Dendritic [2]rotaxanes: Synthesis, characterization, and properties

Article abstract of DOI:10.1021/jo402428y

A series of dendritic ammonium salts have been designed and synthesized. Subsequently, they were used to construct the corresponding [2]rotaxanes by a template-directed clipping approach. Unusually, two unsymmetrical dendritic [2]rotaxanes containing fluorophore (pyrene units) were also obtained; their optical properties, such as UV/vis absorption and fluorescence, were measured. The results indicate that these two rotaxanes possess stronger intermolecular interaction in the solid state than in solution. As a result, solutions of high concentration readily formed the excimer. These special rotaxanes might be applied in dynamic fluorescence-reponsive materials, and the rotaxane structure will also be used as a strategy to adjust the aggregated behaviors of fluorescent molecules.

Full text of DOI:10.1021/jo402428y

Article
pubs.acs.org/joc
Dendritic [2]Rotaxanes: Synthesis, Characterization, and Properties
Guoxing Liu,† Ziyong Li,† Di Wu,† Wen Xue,† Tingting Li,‡ Sheng Hua Liu,*,† and Jun Yin*,†
†Key Laboratory of Pesticide and Chemical Biology, Ministry of Education, College of Chemistry, Central China Normal University,
Wuhan 430079, P.R. China
‡Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430079, P.R. China
S
* Supporting Information
ABSTRACT: A series of dendritic ammonium salts have been designed and synthesized. Subsequently, they were used to
construct the corresponding [2]rotaxanes by a template-directed clipping approach. Unusually, two unsymmetrical dendritic
[2]rotaxanes containing fluorophore (pyrene units) were also obtained; their optical properties, such as UV/vis absorption and
fluorescence, were measured. The results indicate that these two rotaxanes possess stronger intermolecular interaction in the
solid state than in solution. As a result, solutions of high concentration readily formed the excimer. These special rotaxanes might
be applied in dynamic fluorescence-reponsive materials, and the rotaxane structure will also be used as a strategy to adjust the
aggregated behaviors of fluorescent molecules.
Usually, the template-directed clipping reaction based on 2,6-
pyridinedicarboxaldehyde and tetraethylene glycol bis(2-
aminophenyl)ether is considered an efficient strategy for the
synthesis, in high yields, of all types of rotaxanes, such as linear
[2]rotaxanes and oligomers,13 rectangular [4]rotaxanes,14 pH-
induced switchable rotaxanes,15 daisy chains,16 and hetero-
rotaxanes.17 Recently, we also utilized this approach to
efficiently synthesize a series of catenanes.18 The examples
presented above suggested to us that the dynamic clipping
reaction for the construction of mechanically interlocked
molecules would be highly efficient. In addition, the success
of the template-directed clipping reaction is clearly an integral
part of the construction of rotaxane-based dendrimers. Stoddart
et al. reported the preparation of a series of dendritic rotaxanes
by taking advantage of dendritic group-substituted 2,6-
pyridinedicarboxaldehyde with tetraethylene glycol bis(2-
aminophenyl)ether.19 This work reports the design and
synthesis of a series of dendritic rotaxanes in which the
dendritic stoppers were installed on the two sides of
dialkylammonium by implementation of a dynamic covalent
chemical process (Scheme 1). An important point to realize is
that the fluorophore (pyrene units) was introduced to the
stoppering sites to afford fluorescent rotaxane-based den-
drimers. Their photophysical properties in solution and thin
film states and their self-assembly properties as a function of
concentration in solution were investigated.
1. INTRODUCTION
Mechanically interlocked rotaxanes have attracted increasing
attention as a result of their potential application in
nanoelectronics,1 artificial muscles,2 macroscopic liquid trans-
port,3 and mesoporous silica-mounted nanovalves.4 In the
meantime, this intensive study of rotaxanes has promoted
increased understanding of design strategies and more complex
systems such as rotaxane-based polymers.5 Dendrimers, for
instance, contain highly branched and regularly repeating
molecular architectures. They have emerged as one of the most
striking areas of modern supramolecular chemistry since the
middle 1980s.6 During the past few decades, many applications
have been found for dendrimers, such as in the areas of
encapsulation and delivery, catalysis, and materials science.7
Recently, some dendritic rotaxanes have been reported. For
example, Stoddart et al. (1996) reported a series of dendritic
rotaxanes, prepared by using the dendritic groups as a stopper.8
Subsequently, they utilized the “threading-followed-by-stopper-
ing” strategy to construct a rotaxane-based dendrimer in which
the two bis-dendrons acted as stoppers.9 Recently, Smith’s
group made a similar report.10 Yang et al. reported the synthesis
of [6]pseudorotaxanes through the coordinative-driven self-
assembly of tris(crown ether)hexagons, dendritic dibenzylam-
monium and platinum cations.11 On the basis of the above
structural characteristics by which the dendritic groups were
installed on the guest template, the Stoddart group developed a
pseudorotaxane-based dendrimer by using a dendritic crown
ether and dendritic ammonium.12
Received: October 31, 2013
Published: December 23, 2013
© 2013 American Chemical Society
643
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
Scheme 1. Schematic Representation of the “Template-Directed Clipping” Approach for the Construction of the Dendritic
[2]Rotaxanes
Scheme 2. Synthesis of the Dendritic Dialkylammoniums Salt 5b
THF gave the corresponding amine 11, which was used for the
next step without further purification. Condensation of
benzylamine 11 with aldehyde 13 then produced the
corresponding reversible dynamic imine, which was reduced
by NaBH4 in the solution of THF and MeOH to give the
kinetically stable amine 14, in 82% yield. Protonation of the
free amine with excess trifluoroacetic acid (TFA) and
subsequent counterion exchange with saturated NH4PF6
2. RESULTS AND DISCUSSION
The synthesis of the dendritic dialkylammonium salts 5b and
5c is outlined in Schemes 2 and 3. The G0 dendritic
dialkylammonium salt 5a was prepared using a method
reported previously.20 As shown in Scheme 2, the treatment
of 3,5-dihydroxybenzonitrile 8 and 3,5-dihydroxybenzaldehyde
12 with 9 in DMF in the presence of K2CO3 afforded
compounds 10 and 13 in 75% and 77% yields, respectively.
Subsequently, the reduction of compound 10 with LiAlH4 in
644
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
Scheme 3. Synthesis of the Dendritic Dialkylammonium Salt 5c
Scheme 4. Synthesis of the Macrocycles 21
solution afforded the G1 dialkylammonium salt 5b in 92% yield
for the two steps.
simultaneously protonated. Subsequent counterion exchange
with saturated NH4PF6 solution afforded the G2 dialkylammo-
nium salt 5c in an 89% yield. In addition, one group of
substances was needed to aid spectroscopic analysis of the
processes involved in the dendritic [2]rotaxane formation; this
included the N-hetero crown ethers 21a14a and 21b.18 These
were synthesized in 43−75% yields by the condensation of 2,6-
pyridinedicarboxaldehyde 6a, 4-(tetradecyloxy)pyridine-2,6-di-
carboxaldehyde 6b, and tetra(ethylene glycol)-bis(2-
aminophenyl)ether 7, respectively, followed by reduction with
BH3·THF under the template effect of dibenzylammonium 20,
as outlined in Scheme 4.14a The chemical structures of all the
new compounds were confirmed by standard spectroscopic
characterizations, such as NMR, mass spectrometry, and
elemental analyses (see Supporting Information [SI]).
Similarly, the synthesis of the G2 dialkylammonium salt 5c is
outlined in Scheme 3. First, the benzyl alcohol 15 was reacted
with CBr4 and Ph3P to get the requisite intermediate 16.
