Direct access to upper rim substituted mono- and diaryloxy calix[4]arenes via bis(spirodienone) route

Article abstract of DOI:10.1016/j.tet.2010.04.021

A seemingly ipso-like nucleophilic substitution of the upper rim of p-tert-butylcalix[4]arene is accomplished by an indirect method involving calixF4larene derived bis(spirodienone). This method not only provides both mono and 1,3-diaryloxy calixarenes but also enables the synthesis of upper rim monothio substituted calix[4]arenes. A modification of the methodology can be successfully extended for the selective synthesis of mono- and 1,3-diquinone calyx[4]arenes having free hydroxyl groups at the lower rim, in fewer steps.

Full text of DOI:10.1016/j.tet.2010.04.021

Tetrahedron 66 (2010) 5270e5276
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
Direct access to upper rim substituted mono- and diaryloxy calix[4]arenes
via bis(spirodienone) route
*
Sreeja Thulasi, Jisha Babu, Adarsh Babukuttannair, Viji Sreemathi, Ramavarma Luxmi Varma
Organic Chemistry Section, Chemical Sciences and Technology Division, National Institute for Interdisciplinary Science and Technology, Trivandrum-695019, Kerala, India
a r t i c l e i n f o
a b s t r a c t
Article history:
A seemingly ipso-like nucleophilic substitution of the upper rim of p-tert-butylcalix[4]arene is accom-
plished by an indirect method involving calix[4]arene derived bis(spirodienone). This method not only
provides both mono and 1,3-diaryloxy calixarenes but also enables the synthesis of upper rim monothio
substituted calix[4]arenes. A modification of the methodology can be successfully extended for the se-
lective synthesis of mono- and 1,3-diquinone calix[4]arenes having free hydroxyl groups at the lower
rim, in fewer steps.
Received 9 March 2010
Received in revised form 1 April 2010
Accepted 5 April 2010
Available online 20 April 2010
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
oxidation followed by hydrolysis of the formate derivative.17 Selec-
tive hydroxylation at one of the upper rim of calix[4]arene has also
Calixarenes1 are molecular receptors that occupy an envious
position among supramolecular hosts.2 They have been most befit-
tingly described as ‘hosts with (almost) unlimited possibility’ by
Bohmer et al.3 due to their easy availability and amenability for
chemical transformations to 3-dimensional functional molecules
that can perform a myriad of functions as host components in sen-
sors,4 pseudo-stationary phases in capillary electrophoresis,5 phase
transfer catalysts,6 enzyme mimics,6c non-linear optics6c etc. to
mention a few. Hence development of newer techniques for easy
functionalization of calixarenes remains an attractive field. Among
the various types of modifications reported on the calixarene skel-
eton, functionalization of the upper rim either selectively or ex-
haustively is cumbersome due to the involvement of multiple steps
viz. protection of the lower rim hydroxyls and de-tert-butylation
followed by electrophilic substitution at the reactive para-position.
Reactions reported under this category are halogenation,7 nitra-
tion,8 sulfonation,9 chloromethylation,10 acylation,11 formylation12
etc. Selective ipso-substitutions such as sulfonation,13 chlorosulfo-
nation,14 nitration,15 and formylation16 of calixarenes requiring prior
protection of the narrow rim hydroxyls have also been reported.
Direct methodologies to introduce nucleophilic groups (eg.,
eOH, eOR, eSR etc.) to the upper rim of calixarenes are limited due
to the inherent nucleophilicity of the aromatic rings. However, a few
indirect methods are available but often marred by lengthy pro-
cedures. Ungaro et al. have carried out exhaustive hydroxylation of
the lower rim protected formyl calixarene via Bayer/Villiger
been achieved by a six-step synthetic strategy by Lin et al.27a Neri
et al. have reported a novel ‘p-bromodienone route’ to functionalize
the calixarene exo rim with O-nucleophiles.18a Recently the same
group has also reported the reaction of p-bromodienone with aro-
matic nucleophiles forappending aromatic moieties tothe para- and
meta- positions of the calix[4]arene phenol ring.18b Appending ar-
omatic groups at the upper rim give rise to calixarenes with pi-
electron rich extended cavity, which have numerous applications.19
Our group has recently reported a new methodology by which the
calix[4]arene derived bis(spirodienone)20 can be transformed into
functionalized calix[4]arenes having alkoxy substitution at the upper
rim.21 The synthetic methodology adapted involved an acid-mediated
reaction of the bis(spirodienone) with primary alcohols to afford upper
rim substituted mono- and 1,3-dialkoxy calix[4]arenes unprotected at
the lower rim in a single step. These results prompted us to look into
the reactivities of other nucleophiles like phenols, thiols, amines etc.
and our findings in this direction form the subject matter of this article.
The paper also demonstrates the usefulness of our methodology
to synthesize mono- and 1,3-diquinone calix[4]arenes selectively.
To the best of our knowledge this would be the first report of the
synthesis of mono- and diquinones with unprotected hydroxyls at
the lower rim.
2. Results and discussion
Our experiments started by reacting p-cresol, an activated phe-
nol, with bis(spirodienone) 1 in the presence of 5.0 equiv of p-Tol-
uene Sulfonic Acid (p-TSA) under toluene reflux conditions for 6 h.
Despite noticeable charring of the reaction mixture, four products
were isolated from it by column chromatography over silica gel in
* Corresponding author. Tel.: þ91 471 2515275; fax: þ91 471 2491712; e-mail
address: lux_varma@rediffmail.com (R.L. Varma).
0040-4020/$ e see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.04.021

S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
5271
low yields. Subsequently the reaction was repeated at less drastic
conditions: at an optimum temperature of 70 ꢀC after 4 h, the re-
action yielded four products in acceptable yields (Scheme 1).
mono- and di-phenoxy substituted calixarenes in acceptable yields
(Table 1, entries 1e7). In the case of sterically hindered phenols
(entries 5 and 6), the yields of the mono- and di-substituted
Scheme 1. p-TSA mediated reaction of calix[4]bis(spirodienone) 1 with p-cresol.
While products 3 and 6 were identified as p-tert-butylcalix[4]
arene and upper rim monotosylated calixarene on comparison with
literature data,21 the structures of 4a and 5a were established by
various spectroscopic techniques. In the 1H NMR spectrum of
compound 4a, the exclusively hydrogen bonded phenolic hydroxyls
products obtained were comparatively low, with calix[4]arene 3
being the major product. Phenols with electron withdrawing sub-
stituent (entries 8e10) failed to react and the substrate 1 was re-
covered unchanged.
