by complexes of rhodium (I) and platinum (II). New liq-
uid crystalline compounds based on terephthaloyl-bis-4-oxybenzoate with terminal
carbon-carbon double bonds in aliphatic tails were synthesized. The introduction
in aliphatic tails of polar and light polarizible fragments lead to a decrease of
mesomorphogenic ability-resulting compounds. The hydrosilylation of liquid crys-
talline compounds with terminal carbon-carbon double bonds in aliphatic tails with
1-(1ꢀ-arylethoxy)-1,1,3,3-tetramethyl disiloxanes mediated by complexes of rhodium
(I) and platinum (II) was investigated. The main process in these conditions was
the isomerization of olefin fragments.
Keywords Dialkenyl terephthaloyl-bis-4-oxybenzoates; hydrosilylation; isomerization
of olefins
INTRODUCTION
The amount of data for synthesized liquid crystalline (LC) compounds
containing iloxane fragments are limited, despite the fact that the
total number of LC compounds exceeds several tens of thousands.1
However, these LC compounds have excellent properties, including
Received November 14, 2005; accepted December 9, 2005.
This work was made with the support of RFBR (grant 06-08-00195-a).
Address correspondence to Vjacheslav V. Zuev, Institute of Macromolecular Com-
pounds of the Russian Academy of Sciences, Bolshoi pr.31, Sankt Petersburg 199004,
Russian Federation. E-mail: zuev@hq.macro.ru
2063

2064
V. V. Zuev and D. A. de Vekki
pyro- and piezoelectricity in a ferroelectric LC phase with very high val-
ues of pyroelectric and piezoelectric coefficients, and one of the highest
values of spontaneous polarization and low switching time.2−4 Dimethyl
siloxane groups are bulky and more flexible and exhibit more irregu-
lar conformations compared to their alkyl chain counterparts. This has
the effect of reducing the shape anisotropy of the molecules and hence
its degree of crystallinity. A reduction of crystallinity to below ambient
temperatures is of great interest from an application point of view.
This approach of decreasing crystallinity has already been performed
in side chain liquid crystalline polymers.5 For the synthesis of these
polymers, the catalytic hydrosilylation with polymethylhydrosiloxanes
of mesogenic compounds are used with a terminal double carbon-carbon
bond in the aliphatic tail. The number of used catalysts are limited of a
Speier catalyst (1% of H2PtCl6 in isopropyl alcohol) and siloxane- plat-
inum (0) complexes (a Karstedt catalyst). The reaction time is typically
many days at reaction temperatures 70–90◦C and of a multiple excess of
a reagent. But even in these conditions, the quantitative conversion of
reagents is hardhitting, which leads to defects in the polymer chain and
residue Si-H bonds. The presence of Si-H bonds leads to an instability of
the polymer properties in the time and formation of three-dimensional
networks.5
For these reasons, the introduction in LC compounds, the dimethyl
siloxane fragments, and a search of new effective catalysts for the hy-
drosilylation of LC compounds and polymers are a topic of current
importance. In the present article, we report on the synthesis and
investigation of the hydrosilylation of LC compounds with terminal
carbon-carbon double bonds in aliphatic tails mediated by complexes of
rhodium (I) and platinum (II).
RESULTS AND DISCUSSION
We have chosen as reagents for hydrosilylation a cheap and
available 1,1,3,3-tetramethyl disiloxane and 1-(1ꢀ-arylethoxy)-1,1,3,3-
tetramethyl disiloxanes 1a–d (Scheme 1), which have been synthesized
by the hydrosilylation of para-substituted acetophenones using several
coupling catalysts.6 The use of chiral compound 1b allows synthesizing
ferroelectric LC compounds.
The aliphatic esters of terephthaloyl-bis-4-oxy benzoate with ter-
minal carbon-carbon double bonds 2a–b (Scheme 2) have been cho-
sen as substrates for hydrosilylation. These compounds have a meso-
genic fragment potential, which allow it to form a liquid crystalline
state.1 In addition, they may be synthesized as an attractive method by

Terminal Carbon–Carbon Double Bonds
2065
SCHEME 1
acceptorless high temperature condensation from the readily available
terephthaloyl-bis-oxybenzoyl chloride and corresponding alcohol.7,8
SCHEME 2
The LC properties of compounds 2a–b differ greatly from their sat-
urated analogues thereof presence of double carbon bonds in aliphatic
tail. For instance, di-n-propyl terephthaloyl-bis-oxybenzoate have a sta-
ble smectic A phase in temperature interval 194–231◦C.8 Moreover,
lower fusible compound 2a(Tm = 139◦C) is not LC. This behavior might
be attributed to a presence of double carbon bonds in allyl fragment,
which is light polarizible and might interact with phenyl rings of the
mesogenic fragment that prevent the formation of a layer structure.