Subsequently, 3,5-dihydroxybenzaldehyde 12 was treated with
16 in DMF in the presence of K2CO3 to afford compound 17
in 84% yield. Then, condensation of benzylamine 18 with the
aldehyde 17 produced the corresponding reversible dynamic
imine which was reduced by NaBH4 in a solution of THF and
MeOH to give the kinetically stable amine in a yield of 88%. In
spite of the high yield, convenient purification was possible
since the NH of the free amines could be protected by the
Boc2O. Subsequently, the Boc-protected alkylamines 19 were
obtained in overall yields of 76% for the two steps. The Boc
protective group was removed with excess trifluoroacetic acid
(TFA) in dry dichloromethane, and the amine produced was
Next, the G0−G3 dialkylammonium salts were subjected to
the dynamic covalent chemistry. First, 5a was used to
645
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
1
Figure 1. Partial H NMR spectra (600 MHz in CD3CN at rt) of 21a (A), 2a (B), 5b (C), 2b (D), and 21b (E).
1
Figure 2. Partial H NMR spectra (600 MHz in CD3CN at rt) of 3a (A), 5c (B), and 3b (C).
Scheme 5. Synthesis of the Dendritic Dialkylammonium Salt 5d
synthesize the [2]rotaxanes 1a and 1b; [2]rotaxane 1a has been
reported in the literature.13a Meanwhile, the substituted
dialdehyde 6b has also been used by our group to construct
catenanes.18 Here, the ammonium salt 5a was also used to
perform the dynamic clipping reaction with 6b and 7 in
anhydrous CH3CN. The mixture was then treated with BH3·
THF to afford [2]rotaxanes 1b in 85% yield. The simple
[2]rotaxanes have been well characterized by 1H NMR
addition, the resonances for the central methylene (H1) were
shifted downfield. Next, the first-generation dendritic [2]-
rotaxanes 2a and 2b were synthesized using the same method,
in 82% and 78% yields, respectively. Evidence for the formation
1
of 2a and 2b in this process comes from analysis of their H
NMR spectra. As shown in Figure 1, an obvious downfield shift
of the resonance for the methylene protons (H1′) and upfield
shifts for the benzene ring protons (H2′ and H3′) on the
stopper units of 5b, as revealed by a comparison of the spectra
of 2a and 2b, show that the crown ether unit in the former
substance is threaded by the ammonium template. Meanwhile,
other methylene protons (H4′) displayed obvious upfield shifts.
1
spectroscopy. From the H NMR (as shown in Figure S1,
SI), [2]rotaxane 1b displayed some shifts similar to those of
[2]rotaxane 1a. For example, the resonance of the protons on
the stopper units (H2 and H3) showed an obvious upfield shift,
due to the shielding effect of the encircling crown ethers. In
+
It is notable that the protons of NH2 in the template of
646
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
1
Figure 3. Partial H NMR spectra (600 MHz in CDCl3 at rt) of 4a (A), 5d (B), and 4b (C).
Figure 4. UV−vis absorption and photoluminescence spectra of 4a and 4b in CH2Cl2 solution (1.0 × 10−5 M) and in thin film.
rotaxane 2a were detected at 8.97 ppm because of the
stabilizing effect of the hydrogen-bonding interactions of the
oxygens on the N-hetero crown ether 21a with the ammonium
hydrogen atoms. Moreover, similar chemical shift changes for
the characteristic protons on [2]rotaxane 2b were observed.
These results are in good agreement with published
literature.13−19 Subsequently, a similar method was used to
construct the second-generation dendritic [2]rotaxanes. As a
result of steric hindrance, the mixture used for the clipping
reaction had to be stirred for 7 days to afford the target
molecules 3a and 3b, in yields of 72% and 71%, respectively. An
investigation of the 1H NMR indicated that the second-
generation dendritic [2]rotaxanes had shifts similar to those of
the resonances of some other protons, such as the two
neighboring methylene protons (H1″) of ammonium, other
methylene protons (H4″) and benzene ring protons (H2″ and
H3″). This is made clear by a comparison of the spectra of 2a
and 2b, as shown in Figure 2. These results indicate that the N-
hetero crown ether encircled the ammonium site. Further proof
was provided by the ESI-MS or MALDI-MS in acetonitrile. For
example, the peaks at m/z 1009.9, 1342.4, 1555.5, 2430.3, and
corresponding aldehyde 23. Subsequently, 23 was reduced by
NaBH4 in a solution of THF and MeOH to give the desired
alcohol 24. The alcohol was chlorized by SOCl2 to obtain
benzyl chloride 25, subsequently used without further
purification. Then, 3,5-dihydroxybenzaldehyde 12 with the
benzyl chloride 25 in DMF in the presence of K2CO3 afforded
the ester 26, in 75% yield. The amine 27 was synthesized using
a similar condensation reaction. Subsequent protonation of the
free amine with an excess of 1 M HCl in acetone, followed by
counterion exchange with saturated NH4PF6 solution, afforded
the ammonium salt 5d.
A similar clipping reaction was performed by mixing the
ammonium salt 5d with 6 and 7. The process of self-assembly
1
1
could be followed using H NMR. The H NMR spectrum of
the [2]rotaxane 4a is shown in Figure 3A. Compared with the
spectrum of the template 5d (Figure 3B), the resonance of the
protons (H1′ and H1‴) in the two side methylene groups,
adjacent to the ammonium, showed obvious downfield shifts,
while the resonance of the protons (H4′ and H4‴) on the
stopper groups also showed contrary shifts, owing to the
shielding effect of the encircling N-hetero crown ether ring
system. Furthermore, as depicted in Figure 3A, upfield shifts of
the resonances for the benzene ring protons (H2′, H2‴ and H3′,
H3‴) were observed, in comparison to the spectrum of the
template 5d, as shown in Figure 3B. Similar changes of signal
resonances are also reflected in the 1H NMR of [2]rotaxane 4b,
as shown in Figure 3C. The observed shifts in the proton
resonances, which are in good agreement with those described
above for the first- and second-generation dendritic [2]-
rotaxanes, suggest that the newly installed crown ether ring
system in the dendritic [2]rotaxanes 4a and 4b encircled the
ammonium moiety of 5d. In addition, there is an obvious
change, in that the overlapping peaks on the pyrene units of 5d
are split, possibly due to the introduction of N-hetero crown
− +
2642.4 can be assigned to the [M − PF6 ] species, in which M
represents the [2]rotaxanes 1b, 2a, 2b, 3a and 3b, respectively
(see SI).
The success of our synthesis of the dendritic rotaxanes
inspired us to investigate further the functional dendritic
rotaxanes. Subsequent work has focused on the dendritic
[2]rotaxane containing a fluorophore. For this work, we
selected pyrene as the fluorescent unit. The dialkylammonium
salt 5d, which has an asymmetrical structure consisting of
different dendritic stopper units G1 and G1′, was synthesized
according to the synthetic route described by Scheme 5. First,
compound 22 was reacted with n-BuLi in anhydrous THF at
−78 °C for 3 h, then dry DMF was added to obtain the
647
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
Figure 5. Photoluminescence spectra of 4a and 4b in CH2Cl2 solution at different concentrations.
ether weakening the stacking between the pyrene units.
Additional evidence supporting this conclusion comes from
analysis of the MALDI mass spectrum (SI), which contains
peaks at m/z 1581.6, and 1793.9 that correspond to the −PF6
salts of [2]rotaxanes 4a and 4b, respectively.
stronger intermolecular interaction in such a mechanically
interlocked system and tended to form the excimer at higher
concentration, while the excimer will be decreased at low
concentration. In consideration of the fact that pyrene-based
fluorescent [2]rotaxanes 4a and 4b possess optical character
similar to that of pyrene, it thus provides a reference to
construct the fluorescent, mechanically interlocked molecules
and to adjust the aggregated behaviors.
Following the introduction of the fluorescent pyrene units,
an investigation was performed of the optical properties of 4a
and 4b. The UV−vis absorption and fluorescence spectra of 4a
and 4b, in solution and in the solid state, are presented in
Figure 4. The UV−vis absorption spectrum of 4a in
dichloromethane (1.0 × 10−5 M shows four main absorptions,
at 246 nm, 280 nm, 331 and 346 nm. A similar spectrum is also
observed in the UV−vis absorption spectra of 4b in Figure 4B.
