Synthesis and Conformational Characteristics of Benzyl-Substituted p-tert-Butylcalixarenes

Article abstract of DOI:10.1023/A:1013958911953

(m-Methylbenzyloxy)-, bis(p-methylbenzyloxy)-, and bis(m-methylbenzyloxy)-p-tert-butylcalix[4]-arenes were prepared by reactions of p- and tert-butylcalix[4]arene with p- and m-methylbenzyl bromides in the presence of alkali metal carbonates. Silylation o

Full text of DOI:10.1023/A:1013958911953

Russian Journal of General Chemistry, Vol. 71, No. 11, 2001, pp. 1786 1792. Translated from Zhurnal Obshchei Khimii, Vol. 71, No. 11, 2001,
pp. 1887 1894.
Original Russian Text Copyright
2001 by Alekseeva, Mazepa, Gren’.
Synthesis and Conformational Characteristics
of Benzyl-Substituted p-tert-Butylcalixarenes
E. A. Alekseeva, A. V. Mazepa, and A. I. Gren’
Bogatskii Physicochemical Institute, National Academy of Sciences of Ukraine, Odessa, Ukraine
Received April 10, 2000
Abstract (m-Methylbenzyloxy)-, bis(p-methylbenzyloxy)-, and bis(m-methylbenzyloxy)-p-tert-butylcalix[4]-
arenes were prepared by reactions of p-tert-butylcalix[4]arene with p- and m-methylbenzyl bromides in
the presence of alkali metal carbonates. Silylation of these derivatives gave (m-methylbenzyloxy)bis(tri-
methylsilyloxy)-, bis(m-methylbenzyloxy)bis(trimethylsilyloxy)-, and bis(p-methylbenzyloxy)bis(trimethylsilyl-
oxy)-p-tert-butylcalix[4]arenes. With phase-transfer catalysis, bis(p-methylbenzyloxy)bis(2-propenyloxy)- and
bis(m-methylbenzyloxy)bis(2-propenyloxy)-p-tert-butylcalix[4]arenes were obtained. Alkylation of the mono-
substituted calixarene yields the corresponding trisubstituted derivative.
Interest in the calixarene chemistry is due to
the possibility of preparing from these compounds
synthetic receptors selectively binding metal ions
and neutral molecules [1 3]. Numerous studies of
the complexing power of calixarenes and their de-
rivatives and of the complexation selectivity show
that the selectivity depends on many factors, includ-
ing the conformational state of calixarene molecules.
The most stable conformational isomers of p-tert-
butylcalix[4]arene (I) molecules are cone, partial-cone,
1,2-alternate, and 1,3-alternate (see table) [1 7]. It is
also known that introduction into the p-tert-butylcal-
ix[4]arene lower rim of such bulky substituents as
benzyl groups fixes the cone and partial-cone confor-
mations [8]. Arylation of calixarene I was studied
only in a few papers. For example, Gutsche and
Reddy [8] studied the reaction of I and its di- and
triethers in the cone and partial-cone conformations
with p-substituted benzyl bromides in the presence of
various bases (NaH, KOSiMe3, K2CO3) in acetone
and in DMF THF. The reaction yields a mixture of
the tetrasubstituted derivative (in the cone and partial-
cone conformations) with a minor amount of the tri-
substituted derivative. It was shown that reaction of I
with p-substituted benzyl bromides in the presence of
excess NaH yields tetrasubstituted calixarene deriva-
tives in the cone conformation, whereas with K2CO3
diethers in the cone and partial-cone conformations
are formed. Although the yield of target products in
arylation of calixarenes was studied in relation to
many factors (electronic effect of the p-substituent,
temperature, natures of the solvent and base), the
influence of the steric structure of the substituent on
formation of particular reaction products practically
was not examined.
In this work we studied how the structure of the
arylating agent affects the composition, prevailing
conformations, and yields of products in the reaction
of calixarene I with p- and m-methylbenzyl bromides
in the presence of sodium and potassium carbonates,
using the procedure described in [9], and also per-
formed further functional substitution of the products.
Compound I reacts with p-methylbenzyl bromide
in the presence of Na2CO3 or K2CO3 (molar ratio
3:7:3.25) to form 1,3-bis(p-methylbenzyloxy)-p-tert-
II, R1 = p-MeC6H4; III, R2 = m-MeC6H4.
