Triptycene-derived homooxacalixarene analogues: Synthesis, structures, and complexation with fullerenes C60 and C70

Article abstract of DOI:10.1021/jo302459m

A series of triptycene-derived homooxacalixarene analogues were conveniently synthesized by a one-pot approach starting from 2,7-dihydroxytriptycene and 1,3-bisbromomethylbenzene derivatives under mild reaction conditions. Similarly, two pairs of basket-like triptycene-derived homooxacalixarene analogues were also designed and synthesized. Structures of these macrocyclic molecules in both solution and solid state were studied by NMR experiments and X-ray crystallography. Because of the rigid triptycene units, the homooxacalixarene analogues showed large cavities and fixed conformations even up to 380 K. It was also found that these novel macrocycles could be served as efficient host molecules for complexation with fullerenes C₆₀ and C₇₀.

Full text of DOI:10.1021/jo302459m

Article
pubs.acs.org/joc
Triptycene-Derived Homooxacalixarene Analogues: Synthesis,
Structures, and Complexation with Fullerenes C60 and C70
Tao Xie,†,‡ Shu-Zhen Hu,† and Chuan-Feng Chen*,†
†Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Molecular Recognition and Function, Institute of
Chemistry, Chinese Academy of Sciences, Beijing 100190, China
‡University of Chinese Academy of Sciences, Beijing 100049, China
S
* Supporting Information
ABSTRACT: A series of triptycene-derived homooxacalixar-
ene analogues were conveniently synthesized by a one-pot
approach starting from 2,7-dihydroxytriptycene and 1,3-
bisbromomethylbenzene derivatives under mild reaction
conditions. Similarly, two pairs of “basket-like” triptycene-
derived homooxacalixarene analogues were also designed and
synthesized. Structures of these macrocyclic molecules in both
solution and solid state were studied by NMR experiments and
X-ray crystallography. Because of the rigid triptycene units, the
homooxacalixarene analogues showed large cavities and fixed
conformations even up to 380 K. It was also found that these novel macrocycles could be served as efficient host molecules for
complexation with fullerenes C60 and C70.
positions of triptycene-derived oxacalixarenes. Herein, we
report the synthesis of a series of novel triptycene-derived
homooxacalixarene analogues. Their structures and self-
assemblies in the solid state were also investigated. Moreover,
it was found that the homooxacalixarene analogues show
efficient complexation properties toward fullerenes C60 and
C70.10
INTRODUCTION
■
The design and synthesis of novel macrocyclic host molecules
are undoubtedly one of the most important research topics in
host−guest chemistry and also supramolecular chemistry.1
Among various types of known synthetic macrocyclic hosts,
calixarenes have attracted much attention for their ready
availabilities, unique conformations and cavities, and powerful
recognition properties.2 Along with the development of
calixarene chemistry, recent years have witnessed a fast growing
interest in heterocalixarenes,3−6 in which the methylene groups
of calixarenes were replaced by heteroatoms such as oxygen,
nitrogen, and sulfur. Because of the different electronic nature
of heteroatoms, the heterocalixarenes exhibited interesting
conformations, cavity structures, and molecular recognition
properties. Compared with heterocalixarenes, homoheterocalix-
arenes, a class of heterocalixarene analogues in which the
heteroatoms were partly or completely replaced by CH2XCH2
(X = O, NR, et al.) groups, showed the increased cavity sizes,
which could also result in their different conformations and
recognition properties with those of heterocalixarenes as well as
calixarenes.7
During the past several years, we have proven that triptycene
with a unique 3D rigid structure could be used as a useful
building block for the design and synthesis of novel macrocyclic
hosts with specific structures and properties.8,9 Thus, several
different kinds of macrocycles including triptycene-derived
calixarenes9h,i and heterocalixarenes9e,g,j with enlarged cavities
and fixed conformations have been constructed. Our
continuous interest in exploring new kind of macrocyclic
hosts has led us to design and synthesize homooxacalixarene
analogues by the insertion of methylene units into the bridging
RESULTS AND DISCUSSION
■
Synthesis of Triptycene-Derived Homooxacalixarene
Analogues. Synthesis of the macrocyclic molecules 6−9
through a one-pot approach is depicted in Scheme 1. According
to the procedure described previously, 2,7-dihydroxytriptycene
1 was first prepared.9e Owing to the 3D rigid structure of
triptycene, there exist two possible linking modes of 1 for the
cyclization reaction, and two different macrocyclic products as a
pair of diastereomers could be obtained. Consequently, by the
one-pot coupling reaction of 1 and 1,3-bis(bromomethyl)-5-
tert-butyl-2-methoxybenzene 27a in DMF for 48 h in the
presence of Cs2CO3, the macrocycles 6a and 6b were obtained
in 18 and 22% yield, respectively. Under the same reaction
conditions, the target macrocyclic molecules 7a−9a and 7b−9b
were conveniently prepared by the one-pot reaction of 2,7-
dihydroxytriptycene 1 with compounds 3−5, respectively. All
1
new compounds were characterized by the H NMR, 13C
NMR, MALDI-TOF mass spectra, and elemental analysis.