Compared with the absorption in solution, the thin films of 4a
and 4b display 5−9 nm red shifts, which implies that there is
stronger intermolecular interaction in the solid state.
Subsequently, the photoluminescence spectra were also
investigated. As can be seen in Figure 4A and B, the spectra
of [2]rotaxane 4a and 4b have a broad emission from 350 to
650 nm in solution. Usually, pyrene is easy to form an excimer
(dimer) in an electronic excited state, and the emission band
associated with the excimer will occur at a longer wavelength
that is significantly different, often a rather broad featureless
transition over a wide range of wavelengths. Furthermore, the
excimer emission generally locates between 410 and 480 nm,
while monomer emission typically shows three or four
transitions, between 390 and 420 nm.21 The views are well
reflected in our experiment by investigating photoluminescence
spectra of different concentration. The emission spectra in
Figure 5A,B show that the intensity of the emission bands
decreased significantly with decreasing concentration. The
fluorescence spectra of 4a and 4b show broader emission
bands, with three main peaks around at 382, 400, and 464 nm,
when the concentration in dichloromethane solution was 1.0 ×
10−5 M. Additionally, the intensity of the fluorescence bands
clearly decreased by diluting the solution to 1.0 × 10−6 M. In
addition, the bands in the visible region for 4a and 4b became
weak emission bands. The intensity of emission continued to
decrease upon further dilution from 1.0 × 10−6 M to 1.0 × 10−7
M, resulting in the complete disappearance of the fluorescence
bands in the visible region (470−550 nm). Therefore, the
emission bands of 4a and 4b from 350 to 420 nm can be
ascribed to the emission of the monomer of pyrene-based
rotaxanes, while another broader emission band from 430 to
600 nm is assigned to the formation of excimer. Additionally,
the films of 4a and 4b only show a peak around at 464 nm.
These results indicated that [2]rotaxanes 4a and 4b had a
3. CONCLUSION
We have successfully synthesized a series of dendritic
dialkylammonium salts, from G0 to G2, using a template-
directed clipping approach to efficiently self-assemble a series of
[2]rotaxane-based dendrimers. This has proved possible even
though some bigger dendritic groups were introduced.
Subsequently, the pyrene fluorophore was successfully
introduced to the stopper group, and two unsymmetrical
dendritic [2]rotaxanes were synthesized. Their optical proper-
ties indicate that they possess stronger intermolecular
interaction in the solid state than in solution, and readily
form the excimer in solutions of higher concentration. Further
work will focus on their functionalization and application, such
as preparing dynamic self-assembling fluorescent materials,
adjusting the aggregated behaviors and constructing multi-
fluorophore molecules.
4. EXPERIMENTAL SECTION
General Methods. All manipulations were carried out under an
argon atmosphere by using standard Schlenk techniques, unless
otherwise stated. THF was distilled under argon atmosphere from
sodium-benzophenone. 1-(Bromomethyl)-3,5-dimethoxybenzene 9,23
11,24 13,25 14,25 15,26 16,27 17,26 18,24 and 1-bromo-7-(tert-
butyl)pyrene 2228 were prepared by literature methods or modified
literature methods. All other starting materials were obtained
commercially as analytical-grade and used without further purification.
1H NMR spectra were collected with 400 MHz or 600 MHz
spectrometer, while 13C NMR spectra were collected with a 400 MHz
spectrometer. Mass spectra were measured in the ESI or MALDI
mode. UV−vis spectra were obtained on a UV spectrophotometer, and
fluorescence spectra were taken on a luminescence spectrometer.
Synthesis of 10. Into a 250-mL, two-necked, round-bottom flask
equipped with a magnetic stirrer was placed a mixture of 8 (1.35 g,
10.0 mmol), 1-(bromomethyl)-3,5-dimethoxybenzene 9 (4.60 g, 20.0
mmol), and potassium carbonate (4.20 g, 30.0 mmol); then 200 mL
DMF was added. The reaction was stirred for 24 h at 50 °C under
argon atmosphere. The resulting mixture was allowed to cool to room
temperature and was filtered. After that, the solvents were removed
under vacuum, and the residue was extracted by ethyl acetate and then
dried over anhydrous Na2SO4, removed of solvent under reduced
648
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
pressure, and purified on a silica gel column using dichloromethane/
petroleum ether (2:1) as the eluent to obtain 10 as a white solid. Yield:
3.26 g, 75%. Compound 10: H NMR (600 MHz, CDCl3): δ ppm =
6.83 (d, J = 2.4 Hz, 2H), 6.79 (s, 1H), 6.54 (d, J = 1.8 Hz, 4H), 6.43 (t,
J = 1.8 Hz, 2H), 4.98 (s, 4H), 3.80 (s, 12H). 13C NMR (100 MHz,
CDCl3): δ ppm = 161.0, 159.8, 138.0, 118.6, 113.3, 110.9, 107.2,
105.1, 99.9, 70.3, 55.3. ESI MS: m/z = 458.10 [M + Na+], 475.40 [M +
K+]; calculated exact mass: 435.20. Anal. Calcd for C25H25NO6: C,
68.95; H, 5.79; N, 3.22. Found: C, 68.81; H, 5.68; N, 3.29.
with dry THF (120 mL) and then cooled to −78 °C. After n-BuLi (1.6
M in hexane, 5.6 mL, 9.0 mmol) was added to this mixture, the
reaction mixture was stirred at −78 °C for 3 h. DMF (0.6 mL, 7.8
mmol) was added to this reaction mixture at one portion at −78 °C.
The reaction mixture was stirred at −78 °C for 40 min and then
poured into a saturated aqueous NH4Cl solution. The resulting solid
was obtained by filtration, and the organic filtrates were separated. The
aqueous layer was extracted with CH2Cl2, and then the combined
organic extracts were washed with a saturated aqueous NaHCO3
solution and a saturated aqueous NaCl solution, successively. The
organic extracts were dried over anhydrous Na2SO4 and then filtered
and concentrated under reduced pressure; purification on a silica gel
column using petroleum ether/ethyl acetate (8:1) as the eluent
obtained compound 23 as a yellow solid. Yield: 1.52 g, 71%.
Compound 23: 1H NMR (600 MHz, CDCl3): δ ppm = 10.76 (s, 1H),
9.38 (d, J = 9.0 Hz, 1H), 8.39 (d, J = 12 Hz, 1H), 8.34 (d, J = 7.8 Hz,
2H), 8.29 (d, J = 9.6 Hz, 1H), 8.21−8.20 (m, 2H), 8.06 (d, J = 6 Hz,
1H), 1.60 (s, 9H). 13C NMR (100 MHz, CDCl3): δ ppm = 193.1,
149.7, 135.2, 131.0, 130.9, 130.8, 130.7, 130.1, 127.0, 126.9, 124.3,
124.2, 124.0, 122.7, 122.1, 35.2, 31.8. EI MS: m/z = 286.04; calculated
exact mass: 286.14. Anal. Calcd for C21H18O: C, 88.08; H, 6.34.
Found: C, 88.15; H, 6.29.
1
Synthesis of 5b. To a solution of the amine 14 (0.86 g, 1.0 mmol)
in dry CH2Cl2 (20 mL), was added TFA (0.32 mL, 5.0 mmol) at room
tempeature. After the solution stirred for 2 h under argon atmosphere,
the solvent was removed under vacuum. The residue was dissolved in
CH2Cl2 and MeOH, and then saturated NH4PF6 (20 mL, aq) was
added and stirred for several minutes to yield a white creamy solid.
The residue was extracted by CH2Cl2. The organic layer was washed
by H2O for three times and dried over anhydrous Na2SO4, and the
solvent was removed under vacuum to give the compound 5b. Yield:
0.93 g, 92%. Compound 5b: 1H NMR (600 MHz, CD3CN): δ ppm =
6.62 (d, J = 1.8 Hz, 4H), 6.60 (d, J = 1.8 Hz, 2H), 6.58 (d, J = 1.8 Hz,
8H), 6.43 (t, J = 1.8 Hz, 4H), 5.00 (s, 8H), 3.87 (s, 4H), 3.75 (s, 24H).