A mechanism similar to the one proposed for the attack of al-
cohols on spiro(dienones) has been invoked to explain the forma-
tion of new products (Scheme 2).21 Attack of the nucleophile at
carbon bearing tert-butyl group is facilitated by the protonation of
spiro-oxygens.
appeared as a singlet at
cresol part appeared at
protons occurred as two singlets at
ratio. In the 13C NMR spectrum, the signal due to the methyl group
d
10.20 ppm and the methyl group of the
2.33 ppm as a sharp singlet. The tert-butyl
1.22 and 1.19 ppm in a 2:1
d
d
of the p-cresol part appeared at
d
20.0 ppm. The chemical shift
This would in turn result in the cleavage of the spiro bond and in
the formation of a cross-dienone. Aromaticity of the cross-dienone
can be achieved by the removal of the tert-butyl group resulting in
the formation of the disubstituted product 5. The formation of
monosubstituted product 4 can be rationalized on the basis of acid-
assisted reductive cleavage of the remaining spiro bond.23
Thus our methodology offers a single step procedure for the syn-
thesis of mono- and di-phenoxy calix[4]arenes, within very short re-
action times in ‘one-pot’, in contrast to the coupling reactions that has
been earlier reported for the synthesis of deep-cavity calixarenes.7,24
To examine the versatility of this process, we also looked into
the reactivity of bis(spirodienone) with thiols, which turned out to
be excellent nucleophiles for the title reaction. When bis(spi-
rodienone) 1 was reacted with n-pentanethiol under the optimized
conditions, monothio ether derivative 7 was obtained in good yield
(Scheme 3). The structure of 7 was established on the basis of
various spectroscopic techniques. In the 1H NMR spectrum of 7, the
values in 13C NMR and the 1H and 13C NMR pattern further confirm
that 4a is present in the cone conformation.22 The structure was
further confirmed by CHN analysis (Anal. Calcd for C47H54O5: C,
80.77; H, 7.79. Found: C, 80. 74; H, 7.75).
The 1H NMR spectrum of 5a showed one singlet for OH (
d
10.07 ppm), two singlets for the aromatic protons of the calixarene
moiety ( 6.81 and 6.64 ppm), one pair of doublets for the methy-
lene bridges (
4.20 and 3.39 ppm, J¼13.5 Hz) and one singlet for
the tert-butyl protons (
d
d
d
1.23 ppm), in agreement with the C2v
symmetrical structure. The 13C NMR and the elemental analysis
supported the formation of 5a.
The scope of the reaction was explored with other substituted
phenols and the results are summarized in Table 1.
In general, phenols with electron donating substituents were
found to react with bis(spirodienone) 1 satisfactorily to give both
OH protons resonated as a singlet at
protons occurred at 3.77 ppm as a triplet. The tert-butyl groups
appeared as two singlets at 1.22 and 1.19 integrating in 2:1 ratio.
The peak corresponding to eSCH2 carbon was observed at
43.5 ppm in the 13C NMR spectrum. The cone conformation was
confirmed by the 13C NMR spectrum, which showed the methylene
bridge carbons at 34.0and
32.6.22
d 10.21 ppm and the eSCH2
Table 1
Generalization of the reaction with various phenols
d
d
d
d
d
The reaction under the stipulated conditions failed to fetch the
dithiosubstituted product.
As representative examples for aromatic thiols, we chose p-
thiocresol and p-trifluoromethylthiophenol for the title reaction.
Under the above reaction conditions, p-thiocresol reacted smoothly
with bis(spirodienone) to fetch the corresponding monothio ether
derivative in moderate yields, but the p-trifluoromethylthiophenol
failed to react with the substrate. This reaction is noteworthy as it is
the first synthesis of calix[4]arene with a thioether moiety attached
directly at the upper rim.25
Amines were selected as the next nucleophilic candidates to
undergo the reaction. When substrate 1 reacted with diethyl amine
in the presence of p-TSA (5.0 eqiuv) in toluene at reflux tempera-
ture, reaction failed to occur. Substituting p-TSA with other Lewis
acids like AgOTf, Sc(OTf)2 etc. did not produce any results. The non-
Entry
Phenol 2(aej)
Yield (%)
3
4
5
6
1
2
3
4
5
6
7
8
9
(4-Me)C6H4OH (2a)
(4-OMe)C6H4OH (2b)
(4-Br)C6H4OH (2c)
(4-I)C6H4OH (2d)
11
17
20
22
25
30
20
4a/40
4b/42
4c/35
4d/32
4e/22
4f/17
4g/30
No reaction
No reaction
No reaction
5a/33
5b/35
5c/25
5d/23
5e/18
5f/6
15
20
26
28
23
20
17
(2-I)C6H4OH (2e)
(2,4-di-I)C6H3OH (2f)
(4-Ph)C6H4OH (2g)
(4-Nitro)C6H4OH (2h)
(4-Nitro)C6H4OH (2i)
(4-Formyl)C6H4OH (2j)
d
10
Reaction conditions: 2 (4.0 equiv), p-TSA(5.0 equiv), toluene, 70 ꢀC, 4 h.

5272
S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
Scheme 2. Proposed mechanistic pathways for the reaction between bis(spirodienone) 1 and nucleophiles in the presence of p-TSA.
The structure of 12 was established by NMR spectroscopy and
MALDI-TOF MS. The 1H NMR spectra of 12 showed a deshielded
singlet at 10.14 ppm due to the resonance of the hydrogen bonded
tBu
tBu
tBu
RS
d
RSH, p-TSA
OH protons. Other important features of the 1H NMR spectra are the
absence of the methoxy peaks, which were so conspicuous in
the parent compound and the presence of a pair of doublets for the
methylene bridge protons. The upper rim hydroxyl groups however
could not be detected in the 1H NMR spectra probably due to fast
flipping of hydroquinone moiety. The 13C NMR spectra and MALDI-
TOF analyses were in agreement with the assigned structure.
Although there has been a report on the synthesis of detertiar-
ybutylated 5-hydroxy calix[4]arene,26a to best of our knowledge,
this is the first synthesis of 5-hydroxy and 5,17-dihydroxycalix[4]
arenes.
1
3
+
+ 6
toluene, 70 °C, 6 h
HO
OH
OH
OH
7, R = C5H11 (36%)
8
, R = (4-Me)Ph (42%)
Scheme 3. p-TSA mediated reaction of calix[4]bis(spirodienone) 1 with thiols.
reactive nature of amines could be due to its protonation under the
reaction conditions employed. The non-availability of lone-pair of
electrons on the amino group obliterates its nucleophilic character.
We also demonstrate here the usefulness of the bis(spi-
rodienone) methodology of the upper rim modification of calix[4]
arene for the selective synthesis of mono- and diquinone calixar-
enes, which are otherwise difficult to synthesise. The mono- and
dimethoxy calixarenes21 reported in our previous communication
were demethylated using BBr3 to give excellent yields of the cor-
responding upper rim hydroxylated calixarenes (Scheme 4).26
Since compounds 11 and 12 contained one and two hydroqui-
none units, they can be readily oxidised to the respective mono-
and diquinones. Oxidation of 11 with cerium(IV)ammonium nitrate
(CAN) in CH3CN/H2O mixture at 0 ꢀC, calix[4]monoquinone 13 was
obtained in quantitative yield. The oxidation of 9 using CAN also
afforded 13 in 78% yield (Scheme 5).
