A Rare and Exclusive Endoperoxide Photoproduct Derived from a Thiacalix[4]arene Crown-Shaped Derivative Bearing a 9,10-Substituted Anthracene Moiety

Article abstract of DOI:10.1002/asia.201600202

A rare and exclusive endoperoxide photoproduct was quantitatively obtained from a thiacalix[4]arene crown-shaped derivative upon irradiation at λ=365 nm; the structure was unambiguously confirmed by ¹H/¹³C NMR spectroscopy and X-ray crystallography. The prerequisites for the formation of the endoperoxide photoproduct have also been discussed. Furthermore, the photochemical reaction rate could be greatly enhanced in the presence of the thiacalix[4]arene platform because it served as a host to capture oxygen. It's a trap! A rare and exclusive endoperoxide photoproduct (E1) was quantitatively obtained from a thiacalix[4]arene crown-shaped derivative (T1) upon irradiation at λ=365 nm (see scheme). The photochemical reaction rate could be greatly enhanced in the presence of the thiacalix[4]arene platform because it served as a host to capture oxygen.

Full text of DOI:10.1002/asia.201600202

DOI: 10.1002/asia.201600202
Full Paper
Reaction Mechanisms
A Rare and Exclusive Endoperoxide Photoproduct Derived from
a Thiacalix[4]arene Crown-Shaped Derivative Bearing a 9,10-
Substituted Anthracene Moiety
Jiang-Lin Zhao,[a] Chong Wu,[a] Hirotsugu Tomiyasu,[a] Xi Zeng,[b] Mark R. J. Elsegood,[c]
Carl Redshaw,[d] and Takehiko Yamato*[a]
Abstract: A rare and exclusive endoperoxide photoproduct
was quantitatively obtained from a thiacalix[4]arene crown-
shaped derivative upon irradiation at l=365 nm; the struc-
mation of the endoperoxide photoproduct have also been
discussed. Furthermore, the photochemical reaction rate
could be greatly enhanced in the presence of the thiaca-
lix[4]arene platform because it served as a host to capture
oxygen.
1
ture was unambiguously confirmed by H/13C NMR spectros-
copy and X-ray crystallography. The prerequisites for the for-
Introduction
presence of oxygen; these products tend to be overlooked by
scientists owing to their negligible yield.[6,8] Indeed, reports re-
lated to the direct characterization of the photoproducts only
describe UV/Vis absorption spectroscopy to characterize the
photoproduct, but in reality this is not rigorous enough.[8] In
other words, unambiguous confirmation of the photoproduct
is the biggest challenge in a photochemical reaction.
Photochemical reactions have found widespread utility in bio-
logical and polymer science given that the use of photons as
a “reagent” is considered the least invasive switching stimulus,
that is, not requiring addition of any external chemical spe-
cies.[1] Of the many photochemical reaction systems known,
anthracene and its derivatives are of special interest owing to
the possibility of [4+4] reversible photodimerization.[2–5] How-
ever, practical applications of this system are limited given that
the photochemical reactions are often nonselective, leading to
a mixture of products.[3] For example, even in one of the sim-
plest systems, namely, the photodimerization of the 9-substi-
tuted anthracene derivative, tail–tail and tail–head photoprod-
ucts are generated,[2c,4] whereas a multitude of products are
isolated in more complex systems.[5] Additionally, it is notewor-
thy that such photochemical reactions not only form photodi-
merization products, but also endoperoxide products in the
Thiacalix[4]arenes are widely exploited as a molecular plat-
form because of the unlimited possibilities for functionalization
on the lower-rim, upper-rim, and bridging sulfur atoms with
various conformations.[9a] Herein, we report the synthesis and
characterization of a series of novel thiacalix[4]arene deriva-
tives (T1, T2, and T3), which contain the anthracene moiety.
Among them, derivative T1, with the 9,10-substituted anthra-
cene group, is of special interest. The photochemical behavior
of T1 in solution is described and leads to a rare and exclusive
endoperoxide photoproduct. To the best of our knowledge,
this is a rare case in which a photoproduct is confirmed un-
equivocally in macrocyclic chemistry.[9b]
[a] Dr. J.-L. Zhao, Dr. C. Wu, Dr. H. Tomiyasu, Prof. Dr. T. Yamato
Department of Applied Chemistry
Faculty of Science and Engineering
Saga University, Honjo-machi 1
Results and Discussion
The copper(I)-catalyzed azide–alkyne cycloaddition Click reac-
tion was employed to synthesize the novel thiacalix[4]arene
crown-shaped derivative T1 in 36% yield (Scheme 1). As ob-
served in the 1H NMR spectrum of T1, the starting proton
signal of the propargyl hydrogen atoms of 1d[10] disappeared,
whereas a new singlet at d=7.40 ppm was attributed to the
protons of the newly formed triazole skeleton. Two singlets for
the tert-butyl protons were found unusually upfield, namely, at
d=0.79 and 0.30 ppm (owing to the additional shielding effect
of the anthracene moiety); there are two singlets for the aro-
matic protons at d=7.09 and 7.29 ppm. All of these signals are
indicative of the C2-symmetric structure of T1 in the 1,3-alter-
nate conformation (Figure S1 in the Supporting Information).