13C NMR (100 MHz, CD3CN): δ ppm = 161.6, 160.5, 140.0, 138.1,
108.6, 105.9, 102.3, 99.8, 70.1, 55.5, 52.2. ESI MS: m/z = 862.70 [M −
PF6−]; calculated exact mass: 1007.30. Anal. Calcd for C50H56
F6NO12P: C, 59.58; H, 5.60; N, 1.62. Found: C, 59.50; H, 5.48; N,
1.67.
Synthesis of 19. A mixture of 18 (0.98 g, 1.0 mmol) and 17 (0.98
g, 1.0 mmol) in dry toluene (80 mL) was placed into a 100 mL round-
bottom flask and refluxed for 24 h under argon atmosphere. The
solvent was removed under vacuum, and the residue was dissolved in
THF (50 mL) and MeOH (50 mL), and then NaBH4 (0.38 g, 10.0
mmol) was added in portions. After stirring overnight, the solvents
were removed under vacuum, and the residue was extracted by
dichloromethane. The organic layer was washed by brine until clear,
dried over anhydrous Na2SO4, and concentrated in vacuo to give a
kinetically stable amine as a light-yellowish oil in the yield of 88%. The
unpurified amine was dissolved in dry chloroform (20 mL), and then
Boc2O (0.44 g, 2.0 mmol) and triethylamine (0.43 mL) were added.
The mixture was stirred at room temperature for 24 h. Removal of
solvent under reduced pressure and purification on a silica gel column
using petroleum ether/ethyl acetate (1:1) as the eluent obtained the
Boc-protected 19 as a white solid. Yield: 1.37 g, 76%. Compound 19:
1H NMR (600 MHz, CDCl3): δ ppm = 6.64 (s, 4H), 6.57−6.53 (m,
24H), 6.49−6.48 (m, 2H), 6.41−6.39 (m, 12H), 4.98 (s, 4H), 4.92−
4.89 (m, 24H), 3.76 (s, 48H), 1.46 (s, 9H). 13C NMR (100 MHz,
CDCl3): δ ppm = 160.8, 159.9, 139.0, 138.6, 106.8, 106.2, 105.1,
101.4, 100.7, 99.8, 80.1, 69.8, 60.3, 55.2, 28.3, 14.1. ESI MS: m/z =
2072.98 [M + Na+], 2088.94 [M + K+]; calculated exact mass:
2049.84. Anal. Calcd for C119H127NO30: C, 69.68; H, 6.24; N, 0.68.
Found: C, 69.75; H, 6.33; N, 0.61.
Synthesis of 24. In a round-bottom flask charged with a stir bar
was stirred compound 23 (0.63 g, 2.2 mmol) at 0 °C in THF. A
solution of NaBH4 (0.25 g, 6.5 mmol) in 95% ethanol (15 mL) was
prepared along with 10 drops of 1 M NaOH. This solution was added
to the aldehyde and stirred at 0 °C for 15 min; the mixture changed
from a yellow-green color to milky white. The mixture was quenched
with 10% HCl, diluted with water (50 mL), and extracted with CH2Cl2
(3 × 30 mL). The combined organic fractions were washed with
NaHCO3 solution and water successively and then dried with
anhydrous Na2SO4. Filtration and evaporation afforded the desired
1
alcohol 24. Yield: 0.62 g, 98%. Compound 24: H NMR (600 MHz,
CDCl3): δ ppm = 8.32 (d, J = 6.0 Hz, 1H), 8.23 (d, J = 6.0 Hz, 2H),
8.11 (t, J = 12.0 Hz, 2H), 8.04−8.01 (m, 2H), 7.98 (d, J = 6.0 Hz, 1H),
5.38 (s, 2H), 1.59 (s, 9H). 13C NMR (100 MHz, CDCl3): δ ppm =
149.0, 133.4, 131.0, 130.5, 128.4, 128.0, 127.5, 127.2, 125.5, 124.7,
124.4, 122.9, 122.8, 122.5, 122.4, 63.6, 35.2, 31.9. EI MS: m/z =
288.06; calculated exact mass: 288.15. Anal. Calcd for C21H20O: C,
87.45; H, 6.99. Found: C, 87.33; H, 6.89.
Synthesis of 26. To a solution of pyrenemethanol 24 (2.50 g, 8.6
mmol) in CH2Cl2 (50 mL) was added pyridine (1.00 g, 12.6 mmol),
and then SOCl2 (4 mL, 6.53 g, 54.8 mmol) was added dropwise via a
dropping funnel. After the solution was stirred overnight at room
temperature, ice (50 g) was added. The CH2Cl2 phase was collected
and dried with anhydrous Na2SO4. Upon the removal of solvent, 25
was obtained as yellow powders in 90% yield without further
purification because of instability. In a 250 mL two-necked, round-
bottom flask equipped with a magnetic stirrer was placed a mixture of
12 (0.21 g, 1.5 mmol), 25 (0.92 g, 3.0 mmol), and potassium
carbonate (0.62 g, 4.5 mmol); then 150 mL DMF was added. The
reaction was stirred for 24 h at 50 °C under an argon atmosphere. The
resulting mixture was allowed to cool to room temperature and
filtered. After that, the solvent was removed under vacuum, and the
residue was extracted by ethyl acetate, then dried over anhydrous
Na2SO4, and then removed of solvent under reduced pressure and
purified on a silica gel column using petroleum ether/ethyl acetate
(5:1) as the eluent to obtain the compound 26 as a light-yellow solid.
Synthesis of 5c. To a solution of the Boc-protected amine 19
(1.03 g, 0.5 mmol) in dry CH2Cl2 (20 mL) was added TFA (0.16 mL,
2.5 mmol) at room temperature. After stirring for 2 h under argon
atmosphere, the solvent was removed under a vacuum. The residue
was dissolved in CH2Cl2 and MeOH, and then saturated NH4PF6 (10
mL, aq) was added and stirred for several minutes to yield a white
creamy solid. The residue was extracted by CH2Cl2, and the organic
layer was washed by H2O three times and dried over anhydrous
Na2SO4, and the solvents were removed under vacuum to give the
1
Yield: 4.38 g, 75%. Compound 26: H NMR (400 MHz, CDCl3): δ
1
ppm = 9.94 (s, 1H), 8.24−8.22 (m, 6H), 8.12 (d, J = 8.0 Hz, 4H),
8.07−8.01 (m, 6H), 7.30 (s, 2H), 7.09 (s, 1H), 5.75 (s, 4H), 1.58 (s,
18H). 13C NMR (100 MHz, CDCl3): δ ppm = 191.8, 160.5, 149.2,
131.5, 131.0, 130.5, 129.0, 128.7, 127.1, 124.4, 122.8, 122.6, 108.8,
108.5, 69.1, 35.2, 31.9 . ESI MS: m/z = 701.40 [M + Na+], 717.30 [M
+ K+]; calculated exact mass: 678.31. Anal. Calcd for C49H42O3: C,
86.69; H, 6.24. Found: C, 86.77; H, 6.19.
Synthesis of 27. A mixture of 26 (0.68 g, 1.0 mmol) and 11 (0.44
g, 1.0 mmol) in dry toluene (80 mL) in a 100 mL round-bottom flask
was refluxed for 24 h under argon atmosphere. The solvent was
removed under vacuum, and the residue was dissolved in THF (30
compound 5c. Yield: 0.93 g, 89%. Compound 5c: H NMR (600
MHz, CD3CN): δ ppm = 6.60 (s, 8H), 6.52 (d, J = 1.2 Hz, 20H), 6.49
(s, 4H), 6.48 (s, 2H), 6.39 (s, 8H), 4.89−4.87 (m, 24H), 3.78 (s, 4H),
3.70 (s, 48H). 13C NMR (100 MHz, CDCl3): δ ppm = 161.6, 160.6,
140.2, 108.4, 107.1, 106.0, 105.1, 102.3, 102.0, 100.0, 70.1, 55.6, 52.4.