1070-3632/01/7111-1786$25.00 2001 MAIK Nauka/Interperiodica

SYNTHESIS AND CONFORMATIONAL CHARACTERISTICS OF BENZYL-SUBSTITUTED
1787
1H NMR signals of the main molecular fragments of p-tert-butylcalix[4]arene I and its derivatives
Multiplicity and intensity of signals
Conformation
t-Bu
CH2
ArH
I
Cone
s (36H)
2 d (4H)
s (8H)
Partial-cone
1,2-Alternate
1,3-Alternate
Cone
3 s (1: 2: 1)
1 s (36H)
1 s (36H)
2 s (1: 1)
d.d.d (2H) or d.d (2H) and s (4H)
1 s and 2 d (1: 1)
1 s (8H)
2 s (2H) and d.d (2H) or 4 s (1:1:1:1)
2 s (1: 1)
1 s (8H)
2 s (4H)
II
2 d (4H, J 13.6 Hz)
III
IVc
2 s (1: 3)
2 s (1: 1)
2 d (2H, J 13.2 Hz) and d (4H)
2 d (4H, J 12.4 Hz)
2 d (2H, J 2.8 Hz) and 2 s (2H)
2 s (4H)
IVpc Partial-cone
3 s (1: 1: 2)
3 s (1: 2: 1)
2 s (1: 1)
2 d (2H, J 13.4 Hz) and d (4H, J 14.4 Hz) 2 d (2H, J 3.2 Hz) and 2 s (2H)
V
Cone
d.d.d (2H, J 12.8 Hz)
d.d.d (2H, J 12.8 Hz)
2 s (2H) and 2 d (2H, J 3.1 Hz)
2 s (4H)
VI
VIIc Distorted cone 4 s (1: 1: 1: 1) t.d.d (1H, J 12.6 Hz) and d (2H, J 12.6 Hz) t.d.d (1H) and d (2H, J 2.7 Hz)
VIIpc Partial-cone
3 s (2: 1: 1)
d.d.d (2H, J 13.0 Hz)
2 s (2H) and 2 d (2H, J 3.0 Hz)
VIII Cone
3 c (1: 2: 1)
d.d.d (2H, J 12.8 Hz)
3 s (1: 2: 1)
IX
X
Distorted cone 4 s (1: 1: 1: 1) 2 d (2H, J 13.0 Hz) and 2 m (2H)
2 s (2H) and 2 d (2H, J 2.7 Hz)
2 d (2H) and m (4H)
Cone
4 s (1: 1: 1: 1) 4 d (1H, J 12.7 Hz) and 2 m (2H)
1
butylcalix[4]arene II in a high yield. The H NMR
spectrum of this compound suggests its cone confor-
mation [8] (see table). Contrastingly, with m-methyl-
benzyl bromide in the presence of Na2CO3 under sim-
ilar conditions only the monosubstituted product III
is formed even after refluxing for 23 h. According to
the spectrum, the molecules of III exist in the cone
conformation [10].
the macrocyclic system (4H each), and a doublet of
doublets from the methylene bridge protons (J 12.4 Hz)
suggests that a part of the molecules of IV exist in the
1
cone conformation (IVc ). The H NMR spectrum of
the other conformer contains three singlets from the
tert-butyl protons with the ratio of the integral inten-
sities of 1 : 1 : 2, a doublet of doublets (2H each,
J 13.4 Hz,
1.05 ppm) and a singlet (4H) from the
methylene bridge protons, and two singlets and a
doublet of doublets (J 3.2 Hz) from the aromatic pro-
tons. The presence of two sets of proton signals from
the OCH2 and CH3 groups of the methylbenzyl sub-
stituent suggests that in this compound the substitu-
ents are located on different sides of the ring plane.
Such a pattern indicates that these molecules exist in
the partial-cone conformation (IVpc ). The ratio of
the conformers IVc and IVpc is 3 : 2.
1
The H NMR spectrum of III contains two doublets
and two singlets (2H each) from the aromatic protons
of the macroring. The tert-butyl protons give rise to
two singlets with the ratio of integral intensities of
1 : 3, and the protons of the methylene bridges give
a doublet at 3.42 ppm (4H) and doublets of doublets
at 4.22 and 4.34 ppm (2H each). This pattern is appar-
ently due to the effect of the aromatic substituent.
With Na2CO3 replaced by K2CO3, other conditions
being the same, a mixture of III with the disubstituted
product, 1,3-bis(m-methylbenzyloxy)-p-tert-butylcal-
ix[4]arene (IV), is formed, with the monosubstituted
derivative prevailing. Their ratio after TLC separation
(Al2O3, hexane chloroform, 3 : 1) is 7 : 3. The mole-
1
cules III, as follows from the H NMR spectrum of
the isolated compound, exist in the cone conforma-
1
tion. The H NMR spectrum of the second component
(IV) suggests the presence of two conformers. These
conformers were separated by preparative TLC on
Al2O3 in the system hexane chloroform, 4 : 1. The
1
fact that the H NMR spectrum of one of the confor-
mers of IV contains two singlets from tert-butyl pro-
tons (18H each), two signals from aromatic protons of
R = m-MeC6H4.