The product 13 was characterized on the basis of spectroscopic
data. In the IR spectrum of 13, a peak at 3259 cmꢁ1 corresponding
to the eOH absorption and another one at 1647 cmꢁ1 corre-
sponding to the carbonyl was observed. In the 1H NMR spectrum,
the OH protons were discernible as two singlets at
d
9.13 and
t Bu
tBu
R2
tBu
tBu
R1
R4
R3
d
8.88 ppm in 1:2 ratio integrating for three protons. The signal due
to the protons of the quinone was observed at
d 6.68 ppm. Two
BBr3, DCM
singlets at
methylene protons. The tert-butyl appeared as two singlets at
and 1.20 ppm. The structure was further supported by 13C NMR
spectrum showing two carbonyl peaks positioned at 190.5 and
187.4 ppm. The OH attached carbon resonated at 148.2 ppm.
d
3.86 and 3.76 ppm were assigned to the bridging
0 °C - rt, 2 h
d
1.21
HO
OH
OH
OH
HO
OH
OH
OH
9, R1 = OMe, R2 = tBu
d
11, R3 = OH, R4 = tBu, 75%
12, R3 = R4 = OH, 72%
10
, R1 = R2 = OMe
d
Similarly, 10 on oxidation with CAN offered the 1,3-calix[4]
diquinone 14 in 72% yield (Scheme 6). To date there are only a few
Scheme 4. Synthesis of 5-hydroxy and 5,17-dihydroxycalix[4]arenes.

S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
5273
t Bu
t Bu
t Bu
OH
t Bu
t Bu
t Bu
OH
HO
tBu
MeO
t Bu
tBu
O
CAN, CH3CN/H2O
0 °C-rt, 12 h, 98%
CAN, CH3CN/H2O
0 °C-rt, 12 h, 78%
HO
HO
OH
OH
OH
OH
HO
O
OH
13
OH
11
9
Scheme 5. Synthesis of calix[4]monoquinone 13.
tBu
tBu
tBu
OH
O
tBu
OMe
MeO
O
CAN, CH3CN/H2O
0 °C-rt, 12 h, 72%
HO
OH
OH
O
OH
O
OH
10
14
Scheme 6. Synthesis of calix[4]diquinone 14.
reports regarding the synthesis of calixquinones.26c,27 The most
widely used method is the oxidation using thallium triflate starting
from p-tert-butylcalix[4]arene.28 However, for the selective oxida-
tion to mono, di, and triquinones, the procedures encounter pro-
tection of the phenolic OH groups. In this context, using our
methodology, both mono and diquinones having free OH groups at
the lower rim can be selectively synthesized.
The 1H NMR spectrum of 14 showed singlets for all the protons
in the compound. The OH proton appeared at
aromatic region showed two peaks at 6.89 and 6.68 ppm, corre-
sponding to aryl and quinone protons, respectively and the tert-
butyl groups resonated at
1.14 ppm. Interestingly, the 1H NMR
spectrum displayed a broad singlet at 3.72 ppm for the methylene
d 7.31 ppm, the
d
Figure 1. CVs at various scan rates(in the order of increasing amplitude of current: 50,
100, 200 mV sꢁ1) of 14 (1.4ꢂ10ꢁ3 M) in 1:9 CH2Cl2/CH3CN.
d
d
protons, which suggested fast flipping of quinone as well as the
aromatic rings. To understand the conformational preference of 14,
a variable temperature 1H NMR study was conducted and two
significant changes were observed as the temperature was lowered
from 298 to 223 K. The singlet due to the methylene bridge grad-
ually broadens on cooling before collapsing near 223 K. This ob-
servation is a clear indication that 14 is dynamic in solution even at
223 K. Thus, it is concluded that calix[4]diquinone possesses
a highly mobile structure in solution.
Anticipating complexation behavior of calixquinones toward
alkali metal ions, 1H NMR titrations with various alkali metal ions
were conducted. However, addition of Liþ, Naþ, and Kþ to solution
of 13 and 14 (in 4:1 CDCl3/CD3CN) did not cause any change in their
1H NMR spectra, indicating absence of any complexation between
the ligands and the metal ions. This could be due to the presence of
high degree of intramolecular hydrogen bonding present in these
compounds.
Among the functionalized calixarenes, calixquinones are of
particular interest because of their potential use as redox systems,
as participants in charge-transfer complexes29 and as synthetic
intermediates. Hence the electrochemical properties of 13 and 14
were investigated in dichloromethane/acetonitrile (1:9) using cy-
clic voltametry with (Bun)4NPF6 as the supporting electrolyte. The
compound 13 did not give any characteristic peaks of quinone
moieties present, as it was highly insoluble in the medium
employed. The insolubility can be attributed to the high degree of
intramolecular hydrogen bonding present in 13. The calixdiquinone
14 (Fig. 1) showed three redox waves in its voltamogram, two of
which are close together and reversible, 2/20 and 3/30, and the other
wave, 1, occurring at a less negative potential, being irreversible. In
simple calixdiquinones, the redox waves 1 and 2 are considered to
be two one-electron process and wave 3 is considered to be a two-
electron process.30 The irreversibility of wave 1 may be due to the
formation of insoluble hydroquinone species.31
3. Conclusion
In summary, a direct and efficient acid-mediated protocol for the
selective upper rim aryloxy substitution of calix[4]arene via bis(spi-
rodienone) chemistry has been opened up. The transformation is
distinguished by mild reaction conditions, experimental simplicity
and considerable generality. Moreover, this ipso-like nucleophilic
substitution reaction of bis(spirodienone) furnishes upper rim mod-
ification of calix[4]arene without resorting to any protection/depro-
tection strategy involving the lower rim of calixarenes.
A
straightforward methodology for the selective introduction of thio-
ether moiety at the upper rim of calix[4]arene has also been accom-
plished. Our investigations have also uncovered a relatively simple
and efficient strategy for the synthesis of 5-hydroxy and 5,23-dihy-
droxycalix[4]arene, which are otherwise difficult to synthesize. The
paper also deals with a highly selective method for the synthesis of
calix[4]mono- and diquinones in good yield. Our current efforts are
focused on exploring the use of this methodology in the synthesis of
complex molecular receptors for ionic and molecular recognition.
4. Experimental
4.1. General procedures and materials
All reactions were conducted in oven-dried glassware. Solvents
used for the experiments were distilled and dried as specified. All
reactions were monitored by TLC (Silica gel 60 F254, 0.25 mm,
Merck), visualization was effected with UV and/or in I2 chamber.

5274
S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
Chromatography refers to open column chromatography on silica
gel (100e200 mesh). NMR spectra were recorded at 300 (1H) and
75 (13C) MHz, respectively on a Bruker Advance DPX-300 MHz.
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2957, 2859, 1802, 1260,
1055 cmꢁ1. 1H NMR (300 MHz, CDCl3):
10.05 (s, OH, 4H), 7.30 (m,
ArH, 4H), 7.04 (s, ArH, 4H), 6.55 (s, ArH, 4H), 6.52 (s, ArH, 4H), 4.23
d
Chemical shifts are reported in
CDCl3
13C) as internal standards. IR spectra were recorded on
Bomem MB series FT-IR spectrometer; absorptions are reported in
cmꢁ1
Mass spectra were recorded under under MALDI-TOF
d
(ppm) relative to TMS (1H) or
(d, J¼13.2 Hz, ArCH2Ar, 4H), 3.64 (s, OCH3, 6H), 3.43 (d, J¼14.7 Hz,
(
ArCH2Ar, 4H), 1.24 (s, t-Bu, 18H). 13C NMR (125 MHz, CDCl3):
d 156.2
(CeOH), 152.2, 147.4, 145.7, 144.5, 132.3, 130.3, 129.9, 127.8, 126.6,
126.3, 119.2, 118.7, 114.3 (AreC), 55.6 (eOCH3), 34.0, 31.7, 30.8, 20.2,
16.3 (ArCH2Ar, t-Bu). Anal. Calcd for C50H52O8: C, 76.90; H, 6.71.