Saga 840-8502 (Japan)
E-mail: yamatot@cc.saga-u.ac.jp
[b] Prof. X. Zeng
Department Key Laboratory of Macrocyclic and
Supramolecular Chemistry of Guizhou Province
Guizhou University, Guiyang
Guizhou, 550025 (P.R. China)
[c] Dr. M. R. J. Elsegood
Chemistry Department, Loughborough University
Loughborough, Leicestershire LE11 3TU (UK)
[d] Prof. Dr. C. Redshaw
Department of Chemistry, The University of Hull
Cottingham Road, Hull, Yorkshire HU6 7RX (UK)
Supporting information for this article can be found under http://
dx.doi.org/10.1002/asia.201600202.
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Scheme 1. The synthetic route to thiacalix[4]arene crown-shaped derivative T1: a) Cs2CO3, 2-bromoethyl acetate, acetone, reflux; b) NaOH, tetrahydrofuran
(THF)/H2O=1:1, reflux; c) K2CO3, propargyl bromide, acetone, reflux; d) CuI, 9,10-bis(azidomethyl)anthracene, THF/H2O=4:1, reflux.
The target thiacalix[4]arene derivative T1, which possesses
a crown-shaped thiacalix[4]arene recognition motif functional-
ized with the anthracene moiety at the 9,10-positions, was em-
ployed as the photoactive unit. The use of T1 had the advant-
age of limiting the possible photoproduct regioisomers to
1) an intermolecular photodimerization isomer (P1) and 2) an
intramolecular endoperoxide isomer (E1; Scheme 2).
1
The use of H NMR spectroscopy allowed the photochemical
reaction processes of T1 (Figure 1) to be investigated. A 6 mm
solution of T1 in CDCl3 was irradiated at l=365 nm under air.
Upon irradiation, a new group of proton signals (red in
Figure 1) immediately appeared with a concomitant decrease
in the concentration of T1 (blue in Figure 1). An indication of
the photochemical reaction process was the signals of the an-
thracene proton resonances (d=7.83 and 8.65 ppm), which
gradually decreased and finally disappeared. Upon gradually
increasing the irradiation time, the conversion yield gradually
increased, as expected. After 90 min, quantitative conversion
was indicated by the complete disappearance of all T1 proton
resonances, and a new unambiguous group of signals ap-
peared. The photoactive anthracene motif resulted in xylene-
like units, for which proton signals appeared at d=7.35 and
7.58 ppm (for characterization data, see Figure S4 in the Sup-
porting Information). The unusually upfield tert-butyl protons
(d=0.30 ppm) dramatically shifted back to their “normal”
Scheme 2. Two possible photoproduct isomers: E1 and P1.
chemical shift position (d=0.89 ppm) owing to the deshielding
effect after the loss of aromaticity of the central anthracene
ring.
Another indication of the photochemical process was the
appearance of a new signal of the photoproduct at d=
79.7 ppm, corresponding to the bridgehead C9,10 carbon for
the former central anthracene ring in the 13C NMR spectrum
(Figure S5 in the Supporting Information). The resulting UV ab-
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As mentioned previously, normally the characterization of
the photoproduct is the biggest challenge after the photo-
chemical reaction because of the numerous photoproducts
possible. Even for our simplest system, there are two possible
photoproduct isomers: E1 and P1. Fortunately, quantitative
conversion provided a pure photoproduct, which was easily
confirmed by mass spectrometry. The observed signals at m/z
1413.4907 [M+H]+ (Figure S6 in the Supporting Information)
and 1380.4910 [M]+ for unirradiated T1 (Figure S3 in the Sup-
porting Information) strongly suggested that the photoproduct
was the endoperoxide photoproduct E1. Furthermore, X-ray
crystallographic analysis[14] further confirmed the molecular
structure of E1, as shown in Figure 3. C80H80N6O10S4·2(CH4O),
Figure 1. 1H NMR (CDCl3, 400 MHz, 258C) spectra of a 6 mm solution of T1
after irradiation at l=365 nm (0, 30, 50, 90 min).
Figure 3. Single-crystal structure of E1. Hydrogen atoms and two methanol
molecules of crystallization have been omitted for clarity.
one endoperoxide photoproduct E1 in 1,3-alternate conforma-
tion, and two molecules of methanol were in the asymmetric
unit (Figure S7 in the Supporting Information). The central an-
thracene ring moiety of the T1 molecule has been oxidized
rather than linking to another thiacalix[4]arene. These results
for E1 confirmed that the normally expected [4+4] photodime-
rization reaction had not occurred, but rather an unexpected
[4+2] photosensitized oxygenation occurred involving the cy-
Figure 2. UV/Vis (a) and fluorescence (b) spectra of a 2.4”10À5 m solution of
T1 in CHCl3 under irradiation.