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1788
ALEKSEEVA et al.
In accordance with the published data [8 12] that
arylating agent to the monophenoxide anion formed
from the monoether. The lack of the template effect
and the size of the potassium cation allow the calix-
arene molecules to take in the course of the reaction
the conformations of partial-cone and so-called flat-
tened cone; in the process, the distance between the
alkylation reactions in the presence of weak bases are
stepwise and that the distribution of the conformers
in the final product is influenced by the template
factor, we suggested that the reaction with m-methyl-
benzyl bromide in the presence of sodium carbonate
occurs via formation of the conical conformer in the phenolic OH groups increases, and the approach of
first stage. The incorporated substituent sterically
hinders the approach of the second molecule of the
the second molecule of the arylating agent and base
becomes easier.
In order to examine how the steric structure of the
substituent affects further functional substitution of
calixarene benzyl derivatives, we performed a number
of transformations of II IV.
derivative III the silylation occurred only at the two
hydroxy groups adjacent to the benzyl substituents,
yielding (m-methylbenzyloxy)bis(trimethylsilyloxy)-
p-tert-butylcalix[4]arene (V), whereas silylation of II,
IVc, and IVpc yielded the corresponding bis(p-meth-
ylbenzyloxy)bis(trimethylsilyloxy)- (VI) and bis(m-
methylbenzyloxy)bis(trimethylsilyloxy)-p-tert-butyl-
calix[4]arenes (VIIc, VIIpc).
To confirm the structure and composition of II IV,
we silylated these compounds under conditions that
usually ensure complete substitution of phenolic pro-
tons. We found that in the monosubstituted benzyl
R = m-MeC6H4CH2 (III V, VII), p-MeC6H4CH2 (II, VI).
1
The H NMR spectrum of the silylated conical iso-
the trimethylsilyl protons and four singlets from tert-
mer VIIc contains two signals of equal intensity from
butyl protons, which is apparently due to certain dis-
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SYNTHESIS AND CONFORMATIONAL CHARACTERISTICS OF BENZYL-SUBSTITUTED
1789
tortion of the cone shape, resulting in increased dis-
tance between the substituents in the calixarene mole-
cule (see table):
proton ( < 0.6) suggests distortion of the cone con-
formation of these molecules.
In the spectrum of calixarene VIII, the tert-butyl
protons give three singlets with 0.84, 0.867, and
1.338 ppm (intensity ratio 1 : 2 : 1); the arene protons
of the calixarene core also give three singlets with
7.079, 7.097, and 7.153 ppm. The methylene pro-
tons give two pairs of doublets with 3.023, 3.084
and 4.37, 4.72 ppm (J 12.8 Hz). Such a pattern of
the arene and methylene proton signals indicates that
molecules of VIII occur in the cone conformation,
and the magnetic nonequivalence of the protons of
the opposite phenolic fragments bearing benzyl sub-
stituents suggests certain distortion of this conforma-
tion.
1
A different pattern is observed in the H NMR
R = m-MeC6H4CH2.
spectrum of calixarene IX. The tert-butyl protons in
this case give four signals of equal intensity with 0.8,
0.85, 1.31, and 1.33 ppm. The methylene protons of
this compound give rise to two doublets with 3.07
and 4.7 ppm (1H each, J 13 Hz) and two multiplets
in the ranges 4.32 4.39 and 4.4 4.5 ppm (2H each),
probably originating from overlapping doublets with
< 0.2 0.3 ppm. The aromatic protons of the calix-
The 1H NMR spectrum of VIIpc (partial-cone con-
formation) contains three singlets from the tert-butyl
protons (ratio of integral intensities 2 : 1 : 1), two
doublets and two singlets from aromatic protons, and
two pairs of doublets (J 12 Hz,
2.04 ppm) from the
methylene protons of calixarene. The presence in the
1H NMR spectrum of VIIpc of two resonance signals
from trimethylsilyl protons and two signals from the
CH3 protons of the methylbenzyl moiety indicates
that silylation of the initial calixarene IVpc does not
involve the ring inversion, and the benzyl substituents
are located on different sides of the macroring plane.
arene give a doublet of doublets with
7.1 ppm and a pair of singlets with
7.08 and
7.15 and
7.18 ppm. The presence of two resonance signals from
the methyl and methylene components of the substitu-
ent and fragments of the aryl residue indicates that
the molecules of this compound occur in the distorted
cone conformation in which each tert-butylphenol
ring is a unique fragment nonequivalent to the other
fragments.