Similarly, two pairs of “basket-like” triptycene-derived
homooxacalixarene analogues 16a,b and 17a,b in which the
Received: November 9, 2012
Published: December 27, 2012
© 2012 American Chemical Society
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Scheme 1. Synthesis of the Triptycene-Derived Homooxacalixarene Analogues 6−9
Scheme 2. Synthesis of the Triptycene-Derived Homooxacalixarene analogues 16 and 17
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two p-phenyl-substituted benzene rings were linked together by
crown ether chains were also designed, and their synthetic
route is depicted in Scheme 2. First, reaction of 2,5-
dihydroxymethyl-4-phenylphenol with bistosylate 10 in
CH3CN gave compound 12 in 76% yield, which was then
treated with PBr3 in CHCl3 to afford compound 14 in 85%
yield. Finally, the target molecules 16a and 16b were obtained
in 8 and 37% yield, respectively, by the reaction of 14 with 2,7-
dihydroxytriptycene 1 in DMF under high dilution conditions
in the presence of Cs2CO3. Following the same procedure, the
homooxacalixarene analogues 17a and 17b were prepared in 21
and 23%, respectively.
could be a trans-isomer. For other pairs of the triptycene-
derived homooxocalixarene analogues, the similar spectral
properties of the diastereomers were also found, which proved
their structures in solution.
As shown in Figure 1, the methylene protons of both of the
isomers appeared as a pair of well-defined doublet signals,
which indicated that these macrocycles might have fixed
conformations at room temperature due to the presence of
rigid triptycene moieties.9h In order to further investigate the
conformational mobility, variable-temperature 1H NMR experi-
ments of 8a and 8b in o-C6D4Cl2 were carried out. As shown in
Figure 2, the two sets of doublet signals of methylene group in
Structures of the Macrocyclic Molecules in Solution.
The structural characterization of the macrocyclic molecules in
1
solution was studied by the H NMR experiments. Because of
the different orientation of the triptycene moieties in the two
diastereomers, diverse shielding or deshielding effects of the
benzene ring to the triptycene bridgehead protons would lead
to different chemical shifts of the bridgehead protons, which are
important information for the discrimination of the two
diastereomers in solution.9e As a result, it was found that the
1H NMR spectrum of 8b in CDCl3 exhibited two singlets at
5.29 and 5.23 ppm (Δδ = 0.06 ppm) for the bridgehead
protons in triptycenes (Figure 1); meanwhile, the bridgehead
1
Figure 2. Partial H NMR spectra of 8a (o-C6D4Cl2, 300 MHz) at
various temperatures.
the trans-isomer 8a were gradually changed to one set of
doublet signals above 370 K, which meant that the rigid
conformation of 8a was no longer existed at very high
temperature. But in the case of cis-isomer 8b, no obvious
changes in the methylene proton signals were observed with
increasing the temperature up to 380 K (Figure 3). These
results indicated that the structure of the cis-isomer is more
rigid than that of the trans-isomer. For the macrocycles 17a and
17b, because the two p-phenyl-substituted benzene rings were
linked together by crown ether chains and could not rotate
freely; consequently, their conformations kept fixation up to
380 K (see the Supporting Information).
1
Figure 1. Partial H NMR spectra of 8a and 8b in CDCl3 and o-
C6D4Cl2 at 298 K.
proton signals of 8a at 5.32 ppm and 5.23 ppm with Δδ of 0.09
ppm were observed. The similar Δδ values of the bridgehead
proton signals, as well as similar split peaks in the aromatic
region of the two macrocycles, made it difficult to discriminate
between them. However, when the 1H NMR experiments were
carried out in o-C6D4Cl2, the bridgehead protons of 8b showed
two singlets at 5.17 and 5.16 ppm with only Δδ = 0.01 ppm,
which implied that it was a cis-isomer with a high symmetric
structure.9e Meanwhile, macrocycle 8a exhibited two singlets
(5.40 and 5.28 ppm) with Δδ of 0.12 ppm, which indicated it
1
Figure 3. Partial H NMR spectra of 8b (o-C6D4Cl2, 300 MHz) at
various temperatures.
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Structures of the Macrocyclic Molecules in the Solid
State. To investigate the structures of the macrocyclic isomers
in the solid state, we obtained single crystals of 7a and 7b
suitable for X-ray diffraction analysis. The crystal structures
clearly showed that compounds 7a and 7b are a pair of
diastereomers, in which 7a is a trans isomer with chairlike
conformation while 7b is a cis isomer with a boatlike
conformation (Figure 4). These results are consistent with
rings of the triptycene subunits are 11.55 and 10.18 Å,
respectively. For cis-isomer 7b, the dihedral angle between the
two tert-butylphenol rings is 136.03° and the alkoxyl groups
also point to the center of the cavity, while the dihedral angles
between two pairs of face-to-face benzene rings of the
triptycene subunits are 38.27° and 58.40°, respectively, and
the macrocycle has a boatlike conformation with a cavity cross-
section from 10.07 × 12.83 Å (narrower rim) to 10.48 × 15.00
Å (wider rim).
We also obtained a single crystal of macrocycle 9a suitable
for X-ray diffraction analysis by vapor diffusion of diisopropyl
ether into a solution of 9a in CHCl3. The crystal structure
showed that the macrocycle is a trans-isomer with a chairlike
conformation (Figure 5a), which is also consistent with the
result in solution. Moreover, we further studied the self-
assembly of homooxacalixarene analogue 9a in the solid state.
As shown in Figure 5, macrocyclic molecule 9a could form a
tubular assembly9e,11 with the aromatic rings as the wall (Figure
5b), and further 3D microporous architecture (Figure 5c)
viewed along the a-axis by a pair of intermolecular
complementary C−H···π (dC−H···π = 2.86 and 2.89 Å)
interactions between the aromatic proton of the triptycene
moiety of one molecule and the aromatic ring of the triptycene
moiety of its adjacent molecule, and another C−H···π
interactions (dC−H···π = 2.86 Å) between the proton of the
bridging methylene and the aromatic ring of the p-phenyl
moiety of its adjacent molecule.