Found: C, 76.86; H, 6.69.
.
mechanism in Axima-CFR Plus spectrometer. Elemental analysis
was done using PerkineElmer-2400 CHNS analyser. Cyclic vol-
tammetry (CV) measurements were carried out with the model
1100A electrochemical analyzer (CH Instruments). This instrument
is a conventional three electrode cell that uses a Pt button working
electrode of 2 mm in diameter, Pt wire as the counter electrode, and
Ag/AgCl as the reference electrode. The experiment was carried out
using 0.1 M Bu4NPF6 as the supporting electrolyte under nitrogen
gas protection. All the reported analyses were carried out in our
laboratory (NIIST, Trivandrum).
4.2.5. 11,17,23-Tri-tert-butyl-5-O-(4-bromo)phenylcalix[4]arene
(4c). Yield: 35% as white solid. Rf: 0.89 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
1053 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.30 (s, OH, 4H), 7.34 (d,
J¼9.0 Hz, ArH, 2H), 7.05 (m, ArH, 6H), 6.95 (s, ArH, 2H), 6.69 (s, ArH,
2H), 4.24 (d, J¼10.5 Hz, ArCH2Ar, 4H), 3.50 (m, ArCH2Ar, 4H), 1.22 (s,
t-Bu, 18H), 1.21 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d 156.9
(CeOH), 150.3, 146.7, 146.5, 145.1, 144.6, 144.4, 144.2, 132.5, 129.8,
127.8, 127.7, 127.6, 126.9, 126.2, 125.9, 125.8, 119.9, 119.2, 115.1, 114.7
(AreC), 34.0, 32.7, 31.5, 30.8, 29.7, 22.7, 14.1 (ArCH2Ar, t-Bu). Anal.
Calcd for C46H51BrO5: C, 72.33; H, 6.73. Found: C, 72.29; H, 6.75.
4.2. General procedure for the reaction of calix[4]bis
(spirodienone) with phenols
A mixture of bis(spirodienone) 1 (50 mg, 0.08 mmol), phenol
(4.0 equiv), and p-TSA (5.0 equiv) in toluene was taken in a 50 ml R.
B. flask and was stirred at 70 ꢀC. The reaction was continued till the
reaction was complete as shown by TLC (w4 h). The solvent was
removed under reduced pressure. The reaction mixture was
worked up using dichloromethane/water mixture and the solid
mass obtained was purified by column chromatography.
4.2.6. 11,23-Di-tert-butyl-5,17-di-O-(4-bromo)phenylcalix[4]arene
(5c). Yield: 25% as white solid. Rf: 0.81 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2957, 2859, 1802, 1260,
d 10.15 (s, OH, 4H), 7.18 (m,
ArH, 4H), 6.92 (s, ArH, 4H), 6.44 (s, ArH, 4H), 6.40 (s, ArH, 4H), 4.24
1055 cmꢁ1. 1H NMR (300 MHz, CDCl3):
(d, J¼12.9 Hz, ArCH2Ar, 4H), 3.43 (d, J¼11.74 Hz, ArCH2Ar, 4H), 1.24
(s, t-Bu, 18H). 13C NMR (125 MHz, CDCl3):
d 154.1 (CeOH), 147.8,
4.2.1. 11,17,23-Tri-tert-butyl-5-O-(4-methyl)phenylcalix[4]arene
(4a). Yield: 40% as white solid. Rf: 0.90 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
145.1, 144.7, 142.6, 132.5, 132.2, 130.7, 129.2, 128.8, 128.3, 127.3,
125.7, 113.9 (AreC), 34.0, 32.4, 31.5, 30.6, 29.7, 27.7, 21.6, 19.2
(ArCH2Ar, t-Bu). Anal. Calcd for C48H46Br2O6: C, 65.61; H, 5.28.
Found: C, 65.66; H, 5.25.
1053 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.19 (s, OH, 4H), 7.07 (s,
ArH, 4H), 6.98 (s, ArH, 2H), 6.83 (m, ArH, 4H), 6.67 (s, ArH, 2H), 4.22
(d, J¼13.5 Hz, ArCH2Ar, 4H), 3.41 (d, J¼13.5 Hz, ArCH2Ar, 4H), 2.33
(s, eCH3, 3H), 1.22 (s, t-Bu, 18H), 1.19 (s, t-Bu, 9H). 13C NMR
4.2.7. 11,17,23-Tri-tert-butyl-5-O-(4-iodo)phenylcalix[4]arene (4d).
Yield: 32% as white solid. Rf: 0.91 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
(125 MHz, CDCl3):
d 154.3 (CeOH), 150.9, 146.2, 144.0, 143.4, 131.6,
129.4, 128.8, 126.6, 125.3, 125.2, 118.1, 117.8, 113.3 (AreC), 33.4, 31.9,
31.7, 30.9, 30.8, 20.0 (ArCH2Ar, eCH3, t-Bu). Anal. Calcd for
C47H54O5: C, 80.77; H, 7.79. Found: C, 80. 74; H, 7.75.
1053 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.21 (s, OH, 4H), 7.05 (s,
ArH, 4H), 6.96 (m, ArH, 2H), 6.81 (m, ArH, 4H), 6.65 (s, ArH, 2H),
4.23 (d, J¼12.5 Hz, ArCH2Ar, 4H), 3.42 (d, J¼13.5 Hz, ArCH2Ar, 4H),
1.22 (s, t-Bu, 18H), 1.19 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
4.2.2. 11,23-Di-tert-butyl-5,17-di-O-(4-methyl)phenylcalix[4]arene
(5a). Yield: 33% as white solid. Rf: 0.84 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
d 154.3 (CeOH), 150.9, 146.2, 144.0, 143.4, 131.6, 129.4, 128.8, 126.6,
125.3, 125.2, 118.1, 117.8, 113.3 (AreC), 34.0, 32.4, 31.9, 31.2, 30.9,
20.0 (ArCH2Ar, t-Bu). Anal. Calcd for C46H51IO5: C, 68.14; H, 6.34.
Found: C, 68.10; H, 6.29.