1
cloaddition of O2 (singlet oxygen, an excited state of molecu-
lar oxygen generated from ambient air by direct irradiation
with UV light)[8] with the electron-rich carbon atoms of the
central anthracene ring.[6,7] The most noteworthy feature was
the position of the ÀO10ÀO9À bond, which was oriented
inward instead of the normally favorable outward direction;
this may be attributed to the inwardly crown-shaped structure
required to trap singlet oxygen.[9b]
sorption spectrum of T1 after irradiation (Figure 2a) fully sup-
ported the formation of planar-symmetric photoproducts that
involved only the central anthracene ring and not the lateral
anthracene aromatic rings, that is, there was no absorption
beyond l=300 nm.[4a] A similar conclusion can be drawn from
fluorescence studies (Figure 2b). The characteristic anthracene
moiety emission of T1 in the l=375–525 nm region was
switched “off’” after irradiation, which mirrored the formation
of the non-fluorescence photoproduct. In contrast, a 6 mm so-
lution of T1 in degassed CDCl3 was irradiated at l=365 nm
under a nitrogen atmosphere. No detectable changes were ob-
To further investigate the rare endoperoxide photochemical
phenomenon, compounds T2, with a 9-substituted anthracene
moiety as the photoactive unit, and T3, with a similar structure
but short linkage, have been introduced (Scheme 3). Interest-
ingly, the UV absorption and fluorescence spectra of com-
pounds T2 and T3, which were quenched after irradiation,
were almost the same as those of compound T1 (Figure S8 in
1
served in the H NMR spectra, even after irradiating the com-
1
pound for 6 h (Scheme 2).
the Supporting Information). Unfortunately, the H NMR spec-
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those used for compound T1 (Figures S9 and S10 in the Sup-
porting Information). The observed phenomena in T2 and T3
were similar to most reported results crudely defined as photo-
dimerization.[2–8] It strongly suggested that the 9,10-substituted
anthracene crown-shaped moiety of compound T1 was the
key factor for the formation of this rare endoperoxide photo-
product.
Furthermore, two reference compounds, R1 and R2, possess-
ing 9,10-substituted anthracene with different linkages were
also synthesized (Scheme 4). The photochemical reaction pro-
cesses of R1 and R2 were also investigated by1H NMR and UV
absorption spectroscopy. Surprisingly, all of the results were
similar to those of thiacalix[4]arene derivative T1. The UV ab-
sorption spectra of R1 and R2 were quenched after irradiation
(Figure S11 in the Supporting Information); a quantitative con-
version was observed, such that all proton resonances of R1 or
R2 were replaced by a new unambiguous group of signals
after irradiation (Figures S12 and S13 in the Supporting Infor-
mation). All of the observed results strongly suggested that en-
doperoxide photoproducts were also formed during these
photochemical processes of R1 and R2. In other words, the
compounds that possessed 9,10-substituted anthracene in
a symmetric structure (RCH2ÀanthraceneÀCH2R) were favorable
in the formation of the endoperoxide photoproduct, rather
than the dimerization photoproduct. However, more interest-
ingly, we should point out that the time it took to complete
the photochemical reactions of T1, R1, and R2, to form the
corresponding products E1, E2, and E3, was 90, 140, and
120 min, respectively (Figure 4). The thiacalix[4]arene platform
may serve as a host to capture oxygen, which is conducive to
the formation of the endoperoxide photoproduct. This hypoth-
esis was consistent with the unique X-ray diffraction results for
the position of the ÀO10ÀO9À bond, which was oriented
Scheme 3. The synthetic route for the preparation of thiacalix[4]arene deriv-
atives T2 and T3.
tra gradually changed to become very complicated, and could
not be used to identify any of the photoproducts when com-
pounds T2 or T3 were irradiated under the same conditions as
Scheme 4. The synthetic route for the preparation of reference compounds R1 and R2.
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Conclusion
The synthesis of a new thiacalix[4]arene crown-shaped deriva-
tive T1 was reported, and the photochemical behavior was in-
1
vestigated by H NMR, UV/Vis, and fluorescence spectroscopy.
We have demonstrated that the photochemical reaction of T1
(containing anthracene moieties) converted it into the endo-
peroxide E1 in quantitative yield upon irradiation at l=
365 nm. The structure of the rare endoperoxide photoproduct
1
E1 was unambiguously confirmed by H/13C NMR spectroscopy
and X-ray crystallography. Further studies revealed that com-
pounds possessing 9,10-substituted anthracene in a symmetric
structure (RCH2ÀanthraceneÀCH2R) were favorable to form the
endoperoxide photoproduct rather than the dimerization pho-
toproduct. Furthermore, the photochemical reaction rate could
be greatly enhanced in the presence of a thiacalix[4]arene plat-
form; this was attributed to the thiacalix[4]arene platform serv-
ing as a host to capture oxygen.
Figure 4. Conversion yield versus reaction time of 6 mm solutions of T1, R1,
and R2 in CDCl3 under irradiation at l=365 nm.
inward instead of the normally favorable outward direction. In
other words, the unique thiacalix[4]arene platform could great-
ly enhance the photochemical reaction rate.