Figure 4. Crystal structures: (a) top view and (b) side view of 7a; (c)
top view and (d) side view of 7b. Solvent molecules and hydrogen
atoms are omitted for clarity.
Complexation with Fullerenes C60 and C70. After the
triptycene-derived homooxacalixarene analogues with fixed
conformations and large electron-rich cavities were established,
we further investigated their complexation properties toward
fullerenes C60 and C70. Consequently, the complexation
properties of macrocycle 9b toward fullerenes C60 and C70
those in solution. For trans-isomer 7a, it was found that the two
tert-butylphenol rings are nearly parallel each other and the
alkoxyl groups point to the center of the cavity. The centroid
distances between two pairs of face-to-face paralleled benzene
Figure 5. (a) Crystal structure of 9a. (b) Tubular assembly and (c) the 3D microporous architecture of 9a viewed along the a-axis. Solvent molecules
and hydrogen atoms are omitted for clarity.
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were first tested by fluorescence methods. As shown in Figure
6a, the fluorescence of 9b in toluene decreased constantly with
affinity and selectivity toward fullerenes, which implied that the
fluorescence changes mainly resulted from the interaction
between the macrocyclic skeleton and the fullerenes. Moreover,
it was also found that in most cases, the cis-isomers showed a
little larger affinity toward C60 while the trans-isomers have
larger affinity toward C70, which might be due to the relative
symmetrical cavities of the cis-isomers to fit well with the sphere
C60 and the relative flat cavities of the trans-isomers to fit well
with the oval C70.
CONCLUSION
■
In summary, four pairs of novel triptycene-derived homoox-
acalixarene analogues have been conveniently synthesized by a
one-pot approach. Similarly, two pairs of “basket-like”
triptycene-derived homooxacalixarene analogues in which the
two p-phenyl-substituted benzene rings were linked together by
crown ether chains were designed and synthesized as well. The
structural studies revealed that the macrocyclic molecules have
well-defined structures in both solution and solid state.
Moreover, the macrocycles showed fixed conformations even
1
at high temperatures by the variable-temperature H NMR
experiments owing to the introduction of the triptycene moiety
with a rigid 3D structure. We also found that macrocyclic
molecule 9a could form a tubular assembly with the aromatic
rings as the wall, and further 3D microporous architecture in
the solid state. Furthermore, it was found that macrocycles 6−9
showed efficient complexation abilities toward fullerenes C60
and C70. We believe that these novel triptycene-derived
homooxacalixarene analogues could find more applications in
molecular recognition and molecular assembly, which are
underway in our laboratory.
Figure 6. (a) Emission spectra (λex = 293 nm) of 9b (1 × 10−5 mol
dm−3) in the presence of C60 (0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9,
1.0, 1.2, 1.4, 1.6, 1.8, 2.0 equiv) at 298 K in toluene. (b) Emission
spectra (λex = 293 nm) of 9b (1 × 10−5 mol dm−3) in the presence of
C70 (0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0
equiv) at 298 K in toluene.
EXPERIMENTAL SECTION
■
Compounds 6a and 6b. Under an argon atmosphere, a mixture
of 2,7-dihydroxytriptycene (286 mg, 1 mmol), 2 (350 mg, 1 mmol),
and Cs2CO3 (1.30 g, 4 mmol) in dry DMF (100 mL) was stirred at 60
°C for 48 h. The mixture was cooled to room temperature, and the
solvent was removed. The crude residue was dissolved in a mixture of
CH2Cl2 and water. The organic layer was separated, washed with water
and then brine, dried over Na2SO4, and concentrated under reduced
pressure. The crude product was purified by column chromatography
over silica gel with CH2Cl2/petroleum ether as eluent to give the
products 6a (85 mg, 18%) and 6b (104 mg, 22%) as white solids. 6a.
Mp > 300 °C. 1H NMR (300 MHz, CDCl3): δ 1.29 (s, 18H), 3.55 (s,
6H), 4.83 (d, J = 9.6 Hz, 4H), 4.98 (d, J = 9.7 Hz, 4H), 5.20 (s, 2H),
5.30 (s, 2H), 6.57 (dd, J = 2.1, 8.0 Hz, 4H), 6.99−7.01 (m, 8H), 7.23−
7.26 (m, 4H), 7.35−7.41 (m, 8H). 13C NMR (75 MHz, CDCl3): δ
31.4, 34.4, 52.4, 54.3, 63.8, 66.5, 108.7, 112.6, 123.2, 123.7, 125.0,
125.3, 129.1, 129.7, 138.2, 144.7, 145.9, 146.7, 147.0, 156.5, 156.8.
MALDI-TOF MS: m/z 971.6 [M + Na]+. Anal. Calcd for
C66H60O6·H2O: C, 81.96; H, 6.46. Found: C, 81.91; H, 6.50. 6b.
Mp > 300 °C. 1H NMR (300 MHz, CDCl3): δ 1.25 (s, 18H), 3.67 (s,
6H), 4.94 (d, J = 11.5 Hz, 4H), 5.09 (d, J = 11.5 Hz, 4H), 5.20 (s, 2H),
5.29 (s, 2H), 6.59 (d, J = 7.2 Hz, 4H), 6.99−7.01 (m, 8H), 7.21−7.25
(m, 4H), 7.34−7.38 (m, 8H). 13C NMR (75 MHz, CDCl3): δ 31.3,
34.3, 52.4, 54.4, 63.1, 66.3, 111.0, 112.0, 123.1, 123.6, 123.8, 124.9,
125.2, 127.8, 129.6, 138.4, 144.8, 145.9, 146.7, 146.9, 155.1, 156.3.