This effect supports the active role of an aliphatic tail in the formation
of an LC state. The presence long paraffin fragment in the aliphatic
tail of 2b leads to a formation of it a LC state of smectic A type (Tm
=
132◦C, Ti = 140◦C) (Figure 1). This supports the microscopic observa-
tion. Compound 2b forms in an LC state homeotropic or the focal-conic
fan textures (Figure 2). The focal-conic fan texture separates from the
isotropic liquid in the form of batonnets, which themselves consist of
growing focal-conic domains.9 However, the temperature stability of
the mesophase is also lower than on saturated analogous (for decyl
derivative 147–165◦C8).
Ferroelectric LC materials exhibiting r.t. chiral smectic C or chiral
smectic A phases and low melting temperatures are of great interest
in the electro-optic field. They are the basis of a variety of potential de-
vices ranging from large-area flat-panel displays, ultrafast electro-optic
modulators, and spatial optical modulators. They are also considered
for novel nonlinear optical applications. Chiral smectic C materials are

2066
V. V. Zuev and D. A. de Vekki
FIGURE 1 The DSC curves of compounds 2b (1) and 4 (2) at heating rate
2◦C/min.
appropriate for an application where bistability is required, whereas
chiral smectic A materials are suited for gray-scale application. For
these purposes, the hydrosilation of compound 2 with chiral silyl ether
1b mediated by a Karstedt catalyst was carried out. The interaction of
2a with 1b takes place according to the Farmer rule and gives with 90%
yield compound 3 (Scheme 3).
SCHEME 3
Compound 3 has Tm = 185◦C and is not LC. Its specific optical rota-
tion ([α]2D0 = +27.0◦ in chloroform) much increases as compared to that
of starting silyl ether 1b ([α]1D8 = +1.05◦ in ethanol6). The same effects

Terminal Carbon–Carbon Double Bonds
2067
FIGURE 2 The focal-conic fan texture of the smectic A phase of di-10-undecyl
terephthaloyl-bis-4-oxybenzoate 2b at 134◦C.

2068
V. V. Zuev and D. A. de Vekki
are frequently observed at the synthesis of polymers and LC compounds
with elongated hard fragments and are connected with an influence of
supramolecular structures.10
In contrast to compound 2a, an interaction of 2b with 1b (molar ra-
tio 1:2.5) mediated by a Karstedt catalyst did not lead to a hydrosi-
lylation product. As result of this reaction, the 100% conversion of
2b yields a mixture of reduction product—diundecyl terephthaloyl-
bis-4-oxybenzoate (yield 11.2%)—and a mixture of trans isomers of
diundecene terephthaloyl-bis-4-oxybenzoate 4 (Scheme 4) (total yield
ꢀ
88.2%). According NMR data, the ratio of (CH2)(k+k ) groups is 33.2:
36.7:30.1 for k,kꢀ = 0, 1, and 2, correspondingly.
SCHEME 4
The blank experiment of heating 2b with a Karstedt catalyst in
methylene chloride solution did not give any change of 2b. Therefore,
the silyl ether 1b plays the main role in the transformation of 2b. The
use of the Wilkinson catalyst [Rh(Ph3P)3Cl] instead of the Karstedt cat-
alyst leads to the disappearance of a reduction process at 100% conver-
sion of 2b, but the main products of the reaction remains a mixture of 4.
ꢀ
According NMR data, the ratio of (CH2)(k+k ) groups is 36.5:38.4:25.1 for
k,kꢀ = 0, 1, and 2, correspondingly. The LC properties of a nonseparated
mixture of isomers of 4 practically did not change as compared to 2b. It
has a smectic A phase in the temperature range 126–132◦C (Figure 1).
The decrease of the melting point is connected with the fact that 4 is
of a nonseparated mixture of isomers. The same type of mesophase of
compounds 2b and 4 support the practically equal values of enthalpies
of the LC-isotopic melt transition (7.6 J/g, and 7.5 J/g, respectively) and
the same focal-conic fan texture of mesophase melts.