Alkylation of II and IVc with allyl bromide under
conditions of phase-transfer catalysis [13] in the pres-
ence of Bu4NBr and NaOH yields bis(p-methylben-
zyloxy)bis(2-propenyloxy)- (VIII) and bis(m-methyl-
benzyloxy)bis(2-propenyloxy)-p-tert-butylcalix[4]ar-
enes (IX). However, when compound III was alky-
lated under conditions suggesting hydrogen substitu-
tion in all the three OH groups of the calixarene, the
only reaction product was (m-methylbenzyloxy)bis-
1
(2-propenyloxy)-p-tert-butylcalix[4]arene (X). Its H
NMR spectrum contains four singlets from the tert-
butyl protons with 0.85, 0.87, 1.34, and 1.5 ppm
(9H each). The arene protons of the macroring give
rise to a doublet of doublets with 7.09 and 7.1 ppm
(2H each) and a multiplet at 7.15 7.2 ppm (4H) origi-
nating from superposition of doublets. The methylene
protons of the calixarene ring of X give four doublets
with
3.095, 4.7, 4.74, and 4.80 ppm (1H each,
J 12.7 Hz) and two multiplets with 4.35 4.39 and
4.42 4.49 ppm (2H each), which are due to superpo-
R = p-MeC6H4CH2 (II, IX), m-MeC6H4CH2 (VIII, X).
sition of doublets with a small
. Observation of
four signals from the tert-butyl protons of the calix-
arene and of doublets from each methylene bridge
The results of phase-transfer alkylation, along with
those of silylation of II, are due to the template effect
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 11 2001

1790
ALEKSEEVA et al.
4
4
of the sodium ion, fixing the calixarene molecule in
the cone conformation, and also to the steric effect of
the methyl group in the m-position of the benzyl sub-
stituent, shielding the oxygen atom of the phenoxide
anion from the molecule of the alkylating agent as
shown in the scheme. Therefore, inversion of the
phenol rings is hindered, and further reaction becomes
impossible. At the same time, the p-methylbenzyl
substituent does not hinder sterically the alkylation,
and the products of total substitution are formed:
Ar H, JHH 2.8 Hz), 7.05 d (2H, Ar H, JHH 2.8 Hz),
7.12 s (2H, Ar H), 7.13 s (2H, Ar H), 7.27 7.52 m
(4H, Bzl), 9.39 s (2H, OH), 9.99 s (1H, OH). Found,
%: C 83.14; H 8.59. C52H64O4. Calculated, %:
C 82.94; H 8.57.
Di(methylbenzyl) derivatives of calixarene II
and IV. A mixture of 6 mmol of I, 14 mmol of m- or
p-methylbenzyl bromide, and 7.5 mmol of Na2CO3
or K2CO3 in 100 ml of acetonitrile was refluxed with
stirring for 23 h, after which the solvent was distilled
off, the residue was washed with 50 ml of 5% HCl,
the reaction product was extracted with chloroform,
the organic layer was dried over MgSO4, the solvent
was evaporated under reduced pressure, and the re-
sidue was recrystallized from chloroform 1-butanol,
1 : 3.
5, 11, 17, 23-Tetra-tert-butyl-25, 27-dihydroxy-
26, 28-bis[( p-methylbenzyl)oxy]calix[4]arene II.
Yield 86%, mp 256 C, Rf 0.78 (Al2O3, eluent hexane
chloroform, 3 : 1). 1H NMR spectrum, , ppm: 0.934 s
(18H, t-Bu), 1.281 s (18H, t-Bu), 2.438 s (6H, Me),
3.26 d (4H, ArCH2Ar, JH H 13.6 Hz), 4.221 d (4H,
Thus, introduction of such bulky substituents as
m-methylbenzyl groups with further modification of
the resulting derivatives is an example of synthesis
of unsymmetrical calixarenes; it can be used for intro-
ducing and removing protective groups in synthesis of
calixarenes of the required structure with three differ-
ent substituents in the molecule.
A
B
ArCH2Ar, JH H 13.6 Hz), 5.028 s (4H, CH2O),
A
B
6.776 s (4H, Ar H), 7.032 s (4H, Ar H), 7.23 7.38 m
(8H, Bzl), 7.27 s (2H, OH), Found, %: C 84.17;
H 8.49. C60H88O4. Calculated, %: C 84.07; H 8.47.