MALDI-TOF MS: m/z 971.6 [M + Na]+. Anal. Calcd for
C66H60O6·2H2O: C, 80.46; H, 6.55. Found: C, 80.23; H, 6.51.
increasing amount of C60. A Job plot and fluorescence titration
experiments showed that a 1:1 complex between 9b and C60
was formed, and the association constant Ka of complex 9b·C60
was calculated from a plot of F0/Fcal vs C60 concentration to be
(1.50 0.09) × 105 M−1. Similar to the case of C60, macrocycle
9b formed a 1:1 host/guest complex with C70 as well, and the
association constant of (1.44 0.09) × 105 M−1 for complex
9b·C70 was obtained (Figure 6b). Similarly, it was found that
the homooxacalixarene analogues 9a, 6a and 6b, 7a and 7b, and
8a and 8b could all show strong affinities toward both C60 and
C70, and they could all form 1:1 complexes with the
fullerenes.5a,9j As shown in Table 1, the different substituents
of the macrocycles seemed to have no obvious influence on the
Table 1. Association Constants for the 1:1 Complexation
between the Host Molecules and Fullerenes C60 and C70
Ka (1:1 complex with C60
Ka (1:1 complex with C70)
6a
6b
7a
7b
8a
8b
9a
9b
(1.01 0.02) × 105
(1.18 0.05) × 105
(0.96 0.03) × 105
(1.15 0.03) × 105
(1.04 0.05) × 105
(1.13 0.04) × 105
(1.28 0.04) × 105
(1.50 0.09) × 105
(1.05 0.04) × 105
(1.10 0.04) × 105
(1.25 0.06) × 105
(1.06 0.03) × 105
(1.11 0.04) × 105
(1.14 0.04) × 105
(1.48 0.07) × 105
(1.44 0.09) × 105
Compounds 7a and 7b. Starting from 1 (286 mg, 1 mmol) and 3
(392 mg, 1 mmol), following the same procedure for the synthesis of
6, compounds 7a (103 mg, 20%) and 7b (119 mg, 23%) were
obtained. 7a. Mp: 174−176 °C. 1H NMR (300 MHz, CDCl3): δ 0.82
(t, J = 7.7 Hz, 6H), 1.22 (s, 18H), 1.34−1.42 (m, 4H), 1.59−1.66 (m,
4H), 3.71 (t, J = 6.2 Hz, 4H), 4.96 (d, J = 11.9 Hz, 4H), 5.07 (d, J =
11.9 Hz, 4H), 5.16 (s, 2H), 5.27 (s, 2H), 6.58 (dd, J = 2.0, 7.9 Hz,
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4H), 6.95−7.01 (m, 8H), 7.20−7.23 (m, 4H), 7.30−7.36 (m, 8H). 13
C
134.5, 137.4, 140.3, 155.0. MALDI-TOF MS: m/z 597.3 [M + Na]+.
Anal. Calcd for C34H38O8: C, 71.06; H, 6.67. Found: C, 70.75; H, 6.69.
Compound 13. Following the same procedure for the synthesis of
NMR (75 MHz, CDCl3): δ 13.9, 19.3, 31.3, 32.3, 34.3, 52.4, 54.5, 66.0,
75.4, 111.2, 112.1, 123.1, 123.5, 123.7, 124.9, 125.2, 127.2, 129.7,
138.3, 144.9, 146.0, 146.6, 146.7, 153.3, 156.3. MALDI-TOF MS: m/z
1055.7 [M + Na]+. Anal. Calcd for C72H72O6·H2O: C, 82.25; H, 7.09.
Found: C, 82.11; H, 7.32. 7b. Mp: 282−283 °C. 1H NMR (300 MHz,
CDCl3): δ 0.39 (t, J = 7.3 Hz, 6H), 0.80−0.87 (m, 4H), 1.22−1.25 (m,
4H), 1.25 (s, 18H), 3.65 (t, J = 6.8 Hz, 4H), 4.87 (d, J = 10.4 Hz, 4H),
5.02 (d, J = 10.4 Hz, 4H), 5.20 (s, 2H), 5.28 (s, 2H), 6.57 (dd, J = 2.2,
8.0 Hz, 4H), 6.99 (br, s, 8H), 7.20−7.23 (m, 4H), 7.35−7.38 (m, 8H).
13C NMR (75 MHz, CDCl3): δ 13.6, 18.8, 31.4, 32.1, 34.4, 52.4, 54.5,
66.1, 76.1, 109.6, 112.1, 123.1, 123.7, 124.9, 125.3, 128.5, 129.6, 138.2,
144.8, 146.0, 146.7, 146.8, 154.7, 156.5. MALDI-TOF MS: m/z 1055.7
[M + Na]+. Anal. Calcd for C72H72O6: C, 83.69; H, 7.02. Found: C,
83.53; H, 7.20.