We were surprised to find the impossibility of the hydrosilylation of
compound 2 with different silyl ethers 1a–d (the variation of ethers
with different X = H, F, and Cl gave the same result). The hydrosilyla-
tion of α-alkenes with siloxanes is a well-known process.11−14 The iso-
merization accompanies this reaction only as a minor process.11,14,15 In
contrast, the reaction of 2b with the 6 equivalent of 1,1,3,3-tetramethyl
disiloxane mediated by a Karstedt catalyst produces only the hydrosi-
lylation product 5 (Scheme 5) in a quantitative yield.

Terminal Carbon–Carbon Double Bonds
2069
SCHEME 5
Compound 5 has a smectic A phase in the temperature range 130–
139◦C, i.g. practically the same as compounds 2b and 4.
To verify the accuracy of the attribution of signals in NMR spectra
of compounds 2 and 4, they were brominated. It affords compounds 6
and 7 (Scheme 6).
SCHEME 6
Compounds 6 and 7 are not LC (Tm is 98◦C and 102–104◦C corre-
spondingly).
Hence, the introduction of polar or light polarizible groups in an
aliphatic tail of a molecule leads to the disappearance their LC prop-
erties or to a decrease of the temperature range of a mesophase exis-
tence. It is connected with the changing of an anisotropic orientation-
dependent interaction of a dispersion kind and disturbance of layer
order that is a major factor of the formation of the LC order.16
The double-bond isomerization of olefinic hydrocarbons has been me-
diated by acids, bases, and metal complexes of Pd, Pt, Rh, or Ru.17,18
There are two possible mechanisms of isomerization for metal com-
plexes. First needs in hydrogen from the outside and be called mech-
anism of addition-elimination of metal hydride. Second, it has been
suggested that the isomerization take place via π-complexes. It does
not need the hydrogen from the outside and carries out via a hydrogen
1,3-shift. In our case the isomerization did not take place in the pres-
ence of a Karstedt catalyst without silyl ether, which makes preferable
the first mechanism of isomerization. For a detailed investigation of
this process, we synthesized benzoyl esters 8a–b (Scheme 7) because
it allowed us to investigate the hydrosilylation products also by gas
chromatography.

2070
V. V. Zuev and D. A. de Vekki
SCHEME 7
As a catalyst, we chose traditionally for the hydrosilylation com-
plexes of Pt and Rh.13 The selection of catalytic complexes was based
on their solubility in the reaction mixture because hydrosilylation
takes place in homogeneous conditions. We used the Wilkinson cat-
alyst [Rh(Ph3P)3Cl] as well as 1-methylcycloocta-1,5-diene (MCOD)
complexes [Rh(MeCOD)Cl]2. Also the platinum (II) complexes cis-
[Pt(Et2SO)2Cl2] and [Pt(MeCOD)Cl2] were selected.
In a reaction of allyl benzoate 8a with silyl ether 1a medi-
ated by these catalysts hydrosilylation product 9a (Scheme 8) 1-
[3-(phenyloxycarbonyl)propyl]-3-(1ꢀ-phenylethoxy)-1,1,3,3-tetramethyl-
disiloxane- was obtained in a quantitative yield.
SCHEME 8
In contrast to allyl derivatives in a reaction of 1a mediated by the
Wilkinson catalyst in the case of 10-undecyl benzoate, the yield of 9b
(Scheme 8) is 32%, and for [Rh(MeCOD)Cl]2, it is 30%. The main prod-
ucts of these reactions are trans-undecyl benzoates 10 (Scheme 9) with
k from 0 to 2 (the same as the case of compound 2b). For example, the
SCHEME 9

Terminal Carbon–Carbon Double Bonds
2071
ration of (CH2)k group in a reaction mediated by the Wilkinson catalyst
is 36.0:28.8:35.2 for k = 0, 1, and 2 correspondingly.
The use of platinum (II) complexes as catalysts leads to higher
yields of a hydrosilylation product. In the reaction mediated by
[Pt(MeCOD)Cl2], the yield of 9b is 55% (a yield of a mixture of 10 is 45%)
at a 100% conversion of 8b. The best result gives cis-[Pt(Et2SO)2Cl2]
with the yield of 9b 70% at a full conversion of the starting substrate.
If the hydrosilylation is carried out at r.t. (20◦C, 48 h), the conver-
sion of substrate decreases, and part of the isomerization increases.
In the case of [Rh(MeCOD)Cl]2, the conversion of 8b is less than 5%,
and the products are the mixture of 10. The use of platinum complex
cis-[Pt(Et2SO)2Cl2] increases the conversion of 8b up to 15% with a
yield of hydrosilylation product of 8% and an isomerization product of
7%.