1053 cmꢁ1.1H NMR (500 MHz, CDCl3):
d 10.07 (s, OH, 4H), 7.02 (m, ArH,
4H), 6.96 (s, ArH, 4H), 6.81 (m, ArH, 4H), 6.64 (s, ArH, 4H), 4.20 (d,
J¼13.5 Hz, ArCH2Ar, 4H), 3.39 (d, J¼13.5 Hz, ArCH2Ar, 4H), 2.30 (s,
4.2.8. 11,23-Di-tert-butyl-5,17-di-O-(4-iodo)phenylcalix[4]arene
(5d). Yield: 23% as white solid. Rf: 0.80 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2957, 2859, 1802, 1260,
eCH3, 6H), 1.23 (s, t-Bu, 18H). 13C NMR (125 MHz, CDCl3):
d 151.2
(CeOH),146.4,144.7,143.5,131.3,129.3,128.9,126.8,125.6,125.3,118.2,
117.7, 113.4 (AreC), 34.0, 31.7, 30.8, 30.5, 20.1,16.5,16.3 (ArCH2Ar, eCH3,
t-Bu). Anal. Calcd for C50H52O6: C, 80.18; H, 7.00. Found: C, 80.15; H, 6.96.
1055 cmꢁ1. 1H NMR (300 MHz, CDCl3):
d 10.11 (s, OH, 4H), 7.13 (m,
ArH, 8H), 7.07 (s, ArH, 6H), 6.66 (s, ArH, 2H), 4.24 (d, J¼13.2 Hz,
ArCH2Ar, 4H), 3.46 (d, J¼12.3 Hz, ArCH2Ar, 4H), 1.24 (s, t-Bu, 18H).
4.2.3. 11,17,23-Tri-tert-butyl-5-O-(4-methoxy)phenylcalix[4]arene
(4b). Yield: 42% as white solid. Rf: 0.91 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
13C NMR (75 MHz, CDCl3):
d 153.4 (CeOH),146.9,146.3,144.4,144.3,
137.7, 129.2, 129.1, 127.9, 127.7, 127.3, 126.0, 125.8, 125.6, 115.2, 114.5
(AreC), 34.1, 32.6, 32.0, 31.4, 30.1, 29.7, 28.5 (ArCH2Ar, t-Bu). Anal.
Calcd for C48H46I2O6: C, 59.27; H, 4.77. Found: C, 59.24; H, 4.75.
1053 cmꢁ1. 1H NMR (300 MHz, CDCl3):
d 10.14 (s, OH, 4H), 6.96 (m,
ArH, 8H), 6.74 (s, ArH, 2H), 6.49 (s, ArH, 2H), 4.17 (d, J¼11.2 Hz,
ArCH2Ar, 4H), 3.58 (s, OCH3, 3H), 3.39 (br s, ArCH2Ar, 4H), 1.24 (s, t-
4.2.9. 11,17,23-Tri-tert-butyl-5-O-(2-iodo)phenylcalix[4]arene (4e).
Yield: 22% as white solid. Rf: 0.88 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3176, 2957, 2868, 1770, 1269,
d 10.21 (s, OH, 4H), 7.08 (m,
ArH, 4H), 7.02 (m, ArH, 2H), 6.86 (m, ArH, 4H), 6.67 (s, ArH, 2H), 4.23
Bu, 18H), 1.19 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d 154.4
(CeOH), 146.9, 146.3, 144.4, 144.2, 142.5, 137.5, 129.2, 129.1, 127.9,
127.7, 125.8, 125.7, 125.6, 119.2, 118.5 (AreC), 57.2 (eOCH3), 34.1,
34.0, 32.6, 31.9, 31.5, 31.4, 30.1, 29.7, 28.5, 23.6, 15.1 (ArCH2Ar, t-Bu).
Anal. Calcd for C47H54O6: C, 78.96; H, 7.61. Found: C, 79.23; H, 7.57.
1066 cmꢁ1. 1H NMR (500 MHz, CDCl3):
(d, J¼12.5 Hz, ArCH2Ar, 4H), 3.42 (d, J¼13.5 Hz, ArCH2Ar, 4H), 1.22
(s, t-Bu, 18H), 1.19 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d 155.5
4.2.4. 11,23-Di-tert-butyl-5,17-di-O-(4-methyl)phenylcalix[4]arene
(5b). Yield: 35% as white solid. Rf: 0.84 (9:1 hexane/EtOAc). Mp:
(CeOH), 147.9, 147.2, 146.0, 144.4, 132.6, 130.4, 129.8, 126.4, 125.2,
117.1, 116.8, 114.6 (AreC), 34.0, 32.4, 31.9, 31.2, 30.9, 20.0 (ArCH2Ar,

S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
5275
t-Bu). Anal. Calcd for C46H51IO5: C, 68.14; H, 6.34. Found: C, 68.21; H,
0.89 (m, CH3, 3H). 13C NMR (75 MHz, CDCl3):
d
154.4 (CeOH), 146.9,
6.25.
146.3, 144.4, 144.2, 142.3, 129.2, 127.8, 127.6, 127.2, 125.9, 125.8,
125.7, 115.5 (AreC), 43.5 (eSCH2), 34.0, 32.6, 31.5, 31.4, 29.2, 28.1,
22.6, 14.9 (ArCH2Ar, t-Bu). MALDI-TOF MS: calcd for C46H58O4S,
(MþNa)þ: 717.40. Found: 717.86.
4.2.10. 11,23-Di-tert-butyl-5,17-di-O-(2-iodo)phenylcalix[4]arene
(5e). Yield: 18% as white solid. Rf: 0.78 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2957, 2859, 1802, 1260,
1055 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d
10.19 (s, OH, 4H), 7.12 (m,
4.3.2. 11,17,23-Tri-tert-butyl-5-S-(4-methyl)phenylcalix[4]arene (8).
Yield: 42% as white solid. Rf: 0.75 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2958, 2860, 1790, 1259,
ArH, 4H), 6.96 (m, ArH, 8H), 6.62 (m, ArH, 4H), 4.24 (d, J¼13.5 Hz,
ArCH2Ar, 4H), 3.44 (d, J¼12.6 Hz, ArCH2Ar, 4H), 1.23 (s, t-Bu, 18H).
13C NMR (125 MHz, CDCl3):
d
154.9 (CeOH), 146.2, 145.4, 144.8,
1053 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.19 (s, OH, 4H), 7.06 (s,
133.6, 130.7, 129.7, 128.8, 128.5, 127.3, 125.4, 113.9 (AreC), 33.9, 32.4,
31.5, 30.6, 29.7, 27.6, 21.4 (ArCH2Ar, t-Bu). Anal. Calcd for
C48H46I2O6: C, 59.27; H, 4.77. Found: C, 59.16; H, 4.81.
ArH, 4H), 6.98 (s, ArH, 2H), 6.83 (m, ArH, 4H), 6.67 (s, ArH, 2H), 4.23
(d, J¼13.5 Hz, ArCH2Ar, 4H), 3.42 (s, ArCH2Ar, 4H), 2.13 (s, CH3, 3H),
1.22 (s, t-Bu, 18H), 1.19 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d
156.9 (CeOH), 150.3, 146.7, 145.1, 144.6, 144.4, 144.2, 132.5, 129.8,
4.2.11. 11,17,23-Tri-tert-butyl-5-O-(2,4-diiodo)phenylcalix[4]arene
(4f). Yield: 17% as white solid. Rf: 0.91 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2960, 2862, 1814, 1258,
127.7, 127.6, 126.9, 126.2, 125.9, 125.8, 119.9, 119.3, 115.1, 114.7
(AreC), 57.2 (eCH3), 34.0, 32.7, 32.5, 34.4, 31.5, 30.8, 29.7, 22.6
(ArCH2Ar, t-Bu). Anal. Calcd for C47H54O4S: C, 78.95; H, 7.61; S, 4.48.