1
12, compound 13 (73%) was obtained as a colorless oil. H NMR
(300 MHz, CDCl3): δ 3.48 (br, s, 4H), 3.66 (br, s, 8H) 3.70−3.73 (m,
4H), 4.00−4.02 (m, 4H), 4.65 (s, 8H), 7.27−7.29 (m, 2H), 7.33−7.37
(m, 4H), 7.46−7.51 (m, 8H). 13C NMR (75 MHz, CDCl3): δ 60.8,
70.4, 70.5, 70.6, 73.6, 126.9, 127.1, 127.8, 128.7, 134.6, 137.2, 140.3,
154.8. MALDI-TOF MS: m/z 641.3 [M + Na]+. Anal. Calcd for
C36H42O9 ·0.6CH2Cl2: C, 65.64; H, 6.50. Found: C, 65.70; H, 6.54.
Compound 14. At room temperature, PBr3 (5.0 mmol) in CHCl3
(20 mL) were added dropwise to a solution of compound 12 (2.30 g,
4 mmol) in CHCl3 (150 mL) in 0.5h. The resulting mixture was
stirred at room temperature for another 3h. The solvent was then
removed under vacuum, and the residue was chromatographed on a
silica gel column with a mixture of petroleum ether and CH2Cl2 as the
mobile phase to give pure 14 (2.81 g, 85%) as a white solid. Mp: 117−
Compounds 8a and 8b. Starting from 1 (286 mg, 1 mmol) and 4
(370 mg, 1 mmol), following the same procedure for the synthesis of
6, compounds 8a (79 mg, 16%) and 8b (99 mg, 20%) were obtained.
1
119 °C. H NMR (300 MHz, CDCl3): δ 3.90 (br, s, 4H), 3.98−4.01
1
(m, 4H), 4.35−4.38 (m, 4H), 4.71 (s, 8H), 7.33−7.38 (m, 2H), 7.41−
7.46 (m, 4H), 7.54−7.59 (m, 8H). 13C NMR (75 MHz, CDCl3): δ
28.0, 70.6, 71.2, 74.2, 127.0, 127.6, 128.9, 130.9, 132.4, 138.2, 139.5,
154.6. MALDI-TOF MS: m/z 848.9 [M + Na]+. Anal. Calcd for
C34H34Br4O4: C, 49.42; H, 4.15. Found: C, 49.73; H, 4.23.
8a. Mp: 222−224 °C. H NMR (300 MHz, CDCl3): δ 3.64 (s, 6H),
4.92 (d, J = 10.0 Hz, 4H), 5.06 (d, J = 10.0 Hz, 4H), 5.23 (s, 2H), 5.32
(s, 2H), 6.60 (dd, J = 2.4, 8.0 Hz, 4H), 7.00−7.02 (m, 8H), 7.25−7.28
(m, 4H), 7.31−7.33 (m, 2H), 7.37−7.42 (m, 8H), 7.53−7.56 (m, 4H),
7.64 (br, s, 4H). 13C NMR (75 MHz, CDCl3): δ 52.4, 54.3, 63.9, 65.9,
108.9, 112.4, 123.2, 123.7, 123.8, 125.0, 125.3, 127.0, 127.2, 128.7,
130.4, 130.8, 137.4, 138.2, 140.1, 144.6, 145.8, 146.7, 156.3, 158.0.
MALDI-TOF MS: m/z 1011.5 [M + Na]+. Anal. Calcd for
C70H52O6·0.5H2O: C, 84.23; H, 5.35. Found: C, 83.98; H, 5.57. 8b.
Mp >300 °C. 1H NMR (300 MHz, CDCl3): δ 3.71 (s, 6H), 5.03 (d, J
= 11.9 Hz, 4H), 5.16 (d, J = 11.9 Hz, 4H), 5.23 (s, 2H), 5.29 (s, 2H),
6.61 (dd, J = 2.4, 8.0 Hz, 4H), 6.96−7.03 (m, 8H), 7.22−7.24 (m,
4H), 7.30−7.40 (m, 10H), 7.47−7.50 (m, 4H), 7.60 (br, s, 4H). 13C
NMR (75 MHz, CDCl3): δ 52.4, 54.3, 64.0, 65.9, 108.9, 112.4, 123.2,
123.7, 123.8, 125.0, 125.3, 127.1, 127.2, 128.7, 130.4, 130.8, 137.4,
138.3, 140.1, 144.6, 145.9, 146.7. MALDI-TOF MS: m/z 1011.5 [M +
Na]+. Anal. Calcd for C70H52O6·0.5H2O: C, 84.23; H, 5.35. Found: C,
84.11; H, 5.38.
Compound 15. Following the same procedure for the synthesis of
14, compound 15 (85%) was obtained as a white solid. Mp: 79−81
1
°C. H NMR (300 MHz, CDCl3): δ 3.83−3.84 (m, 8H) 3.94−3.97
(m, 4H), 4.33−4.35 (m, 4H), 4.69 (s, 8H), 7.32−7.37 (m, 2H), 7.40−
7.45 (m, 4H), 7.53−7.58 (m, 8H). 13C NMR (75 MHz, CDCl3): δ
27.9, 70.3, 70.8, 70.9, 74.0, 126.8, 127.5, 128.7, 130.7, 132.3, 138.0,
139.3, 154.4. MALDI-TOF MS: m/z 893.0 [M + Na]+, 908.9 [M +
K]+. Anal. Calcd for C36H38Br4O5·0.6CH2Cl2: C, 47.72; H, 4.29.
Found: C, 47.53; H, 4.20.