EXPERIMENTAL
5, 11, 17, 23-Tetra-tert-butyl-25, 27-dihydroxy-
26, 28-bis[(m-methylbenzyl)oxy]calix[4]arene [cone
(IVc)]. mp 240 C, Rf 0.75 (Al2O3, eluent hexane
chloroform, 4 : 1). 1H NMR spectrum, , ppm: 0.951 s
(18H, t-Bu), 1.238 s (18H, t-Bu), 2.284 s (3H, Me),
3.273 d (4H, ArCH2Ar, JH H 12.4 Hz), 4.279 d (4H,
1
The H NMR spectra were recorded on a Varian
XL-300 spectrometer (300 MHz, 10% solutions in
CCl4, internal reference TMS). As eluents for column
chromatography we used 3 : 1 and 4 : 1 hexane chlo-
roform mixtures. All solvents were preliminarily puri-
fied by distillation and dried over 3 or 4 molecu-
lar sieves.
A
B
ArCH2Ar, JH H 12.4 Hz), 5.01 s (4H, CH2O),
A
6.706 s (4H, ArB H), 7.038 s (4H, Ar H), 7.34 s (2H,
OH), 7.16 7.57 m (8H, Bzl). Found, %: C 84.17;
H 8.49. C60H88O4. Calculated, %: C 84.07; H 8.47.
5,11,17,23-Tetra-tert-butyl-25-[(m-methylbenzyl)-
oxy]-26,27,28-trihydroxycalix[4]arene III. A mixture
of 6 mmol of I, 14 mmol of m-methylbenzyl bromide,
and 7.5 mmol of Na2CO3 in 100 ml of acetonitrile
was refluxed with stirring for 23 h, after which the
solvent was distilled off, the residue was washed with
50 ml of 5% HCl, the products was extracted with
chloroform, the organic layer was dried over MgSO4,
the solvent was evaporated under reduced pressure,
and the residue was recrystallized from 1-butanol.
Yield 85%; mp 218 C, Rf 0.75 (Al2O3, eluent hexane
5, 11, 17, 23-Tetra-tert-butyl-25, 27-dihydroxy-
26,28-bis[(m-methylbenzyl)oxy]calix[4]arene [ par-
tial-cone (IVpc)]. mp 258 C, Rf 0.35 (Al2O3, eluent
1
hexane chloroform, 4:1). H NMR spectrum, , ppm:
0.94 s (9H, t-Bu), 0.99 s (9H, t-Bu), 1.27 s (18H,
t-Bu), 2.33 s (3H, Me), 2.36 s (3H, Me), 3.21 d (2H,
ArCH2Ar, JH H 13.4 Hz), 4.14 d (4H, ArCH2Ar,
JH H 12.4 HzA), B4.26 d (2H, ArCH2Ar, JH H 13.4 Hz),
A
4.94Bs (2H, CH2O), 4.96 s (2H, CH2O),A7B.05 d (2H,
1
chloroform, 3 : 1). H NMR spectrum, , ppm: 1.20 s
(9H, t-Bu), 1.21 s (27H, t-Bu), 2.45 s (3H, Me),
3.42 d (4H, ArCH2Ar, JH H 13.2 Hz), 4.22 d (2H,
4
4
Ar H, JHH 3.2 Hz), 7.12 d (2H, Ar H, JHH 3.2 Hz),
7.16 s (2H, Ar H), 7.18 s (2H, Ar H), 7.21 s (2H,
OH), 7.25 7.5 m (8H, Bzl). Found, %: C 84.17;
H 8.49. C60H88O4. Calculated, %: C 84.07; H 8.47.
A
B
ArCH2Ar, JH H 13.2 Hz), 4.34 d (2H, ArCH2Ar,
JH H 13.2 Hz)B, 5.132 s (2H, CH2O), 6.95 d (2H,
A
A
B
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SYNTHESIS AND CONFORMATIONAL CHARACTERISTICS OF BENZYL-SUBSTITUTED
1791
5,11,17,23-Tetra-tert-butyl-25-[(m-methylbenzyl-
oxy]-26,28-bis(trimethylsilyloxy)-27-hydroxycalix-
[4]arene (V). A solution of 10 mmol of N,N-bis(tri-
methylsilyl)acetamide in 10 ml of CH3CN was added
dropwise under nitrogen to a solution of 1 mmol of
III in 25 ml of CH3CN. The mixture was refluxed
with stirring for 6 h. Then the solvent was distilled
off, and the crude product was recrystallized from
toluene MeCN, 1 : 2. Yield 80%, mp 244 246 C.