−
ESI MS: m/z = 1950.710 [M − PF6 ], 1972.66 [M − HPF6 + Na+],
1988.64 [M − HPF6 + K+]; calculated exact mass: 2095.76. Anal.
Calcd for C50H56 F6NO12P: C, 65.29; H, 5.77; N, 0.72. Found: C,
65.39; H, 5.89; N, 0.76.
Synthesis of 23. Bromopyrene derivative 22 (2.50 g, 7.5 mmol)
was placed in a 250 mL two-necked round-bottomed flask and mixed
649
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
mL) and MeOH (30 mL), and then NaBH4 (0.38 g, 10.0 mmol) was
added in portions. After stirring overnight, the solvents were removed
under vacuum, and the residue was extracted by CH2Cl2. The organic
layer was washed by brine until clear, dried over anhydrous Na2SO4,
removed of solvent under reduced pressure, and purified on a silica gel
column using petroleum ether/ethyl acetate (2:1) as the eluent to
obtain the compound 27 as a light-yellow solid. Yield: 0.72 g, 65%.
Compound 27: 1H NMR (400 MHz, CDCl3): δ ppm = 8.26−8.22 (m,
6H), 8.10−8.08 (m, 4H), 8.05−7.99 (m, 6H), 6.80 (s, 3H), 6.63 (s,
2H), 6.54 (s, 3H), 6.51 (s, 2H), 6.36 (s, 2H), 5.71 (s, 4H), 4.95 (s,
4H), 3.80−3.78 (m, 4H), 3.72 (s, 12H), 1.58 (s, 18H). 13C NMR (100
MHz, CDCl3): δ ppm = 161.0, 160.9, 160.3, 160.0, 159.9, 149.1, 139.3,
139.2, 131.3, 129.0, 127.1, 122.8, 122.5, 122.5, 107.6, 107.4, 107.2,
105.3, 105.2, 100.0, 70.1, 68.9, 55.2, 53.2, 35.1, 31.8. ESI MS: m/z =
1102.50 [M + H+]; calculated exact mass: 1101.52. Anal. Calcd for
C74H71NO8: C, 80.63; H, 6.49; N, 1.27. Found: C, 80.50; H, 6.42; N,
1.36.
5H), 6.54 (d, J = 1.8 Hz, 2H), 6.50 (d, J = 7.8 Hz, 2H), 6.46 (s, 1H),
6.44 (s, 2H), 6.42 (s, 2H), 6.40 (d, J = 1.8 Hz, 6H), 6.32 (br, 3H), 6.11
(d, J = 1.8 Hz, 3H), 5.00 (s, 2H), 4.54 (br, 5H), 4.46 (br, 3H), 4.02 (s,
2H), 3.92−3.90 (m, 6H), 3.84−3.83 (m 3H), 3.75 (br, 7H), 3.73 (br,
5H), 3.72 (s, 4H), 3.70 (s, 18H), 3.64−3.63 (m, 3H), 1.68 (t, J = 7.2,
2H), 1.30 (br, 22H), 0.89 (t, J = 6.6 Hz, 3H). 13C NMR (100 MHz,
CD3CN): δ ppm = 161.6, 160.2, 147.3, 139.8, 137.3, 135.0, 121.8,
112.7, 110.5, 109.2, 108.8, 108.1, 105.9, 105.5, 104.1, 99.9, 99.2, 71.7,
71.0, 70.1, 69.5, 67.9, 55.5, 53.0, 50.1, 32.3, 30.0, 29.7, 29.1, 26.1, 23.0,
−
14.1. ESI MS: m/z = 1555.50 [M − PF6 ]; calculated exact mass:
1698.80. Anal. Calcd for C91H117F6N4O18P: C, 64.30; H, 6.94; N, 3.30.
Found: C, 64.39; H, 6.87; N, 3.23.
Synthesis of 3a. The synthesis procedure of 3a was similar to the
1
synthesis of 1b. Yield: 0.19 g, 72%. Compound 3a: H NMR (600
MHz, CD3CN): δ ppm = 8.92 (s, 2H), 7.52 (t, J = 7.8 Hz, 1H), 7.14
(d, J = 7.8 Hz, 2H), 6.59 (br, 3H), 6.54 (br, 11H), 6.52 (s, 2H), 6.50
(s, 2H), 6.48 (s, 3H), 6.46 (s, 1H), 6.44 (br, 11H), 6.41−6.40 (m,
7H), 6.37 (s, 2H), 6.32 (br, 3H), 6.21 (d, J = 7.2 Hz, 2H), 6.03 (br,
3H), 4.90 (s, 1H), 4.88 (br, 9H), 4.86 (br, 3H), 4.83 (s, 1H), 4.78 (s,
2H), 4.75 (s, 3H), 4.70 (s, 1H), 4.52 (br, 5H), 4.41 (br, 3H), 4.05 (s,
2H), 3.86 (br, 3H), 3.79 (br, 3H), 3.71 (br, 28H), 3.68 (br, 12H), 3.65
(br, 5H), 3.61 (br, 14H). 13C NMR (100 MHz, CD3CN): δ ppm =
161.9, 161.8, 160.7, 160.6, 147.6, 140.3, 140.2, 137.4, 135.1, 122.1,
110.9, 110.0, 108.6, 107.3, 107.2, 107.1, 106.2, 104.1, 102.2, 101.7,
100.1, 70.3, 69.9, 55.8, 55.7, 32.0, 23.1, 14.1. MALDI MS: m/z =
Synthesis of 5d. 27 (1.10 g, 1.0 mmol) was dissolved in acetone
(200 mL) and treated sequentially with HCl (aq) (1 M, 2 mL) and
saturated NH4PF6 (aq) (20 mL). The organic solvent was evaporated
under reduced pressure; the precipitate was filtered off and washed
with water (10 mL) for several times to afford 5d as a yellow solid.
1
Yield: 1.10 g, 88%. Compound 5d: H NMR (400 MHz, CDCl3): δ
ppm = 8.15 (d, J = 8.8 Hz, 6H), 8.00−7.87 (m, 10H), 6.75 − 6.73 (m,
2H), 6.54 (s, 2H), 6.51 (s, 2H), 6.47 (s, 4H), 6.28 (s, 2H), 5.59 (s,
4H), 4.88 (s, 4H), 3.83 (s, 4H), 3.63 (s, 12H), 1.55 (s, 18H). 13C
NMR (100 MHz, CDCl3): δ ppm = 160.8, 160.5, 160.2, 149.0, 138.8,
138.7, 131.1, 130.9, 130.4, 128.9, 128.8, 122.7, 122.5, 108.6, 108.3,
105.1, 99.8, 69.8, 68.7, 55.1, 35.1, 31.8, 29.7. ESI MS: m/z = 1102.80
−
2430.25 [M − PF6 ]; calculated exact mass: 2575.01. Anal. Calcd for
C141H153F6N4O33P: C, 65.72; H, 5.98; N, 2.17. Found: C, 65.66; H,
5.84; N, 2.25.
Synthesis of 3b. The synthesis procedure of 3b was similar to the
−
1
[M − PF6 ]; calculated exact mass: 1247.50. Anal. Calcd for
synthesis of 1b. Yield: 0.20 g, 71%. Compound 3b: H NMR (600
C74H72F6NO8P: C, 71.20; H, 5.81; N, 1.12. Found: C, 71.09; H,
5.73; N, 1.21.