Compounds 16a and 16b. Under an argon atmosphere, a
mixture of 2,7-dihydroxytriptycene 1 (286 mg, 1 mmol), compound
14 (413 mg, 0.5 mmol), and Cs2CO3 (1.30 g, 4 mmol) in dry DMF
(100 mL) was stirred at 60 °C for 48 h. The mixture was cooled down
to room temperature, and the solvent was removed. The crude residue
was dissolved in CH2Cl2 and water. The organic layer was separated,
washed with water and brine, dried over Na2SO4, and then
concentrated under reduced pressure. The crude product was purified
by column chromatography over silica gel with CH2Cl2/petroleum
ether as eluent to give the products 16a (43 mg, 8%) and 16b (199
Compounds 9a and 9b. Starting from 1 (286 mg, 1 mmol) and 5
(412 mg, 1 mmol), following the same procedure for the synthesis of
6, compounds 9a (101 mg, 19%) and 9b (123 mg, 23%) were
obtained. 9a. Mp: 105−107 °C. 1H NMR (300 MHz, CDCl3): δ 0.84
(t, J = 7.3 Hz, 6H), 1.26−1.41 (m, 4H), 1.60−1.67 (m, 4H), 3.74 (t, J
= 6.5 Hz, 4H), 5.04 (d, J = 12.4 Hz, 4H), 5.14 (d, J = 12.4 Hz, 4H),
5.19 (s, 2H), 5.28 (s, 2H), 6.60 (dd, J = 2.2, 8.0 Hz, 4H), 6.96−7.01
(m, 8H), 7.21−7.37 (m, 14H), 7.43−7.46 (m, 4H), 7.58 (br, s, 4H).
13C NMR (75 MHz, CDCl3): δ 13.9, 19.2, 32.3, 52.5, 54.5, 65.7, 75.5,
111.3, 111.9, 123.2, 123.5, 123.8, 124.9, 125.3, 127.0, 127.1, 128.5,
128.7, 131.0, 137.2, 138.5, 140.4, 144.9, 146.0, 146.7, 154.8, 156.3.
MALDI-TOF MS: m/z 1095.3 [M + Na]+. Anal. Calcd for
C76H64O6·0.5H2O: C, 84.34; H, 6.05. Found: C, 84.48; H, 6.08. 9b.
Mp: 205−206 °C. 1H NMR (300 MHz, CDCl3): δ 0.54 (t, J = 7.3 Hz,
6H), 0.97−1.09 (m, 4H), 1.35−1.45 (m, 4H), 3.73 (t, J = 6.6 Hz, 4H),
4.97 (d, J = 11.3 Hz, 4H), 5.10 (d, J = 11.2 Hz, 4H), 5.22 (s, 2H), 5.29
(s, 2H), 6.58 (dd, J = 2.0, 8.0 Hz, 4H), 6.95−6.99 (m, 8H), 7.20−7.35
(m, 14H), 7.45−7.47 (m, 4H), 7.58 (br, s, 4H). 13C NMR (75 MHz,
CDCl3): δ 13.6, 18.9, 32.1, 52.4, 54.4, 65.2, 76.2, 109.7, 111.9, 123.1,
123.6, 123.7, 124.9, 125.3, 127.0, 127.1, 128.6, 129.3, 130.8, 137.4,
138.2, 140.1, 144.8, 146.0, 146.6, 155.7, 156.2. MALDI-TOF MS: m/z
1095.3 [M + Na]+. Anal. Calcd for C76H64O6: C, 85.05; H, 6.01.
Found: C, 84.79; H, 6.23.
1
mg, 37%) as white solids. 16a. Mp: >300 °C. H NMR (300 MHz,
CDCl3): δ 2.03 (m, 2H), 2.30 (m, 2H), 3.03 (m, 4H), 3.84 (m, 4H),
4.80 (d, J = 9.3 Hz, 4H), 5.14 (d, J = 9.4 Hz, 4H), 5.19 (s, 2H), 5.31
(s, 2H), 6.58 (dd, J = 2.1, 7.9 Hz, 4H), 6.95−7.01 (m, 8H), 7.25−7.45
(m, 14H), 7.59−7.61 (m, 4H), 7.67 (br,s, 4H). 13C NMR (75 MHz,
CD2Cl2): δ 30.1, 52.7, 67.3, 70.4, 70.8, 75.8, 111.4, 112.4, 123.5, 124.0,
124.2, 125.3, 125.7, 127.3, 127.7, 129.2, 130.4, 131.5, 137.5, 139.0,
140.4, 145.1, 146.3, 147.3, 156.8, 157.1. MALDI-TOF MS: m/z 1097.7
[M + Na]+. Anal. Calcd for C74H58O8·0.1CH2Cl2: C, 82.12; H, 5.41.
1
Found: C, 82.00; H, 5.48. 16b. Mp: >300 °C . H NMR (300 MHz,
CDCl3): δ 2.80−2.82 (m, 2H), 3.11−3.24 (m, 6H), 3.89−3.93 (m,
4H), 5.01 (d, J = 10.7 Hz, 4H), 5.14 (d, J = 10.7 Hz, 4H), 5.23 (s, 2H),
5.30 (s, 2H), 6.60 (dd, J = 2.3, 8.0 Hz, 4H), 6.94−7.03 (m, 8H), 7.23−
7.25 (m, 4H), 7.28−7.42 (m, 10H), 7.53−7.56 (m, 4H), 7.65 (br, s,
4H). 13C NMR (75 MHz, CDCl3): δ 52.4, 54. 5, 66.8, 70.1, 70.5, 75.4,
110.9, 112.0, 123.2, 123.7, 123.8, 125.0, 125.4, 127.1, 127.3, 128.8,
130.3, 131.0, 137.4, 138.6, 140.2, 144.6, 145.7, 146.9, 156.4, 156.6.