1H NMR spectrum, , ppm: 0.047 s (18H, Me3Si),
0.84 s (9H, t-Bu), 1.29 s (18H, t-Bu), 1.31 s (9H,
t-Bu), 1.94 s (3H, Me), 2.865 d (2H, ArCH2Ar,
5.25 d (1H, ArCH2Ar, JH H 12.6 Hz), 6.37 br.s
A
B
4
(4H, CH2O), 6.4 d (1H, Ar H, JHH 2.7 Hz), 6.44 d
4
4
(1H, Ar H, JHH 2.7 Hz), 6.98 d (1H, Ar H, JHH
4
2.7 Hz), 7.03 d (1H, Ar H, JHH 2.7 Hz), 7.1 d (2H,
Ar H, JHH 2.7 Hz), 7.12 d (1H, Ar H, JHH 2.7 Hz),
7.22 d (1H, Ar H, JHH 2.7 Hz), 7.15 7.38 m (8H,
4
4
4
Bzl). Found, %: C 79.25; H 8.88. C66H88O4Si2. Cal-
culated, %: C 79.15; H 8.86.
5,11,17,23-Tetra-tert-butyl-25,27-bis[(m-methyl-
benzyl)oxy]-26, 28-bis(trimethylsilyloxy)calix[4]-
1
arene VIIpc. Yield 76%, mp 295 297 C. H NMR
J
12.8 Hz), 2.93 d (2H, ArCH2Ar, J
HAHB
HAHB
spectrum, , ppm: 0.04 s (9H, Me3Si), 0.082 s (9H,
Me3Si), 0.9 s (18H, t-Bu), 1.29 s (9H, t-Bu), 1.31 s
(9H, t-Bu), 1.94 s (3H, Me), 2.1 s (3H, Me), 2.28 d
(2H, ArCH2Ar, JH H 13.0 Hz), 2.87 d (2H, ArCH2Ar,
12.8 Hz), 4.20 d (2H, ArCH2Ar, JH H 12.8 Hz),
A
B
4.25 d (2H, ArCH2Ar, JH H 12.8 Hz), 5.21 s (2H,
A
B
4
CH2O), 6.37 s (2H, Ar H), 6.43 d (2H, Ar H, JHH
3.1 Hz), 6.98 d (2H, Ar H, JHH 3.1 Hz), 7.03 s (2H,
A
B
4
JH H 13.0 Hz), 4.32 d (2H, ArCH2Ar, JH H
A
B
A B
Ar H), 7.12 7.38 m (2H, 3H, Bzl). Found, %: C
77.72; H 9.01. C58H80O4Si2. Calculated, %: C 77.62;
H 8.99.
13.0 Hz), 4.41 d (2H, ArCH2Ar, JH H 13.0 Hz),
A
B
6.4 s (2H, CH2O), 6.438 s (2H, CH2O), 6.5 d (1H,
4
4
Ar H, JHH 3.0 Hz), 6.56 d (2H, Ar H, JHH 3.0 Hz),
7.12 s (2H, Ar H), 7.15 s (2H, Ar H), 7.2 7.42 m
(8H, Bzl). Found, %: C 79.25; H 8.88. C66H88O4Si2.
Calculated, %: C 79.15; H 8.86.
Silylated di(methylbenzyl)-substituted calix-
arenes VI and VIIc. A solution of 6.66 mmol of
N,N-bis(trimethylsilyl)acetamide in 5 ml of MeCN
was added dropwise under nitrogen to a solution of
1 mmol of II or IV in 25 ml of MeCN. The mixture
was refluxed with stirring for 6 h. Then the solvent
was distilled off, and the crude product was recrystal-
lized from toluene MeCN, 1 : 2.
Alkylated di(methylbenzyl)-substituted calix-
arenes VIII and IX. A mixture of 2 mmol of III
or IVc and 10 mmol of allyl bromide in 50 ml of
toluene, 2 ml of 50% aqueous NaOH, and 0.2 mmol
of Bu4NBr was stirred at 90 100 C for 6 h. After
cooling, 20 ml of water was added, and the organic
phase was separated and washed successively with
40 ml of 5% HCl and 40 ml of water. The solution
was dried over Na2SO4, the solvent was removed at
reduced pressure, and the crude product was recrystal-
lized from methanol CHCl3, 3 : 1.