Found: C, 78.92; H, 7.59, S, 4.50.
1050 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.21 (s, OH, 4H), 7.06 (m,
ArH, 4H), 6.93 (m, ArH, 5H), 6.63 (s, ArH, 2H), 4.23 (d, J¼13.3 Hz,
ArCH2Ar, 4H), 3.43 (d, J¼14.4 Hz, ArCH2Ar, 4H), 1.22 (s, t-Bu, 18H),
4.4. Procedure for the synthesis of 5,17-dihydroxycalix[4]
arene (12)
1.19 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d 154.6 (CeOH), 146.7,
145.1, 144.6, 144.4, 132.6, 129.7, 128.1, 127.6, 125.9, 125.3, 119.9, 119.1,
114.7 (AreC), 34.0, 32.6, 32.5, 31.4, 29.3 (ArCH2Ar, t-Bu). Anal. Calcd
for C46H50I2O5: C, 58.98; H, 5.38. Found: C, 59.12; H, 5.47.
11,23-Di-tert-butyl-5,17-dimethoxycalix[4]arene, 10 (50 mg,
0.09 mmol) dissolved in 10 ml dry dichloromethane in a two
necked R.B, was cooled in ice-salt mixture, BBr3 (87 mg, 0.35 mmol)
was added to it over a period of half-an-hour and the reaction
mixture was allowed to stir under argon for 3 h (0 ꢀC). The com-
pletion of the reaction was tested by TLC. The product was obtained
using column chromatography [petroleum ether/ethyl acetate
(90:10)] as a colorless mass 12 (34 mg, 72%).
4.2.12. 11,23-Di-tert-butyl-5,17-di-O-(2,4-diiodo)phenylcalix[4]arene
(5f). Yield: 6% as white solid. Rf: 0.83 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3172, 2958, 2860, 1813, 1256,
1044 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d 10.07 (s, OH, 4H), 7.26 (m,
ArH, 4H), 7.12 (m, ArH, 6H), 6.76 (s, ArH, 4H), 4.23 (d, J¼13.2 Hz,
ArCH2Ar, 4H), 3.46 (d, J¼12.7 Hz, ArCH2Ar, 4H), 1.25 (s, t-Bu, 18H).
13C NMR (125 MHz, CDCl3):
d 152.5 (CeOH), 149.6, 146.5, 144.6,
4.4.1. 11,23-Di-p-tert-butyl-5,17-dihydroxycalix[4]arene (12). Yield:
143.3, 131.6, 129.7, 128.8, 126.8, 125.6, 118.2, 117.4, 114.3 (AreC), 34.1,
32.0, 31.4, 30.8, 29.4 (ArCH2Ar, t-Bu). Anal. Calcd for C48H44I4O6: C,
47.08; H, 3.62. Found: C, 47.14; H, 3.71.
72% as a pasty mass. Rf: 0.60 (7:3 hexane/EtOAc). IR (KBr) nmax
3172, 2960, 2860, 1786, 1060 cmꢁ1 1H NMR (300 MHz, CDCl3):
10.14 (s, OH, 4H), 7.06 (s, ArH, 4H), 6.52 (s, ArH, 4H), 4.22 (d,
:
.
d
J¼13.8 Hz, ArCH2Ar, 4H), 3.45 (broad s, ArCH2Ar, 4H), 1.24 (s, t-Bu,
4.2.13. 11,17,23-Tri-tert-butyl-5-O-(4-phenyl)phenylcalix[4]arene
(4g). Yield: 30% as white solid. Rf: 0.89 (9:1 hexane/EtOAc). Mp:
decomposed >240 ꢀC. IR (KBr) nmax: 3173, 2960, 2858, 1800, 1259,
d 10.29 (s, OH, 4H), 7.83 (m,
ArH, 2H), 7.53 (m, ArH, 5H), 7.05 (m, ArH, 8H), 6.75 (s, ArH, 2H), 4.25
18H), two of the OH protons could not be detected. 13C NMR
(125 MHz, CDCl3):
d 154.7 (CeOH), 147.2, 144.0, 143.4, 142.6, 132.4,
130.8, 129.8, 129.2, 128.8, 128.3, 128.1, 127.3, 125.7, 114.1 (AreC),
34.1, 32.3, 31.5, 30.6, 29.7, 27.7, 21.6, 19.2 (ArCH2Ar, t-Bu). MALDI-
TOF MS: calcd for C36H40O6, (MþNa)þ: 591.28. Found: 591.77.
1053 cmꢁ1. 1H NMR (500 MHz, CDCl3):
(d, J¼13.0 Hz, ArCH2Ar, 4H), 3.48 (d, J¼14.0 Hz, ArCH2Ar, 4H), 1.22
(s, t-Bu, 18H), 1.20 (s, t-Bu, 9H). 13C NMR (125 MHz, CDCl3):
d 156.4
(CeOH), 146.6, 146.4, 145.0, 144.4, 144.1, 138.0, 129.7, 128.8, 127.9,
127.7,127.6,127.5,127.3,126.9,126.7,126.6,126.0, 125.8, 125.7,119.0,
118.2 (AreC), 34.0, 33.9, 32.5, 32.3, 31.4, 31.3, 29.630 (ArCH2Ar, t-
Bu). Anal. Calcd for C52H56O5: C, 82.07; H, 7.42. Found: C, 82.02; H,
7.39.
4.5. Procedure for the synthesis of calix[4]monoquinone (13)
To 5-hydroxycalix[4]arene 11 (25 mg, 0.04 mmol) dissolved in
minimum amount of dichloromethane, CH3CN (8 mL)/H2O (2 mL)
mixture was added and cooled to 0 ꢀC. CAN (45 mg, 0.08 mmol)
dissolved in CH3CN (6 mL)/H2O(4 mL) mixture was added over
a period of 1 h, stirred at 0 ꢀC for 12 h. The completion of the re-
action was checked using TLC. The color of the reaction mixture
turned from light yellow to dark red. Solvent was removed under
reduced pressure. The solid mass obtained was extracted with
dichloromethane and dried over anhydrous sodium sulfate. The
residue obtained after removal of the solvent was purified by col-
umn chromatography [petroleum ether/ethyl acetate (90:10)] to
afford 13 as a red crystalline solid (24 mg, 98%).
4.3. General procedure for the reaction of calix[4]bis
(spirodienone) with thiols
A mixture of bis(spirodienone) 1 (50 mg, 0.08 mmol), thiol
(4.0 equiv), and p-TSA (5.0 equiv) in toluene was taken in a 50 ml R.
B. flask and was stirred at 70 ꢀC. The reaction was continued till it
was complete as shown by TLC (w6 h). The solvent was removed
under reduced pressure. The reaction mixture was worked up using
dichloromethane/water mixture and the solid mass obtained was
purified by column chromatography.