MALDI-TOF MS: m/z 1097.7 [M + Na]+. Anal. Calcd for C74H58O8:
C, 82.66; H, 5.44. Found: C, 82.31; H, 5.63.
Compound 12. A mixture of 2,5-dihydroxymethyl-4-phenylphenol
(1.15 g, 5 mmol), the bistosylate 10 (1.145 g, 2.5 mmol), and K2CO3
(2.76 g, 20 mmol) in CH3CN (100 mL) was refluxed for 12 h. The
resulting mixture was cooled to room temperature and the solvent was
removed under vacuum, and the residue was chromatographed on a
silica gel column with a mixture of CH2Cl2 and ethyl acetate as the
mobile phase to give pure 12 (1.09 g, 76%) as a white solid. Mp: 139−
Compounds 17a and 17b. From starting materials 1 (286 mg,1
mmol) and 15 (435 mg, 0.5 mmol), following the same procedure for
the synthesis of 16, compounds 17a (117 mg, 21%) and 17b (128 mg,
23%) were obtained as white solids. 17a. Mp: 269−271 °C. 1H NMR
(300 MHz, CDCl3): δ 2.99−3.00 (m, 4H), 3.09 (brs, 8H), 3.84 (m,
4H), 4.82 (d, J = 9.7 Hz, 4H), 5.21 (d, J = 8.3 Hz, 4H), 5.22 (s, 2H),
5.30 (s, 2H), 6.58 (dd, J = 2.0, 8.0 Hz, 4H), 6.98−7.00 (m, 8H), 7.23−
7.26 (m, 4H), 7.29−7.44 (m, 10H), 7.57−7.60 (m, 4H), 7.66 (brs,
4H). 13C NMR (75 MHz, CDCl3): δ 52.3, 54.3, 65.8, 69.5, 70.0, 70.5,
1
140 °C. H NMR (300 MHz, CDCl3): δ 2.51 (br, s, 4H) 3.81 (br, s,
4H), 3.87−3.90 (m, 4H), 4.21−4.23 (m, 4H), 4.74 (s, 8H), 7.28−7.33
(m, 2H), 7.37−7.42 (m, 4H), 7.50−7.55 (m, 8H). 13C NMR (75
MHz, CDCl3): δ 61.1, 70.5, 70.7, 73.7, 126.9, 127.2, 128.2, 128.7,
986
dx.doi.org/10.1021/jo302459m | J. Org. Chem. 2013, 78, 981−987

The Journal of Organic Chemistry
Article
75.2, 108.4, 112.6, 123.1, 123.6, 123.6, 124.9, 125.3, 127.0, 127.2,
128.7, 130.8, 137.4, 138.2, 140.0, 144.5, 145.8, 146.7, 156.4, 157.0.
MALDI-TOF MS: m/z 1141.6 [M + Na]+. Anal. Calcd for
C76H62O9·0.1CH2Cl21: C, 81.04; H, 5.56. Found: C, 81.11; H, 5.71.
17b. Mp: >300 °C. H NMR (300 MHz, CDCl3): δ 3.20−3.26 (m,
6H), 3.35−3.47 (m, 4H), 3.56−3.62 (m, 2H), 3.70−3.84 (m, 4H),
5.06 (d, J = 11.5 Hz, 4H), 5.13 (d, J = 11.5 Hz, 4H), 5.23 (s, 2H), 5.29
(s, 2H), 6.64 (dd, J = 2.4, 8.0 Hz, 4H), 6.94−7.03 (m, 8H), 7.23−7.25
(m, 4H), 7.28−7.42 (m, 10H), 7.53−7.56 (m, 4H), 7.65 (br, s, 4H).
13C NMR (75 MHz, CDCl3): δ 52.4, 54.3, 66.3, 69. 9, 70.5, 70.6, 74.6,
111.1, 112.4, 123.2, 123.6, 123.8, 125.0, 125.3, 127.0, 127.2, 128.7,
129.3, 131.0, 137.4, 138.7, 140.3, 144.6, 145.7, 146.8, 155.2, 156.5.
MALDI-TOF MS: m/z 1141.6 [M + Na]+. Anal. Calcd for
C76H62O9·0.6CH2Cl2: C, 78.62; H, 5.44. Found: C, 78.50; H, 5.67.
Crystal Data for 7a. C72H72O6, Mw = 1033.30, trigonal, space
group R-3, a = 38.388(1) Å, b = 38.388 (1) Å, c = 12.218(2) Å, α =
90.00(1)°, β = 90.00(1)°, γ = 120.00(15)°, V = 15593(3) Å3, Z = 9, D
= 0.99 Mg m−3, T = 173(2) K, 46470 reflections measured, 7907
unique (Rint = 0.0935), final R indices [I > 2σ(I)]: R1 = 0.1550, wR2 =
0.3120, R indices (all data): R1 = 0.1742, wR2 = 0.3246.
2008, 4541. (c) Maes, W.; Dehaen, W. Chem. Soc. Rev. 2008, 37, 2393.
(d) Wang, M. X. Acc. Chem. Res. 2012, 45, 182.
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X.; Yang, H. B. J. Am. Chem. Soc. 2004, 126, 15412. (b) Katz, J. L.;
Feldman, M. B.; Conry, R. R. Org. Lett. 2005, 7, 91. (c) Katz, J. L.;
Selby, K. J.; Conry, R. R. Org. Lett. 2005, 7, 3505. (d) Katz, J. L.;
Geller, B. J.; Conry, R. R. Org. Lett. 2006, 8, 2755. (e) Maes, W.; Van
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L.; Li, X.-Y.; Wen, K. J. Am. Chem. Soc. 2009, 131, 8338−8339. (k) Li,
S.; Fa, S. X.; Wang, Q. Q.; Wang, D. X.; Wang, M. X. J. Org. Chem.