MHz, CD3CN): δ ppm = 8.88 (s, 2H), 6.73 (s, 1H), 6.57 (br, 4H),
6.53 (br, 9H), 6.49 (br, 9H), 6.45 (br, 7H), 6.43 (br, 5H), 6.40 (br,
6H), 6.36 (br, 5H), 6.32 (br, 3H), 6.06 (s, 3H), 4.87 (br, 8H), 4.84
(br, 10H), 4.73 (s, 3H), 4.47 (s, 4H), 4.42 (br, 3H), 4.02 (s, 2H), 3.84
(s, 2H), 3.78−3.76 (m, 3H), 3.71−3.70 (m, 22H), 3.67−3.66 (m,
32H), 3.61 (d, J = 1.8 Hz, 9H), 1.44 (s, 2H), 1.24−0.89 (m, 22H),
0.85 (t, J = 7.2 Hz, 3H). 13C NMR (100 MHz, CD3CN): δ ppm =
161.8, 161.8, 161.4, 160.7, 160.5, 147.5, 140.5, 140.3, 140.3, 140.1,
137.5, 135.2, 113.0, 108.5, 107.3, 107.0, 106.1, 102.2, 101.7, 100.2,
100.1, 71.9, 71.1, 71.0, 70.3, 69.9, 69.3, 68.2, 55.7, 55.7, 53.2, 52.8,
50.4, 32.4, 30.2, 29.8, 26.3, 23.1, 14.2. MALDI MS: m/z = 2642.39 [M
− PF6−]; calculated exact mass: 2787.22. Anal. Calcd for
C155H181F6N4O34P: C, 66.75; H, 6.54; N, 2.01. Found: C, 66.65; H,
6.59; N, 2.12.
Synthesis of 1b. A mixture of salt 5a (93 mg, 0.2 mmol),
tetraethylene glycol bis(2-aminophenyl)ether 7 (75 mg, 0.2 mmol),
and 2,6-pyridinedicarboxaldehyde derivative 6b (69 mg, 0.2 mmol)
was stirred for 24 h in dry CH3CN (10 mL) under argon atmosphere
at room temperature. Then 1 M BH3·THF solution (1.6 mL) was
added, and the mixture was further stirred overnight. The solvents
were removed under vacuum, and the residue was purified by column
chromatography (silica gel, CH2Cl2/MeCN/MeOH = 100:0:0−
75:25:1) to give the [2]rotaxane 1b. Yield: 0.20 g, 85%. Compound
1
1b: H NMR (600 MHz, CD3CN): δ ppm = 8.80 (s, 2H), 6.95 (s,
2H), 6.70−6.64 (m, 4H), 6.61−6.60 (m, 2H), 6.45 (d, J = 7.2 Hz,
2H), 6.27 (s, 2H), 6.14 (s, 4H), 4.52 (br, 4H), 4.41 (s, 2H), 4.15−4.13
(m, 2H), 4.04 (s, 4H), 3.92 (d, J = 3.0 Hz, 4H), 3.83 (s, 4H), 3.77 (s,
2H), 3.75 (s, 4H), 3.42 (s, 12H), 1.82 (t, J = 5.4 Hz, 2H), 1.49 (br,
2H), 1.40 (br, 2H), 1.29 (br, 18H), 0.89 (m, 3H). 13C NMR (100
MHz, CD3CN): δ ppm = 161.5, 147.2, 137.6, 134.7, 122.0, 120.0,
112.9, 110.8, 109.4, 108.4, 108.1, 107.3, 101.4, 71.6, 71.0, 70.7, 69.9,
68.1, 55.6, 53.2, 50.1, 32.3, 30.0, 29.7, 29.1, 26.2, 23.0, 14.1. ESI MS:
Synthesis of 4a. A mixture of 5d (125 mg, 0.1 mmol),
tetraethylene glycol bis(2-aminophenyl)ether 7 (38 mg, 0.1 mmol),
and 2,6-pyridinedicarboxaldehyde 6a (14 mg, 0.1 mmol) were stirred
for 24 h in dry CH3NO2 (20 mL) under argon atmosphere at room
temperature. Then 1 M BH3·THF solution (0.8 mL) was added, and
the mixture was further stirred overnight. The solvents were removed
under vacuum, and the residue was purified by column chromatog-
raphy (silica gel, CH2Cl2/MeCN/MeOH = 100:0:0−75:25:1) to give
the [2]rotaxane 4a. Yield: 36 mg, 21%. Compound 4a: 1H NMR (600
MHz, CDCl3): δ ppm = 9.08 (s, 2H), 8.20 (d, J = 12.6 Hz, 4H), 7.99
(s, 6H), 7.92 (d, J = 7.8 Hz, 2H), 7.88 (d, J = 9.0 Hz, 2H), 7.71 (d, J =
7.8 Hz, 2H), 7.53 (t, J = 7.2 Hz, 1H), 7.02 (d, J = 7.2 Hz, 2H), 6.75 (s,
1H), 6.52 (t, J = 6.6 Hz, 3H), 6.41 (d, J = 7.2 Hz, 2H), 6.35 (s, 1H),
6.27 (s, 6H), 6.17 (s, 2H), 6.10 (br, 3H), 5.83 (s, 2H), 5.22 (s, 4H),
4.40 (br, 5H), 4.24 (br, 2H), 3.78 (br, 3H), 3.70−3.60 (m, 26H),
3.20−3.05 (m, 4H), 1.59 (s, 18H). The 13C NMR spectrum could not
be collected due to the poor solubility of 4a. MALDI MS: m/z =
−
m/z = 1009.90 [M − PF6 ]; calculated exact mass: 1154.59. Anal.
Calcd for C59H85F6N4O10P: C, 61.34; H, 7.42; N, 4.85. Found: C,
61.22; H, 7.51; N, 4.80.
Synthesis of 2a. The synthesis procedure of 2a was similar to the
1
synthesis of 1b. Yield: 0.12 g, 82%. Compound 2a: H NMR (600
MHz, CD3CN): δ ppm = 8.97 (s, 2H), 7.76 (t, J = 7.8 Hz, 1H), 7.36
(d, J = 7.8 Hz, 2H), 6.63−6.61 (m, 3H), 6.55−6.51 (m, 7H), 6.46−
6.45 (m, 3H), 6.40−6.39 (m, 7H), 6.35−6.34 (m, 2H), 6.32−6.31 (m,
2H), 6.08 (d, J = 1.8 Hz, 2H), 5.02−4.99 (m, 2H), 4.92 (d, J = 6.6 Hz,
2H), 4.59 (s, 5H), 4.45 (br, 3H), 4.04 (s, 2H), 3.94−3.93 (m, 3H),
3.85−3.84 (m, 3H), 3.76 (s, 2H), 3.73−3.68 (m, 31H), 3.65 (d, J = 3.6
Hz, 3H). 13C NMR (100 MHz, CD3CN): δ ppm = 161.5, 160.2,
147.5, 139.9, 137.2, 135.0, 122.8, 121.8, 120.2, 112.9, 110.6, 108.3,
105.9, 105,5, 103.9, 99.9, 99.2, 71.6, 71.0, 70.1, 69.5, 67.9, 55.5, 53.0,
−
1581.62 [M − PF6 ]; calculated exact mass: 1726.73. Anal. Calcd for
C101H105F6N4O13P: C, 70.21; H, 6.12; N, 3.24. Found: C, 70.29; H,
6.01; N, 3.29.
−
49.9. ESI MS: m/z = 1342.40 [M − PF6 ]; calculated exact mass:
Synthesis of 4b. The synthesis procedure of 4b was similar to that
of 4a. Yield: 37 mg, 19%. Compound 4b: 1H NMR (600 MHz,
CDCl3): δ ppm = 9.07 (s, 2H), 8.21 (d, J = 12.6 Hz, 4H), 8.03−8.00
(m, 6H), 7.96 (t, J = 4.8 Hz, 2H), 7.90−7.89 (m, 2H), 7.74 (d, J = 7.8
Hz, 2H), 6.72 (s, 1H), 6.68 (s, 1H), 6.52−6.50 (m, 4H), 6.40−6.37
(m, 4H), 6.31 (br, 5H), 6.22−6.21 (m, 2H), 6.17 (d, J = 10.8 Hz, 3H),
1486.59. Anal. Calcd for C77H89F6N4O17P: C, 62.17; H, 6.03; N, 3.77.
Found: C, 62.09; H, 6.17; N, 3.82.