The use of reagent 1,1,3,3-tetramethyl disiloxane instead of silyl
ethers 1 leads to a quantitative yield of hydrosilylation product 9b if a
reaction occurs at 70◦C for 24 h.
Hence, the hydrosilylation of alkenyl esters with 1,1,3,3-tetramethyl
disiloxane is suitable for the preparative synthesis of LC compounds,
but the use of silyl ethers 1 leads to a complex mixture of many products
and will not use a preparative route.
The hydrosilylation of olefins is often accompanied by the isomeriza-
tion of the double bond. The reaction occurs in the presence of a variety
of rhodium compounds.19 The fact that the isomerization of the dou-
ble bond accompanies the hydrosilylation was very important for the
postulation of the hydrosilylation mechanism by Chalk and Harrod.20
To make a comparison of isomerization of α-olefins and compounds 2b,
we investigate the behaviour of heptene-1 (70◦C, 24 h) in the presence of
catalysts [Rh(Ph3P)3Cl] and cis-[Pt(Et2SO)2Cl2]. According NMR data,
the part of isomerization for platinum complexes is less than 1%. In
the case the use of the Wilkinson catalyst, the part of isomerization
increases up to 81% (the ratio of heptene-2 (CH3, 0.94 ppm):heptene-3
(CH3, 0.89 ppm) is 52.1:47.9). The interaction at the same condition of
heptene-1 with 1-(1ꢀ-phenylethoxy)-1,1,3,3-tetramethyl disiloxane 1a
(the molar ratio heptene-1:1a is 1:1.2) mediated by cis-[Pt(Et2SO)2Cl2]
leads to a 100% conversion of the substrate and gives 17.3% of iso-
merization products (heptene-2 and heptene-3 are in about equal pro-
portion) and 82.3% of a hydrosilylation product (1-(1ꢀ-phenylethoxy)-3-
heptyl-1,1,3,3-tetramethyl disiloxane). In the case of the Wilkinson cat-
alyst, the yield of isomerization products is 71.4% (the ratio of heptene-
2:heptene-3 is 49.9:50.1), and part of the hydrosilylation product is
28.6%, i.e., it reproduces a result of the reaction of silyl ethers 1 with
benzoate 8b. If the silyl ether 1a is changed on 1,1,3,3-tetramethyl

2072
V. V. Zuev and D. A. de Vekki
disiloxane, yields of the hydrosilylation product are 77% and 23% of a
mixture of isomers of heptene.
Hence, the hydrosilylation of ester 2b takes place similar to the
hydrosilylation of α-olefins, but the yield of isomerization products is
higher.
The reason for
a
low reactivity of 1-(1ꢀ-arylethoxy)-1,1,3,3-
tetramethyl disiloxanes 1a–d in the hydrosilylation of α-olefines and
correspondingly in the activity in isomerization is because of a more
strong Si-H bond of this in comparison with 1,1,3,3-tetramethyl dis-
iloxane. According to a calculation with a STO-3G ,basis the partial
charge on silicon of Si-H bond is +0.990 for 1a and only +0.622 for
1,1,3,3-tetramethyl disiloxane. This fact hinders the coordination of
silyl ethers 1a–d on a platinum atom. It leads to a preferable coordi-
nation of α-olefin with following isomerization of a double carbon bond.
The activity of internal double carbon-carbon bonds in hydrosilylation
is low,11,12 and as result the isomerization dominated.
CONCLUSIONS
In the present article, we report on the synthesis and investigation
of the hydrosilylation of LC compounds with terminal carbon-carbon
double bonds in aliphatic tails mediated by complexes of rhodium (I)
and platinum (II).
New liquid crystalline compounds based on terephthaloyl-bis-4-
oxybenzoate with terminal carbon-carbon double bonds in aliphatic
tails were synthesized. The introduction in aliphatic tails of polar and
light polarizible fragments leads to a decrease of mesomorphogenic
ability-resulting compounds.
The hydrosilylation of liquid crystalline compounds with terminal
carbon-carbon double bonds in aliphatic tails with 1-(1ꢀ-arylethoxy)-
1,1,3,3-tetramethyl disiloxanes mediated by complexes of rhodium (I)
and platinum (II) was investigated. The main process in these con-
ditions is the isomerization of olefin fragments. The reason for a low
reactivity of 1-(1ꢀ-arylethoxy)-1,1,3,3-tetramethyl disiloxanes 1a–d in
the hydrosilylation of α-olefines and corresponding activity in the iso-
merization is a more strong Si-H bond of this incomparison with 1,1,3,3-
tetramethyl disiloxane. The use of reagent 1,1,3,3-tetramethyl disilox-
ane instead of silyl ethers 1 leads to quantitative yield of hydrosilylation
products.