Many studies have revealed that the decomposition of pho-
toproducts occurs either thermally (ꢀ608C) or by irradiation
with deep UV light (l<300 nm), or can even occur natural-
ly.[2b,11] However, in our case, the thermal cycloreversion of en-
doperoxide photoproduct E1 was also investigated, and no
Experimental Section
General Procedures
All melting points (Yanagimoto MP-S1) are uncorrected. 1H and
13C NMR spectra were recorded on a Varian-400MR-vnmrs400 spec-
trometer with SiMe4 as an internal reference: J values are given in
Hz. Mass spectra were obtained with a Nippon Denshi JMS-
HX110A ultrahigh performance mass spectrometer at 75 eV by
using a direct-inlet system. UV/Vis spectra were recorded by using
a Shimadzu UV-3150UV/Vis/near-IR spectrophotometer. Fluores-
cence spectroscopic studies of compounds in solution were per-
formed in a semimicro fluorescence cell (Hellmaꢁ, 104F-QS, 10”
4 mm, 1400 mL) with a Varian Cary Eclipse spectrophotometer. Irra-
diation at l=365 nm was performed with a UV lamp (AH 400PR,
AC 100 V, 60 Hz). Irradiation at l=254 nm was performed with
a 4 W TLC UV lamp (ASONE Handy UV Lamp, SLUV-4).
1
change in the H NMR spectra was observed, even after heat-
ing the compound to 1508C for 8 h. Another typical cyclore-
version method was performed by irradiating a solution of E1
1
at l=254 nm. However, even after 4 h, the UV/Vis and H NMR
spectra also showed no change. These relative photon/thermal
stabilities of the photoproduct suggest that the E1 photoprod-
uct is very stable under these conditions.
Singlet oxygen (1O2) is an excited state of molecular oxygen
that has attracted great interest because 1O2 is believed to
play an important role in species for organic synthesis; bleach-
ing processes; and, most importantly, the photodynamic thera-
py of cancer, which has now obtained regulatory approval in
most countries for the treatment of several types of
1
tumors.[12,13] However, excessive levels of O2 can often be toxic
Materials
to certain biological systems and the technique for detecting
1O2 is still limited owing to its short lifetime.[12] Monitoring the
direct emission of 1O2 at l=1270 nm is the most common
method,[13c] but such detection is limited by low sensitivity.[15e]
To improve the sensitivity, fluorimetry is the first choice and
can be rapidly performed, is nondestructive, and has greater
sensitivity.[7a,16] Indeed, scientists have successfully designed
fluorescent probes that trap 1O2 to give a sensitive fluores-
Unless otherwise stated, all reagents used were purchased from
commercial sources and were used without further purification.
Compounds 1a,[17] 1b,[18] 1c,[18] 1d,[10] 2,[19] 3a,[20] 3c,[21] 3d,[21] 9-
(azidomethyl)anthracene,[22] and 9,10-bis(azidomethyl)anthracene[23]
were prepared by following reported procedures. All solvents used
were dried and distilled by standard procedures prior to use.
Synthesis of Thiacalix[4]arene Derivative T1
1
cence response.[16] However, designing a suitable O2 fluores-
Copper iodide (20 mg) was added to a mixture of 1d (219 mg,
cent probe is still a big challenge. Modified T1, with an anthra-
0.20 mmol)
and
9,10-bis(azidomethyl)anthracene
(70 mg,
cene functionality, allows for a rapid reaction with low concen-
0.24 mmol) in THF/H2O (75 mL, 4:1) and heated at reflux for 15 h.
The resulting solution was cooled and diluted with water and ex-
tracted with CH2Cl2. The organic layer was separated, dried
(MgSO4), and evaporated to give the solid crude product. The resi-
due was purified by column chromatography on silica gel with
CH2Cl2/EtOAc (20:1) and gave the desired product T1 (100 mg,
1
trations of O2 concomitant with UV/Vis and fluorescence spec-
tral changes at room temperature. In other words, compound
T1 has potential applications as a high selectivity and high
sensitivity chemosensor for the detection of singlet oxygen.
Current studies are aimed to explore T1 as a practical chemo-
sensor for singlet oxygen.
1
36%) as a light yellow powder. M.p. 361–3628C; H NMR (400 MHz,
CDCl3): d=0.30 (s, 18H; tBu), 0.79 (s, 18H; tBu), 4.50 (s, 4H;
-OCH2COO-), 4.88 (s, 4H; -OCH2Benzyl), 5.29 (s, 4H; -OCH2Triazole-),
6.62 (s, 4H; -TriazoleCH2An), 7.09 (s, 4H; ArH), 7.18 (s, 10H; PhH),
7.29 (s, 4H; ArH), 7.59 (s, 2H; Triazole-H), 7.82–7.84 (m, 4H; An-H),
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8.65–8.66 ppm (m, 4H; An-H); 13C NMR (100 MHz): d=29.8, 30.7,
33.2, 33.8, 47.3, 57.9, 67.0, 73.4, 123.5, 124.6, 127.1, 127.2, 127.4,
127.5, 128.0, 128.2, 128.5, 131.1, 131.2, 133.5, 137.9, 143.6, 145.4,
145.9, 156.9, 158.4, 168.3 ppm; HRMS (FAB): m/z calcd for
C80H80N6O8S4 [M]+: 1380.4921; found: 1380.4910.
146.8, 152.9 ppm; HRMS (FAB): m/z calcd for C46H53N6O2 [M+H]+:
721.4230; found: 721.4244.