5,11,17,23-Tetra-tert-butyl-25,27-bis[( p-methyl-
benzyl)oxy]-26, 28-bis(trimethylsilyloxy)calix[4]-
1
arene VI. Yield 78%, mp 276 278 C. H NMR spec-
trum, , ppm: 0.087 s (18H, Me3Si), 0.919 s (18H,
t-Bu), 1.362 s (18H, t-Bu), 2.331 s (6H, Me), 2.98 d
(2H, ArCH2Ar, JH H 12.8 Hz), 3.22 d (4H, ArCH2Ar,
B
JH H 12.8 Hz),A 4.27 d (2H, ArCH2Ar, JH H
A
12A.8B Hz), 4.417 d (2H, ArCH2Ar, J
12.8 Hz)B,
HAHB
5,11,17,23-Tetra-tert-butyl-25,27-bis[( p-methyl-
6.37 s (2H, CH2O), 6.44 s (4H, Ar H), 7.10 s (2H,
Ar H), 7.18 7.42 m (8H, Bzl). Found, %: C 79.25;
H 8.88. C66H88O4Si2. Calculated, %: C 79.15; H 8.86.
benzyl)oxy]-26,28-bis(2-propenyloxy)calix[4]arene
VIII. Yield 90%, mp 193 195 C. H NMR spectrum,
1
, ppm: 0.84 s (9H, t-Bu), 0.867 s (18H, t-Bu),
1.338 s (9H, t-Bu), 2.33 s (3H, Me), 2.38 s (3H, Me),
3.023 d (2H, ArCH2Ar, JH H 12.8 Hz), 3.084 d
5,11,17,23-Tetra-tert-butyl-25,27-bis[(m-methyl-
benzyl)oxy]-26, 28-bis(trimethylsilyloxy)calix[4]-
A
B
1
(2H, ArCH2Ar, JH H 12.8 Hz), 4.37 d (2H,
arene VIIc. Yield 80%, mp 280 281 C. H NMR
A
B
spectrum, , ppm: 0.07 s (9H, Me3Si), 0.084 s (9H,
Me3Si), 0.874 s (9H, t-Bu), 0.897 s (9H, t-Bu), 1.27 s
(9H, t-Bu), 1.353 s (9H, t-Bu), 2.26 s (3H, Me), 2.3 s
(3H, Me), 2.865 d (1H, ArCH2Ar, JH H 12.6 Hz),
ArCH2Ar, JH H 12.8 Hz), 4.5 d (1H, CH2=, J
A
B
8.54 Hz), 4.6 d (1H, CH2 , J 8.54 Hz), 4.67 m (2H,
CH2O), 4.73 d (2H, ArCH2Ar, JH H 12.8 Hz), 4.8
A
B
A
B
4.96 m (2H, CH2=), 5.3 m (2H, CH2O), 6.37 m (2H,
CH=), 6.434 s (2H, CH2O), 6.466 s (2H, CH2O),
7.079 s (2H, Ar H), 7.097 s (4H, Ar H), 7.153 s (2H,
Ar H), 7.195 7.35 m (8H, Bzl). Found, %: C 84.67;
H 8.62. C66H80O4. Calculated, %: C 84.57; H 8.60.
2.93 d (1H, ArCH2Ar, JH H 12.6 Hz), 4.20 d (1H,
A
B
ArCH2Ar, JH H 12.6 Hz), 4.25 d (1H, ArCH2Ar,
A
B
J
12.6 Hz), 5.10 d (1H, ArCH2Ar, J
HAHB
HAHB
12.6 Hz), 5.21 d (2H, ArCH2Ar, JH H 12.6 Hz),
A
B
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 11 2001

1792
ALEKSEEVA et al.
4
5,11,17,23-Tetra-tert-butyl-25,27-bis[(m-methyl-
benzyl)oxy]-26,28-bis(2-propenyloxy)calix[4]arene
(2H, CH2O), 7.08 d (2H, Ar H, JHH 2.7 Hz), 7.1 d
4
(2H, Ar H, JHH 2.7 Hz), 7.15 7.2 m (4H, Ar H),
7.21 7.3 m (4H, Bzl). Found, %: C 83.71; H 8.74.
C58H72O4. Calculated, %: C 83.61; H 8.71.
1
IX. Yield 92%, mp 215 C. H NMR spectrum,
,
ppm: 0.8 s (9H, t-Bu), 0.85 s (9H, t-Bu), 1.31 s (9H,
t-Bu), 1.33 s (9H, t-Bu), 2.31 s (3H, Me), 2.34 s (3H,
Me), 3.07 d (2H, ArCH2Ar, JH H 13.0 Hz), 4.32
REFERENCES
A
B
4.39 m (2H, ArCH2Ar), 4.4 4.5 m (2H, ArCH2Ar),
4.52 4.61 m (2H, CH2=), 4.65 m (2H, CH2O), 4.7 d
1. Vicens, J. and Bohmer, V., Calixarenes, Dordrecht:
Kluwer Academic, 1991.