4.5.1. 11,17,23-Tri-p-tert-butylcalix[4]monoquinone (13). Yield: 98%
as a dark red solid. Rf: 0.69 (7:3 hexane/EtOAc). Mp: 330e334 ꢀC. IR
(KBr) nmax: 3259, 2956, 1647, 1485 cmꢁ1. 1H NMR (300 MHz, CDCl3):
4.3.1. 11,17,23-Tri-tert-butyl-5-S-pentylcalix[4]arene (7). Yield: 36%
as a pasty mass. Rf: 0.78 (9:1 hexane/EtOAc). IR (KBr) nmax: 3170,
d
9.13 (s, OH,1H), 8.88 (s, OH, 2H), 7.10 (d, J¼2.0 Hz, ArH, 2H), 7.03 (s,
2956, 2860, 1784, 1058 cmꢁ1. 1H NMR (300 MHz, CDCl3):
d
10.21 (s,
ArH, 2H), 6.89 (d, J¼2.0 Hz, ArH, 2H), 6.68 (s, quinone H, 2H), 3.86
OH, 4H), 7.02 (m, ArH, 6H), 6.55 (s, ArH, 2H), 4.23 (d, J¼12.3 Hz,
ArCH2Ar, 4H), 3.77 (t, J¼6.0 Hz, CH2, 2H), 3.46 (d, J¼13.5 Hz,
ArCH2Ar, 4H), 1.68 (m, CH2, 2H), 1.34, 1.23, 1.19 (m, CH2, t-Bu, 31H),
(s, ArCH2Ar, 4H), 3.76 (s, ArCH2Ar, 4H), 1.21 (s, t-Bu, 18H), 1.20 (s, t-
Bu, 9H). 13C NMR (75 MHz, CDCl3):
d
190.5, 187.4, 148.2, 148.0, 147.2,
144.3, 144.1, 134.2, 129.6, 127.5, 127.1, 125.5, 123.2, 34.1, 34.0, 32.4,

5276
S. Thulasi et al. / Tetrahedron 66 (2010) 5270e5276
5. Shohat, D.; Grushka, E. Anal. Chem. 1994, 66, 747.
31.5, 31.4, 30.7. Anal. Calcd for C40H46O5: C, 78.19; H, 7.64. Found: C,
78.34; H, 7.91.
6. (a) Gomez-Kaifer, M.; Reddy, P. A.; Gutsche, C. D.; Echegoyen, I. J. Am. Chem. Soc.
1994, 116, 3580; (b) Beer, P. D.; Cheng, Z.; Drew, M. G. B.; Gale, P. A. J. Chem. Soc.,
Chem. Commun. 1994, 2207; (c) Mandolini, L.; Ungaro, R. Calixarenes in Action;
Imperial College: London, 2000.
7. Arduini, A.; Pochini, A.; Sicuri, A. R.; Secchi, A.; Ungaro, R. Gazz. Chim. Ital. 1994,
124, 129.
4.6. Procedure for the synthesis of calix[4]diquinone (14)
To 11,23-di-tert-butyl-5,17-dimethoxycalix[4]arene 10 (25 mg,
0.04 mmol) dissolved in minimum amount of dichloromethane,
CH3CN (8 mL)/H2O (2 mL) mixture was added and cooled to 0 ꢀC.
CAN (45 mg, 0.08 mmol) dissolved in CH3CN (6 mL)/H2O(4 mL)
mixture was added over a period of one hour, stirred at 0 ꢀC for
12 h. The completion of the reaction was checked using TLC. The
color of the reaction mixture turned from light yellow to dark red.
Solvent was removed under reduced pressure. The solid mass
obtained was extracted with dichloromethane and dried over
anhydrous sodium sulfate. The residue obtained after removal of
the solvent was purified by column chromatography [petroleum
ether/ethyl acetate (90:10)] to afford 14 as a red crystalline solid
(17 mg, 72%).
8. (a) Verboom, W.; Durie, A.; Egberink, R. J. M.; Asfari, Z.; Reinhoudt, D. N. J. Org.
Chem. 1992, 57, 1313; (b) Kelderman, E.; Derhaeg, L.; Heesnik, G. J. T.; Verboom,
W.; Engbersen, J. F. J.; van Hulst, N. F.; Persoons, A.; Reinhoudt, D. N. Angew.
Chem., Int. Ed. Engl. 1992, 31, 1057.
9. Casnati, A.; Ting, Y.; Berti, D.; Fabbi, M.; Pochini, A.; Ungaro, R.; Sciotto, D.;
Lombardo, G. G. Tetrahedron 1993, 49, 9815.
10. Almi, M.; Arduini, A.; Casnati, A.; Pochini, A.; Ungaro, R. Tetrahedron 1989, 45,
2177.
11. (a) Shinkai, S.; Nagasaki, T.; Iwamoto, K.; Ikeda, A.; Matsuda, T.; Iwamoto, M.
Bull. Chem. Soc. Jpn. 1991, 64, 381; (b) Conner, M.; Janout, V.; Regen, S. L. J. Org.
Chem. 1992, 57, 3744.
12. Arduini, A.; Manfredi, G.; Pochini, A.; Sicuri, A. R.; Ungaro, R. J. Chem. Soc., Chem.
Commun. 1991, 936.
13. Shinkai, S.; Kawaguchi, H.; Manabe, O. J. Polym. Sci 1988, 26, 391.
14. Coquiere, D.; Cadeau, H.; Rondelez, Y.; Giorgi, M.; Reinaud, O. J. Org. Chem. 2006,
71, 4059.
15. Redon, S.; Li, Y.; Reinaud, O. J. Org. Chem. 2003, 68, 7004.
16. Arora, V.; Chawla, H. M.; Santra, A. Tetrahedron 2002, 58, 5591.
17. Arduini, A.; Mirone, L.; Peganuzzi, D.; Pinalli, A.; Pochini, A.; Secchi, A.; Ungaro,
R. Tetrahedron 1996, 52, 6011.
18. (a) Troisi, F.; Pierro, T.; Gaeta, C.; Neri, P. Org. Lett. 2009, 11, 697; (b) Troisi, F.;
Pierro, T.; Gaeta, C.; Carratù, M.; Neri, P. Tetrahedron Lett. 2009, 50, 4416.
19. Cho, Y. L.; Rudkevich, D. M.; Rebek, J., Jr. J. Am. Chem. Soc. 2000, 122, 9868.
20. (a) Litwak, A. M.; Biali, S. E. J. Org. Chem. 1992, 57, 1943; (b) Aleksuik, O.;
Grynszpan, F.; Biali, S. E. J. Org. Chem. 1993, 58, 1994; (c) Grynszpan, F.; Biali, S.
E. J. Chem. Soc., Chem. Commun. 1994, 2545; (d) Grynszpan, F.; Aleksiuk, F.; Biali,
S. E. J. Org. Chem. 1994, 59, 2070; (e) Simaan, S.; Agbaria, K.; Biali, S. E. J. Org.
Chem. 2002, 67, 6136; (f) Biali, S. E. Synlett 2003, 1.