EXPERIMENTAL
1H and 13C NMR spectra were recorded on a Bruker DRX300 spec-
trometer at 300.13 and 75.468 MHz, respectively. Chemical shifts are

Terminal Carbon–Carbon Double Bonds
2073
1
reported in ppm relative to CHCl3 (δ 7.26 for H) and CDCl3 (δ 76.9
for 13C).1HNMR data are reported as follows: chemical shift in ppm
(δ), multiplicity (s = singlet, d = doublet, t = triplet, q = quartet, m =
multiplet, br = broad), relative intensity, coupling constant (Hz), and
interpretation; 13C NMR data are reported as follows: chemical shift
in ppm (δ), and interpretation. IR spectra were obtained on a Bruker
IFS-88 infrared spectrometer (liquid on KBr disk or in KBr tablets for
powder). Specific optical rotations [α]D were measured with a Perkin
Elmer 241A polarimeter for 1% wt solutions in chloroform. A refrac-
tion index was obtained on an IFS-22 (USSR) Abbe type refractometer.
POM studies have been performed with a Boethius stage (DDR Dres-
den). Differential scanning calorimetry (DSC) scans were carried out
on a Perkin Elmer Pyris 1 instrument. Typically, ca. 4 mg. of a sample
were analyzed in each run, while the scan rate was 2◦C/min under a
nitrogen atmosphere.
The computation was made ab initio method in an orbital basis
STO-3G on program HyperChem, version 6.03.
Metal complexes were synthesized following the standard literature
methods.21 1-(1ꢀ-arylethoxy)-1,1,3,3-tetramethyl disiloxanes I a–d were
synthesized accordingly.6
The hydrosilylation and isomerization were performed in sealed
glass tubes at 70◦C and at a catalyst concentration of (1 ÷ 20) ×
10−4 mol/L.
Diallyl terephthaloyl-bis-4-oxybenzoate (2a, C28H22O8)
Terephthaloyl-bis-4oxybenzoyl chloride (1 g, 2.25 mmol) and allyl al-
cohol (3 mL, 44 mmol) was heated in 5 mL of tetradecane at bade
temperature 150◦C for 30 min. The reaction mixture was poured out
in petroleum ether, filtered, and recrystallized from tetradecane. 2a
was obtained as a white crystal with a quantitative yield (1.05 g), m.p.
139◦C. IR, cm−1: 1020, 1090, 1120, 1165, 1215, 1280, 1310, 1415, 1468,
1505, 1605, 1720, 1730, 2850, 2920. 1HNMR, δ, ppm (J, Hz): 4.85 d (4H,
4.9), 5.28, 5.34, 5.38, 5.47 (4H, CH2 ), 5.94–6.15 m (2H, CH ), 7.34 d
(4H, 8.54), 8.18 d (4H, 8.54), 8.35 s (4H). Found, %: C, 68.72; H, 4.42.
C28H22O8. calcd. %: C,69.13; H, 4.560
Di-10-undecyl terephthaloyl-bis-4-oxybenzoate (2b, C44H54O8)
The same procedure was used for preparation. White solid, m.p. 134◦C.
IR, cm−1: 1020, 1075, 1085, 1120, 1160, 1215, 1285, 1310, 1410, 1465,
1
1505, 1605, 1710, 1730, 2850, 2920, 2950. H NMR, δ, ppm (J, Hz):

2074
V. V. Zuev and D. A. de Vekki
1.31 (shoulder 1.38) broad s (24H), 1.71–1.82 m (4H), 1.99–2.09 m (4H),
4.34 t (4H, 7.5), 4.91–5.03 m (4H, CH2 ), 5.71–5.91 m (2H,CH ), 7.34
d (4H, 8.54), 8.16 d (4H, 8.54), 8.35 c (4H). 13C NMR, δ, ppm: 65.22
(OCH2, α), 29.33 (β), 25.89 (γ ), 28.59 (δ), 28.97 (ε), 29.27 (ζ), 29.12 (η),
28.79 (θ), 33.66 (ι), 139.06 (CH ), 114.0 (CH2 ), 163.56 (CO, tereph-
thaloyl), 133.57 (ipso), 130.28 (ortho), 165.67 (CO, benzoyl), 128.40
(ipso), 131.14 (ortho), 121.45 (meta), 154.06 (para). Found, %: C, 74.72;
H, 7.54. C44H54O8. calcd %: C, 74.34; H, 7.66.