Photoproduct from T1 (E1)
Photoproduct from T1 (E1) was obtained as a yellow solid (5 mg,
100%). M.p. 289–2908C; 1H NMR (400 MHz, CDCl3): d=0.81 (s,
18H; tBu), 0.89 (s, 18H; tBu), 4.57 (s, 4H; -OCH2COO-), 4.95 (s, 4H;
-OCH2Benzyl), 5.37 (s, 4H; -OCH2Triazole-), 5.79 (s, 4H; -Triazo-
leCH2C), 7.03–7.08 (m, 8H; PhH), 7.11 (s, 4H; ArH), 7.14–7.17 (m,
2H; PhH), 7.35 (br, 4H; Benzene-H), 7.44 (s, 4H; ArH), 7.58 (br, 4H;
Benzene-H), 7.83 ppm (s, 2H; Triazole-H); 13C NMR (100 MHz): d=
30.5, 30.7, 33.8, 48.8, 58.5, 66.9, 72. 5, 79.7, 121.4, 126.2, 126.9,
127.0, 127.9, 128.12, 128.15, 128.4, 129.9, 132.5, 137.8, 138.2, 144.0,
145.98, 146.02, 155.8, 158.2, 168.5 ppm; HRMS (FAB): m/z calcd for
C80H81N6O10S4 [M+H]+: 1413.4897; found: 1413.4907.
A similar procedure with 1d, 2, 3b, and 3e was followed for the
synthesis of T2, T3, R1, and R2, respectively.
Thiacalix[4]arene Derivative T2
Thiacalix[4]arene derivative T2 was obtained as a light yellow solid
(column chromatography on silica gel with hexane/CH2Cl2/EtOAc
(10:10:1); 104 mg, 48%). M.p. 231–2328C; 1H NMR (400 MHz,
CDCl3): d=0.80 (s, 18H; tBu), 1.01 (s, 18H; tBu), 4.47 (s, 4H;
-OCH2COO-), 4.91 (s, 4H; -OCH2Benzyl), 5.11 (s, 4H; -OCH2Triazole-),
6.54 (s, 4H; -TriazoleCH2An), 7.05 (s, 4H; ArH), 7.18 (s, 10H; PhH),
7.22 (s, 2H; Triazole-H), 7.34 (s, 4H; ArH), 7.45–7.54 (m, 4H; An-H),
7.54–7.63 (m, 4H; An-H), 8.05–8.07 (m, 4H; An-H), 8.29–8.31 (m,
4H; An-H), 8.57 ppm (s, 2H; An-H); 13C NMR (100 MHz): d=30.8,
30.9, 46.5, 57.6, 66.8, 73.1, 122.9, 123.1, 123.5, 125.4, 127.1, 127.4,
127.8, 128.2, 128.5, 129.5, 130.0, 130.80, 130.83, 131.5, 133.0, 138.0,
142.7, 145.9, 146.0, 156.0, 158.2, 167.6 ppm; HRMS (FAB): m/z calcd
for C94H91N6O8S4 [M+H]+: 1559.5781; found: 1559.5780.
Photoproduct from R1 (E2)
Photoproduct from R1 (E2) was obtained as a light yellow solid
1
(6 mg, 100%). M.p. 114–1158C; H NMR (400 MHz, CDCl3): d=1.27
(s, 18H; tBu), 2.22 (s, 12H; CH3), 4.39 (s, 4H; -OCH2COO), 5.31 (s,
4H; -OCH2Triazole-), 5.75 (s, 4H; -TriazoleCH2C), 6.96 (s, 4H; ArH),
7.26 (s, 4H; Ph-H), 7.43 (s, 4H; Ph-H), 8.00 ppm (s, 2H; Triazole-H);
13C NMR (100 MHz): d=16.5, 31.4, 34.1, 48.7, 57.9, 69.0, 80.0 121.2,
125.9, 126.7, 128.3, 129.7, 137.8, 143.2, 147.0, 153.0, 169.0 ppm;
FABMS: m/z calcd for C50H57N6O8 [M+H]+: 869.4238; found:
869.4236.
Thiacalix[4]arene Derivative T3
Thiacalix[4]arene derivative T3 was obtained as a light yellow solid
(column chromatography on silica gel with hexane/CH2Cl2/EtOAc
(20:10:1); 580 mg, 74%). M.p. 284–2858C; 1H NMR (400 MHz,
CDCl3): d=0.60 (s, 18H; tBu), 1.20 (s, 18H; tBu), 4.66 (s, 4H;
-OCH2Benzyl), 5.03 (s, 4H; -OCH2Triazole-), 6.50 (s, 4H; -Triazole-
CH2An), 6.58 (s, 2H; Triazole-H), 6.75 (s, 4H; ArH), 7.06–7.07 (m, 4H;
PhH), 7.12–7.17 (m, 6H; PhH), 7.47 (s, 4H; ArH), 7.46–7.49 (m, 4H;
An-H), 7.53–7.56 (m, 4H; An-H), 8.01–8.03 (m, 4H; An-H), 8.24–8.26
(m, 4H; An-H), 8.51 ppm (s, 2H; An-H); 13C NMR (100 MHz): d=
29.6, 30.3, 32.5, 33.2, 45.3, 61.9, 72.1, 121.9, 122.0, 122.6, 124.3,
125.8, 126.3, 126.6, 127.0, 128.3, 128.7, 128.9, 129.0, 129.8, 130.3,
133.0, 137.1, 142.5, 144.3, 144.9, 154.5, 157.5 ppm; HRMS (FAB): m/
z calcd for C90H87N6O4S4 [M+H]+: 1443.5672; found: 1443.5670.