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(5) Some examples on azacalixarenes: (a) Wang, M. X.; Zhang, X. H.;
Zheng, Q. Y. Angew. Chem., Int. Ed. 2004, 43, 838. (b) Gong, H. Y.;
Zhang, X. H.; Wang, D. X.; Zheng, Q. Y.; Wang, M. X. Chem.Eur. J.
2006, 12, 9262. (c) Gong, H. Y.; Zheng, Q. Y.; Wang, D. X.; Wang, M.
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S.; Matsui, K.; Takahashi, H.; Tamura, R. Org. Lett. 2006, 8, 5991.
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Crystal Data for 7b. C72H72O6, Mw = 1033.30, triclinic, space
group P-1, a = 12.299(3) Å, b = 16.054(3) Å, c = 17.763(4) Å, α =
81.15(3)°, β = 88.58(3)°, γ = 74.64(3)°, V = 3341.2(12) Å3, Z = 2, D
= 1.027 Mg m−3, T = 173(2) K, 43959 reflections measured, 15246
unique (Rint = 0.0563), final R indices [I > 2σ(I)]: R1 = 0.0840, wR2 =
0.2302, R indices (all data): R1 = 0.1092, wR2 = 0.2483.
Crystal Data for 9a. C78H66Cl6O6, Mw = 1312.01, triclinic, space
group P-1, a = 8.884(2) Å, b = 17.286(5) Å, c = 23.428(6) Å, α =
109.558(3)°, β = 90.173(5)°, γ = 100.381(6)°, V = 3326.7(16) Å3, Z =
2, D = 1.310 Mg m−3, T = 173(2) K, 36598 reflections measured,
11725 unique (Rint = 0.0675), final R indices [I > 2σ(I)]: R1 = 0.1084,
wR2 = 0.2376, R indices (all data): R1 = 0.1367, wR2 = 0.2545.
(6) A recent review on thiacalixarenes, see: Morohashi, N.; Narumi,
F.; Iki, N.; Hattori, T.; Miyano, S. Chem. Rev. 2006, 106, 5291.
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(b) Ibach, S.; Prautzsch, V.; Vogtle, F. Acc. Chem. Res. 1999, 32, 729.
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(c) Thomas, J.; Van Hecke, K.; Robeyns, K.; Van Rossom, W.; Van
Meervelt, L.; Smet, M.; Maes, W.; Dehaen, W. Chem.Eur. J. 2011,
17, 10339. (d) Chen, Y.; Wang, D, X.; Wang, M. X. J. Org. Chem.
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T.; Jiang, Y. Chin. Sci. Bull. 2007, 52, 1349.
ASSOCIATED CONTENT
■
S
* Supporting Information
Copies of 1H and 13C NMR spectra of new compounds.
Variable-temperature 1H NMR spectra of 17a and 17b.
Fluorescence titrations of 6−9 with C60 and C70. X-ray
crystallographic files (CIF) for compounds 7a, 7b, and 9a.
This material is available free of charge via the Internet at
http://pubs.acs.org.
(9) (a) Zhu, X.-Z.; Chen, C.-F. J. Am. Chem. Soc. 2005, 127, 13158.
(b) Zong, Q.-S.; Chen, C.-F. Org. Lett. 2006, 8, 211. (c) Zhu, X.-Z.;
Chen, C.-F. Chem.Eur. J. 2006, 12, 5603. (d) Peng, X.-X.; Lu, H.-Y.;
Han, T.; Chen, C.-F. Org. Lett. 2007, 9, 895. (e) Zhang, C.; Chen, C.-
F. J. Org. Chem. 2007, 72, 3880. (f) Xue, M.; Chen, C.-F. Chem.
Commun. 2008, 6128. (g) Xue, M.; Chen, C.-F. Org. Lett. 2009, 11,
5294. (h) Tian, X.-H.; Chen, C.-F. Chem.Eur. J. 2010, 16, 8072.
(i) Tian, X.-H.; Hao, X.; Chen, C.-F. Org. Lett. 2010, 12, 524. (j) Hu,
S.-Z.; Chen, C.-F. Chem. Commun. 2010, 46, 4199.
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Commun. 1998, 895. (b) Ikeda, A.; Hatano, T.; Kawaguchi, M. Chem.
Commun. 1999, 1403. (c) Ikeda, A.; Yoshimura, M.; Udzu, H. J. Am.
Chem. Soc. 1999, 121, 4296. (d) Ikeda, A.; Udzu, H.; Yoshimura, M.
Tetrahedron 2000, 56, 1825. (e) Hirsh, A. Angew. Chem., Int. Ed. 2004,
43, 2326. (f) Kawase, T.; Kurata, H. Chem. Rev. 2006, 106, 5250.
(g) Perez, E. M.; Martin, N. Chem. Soc. Rev. 2008, 37, 1512.
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Guichard, G. Angew. Chem., Int. Ed. 2002, 41, 1895. (b) Amorin, M.;
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125, 9372.
AUTHOR INFORMATION
■
Corresponding Author
*E-mail: cchen@iccas.ac.cn.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
We thank the National Natural Science Foundation of China
(20972162, 91127009) and the National Basic Research
Program (2011CB932501) for financial support.
REFERENCES
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