Synthesis of 2b. The synthesis procedure of 2b was similar to the
1
synthesis of 1b. Yield: 0.13 g, 78%. Compound 2b: H NMR (600
MHz, CD3CN): δ ppm = 8.92 (s, 2H), 6.88 (s, 2H), 6.59−6.58 (m,
650
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
5.91 (s, 2H), 5.18 (s, 3H), 4.41 (br, 5H), 4.28 (s, 2H), 3.98 (s, 1H),
3.84−3.77 (m, 4H), 3.68 (s, 2H), 3.65 (br, 13H), 3.62−3.60 (m,
12H), 3.30 (d, J = 15.6 Hz, 2H), 3.18 (d, J = 15.6 Hz, 2H), 1.76 (s,
2H), 1.59 (s, 18H), 1.26 (br, 22H), 0.89 (s, 3H). The 13C NMR
spectrum could not be collected due to the poor solubility of 4b.
MALDI MS: m/z = 1793.95 [M − PF6 ]; calculated exact mass:
1938.95. Anal. Calcd for C115H133F6N4O14P: C, 71.19; H, 6.91; N,
2.89. Found: C, 71.10; H, 6.84; N, 2.92.
Chem. Soc. 2007, 129, 626. (d) Saha, S.; Leung, K. C. F.; Nguyen, T.
D.; Stoddart, J. F.; Zink, J. I. Adv. Funct. Mater. 2007, 17, 685.
(5) (a) Fyfe, M. C. T.; Stoddart, J. F. Coord. Chem. Rev. 1999, 183,
139. (b) Harada, A.; Hashidzume, A.; Yamaguchi, H.; Takashima, Y.
Chem. Rev. 2009, 109, 5974. (c) Harada, A.; Takashima, Y.;
Yamaguchi, H. Chem. Soc. Rev. 2009, 38, 875. (d) Zheng, B.; Wang,
F.; Dong, S.; Huang, F. Chem. Soc. Rev. 2012, 41, 1621. (e) Avestro,
A.-J.; Belowich, M. E.; Stoddart, J. F. Chem. Soc. Rev. 2012, 41, 5881.
(f) Vukotic, V. N.; Loeb, S. J. Chem. Soc. Rev. 2012, 41, 5896. (g) Li,
S.-L.; Xiao, T.; Lin, C.; Wang, L. Chem. Soc. Rev. 2012, 41, 5950.
(h) Yan, X.; Wang, F.; Zheng, B.; Huang, F. Chem. Soc. Rev. 2012, 41,
6042. (i) Yan, X.; Zheng, B.; Huang, F. Polym. Chem. 2013, 4, 2395.
−
ASSOCIATED CONTENT
■
S
* Supporting Information
1
Partial H NMR spectra of [2]rotaxanes 1a−b; UV spectra of
(6) (a) Frec
́
het, J. M. J.; Tomalia, D. A. Dendrimers and Other
4a,b and NMR, MS spectra of all the interminates and dendritic
[2]rotaxanes. This material is available free of charge via the
Internet at http://pubs.acs.org.
Dendritic Polymers; VCH-Wiley: New York, NY, 2000; (b) Newkome,
G. R.; Moorefield, C. N.; Vogtle, F. Dendrimers and Dendrons:
̈
Concepts, Synthesis, Perspectives; Wiley-VCH: Weinheim, 2001;
(c) Zimmerman, S. C.; Lawless, L. J. Supramolecular Chemistry of
Dendrimers; Topics in Current Chemistry, Vol. 217; Springer: Berlin,
AUTHOR INFORMATION
Corresponding Authors
*E-mail: yinj@mail.ccnu.edu.cn
*E-mail: chshliu@mail.ccnu.edu.cn
■
́
2001; pp 95−120; (d) Grayson, S. M.; Frechet, J. M. J. Chem. Rev.
2001, 101, 3819. (e) Newkome, G. R.; Shreiner, C. D. Polymer 2008,
49, 1. (f) Newkome, G. R.; Shreiner, C. D. Chem. Rev. 2010, 110,
6338. (g) Astruc, D.; Ruiz, J. Tetrahedron 2010, 66, 1769. (h) Smith,
D. K. Tetrahedron 2003, 59, 3797.
Notes
The authors declare no competing financial interest.
(7) (a) Gorman, C. B.; Smith, J. C. J. Am. Chem. Soc. 2000, 122,
9342. (b) Wang, P.; Moorefield, C. N.; Newkome, G. R. Org. Lett.
2004, 6, 1197. (c) Astruc, D.; Chardac, F. Chem. Rev. 2001, 101, 2991.
(d) Li, W.-S.; Jiang, D.-L.; Suna, Y.; Aida, T. J. Am. Chem. Soc. 2005,
127, 7700. (e) Weener, J.-W.; Meijer, E. W. Adv. Mater. 2000, 12, 741.
(f) Freeman, A. W.; Koene, S. C.; Malenfant, P. R. L.; Thompson, M.
ACKNOWLEDGMENTS
■
We acknowledge financial support from National Natural
Science Foundation of China (20931006, 21072070,
21272088) and the Program for Academic Leader in Wuhan
Municipality (201271130441). The work was also supported by
the Scientific Research Foundation for the Returned Overseas
Chinese Scholars, Ministry of Education, the Natural Science
Foundation of Hubei Province (2013CFB207) and excellent
doctorial dissertation cultivation grant from Central China
Normal University (CCNU13T04095).
́
E.; Frechet, J. M. J. J. Am. Chem. Soc. 2000, 122, 12385. (g) Astruc, D.;
Boisselier, E.; Ornelas, C. Chem. Rev. 2010, 110, 1857. (h) Rosen, B.
M.; Wilson, C. J.; Wilson, D. A.; Peterca, M.; Imam, M. R.; Percec, V.
Chem. Rev. 2009, 109, 6275. (i) Kozaki, M.; Tujimura, H.; Suzuki, S.;
Okada, K. Tetrahedron Lett. 2008, 49, 2931. (j) Dykes, G. M.; Smith,
D. K. Tetrahedron 2003, 59, 3999. (k) Drouet, S.; Paul-Roth, C. O.
Tetrahedron 2009, 65, 10693. (l) Lee, J. W.; Kim, J. H.; Kim, B.-K.;
Shin, W. S.; Jin, S.-H. Tetrahedron 2006, 62, 894.
(8) Amabilino, D. B.; Ashton, P. R.; Balzani, V.; Brown, C. L.; Credi,
A.; Frechet, J. M. J.; Leon, J. W.; Raymo, F. M.; Spencer, N.; Stoddart,
́
J. F.; Venturi, M. J. Am. Chem. Soc. 1996, 118, 12012.
(9) Elizarov, A. M.; Chiu, S.-H.; Glink, P. T.; Stoddart, J. F. Org. Lett.
2002, 4, 679.
(10) Xiao, S.; Fu, N.; Peckham, K.; Smith, B. D. Org. Lett. 2010, 12,
140.
(11) Xu, X.-D.; Ou-Yang, J.-K.; Zhang, J.; Zhang, Y.-Y.; Gong, H.-Y.;
Yu, Y.h.; Yang, H.-B. Tetrahedron 2013, 69, 1086.
(12) Elizarov, A. M.; Chang, T.; Chiu, S.-H.; Stoddart, J. F. Org. Lett.
2002, 4, 3565.
REFERENCES
■
(1) (a) Collier, C. P.; Mattersteig, G.; Wong, E. W.; Luo, Y.; Beverly,
K.; Sampaio, J.; Raymo, F. M.; Stoddart, J. F.; Heath, J. R. Science
2000, 289, 1172. (b) Yu, H.; Luo, Y.; Beverly, K.; Stoddart, J. F.;
Tseng, H.-R.; Heath, J. R. Angew. Chem., Int. Ed. 2003, 42, 5706.