(+)-di[4-(3-{1-(1-[para-methoxyphenyl]ethoxy)-1,1, 3,
3-tetramethyl disiloxane} propyl) oxybenzoyl]terephthalate (3)
160 mg (0.3 mmol) of 2a and 400 mg (0.8 mmol) of 1b were heated in a
sealed tube with a solution of a Karstedt catalyst in methylene chloride
(Ccat1.5× 10−3 mol/L) at 70◦C for 21 h. The reaction mixture was passed
througha thin layer of silica on a Shot funnel; silica was washed with
a small amount of methylene chloride, and unified filtrate was poured
out in petroleum ether. The residue was filtered up and once again
precipitated from methylene chloride to petroleum ether. Yield 280 mg
(90%) of 3 as white crystals, m.p. 185◦C. [α]D20 = +27.0◦ (δ0.2C, HCl3).
IR, cm−1: 703, 805, 960, 1020, 1060, 1103, 1275, 1410, 1450, 1600, 1715,
1730, 2850, 2950, 3025, 3060. 1H NMR, δ, ppm (J, Hz): 0.08, 0.12, 0.13
(24H, Si-CH3), 0.50–0.57 m (4H, Si-CH2),1.74–1.88 m (4H, CH2), 3.79 s
(6H, OCH3), 4.31 t (4H, 6.9), 7.34 d (4H, 8.54), 8.16 d (4H, 8.54), 8.35 s
(4H), 6.86 d (4H, 8.54), 7.38 d (4H, 8.54).
A mixture of Di-undecyl terephthaloyl-bis-4-oxybenzoate(4)
The same procedure was used for its preparation with a 95% yield as a
white solid, m.p. 134◦C. IR, cm−1: 1020, 1075, 1085, 1120, 1160, 1215,
1
1285, 1310, 1410, 1465, 1505, 1605, 1710, 1730, 2850, 2920, 2950. H
NMR, δ, ppm (J, Hz): 1.30–1.45 m (24H), 1.75–1.84 m (4H), 1.96–2.08 m
(6H), 1.60–1.67 m (2H), 4.34 t (4H, 7.5), 5.35–5.50 t (4H, CH ), 7.34 d
(4H, 8.54), 8.16 d (4H, 8.54), 8.35 s (4H); k = 0 0.98 t (CH3), k = 1 0.91 t
(CH3), k = 2 0.90 t (CH3). 13C NMR, δ, ppm: 65.19 (OCH2, α), 163.56
(CO, terephthaloyl), 133.57 (ipso), 130.28 (ortho), 165.67 (CO, benzoyl),
128.40 (ipso), 131.14 (ortho), 121.45 (meta), 154.06 (para); k = 0 17.77
(CH3), 124.45 ( CH CH3), 131.44 ( CH), 34.54 (θ), 28.8–29.4 (β − η);
k = 1 13.86 (CH3), 131.85 ( CHCH2CH3), 129.08 ( CH); k = 2 13.96
(CH3), 133.64 ( CH(CH2)2CH3), 129.66 ( CH), 32.43 ( CHCH2), 32.36
(CH2CH3).

Terminal Carbon–Carbon Double Bonds
2075
Di{4-(11-[1,1,3,3-Tetramethyldisiloxane]undecyl)-
oxybenzoate}terephthalate(5, C52H68O10Si4)
210 mg (0.3 mmol) of 2b and 0.4 mL (2.4 mmol) of 1,1,3,3-tetramethyl
disiloxane were heated in a sealed tube with a solution of a Karstedt
catalyst in methylene chloride (Ccat 1.42 × 10−3 mol/L) at 70◦C for 21 h.
The reaction mixture was passed through a thin layer of silica on a
Shot funnel; silica was washed with small amount of methylene chlo-
ride; a unified filtrate was poured out in petroleum ether. The residue
was filtered up and once again precipitated from methylene chloride to
petroleum ether. Yield 260 mg (90%) of 5 as white crystals, m.p. 130◦C.