Photoproduct from R2 (E3)
Photoproduct from R2 (E3) was obtained as a light yellow solid
(5 mg, 100%). M.p. 128–1298C; H NMR (400 MHz, CDCl3): d=1.27
1
(s, 18H; tBu), 2.25 (s, 12H; CH3), 4.92 (s, 4H; -OCH2Triazole-), 5.78 (s,
4H; -TriazoleCH2C), 6.99 (s, 4H; ArH), 7.26–7.27 (m, 4H; Ph-H), 7.46–
7.48 (m, 4H; Ph-H), 8.00 ppm (s, 2H; Triazole-H); 13C NMR
(100 MHz): d=16.7, 31.5, 34.1, 48.7, 65.5, 80.2, 121.3, 125.6, 125.8,
128.3, 130.0, 137.9, 145.7, 146.8, 153.2 ppm; HRMS (FAB): m/z calcd
for C46H53N6O4 [M+H]+: 753.4128; found: 753.4128.
Synthesis of Reference Propargyl Derivative (3e)
A
suspension of 3d (1.20 g, 5.08 mmol) and K2CO3 (2.80 g,
Reference Compound R1
20.32 mmol) was heated at reflux for 1 h in dry acetone (70 mL),
and a solution of propargyl bromide (1.20 g, 10.16 mmol) in dry
acetone (10 mL) was added. The reaction mixture was heated at
reflux for 17 h. The solvents were evaporated and the residue was
partitioned between 10% HCl and CH2Cl2. The organic layer was
separated, dried (MgSO4), and the solvents were evaporated. The
residue was eluted from a column of silica gel with CH2Cl2/Hexane
(1:1) to give the desired product 3e (1.30 g, 94%) as a colorless oil.
1H NMR (400 MHz, CDCl3): d=1.28 (s, 9H; tBu), 2.29 (s, 6H; CH3)
2.51 (d, J=2.3 Hz, 1H; HCC), 4.45 (s, 2H; HCCCH2O-), 4.82 (d, J=
2.2 Hz, 4H; -OCH2COO-), 7.00 ppm (s, 2H; ArH); 13C NMR (100 MHz):
d=16.6, 31.5, 34.1, 52.4, 69.0, 75.5, 77.1, 125.9, 129.7, 147.1, 153.0,
168.5 ppm; HRMS (ESI/TOF-Q): m/z calcd for C17H22O3 [M]+:
274.1569; found: 274.1600.
Reference compound R1 was obtained as a light yellow solid
(column chromatography on silica gel with CH2Cl2/EtOAc (20:1);
1
260 mg, 57%). M.p. 256–2578C; H NMR (400 MHz, CDCl3): d=1.26
(s, 18H; tBu), 2.13 (s, 12H; CH3), 4.29 (s, 4H; -OCH2COO), 5.19 (s,
4H; -OCH2Triazole-), 6.60 (s, 4H; -TriazoleCH2An), 6.94 (s, 4H; ArH),
7.32 (s, 2H; Triazole-H), 7.67–7.70 (m, 4H; An-H), 8.43–8.46 ppm (m,
4H; An-H); 13C NMR (100 MHz): d=16.4, 31.4, 34.1, 46.6, 57.9, 68.9,
123.5, 124.1, 125.8, 126.9, 127.8, 129.6, 130.7, 142.6, 147.1, 152.9,
169.1 ppm; HRMS (FAB): m/z calcd for C50H57N6O6 [M+H]+:
837.4340; found: 837.4376.
Reference Compound R2
Reference compound R2 was obtained as a yellow solid (recrystal-
lized from 1:3 CHCl3/hexane; 145 mg, 87%). M.p. 302–3038C;
1H NMR (400 MHz, CDCl3): d=1.23 (s, 18H; tBu), 2.13 (s, 12H; CH3),
4.80 (s, 4H;-OCH2Triazole-), 6.63 (s, 4H; -TriazoleCH2An), 6.91 (s, 4H;
ArH), 7.30 (s, 2H; Triazole-H), 7.68–7.71 (m, 4H; An-H), 8.48–
8.50 ppm (m, 4H; An-H); 13C NMR (100 MHz): d=16.6, 31.4, 34.1,
46.6, 65.6, 122.1, 124.2, 125.7, 127.1, 127.7, 129.9, 130.7, 145.2,
A similar procedure with 3a was followed for the synthesis of 3b.
Reference Propargyl Derivative 3b
Reference propargyl derivative 3b was obtained as a colorless oil
1
(1.15 g, 95%). H NMR (400 MHz, CDCl3): d=1.28 (s, 9H; tBu), 2.31
Chem. Asian J. 2016, 11, 1606 – 1612
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ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim

Full Paper
[10] J. L. Zhao, H. Tomiyasu, C. Wu, H. Cong, X. Zeng, S. Rahman, P. E. Geor-
ghiou, D. L. Hughes, C. Redshaw, T. Yamato, Tetrahedron 2015, 71,
8521–8527.