(c) Choi, J. W.; Flood, A. H.; Steuerman, D. W.; Nygaard, S.;
Braunschweig, A. B.; Moonen, N. N. P.; Laursen, B. W.; Luo, Y.;
DeIonno, E.; Peters, A. J.; Jeppesen, J. O.; Xu, K.; Stoddart, J. F.;
Heath, J. R. Chem.Eur. J. 2006, 12, 261. (d) Green, J. E.; Choi, J. W.;
Boukai, A.; Bunimovich, Y.; Johnston- Halperin, E.; Delonno, E.; Luo,
Y.; Sheriff, B. A.; Xu, K.; Shin, Y. S.; Tseng, H.-R.; Stoddart, J. F.;
Heath, J. R. Nature 2007, 445, 414.
(13) (a) Glink, P. T.; Oliva, A. I.; Stoddart, J. F.; White, A. J. P.;
Williams, D. J. Angew. Chem., Int. Ed. 2001, 40, 1870. (b) Horn, M.;
Ihringer, J.; Glink, P. T.; Stoddart, J. F. Chem.Eur. J. 2003, 9, 4046.
(2) (a) Jimen
́
ez-Molero, M. C.; Dietrich-Buchecker, C.; Sauvage, J.-
P.; De Cian, A. Angew. Chem., Int. Ed. 2000, 39, 1295. (b) Collin, J.- P.;
́
(c) Leung, K. C.-F.; Wong, W.-Y.; Arico, F.; Haussmann, P. C.;
Dietrich-Buchecker, C.; Gavina, P.; Jimenez-Molero, M. C.; Sauvage,
̃
Stoddart, J. F. Org. Biomol. Chem. 2010, 8, 83. (d) Wong, W.-Y.;
Leung, K. C.-F.; Stoddart, J. F. Org. Biomol. Chem. 2010, 8, 2332.
(e) Belowich, M. E.; Valente, C.; Stoddart, J. F. Angew. Chem., Int. Ed.
2010, 49, 7208. (f) Belowich, M. E.; Valente, C.; Smaldone, R. A.;
Friedman, D. C.; Thiel, J.; Cronin, L.; Stoddart, J. F. J. Am. Chem. Soc.
2012, 134, 5243. (g) Chen, S.; Do, J. T.; Zhang, Q.; Yao, S.; Yan, F.;
J.-P. Acc. Chem. Res. 2001, 34, 477. (c) Huang, T. J.; Brough, B.; Ho,
C.-M.; Liu, Y.; Flood, A. H.; Bonvallet, P. A.; Tseng, H.-R.; Stoddart, J.
F.; Baller, M.; Magonov, S. Appl. Phys. Lett. 2004, 85, 5391. (d) Liu, Y.;
Flood, A. H.; Bonvallet, P. A.; Vignon, S. A.; Northrop, B. H.; Tseng,
H.-R.; Jeppesen, J. O.; Huang, T. J.; Brough, B.; Baller, M.; Magonov,
S.; Solares, S. D.; Goddard, W. A.; Ho, C.-M.; Stoddart, J. F. J. Am.
Chem. Soc. 2005, 127, 9745. (e) Wu, J.; Leung, K. C. F.; Benítez, D.;
Han, J. Y.; Cantrill, S. J.; Fang, L.; Stoddart, J. F. Angew. Chem., Int. Ed.
2008, 47, 7470.
Peters, E. C.; Scholer, H. R.; Schultz, P. G.; Ding, S. Proc. Natl. Acad.
̈
Sci. U.S.A. 2007, 104, 17266.
́
(14) (a) Arico, F.; Chang, T.; Cantrill, S. J.; Khan, S. I.; Stoddart, J. F.
Chem.Eur. J. 2005, 11, 4655. (b) Yin, J.; Dasgupta, S.; Wu, J. Org.
́ ́
(3) Berna, J.; Leigh, D. A.; Lubomska, M.; Mendoza, S. M.; Perez, E.
Lett. 2010, 12, 1712.
M.; Rudolf, P.; Teobaldi, G.; Zerbetto, F. Nat. Mater. 2005, 4, 704.
(4) (a) Hernandez, R.; Tseng, H.-R.; Wong, J. W.; Stoddart, J. F.;
Zink, J. I. J. Am. Chem. Soc. 2004, 126, 3370. (b) Nguyen, T. D.;
Tseng, H.-R.; Celestre, P. C.; Flood, A. H.; Liu, Y.; Stoddart, J. F.;
Zink, J. I. Proc. Natl. Acad. Sci. U.S.A. 2005, 102, 10029. (c) Nguyen, T.
D.; Liu, Y.; Saha, S.; Leung, K. C. F.; Stoddart, J. F.; Zink, J. I. J. Am.
(15) Zhou, W.; Li, J.; He, X.; Li, C.; Lv, J.; Li, Y.; Wang, S.; Liu, H.;
Zhu, D. Chem.Eur. J. 2008, 14, 754.
(16) Bozdemir, O. A.; Barin, G.; Belowich, M. E.; Basuray, A. N.;
Beuerlea, F.; Stoddart, J. F. Chem. Commun. 2012, 48, 10401.
(17) Yin, J.; Chi, C.; Wu, J. Org. Biomol. Chem. 2010, 8, 2594.
651
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652

The Journal of Organic Chemistry
Article
(18) Li, Z.; Liu, W.; Wu, J.; Liu, S. H.; Yin, J. J. Org. Chem. 2012, 77,
7129.
(19) (a) Leung, K. C.-F.; Arico, F.; Cantrill, S. J.; Stoddart, J. F. J. Am.
́
Chem. Soc. 2005, 127, 5808. (b) Leung, K. C.-F.; Aric, F.; Cantrill, S. J.;
Stoddart, J. F. Macromolecules 2007, 40, 3951.
(20) Glink, P. T.; Oliva, A. I.; Stoddart, J. F.; White, A. J. P.; Williams,
D. J. Angew. Chem., Int. Ed. 2001, 40, 1870.
(21) (a) Luo, J.; Qu, H.; Yin, J.; Zhang, X.; Huang, K.-W.; Chi, C. J.
Mater. Chem. 2009, 19, 8202. (b) Liu, X.; Yang, X.; Fu, Y.; Zhu, C.;
Cheng, Y. Tetrahedron 2011, 67, 3181. (c) Manandhar, E.; Wallace, K.
J. Inorg. Chim. Acta 2012, 381, 15. (d) Ingale, S. A.; Seela, F. J. Org.
Chem. 2012, 77, 9352. (e) Hwang, J.; Choi, M. G.; Eor, S.; Chang, S.-
K. Inorg. Chem. 2012, 51, 1634. (f) Nishimura, T.; Xu, S.-Y.; Jiang, Y.-
B.; Fossey, J. S.; Sakurai, K.; Bull, S. D.; James, T. D. Chem. Commun.
2013, 49, 478.
(22) (a) Gadde, S.; Batchelor, E. K.; Weiss, J. P.; Ling, Y.; Kaifer, A.
E. J. Am. Chem. Soc. 2008, 130, 17114. (b) Biedermann, F.; Elmalem,
E.; Ghosh, I.; Nau, W. M.; Scherman, O. A. Angew. Chem., Int. Ed.
2012, 51, 7739.
(23) Lu, C.; Guo, Y.; Li, J.; Yao, M.; Liao, Q.; Xie, Z.; Li, X. Bioorg.
Med. Chem. Lett. 2012, 22, 7683.
(24) Kim, J.-H.; Lee, E.; Jeong, Y.-H.; Jang, W.-D. Chem. Mater. 2012,
24, 2356.
(25) Han, S. C.; Lee, J. W.; Jin, S.-H. Macromol. Res. 2012, 20, 1083.
(26) Han, S. C.; Jin, S.-H.; Lee, J. W. Bull. Korean Chem. Soc. 2011,
32, 3624.
(27) Fujimoto, Y.; Ubukata, T.; Yokoyama, Y. Chem. Commun. 2008,
5755.
(28) Figueira-Duarte, T. M.; Simon, S. C.; Wagner, M.; Druzhinin, S.
I.; Zachariasse, K. A.; Mullen, K. Angew. Chem., Int. Ed. 2008, 47,
̈
10175.
652
dx.doi.org/10.1021/jo402428y | J. Org. Chem. 2014, 79, 643−652