2. Ikeda, A. and Shinkai, S., Chem. Rev., 1997, vol. 97,
(2H, ArCH2Ar, JH H 13.0 Hz), 4.73 4.9 m (2H,
A
CH2=), 5.1 5.2 m (2BH, CH2O), 6.37 m (2H, CH=),
no. 5, pp. 1713 1734.
6.44 s (2H, CH2O), 6.5 s (2H, CH2O), 7.08 d (2H,
3. Arduini, A., McGregor, W.M., Paganuzzi, D., Pochi-
ni, A., Secchi, A., Ugozzoli, F., and Ungaro, R.,
J. Chem. Soc., Perkin Trans. 2, 1996, no. 1,
pp. 839 846.
4
4
Ar H, JHH 2.8 Hz), 7.1 d (2H, Ar H, JHH 2.8 Hz),
7.15 s (2H, Ar H), 7.18 s (2H, Ar H), 7.2 7.45 m
(8H, Bzl). Found, %: C 84.67; H 8.62. C66H80O4.
Calculated, %: C 84.57; H 8.60.
4. Casnati, A., Gazz. Chim. Ital., 1997, vol. 127, no. 11,
pp. 637 649.
5,11,17,23-Tetra-tert-butyl-25-[(m-methylbenzyl)-
oxy]-26,28-bis(2-propenyloxy)-27-hydroxycalix[4]-
arene X. A mixture of 2 mmol of III and 15 mmol
of allyl bromide in 75 ml of toluene, 3 ml of 50%
aqueous NaOH, and 0.3 mmol of Bu4NBr was stirred
at 90 100 C for 8 h. After cooling, 30 ml of water
was added, and the organic phase was separated and
washed successively with 60 ml of 5% HCl and 60 ml
of water. The solution was dried over Na2SO4, the
solvent was removed at reduced pressure, and the
residue was recrystallized from methanol CHCl3,
5. Gutsche, C.D., Dhawan, B., No, K.H., and Muthu-
krishnan, R., J. Am. Chem. Soc., 1981, vol. 103,
no. 16, pp. 3782 3881.
6. Araki, K., Iwamoto, K., Shinkai, S., and Matsudo, T.,
Chem. Lett., 1989, no. 4, pp. 1747 1749.
7. Gutsche, C.D. and Pagoria, P.F., J. Org. Chem., 1985,
vol. 50, no. 26, pp. 5795 5802.
8. Gutsche, C.D. and Reddy, P.A., J. Org. Chem., 1991,
vol. 56, no. 15, pp. 4783 4791.
9. Iwamoto, K., Araki, K., and Shinkai, S., Tetrahedron,
1991, vol. 47, no. 25, pp. 4325 4342.
10. Alekseeva, E.A., Bacherikov, V.A., and Gren’, A.I.,
Zh. Obshch. Khim., 2000, vol. 70, no. 5, pp. 866 867.
11. Iwamoto, K., Araki, K., and Shinkai, S., J. Org.
Chem., 1991, vol. 56, no. 16, pp. 4955 4962.
1
3 : 1. Yield 94%, mp 200 201 C. H NMR spectrum,
, ppm: 0.85 s (9H, t-Bu), 0.87 s (9H, t-Bu), 1.34 s
(9H, t-Bu), 1.5 s (9H, t-Bu), 2.35 s (3H, Me), 3.095 d
(1H, ArCH2Ar, JH H 12.7 Hz), 4.35 4.39 m (2H,
A
B
ArCH2Ar), 4.42 4.49 m (2H, ArCH2Ar), 4.5 4.55 m
12. Iwamoto, K., Fujimoto, K., Matsuda, T., and Shin-
kai, S., Tetrahedron Lett., 1990, vol. 31, no. 49,
pp. 7169 7172.
13. Bitter, I., Grun, A., Agai, B., and Toke, L., Tetra-
hedron, 1995, vol. 51, no. 28, pp. 7835 7840.
(2H, CH2=), 4.65 d (1H, ArCH2Ar, JH H 12.7 Hz),
B
4.74 d (1H, ArCH2Ar, JH H 12.7 Hz),A 4.80 d (1H,
B
ArCH2Ar, JH H 12.7 Hz),A4.83 4.91 m (2H, CH2=),
B
5.18 m (4H,ACH2O), 6.3 6.4 m (2H, CH=), 6.46 s
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 11 2001