IR, cm−1: 703, 805, 960, 1020, 1060, 1103, 1275, 1410, 1450, 1600, 1715,
1730, 2850, 2950, 3025, 3060. 1H NMR, δ, ppm (J, Hz): 0.08, 0.12, 0.13
(24H, Si-CH3), 0.50–0.57 m (4H, Si-CH2), 1.33 broad s (24H), 1.63 broad
s (4H), 1.79–1.84 m (4H), 4.31 t (4H, 6.9), 7.34 d (4H, 8.54), 8.16 d (4H,
8.54), 8.35 s (4Õ). Found%: C, 64.32; H, 6.83; Si, 11.32. C52H68O10Si4.
calcd. %: C, 64.69; H, 7.10; Si, 11.64.
Di(10,11-Dibromineundecyl)-terephthaloyl-bis-4-oxybenzoate
(6, C44H54O8Br2)
To a solution of 0.5 g (0.75 mmol) of 2b in 3 mL of chloroform was added
1 mL of bromine. After 30 min, the solution was poured in methanol
and filtered, and a residue was recipitated from chloroform to methanol.
Yield 0.6 g of 6 (quantitative), m.p. 98◦C IR, cm−1: 715, 880, 1020, 1072,
1095, 1112, 1162, 1275, 1310, 1455, 1465, 1502, 1605, 1720, 1730, 2850,
2920.1H NMR, δ, ppm (J, Hz): 1.33 broad s (24H), 1.63 broad s (4H),
1.79–1.84 m (4H), 4.34 t (4H, 7.5), 4.10–4.20 m (2H, CHBr), trans t
3.62 (9.77), cis-dd 3.82, 3.87 (9.77, 4.26) (4H, CH2Br), 7.34 d (4H, 8.54),
8.16 d (4H, 8.54), 8.35 s (4H). Found %: C, 60.72; H, 6.53; Br, 18.20.
C44H54O8Br2. calcd. %: C, 60.69; H, 6.25; Br, 18.35.
A mixture of Di(dibromineundecyl)-terephthaloyl-bis-4-
oxybenzoate (7)
The same procedure was used for its preparation with a 95% yield. M.p.
102–104◦C. IR, cm−1: 715, 880, 1020, 1072, 1095, 1112, 1162, 1275,
1310, 1455, 1465, 1502, 1605, 1720, 1730, 2850, 2920. 1H NMR, δ, ppm
(J, Hz): 0.95 (6H), 1.33 broad s (24H), 1.63 broad s (4H), 1.79–1.84 m
(4H), 4.34 t (4H, 7.5), 4.10–4.20 m (4H, CHBr), 7.34 d (4H, 8.54), 8.16 d
(4H, 8.54), 8.35 s (4H).
Allyl- and 10-undecylbenzoates(8) was synthesized by a high-
temperature acceptorless condensation from corresponding alcohol and

2076
V. V. Zuev and D. A. de Vekki
benzoyl chloride. 8a. B.p. 96◦C (5 mm of Hg), n2D0 = 1.5180 {lit.: b.p. 106
(12 mm of Hg), n2D0 = 1.5180.22 8b B.p. 162 (2 mm of Hg n2D0 = 1.4967.
IR, cm−1: 1020, 1075, 1085, 1120, 1160, 1215, 1285, 1310, 1410, 1465,
1505, 1605, 1730, 2850, 2920, 2950. 1H NMR, δ, ppm (J, Hz): 1.31 broad
s (12H), 1.78 m (2H), 2.06 q (2H, 6.75), 4.34 t (2H, 6.75), 4.93–5.04 m
(2H, CH2 ), 5.76–5.90 m (1H, CH ), 7.44 t (2H, 6.75, meta), 7.56T (1H,
7.5, para), 8.07 ‰ (1H, 6.75, ortho). 13C NMR, δ, ppm: 64.88 (OCH2,
α), 29.27 (β), 25.85 (γ ), 28.72 (δ), 28.91 (ε), 29.21 (ζ), 29.07 (η), 28.54
(θ), 33.61 (ι), 138.91 (CH ), 113.94 (CH2 ), 166.41 (CO), 130.36 (ipso),
129.32 (ortho), 128.09 (meta), 132.54 (para).
1-[3-(Phenyloxycarbonyl)propyl]-3-(1ꢀ-phenylethoxy)-1,1,3,3-
tetramethyl disiloxane (9a, C22H32O4Si2)
375 mg (2.3 mmol) of allyl benzoate and 540 mg (2.7 mmol) of 1a (a molar
ratio 1:1.2) were heated in a sealed tube with a solution of a Karstedt
catalyst in methylene chloride (Ccat 1.42 × 10−3 mol/L) at 70◦C for 20 h.