4.6.1. 11,23-Di-p-tert-butylcalix[4]diquinone (14). Yield: 72% as
a red solid. Rf: 0.71 (7:3 hexane/EtOAc). Mp: 330e334 ꢀC. IR (KBr)
nmax: 3259, 2956,1647,1485 cmꢁ1. 1H NMR (500 MHz, CDCl3):
d
7.31
(s, OH, 2H), 6.89 (s, ArH, 4H), 6.68 (s, quinone H, 4H), 3.72 (s,
ArCH2Ar, 8H), 1.14 (s, t-Bu, 18H). 13C NMR (125 MHz, CDCl3):
189.0,
d
187.5, 149.4, 148.8, 144.4, 133.3, 126.4, 125.4, 34.1, 31.9, 31.5, 30.9.
Anal. Calcd for C36H36O6: C, 76.57; H, 6.48. Found: C, 76.53; H, 6.45.
21. Thulasi, S.; Bhagavathy, G. V.; Eliyan, J.; Varma, L. R. Tetrahedron Lett. 2009, 50,
770.
22. (a) Jaime, C.; de Mendoza, J.; Prados, P.; Neito, P. M.; Sanchez, C. J. Org. Chem.
1991, 56, 3372; (b) Bifulco, G.; Gomez-Paloma, L.; Riccio, R.; Gaeta, C.; Troisi, F.;
Neri, P. Org. Lett. 2005, 7, 5757; (c) Bifulco, G.; Riccio, R.; Gaeta, C.; Neri, P. Chem.
dEur. J. 2007, 13, 7185.
Acknowledgements
This work has been supported by Council of Scientific and In-
dustrial Research (NWP 0023), and Department of Science and
Technology (DST), New Delhi. S.T. acknowledges University Grants
Commission for research fellowship.
23. Litwak, A. M.; Grynszpan, F.; Aleksiuk, O.; Biali, S. E. J. Org. Chem. 1993, 58, 393.
24. (a) Gutsche, C. D.; Pagoria, P. F. J. Org. Chem. 1985, 50, 5795; (b) No, K. H.; Kim, J.
S.; Shon, O. J.; Yang, S. H.; Suh, I. H.; Kim, J. G.; Bartsch, R. A.; Kim, J. Y. J. Org.
Chem. 2001, 66, 5976; (c) Haino, T.; Harano, T.; Matsumura, K.; Fukazawa, Y.
Tetrahedron Lett. 1995, 36, 5793; (d) Wong, M. S.; Nicoud, J.-F. Tetrahedron Lett.
1993, 34, 8237; (e) Arduini, A.; Pochini, A.; Rizzi, A.; Sicuri, A. R.; Ungaro, R.
Supplementary data
€
Tetrahedron Lett. 1990, 31, 4653; (f) Bohmer, V.; Brusko, V.; Rissanen, K.
Supplementary data associated with this article can be found in
online version at doi:10.1016/j.tet.2010.04.021. This data include
MOL files and In ChiKeys of the most important compounds de-
scribed in this article.
Synthesis 2002, 1898.
25. A thiomethyl group have been exhaustively appended onto the upper rim of
calix[4]arene by Yilmaz et al. Memon, S.; Tabakci, M.; Roundhill, D. M.; Yilmaz,
M. Polymer 2005, 46, 1553.
26. (a) Lee, M.-D.; Yang, K.-M.; Tsoo, C.-Y.; Shu, C.-M.; Lin, L.-G. Tetrahedron 2001,
57, 8095; (b) Mascal, M.; Warmuth, R.; Naven, R. T.; Edwards, R. A.; Hursthouse,
M. B.; Hibbs, D. E. J. Chem. Soc., Perkin Trans. 1 1999, 3435; (c) Morita, Y.; Agawa,
T.; Nomura, E.; Taniguchi, H. J. Org. Chem. 1992, 57, 3658; (d) Gaeta, C.; Procida,
G.; Gavuzzo, E.; Neri, P. J. Incl. Phenom. Macrocycl. Chem. 2008, 60, 115.
27. (a) Rosik, L.O. Ph.D. Thesis, Washington University, St. Louis, MO, 1986; p 29. (b)
Morita, Y.; Agawa, T.; Kai, Y.; Kanehisa, N.; Kasai, N.; Normura, E. Chem. Lett.
1989, 1349.
References and notes
1. (a) Gutsche, C. D. Acc. Chem. Res. 1983, 16, 161; (b) Wieser, C.; Dieleman, C. B.;
Matt, D. Coord. Chem. Rev. 1997, 165, 93; (c) Cafeo, G.; Kohnke, F. H.; La Torre, G.
L.; Parisi, M. F.; Nascone, R. P.; White, A. J. P.; Williams, D. J. Chem.dEur. J. 2002,
8, 3148; (d) Ikeda, A.; Shinkai, S. Chem. Rev. 1997, 97, 1713; (e) Casnati, A.;
Sansone, F.; Ungaro, R. Acc. Chem. Res. 2003, 36, 246.
28. (a) van Loon, J. D.; Arduini, A.; Coppi, L.; Verboom, W.; Pochini, A.; Ungaro, R.;
Reinhoudt, D. J. Org. Chem. 1990, 55, 5639; (b) Reddy, P. A.; Gutsche, C. D. J. Org.
Chem. 1993, 58, 3245.
2. Lehn, J.-M. Supramolecular Chemistry: Concepts and Perspectives; VCH: Wein-
29. Aviram, A.; Seiden, P. E. In Molecular Electronic Devices; Carter, F. L., Ed.; Marcel
Dekker: New York, NY, 1982; p 5.
heim, 1995.
€
3. Bohmer, V. Angew. Chem., Int. Ed. Engl. 1995, 34, 713.
30. (a) Beer, P. D.; Gale, P. A.; Chen, Z.; Drew, M. G. B.; Heath, J. A.; Ogden, M. I.;
Powell, H. R. Inorg. Chem. 1997, 36, 5880; (b) Chung, T. D.; Choi, D.; Kang, S. K.;
Lee, S. K.; Chang, S.-K.; Kim, H. J. Electroanal. Chem. 1995, 396, 431; (c) Chung, T.
D.; Kang, S. K.; Kim, J.; Kim, H.-S.; Kim, H. J. Electroanal. Chem. 1997, 438, 71.
31. Casnati, A.; Comelli, E.; Fabbi, M.; Bocchi, V.; Mori, G.; Ugozzoli, F.; Lanfredi, A.
M. M.; Pochini, A.; Ungaro, R. Recl. Trav. Chim. Pays-Bas 1993, 112, 384.
4. (a) Sensors for neutral molecules. see: Schierbaum, K.-D.; Gerlach, A.; Gopel,
W.; Miiller, W. M.; Vogtle, F.; Dominik, A.; Rorh, H. J. Fresenius J. Anal. Chem.
1994, 349, 372; (b) Kremer, F. J. B.; Chiosis, G.; Engbersen, J. F. J.; Reiuhoudt, D.
N. J. Chem. Soc., Perkin Trans. 2. 1994, 677; (c) Yainamoto, H.; Shinkai, S. Chem.
Lett. 1994, 1115; (d) Wang, J.; Liu, J. Anal. Chim. Acta 1994, 194, 201; (e) Chan, W.
H.; Cai, P. X.; Gu, X. H. Analyst 1994, 119, 1853.