(s, 6H; CH3) 2.49 (s, 1H; HCC), 4.47 (s, 2H; HCCCH2O-), 7.00 ppm (s,
2H; ArH); 13C NMR (100 MHz): d=16.7, 16.8, 31.4, 31.5, 34.1, 59.72,
59.76, 59.80, 74.6, 74.8, 79.58, 79.62, 125.7, 130.2, 146.9, 153.0 ppm;
HRMS (ESI/TOF-Q): m/z calcd for C15H20O [M]+: 216.1514; found:
216.1451.
[11] a) C. Schäfer, R. Eckel, R. Ros, J. Mattay, D. Anselmetti, J. Am. Chem. Soc.
2007, 129, 1488–1489; b) C. Schäfer, B. Decker, M. Letzel, F. Novara, R.
Eckel, R. Ros, D. Anselmetti, J. Mattay, Pure Appl. Chem. 2006, 78, 2247–
2259; c) C. Schäfer, J. Mattay, Photochem. Photobiol. Sci. 2004, 3, 331–
333; d) S. i. Nakatsuji, T. Ojima, H. Akutsu, J.-i. Yamada, J. Org. Chem.
2002, 67, 916–921; e) T. Tsudera, A. Ikeda, S. Shinkai, Tetrahedron 1997,
53, 13609–13620; f) G. Deng, T. Sakaki, Y. Kawahara, S. Shinkai, Supra-
mol. Chem. 1993, 2, 71–76; g) G. Deng, T. Sakaki, K. Nakashima, S. Shin-
kai, Chem. Lett. 1992, 1287–1290; h) G. Deng, T. Sakaki, Y. Kawahara, S.
Shinkai, Tetrahedron Lett. 1992, 33, 2163–2166.
[12] a) G. Terentyuk, E. Panfilova, V. Khanadeev, D. Chumakov, E. Genina, A.
Bashkatov, V. Tuchin, A. Bucharskaya, G. Maslyakova, N. Khlebtsov, B.
Khlebtsov, Nano Res. 2014, 7, 325–337; b) P. Kang, C. S. Foote, J. Am.
Chem. Soc. 2002, 124, 4865–4873; c) J. Cadet, T. Douki, J. P. Pouget, J. L.
Ravanat, Methods Enzymol. 2000, 319, 143–153; d) L. O. Klotz, K. Briviba,
H. Sies, Methods Enzymol. 2000, 319, 130–143; e) S. W. Ryter, R. M. Tyr-
rell, Free Radical Biol. Med. 1998, 24, 1520–1534; f) H. H. Wasserman,
R. W. Murray, Singlet Oxygen, Academic Press, New York, 1979.
[13] a) C. Laloi, M. Havaux, Front. Plant Sci. 2015, 6, 39; b) D. Maggioni, M.
Galli, L. D’Alfonso, D. Inverso, M. V. Dozzi, L. Sironi, M. Iannacone, M.
Collini, P. Ferruti, E. Ranucci, G. D’Alfonso, Inorg. Chem. 2015, 54, 544–
553; c) C. Schweitzer, R. Schmidt, Chem. Rev. 2003, 103, 1685–1758.
[14] Crystal data for T1: C80H80N6O10S4·2(CH4O); Mr =1477.82; monoclinic;
P21/n; a=18.515(4), b=20.431(4), c=21.572(4) Š; b=115.272(3)8; V=
7379(3) Š3; Z=4; m(MoKa)=0.197 mmÀ1; 57265 reflections measured;
12990 unique; Rint =0.091; R1[F2 >2s(F2)]=0.091; wR2 (all data)=0.288.
CCDC 1432129 contains the supplementary crystallographic data for
this paper. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre.
Acknowledgements
This work was performed under the Cooperative Research Pro-
gram of “Network Joint Research Center for Materials and Devi-
ces (Institute for Materials Chemistry and Engineering, Kyushu
University)”. We would like to thank the OTEC at Saga Universi-
ty and the International Cooperation Projects of Guizhou Prov-
ince (no. 20137005) for financial support. The EPSRC is thanked
for a travel grant (to C.R.)
Keywords: anthracenes · cycloaddition · photochemistry ·
reaction mechanisms · thiacalixarenes
[1] a) P. K. Kundu, G. L. Olsen, V. Kiss, R. Klajn, Nat. Commun. 2014, 5, 3588;
b) S. Chatani, C. J. Kloxin, C. N. Bowman, Polym. Chem. 2014, 5, 2187–
2201; c) S. Monti, I. Manet, Chem. Soc. Rev. 2014, 43, 4051–4067; d) D.
Habault, H. Zhang, Y. Zhao, Chem. Soc. Rev. 2013, 42, 7244–7256; e) D.
Gust, J. Andreasson, U. Pischel, T. A. Moore, A. L. Moore, Chem.
Commun. 2012, 48, 1947–1957; f) O. Yaroshchuk, Y. Reznikov, J. Mater.
Chem. 2012, 22, 286–300; g) J. M. Spruell, C. J. Hawker, Chem. Sci. 2011,
2, 18–26; h) M. M. Russew, S. Hecht, Adv. Mater. 2010, 22, 3348–3360;
i) T. F. Scott, B. A. Kowalski, A. C. Sullivan, C. N. Bowman, R. R. McLeod,
Science 2009, 324, 913–917.