The reaction mixture was distillated in vacuum. Yield 560 mg (85%) of
9a as transparent liquid. B.p. 134◦C (2 mm of Hg), nD20 = 1.4790. IR,
cm−1: 703, 805, 960, 1020, 1060, 1103, 1275, 1410, 1450, 1600, 1730,
2850, 2950, 3025, 3060. 1H NMR, δ, ppm (J, Hz): 0.03, 0.12, 0.13 (12 H,
Si-CH3), 0.4 s (2H, Si-CH2), 1.56 d (CH3, 3H, 6.9); 1.78–1.86 m (2H), 4.28
t (2H, 6.9), 7.55 t (1H, 6.75), 7.44 t (2H, 6.75), 8.07 d (2H, 6.75), 5.09 q
(CH, 1H, 6.9); 7.33–7.46 m (ortho and para CH, 4H); 7.25–7.31 m (para
CH, 1H). Found %: C, 63.72; H, 7.89; Si, 13.68. C22H32O4Si,2. calcd. %:
C, 63.42; H, 7.74; Si, 13.48.
1-[11-(Phenyloxycarbonyl)propyl]-3-(1ꢀ-phenylethoxy)-
1,1,3,3-tetramethyl disiloxane (9b, C32H48O4Si2)
The same procedure was used for it preparation with a 15% yield as
transparent liquid. B.p. 164◦C (2 mm of Hg), n2D0 = 1.4771. IR, cm−1
:
703, 805, 960, 1020, 1060, 1103, 1275, 1410, 1450, 1600, 1730, 2850,
2950, 3025, 3060. 1H NMR, δ, ppm (J, Hz): 0.03, 0.12, 0.13 (12 H,
Si-CH3), 0.57 c (2H, Si-CH2), 1.34 c (16H), 1.49 d (CH3, 3H, 6.9); 1.79–
1.86 m (2H), 4.34 t (2H, 6.9), 7.57 t (1H, 6.75), 7.46 t (2H, 6.75), 8.08 d
(2H, 7.5), 5.08 q (CH, 1H, 6.9); 7.30–7.36 m (ortho and para CH, 4H);
7.22–7.31 m(para CH, 1H). 13C NMR, δ, ppm: 64.87 (OCH2, α), 29.44
(β), 25.86 (γ ), 28.56 (δ), 29.36 (ε), 29.27 (ζ), 29.12 (η), 29.51 (θ), 33.28
(ι), 23.06 (κ), 18.08 (λ), 0.02, 088, 0.99 (SiCH3), 26.58 (CH3), 69.91 (CH),
166.35 (CO), 130.38 (ipso), 129.32 (ortho), 128.08 (meta), 132.52 (para),
(benzyl) 146.08 (ipso), 125.12 (ortho), 127.89 (meta), 126.57 (para).

Terminal Carbon–Carbon Double Bonds
2077
Found %: C, 69.32; H, 8.80; Si, 10.54. C32H48O4Si2. calcd. %: C, 69.51;
H, 8.75; Si, 10.16.
A Mixture of Undecyl Benzoates (10)
B.p. 148–154◦C (2 mm of Hg). IR, cm−1: 1020, 1075, 1085, 1120, 1160,
1
1215, 1285, 1310, 1410, 1465, 1505, 1605, 1730, 2850, 2920, 2950. H
NMR, δ, ppm (J, Hz): 1.30–1.45 m (24H), 1.75–1.84 m (4H), 1.96–2.08
m (6H), 1.60–1.67 m (2H), 4.34 t (4H, 7.5), 5.35–5.50 m (4H, CH ), 7.34
d (4H, 8.54), 8.16 d (4H, 8.54), 8.35 s (4H); k = 0 0.98 t CH3), k = 1 0.91
t (CH3), k = 2 0.90 t (CH3). 13C NMR, δ, ppm: 64.87 (OCH2, α), 166.35
(CO), 130.38 (ipso), 129.32 (ortho), 128.08 (meta), 132.52 (para); k =
0 17.77 (CH3), 124.45 ( CHCH3), 131.44 ( CH), 34.54 (θ), 28.8–29.4
(β − η); k = 1 13.86 (CH3), 131.85 ( CHCH2CH3), 129.08 ( CH); k = 2
13.96 (CH3), 133.64 ( CH(CH2)2CH3), 129.66 ( CH), 32.43 ( CHCH2),
32.36 (CH2CH3).
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