[15] a) Z. Xu, J. Yoon, D. R. Spring, Chem. Soc. Rev. 2010, 39, 1996–2006;
b) J. S. Kim, D. T. Quang, Chem. Rev. 2007, 107, 3780–3799.
[2] a) S. V. Radl, M. Roth, M. Gassner, A. Wolfberger, A. Lang, B. Hirschmann,
G. Trimmel, W. Kern, T. Griesser, Eur. Polym. J. 2014, 52, 98–104; b) J. F.
Xu, Y.-Z. Chen, L.-Z. Wu, C.-H. Tung, Q.-Z. Yang, Org. Lett. 2013, 15,
6148–6151; c) H. Bouas-Laurent, J. P. Desvergne, A. Castellan, R. La-
pouyade, Chem. Soc. Rev. 2001, 30, 248–263; d) H. D. Becker, Chem. Rev.
1993, 93, 145–172.
[16] a) H. Yu, X. Liu, Q. f. Wu, Q. Li, S. Wang, Y. Guo, Chem. Lett. 2015, 44,
244–246; b) S. Kim, T. Tachikawa, M. Fujitsuka, T. Majima, J. Am. Chem.
Soc. 2014, 136, 11707–11715; c) S. K. Pedersen, J. Holmehave, F. H.
Blaikie, A. Gollmer, T. Breitenbach, H. H. Jensen, P. R. Ogilby, J. Org.
Chem. 2014, 79, 3079–3087; d) R. Ruiz-Gonzµlez, R. Zanocco, Y. Gidi,
A. L. Zanocco, S. Nonell, E. Lemp, Photochem. Photobiol. 2013, 89,
1427–1432; e) K. Tanaka, T. Miura, N. Umezawa, Y. Urano, K. Kikuchi, T.
Higuchi, T. Nagano, J. Am. Chem. Soc. 2001, 123, 2530–2536.
[3] V. Ramamurthy, Y. Inoue, Supramolecular Photochemistry: Controlling
Photochemical Processes, Wiley-VCH, Weinheim, 2011.
[4] a) A. Tron, H. P. J. D. Rouville, A. Ducrot, J. H. Tucker, M. Baroncini, A.
Credi, N. D. McClenaghan, Chem. Commun. 2015, 51, 2810–2813; b) L.
López-Vilanova, I. Martínez, T. Corrales, F. Catalina, Eur. Polym. J. 2014,
56, 69–76.
[17] T. Yamato, C. PØrez-Casas, H. Yamamoto, R. J. M. Elsegood, S. H. Dale, C.
Redshaw, J. Inclusion Phenom. Macrocyclic Chem. 2006, 54, 261–269.
[18] C. PØrez-Casas, S. Rahman, N. Begum, Z. Xi, T. Yamato, J. Inclusion
Phenom. Macrocyclic Chem. 2008, 60, 173–185.
[5] a) Y. Kawanami, H. Umehara, J. Mizoguchi, M. Nishijima, G. Fukuhara, C.
Yang, T. Mori, Y. Inoue, J. Org. Chem. 2013, 78, 3073–3085; b) C. Yang, T.
Mori, Y. Origane, Y. H. Ko, N. Selvapalam, K. Kim, Y. Inoue, J. Am. Chem.
Soc. 2008, 130, 8574–8575.
[6] a) A. Lauer, A. L. Dobryakov, S. A. Kovalenko, H. Feder, K. Heyne, Phys.
Chem. Chem. Phys. 2011, 13, 8723–8732; b) M. A. Fox, S. Olive, Science
1979, 205, 582–583.
[19] X.-L. Ni, X. Zeng, D. L. Hughes, C. Redshaw, T. Yamato, Supramol. Chem.
2011, 23, 689–695.
[20] U. Svanholm, V. D. Parker, J. Chem. Soc. Perkin Trans. 1 1973, 562–566.
[21] T. Yamato, F. Zhang, J. Inclusion Phenom. Macrocyclic Chem. 2001, 39,
55–64.
[22] O. Tosic, J. Mattay, Eur. J. Org. Chem. 2011, 371–376.
[23] R. Reuter, H. A. Wegner, Chem. Commun. 2013, 49, 146–148.
[7] a) X. Li, G. Zhang, H. Ma, D. Zhang, J. Li, D. Zhu, J. Am. Chem. Soc. 2004,
126, 11543–11548; b) J. M. Aubry, C. Pierlot, J. Rigaudy, R. Schmidt, Acc.
Chem. Res. 2003, 36, 668–675.
[8] a) W. Fudickar, T. Linker, Langmuir 2010, 26, 4421–4428; b) C. Bratsch-
kov, Eur. Polym. J. 2001, 37, 1145–1149.
[9] a) R. Kumar, Y. O. Lee, V. Bhalla, M. Kumar, J. S. Kim, Chem. Soc. Rev.
2014, 43, 4824–4870; b) J. J. Gassensmith, J. M. Baumes, J. Eberhard,
B. D. Smith, Chem. Commun. 2009, 2517–2519.
Manuscript received: February 18, 2016
Revised: March 10, 2016
Accepted Article published: March 20, 2016
Final Article published: May 11, 2016
Chem. Asian J. 2016, 11, 1606 – 1612
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ꢀ 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim