Poly(benzyl ether) dendrimers with strongly fluorescent distyrylbenzene cores as the fluorophores for peroxyoxalate chemiluminescence: Insulating effect of dendritic structures on fluorescent sites

Article abstract of DOI:10.1016/j.tet.2005.08.108

Poly(benzyl ether) dendrimers containing strongly fluorescent distyrylbenzene cores were synthesized, and their fluorescence and electrochemical properties as well as the action as fluorophores in the chemiluminescence reactions were investigated. While a

Full text of DOI:10.1016/j.tet.2005.08.108

Tetrahedron 61 (2005) 11020–11026
Poly(benzyl ether) dendrimers with strongly fluorescent
distyrylbenzene cores as the fluorophores for peroxyoxalate
chemiluminescence: insulating effect of dendritic structures
on fluorescent sites
a
Ryu Koike,a Yoshiaki Katayose,a Akira Ohta,b Jiro Motoyoshiya,a, Yoshinori Nishii
*
and Hiromu Aoyamaa
aDepartment of Chemistry, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
bDepartment of Chemistry, Faculty of Science, Shinshu University, Matsumoto, Nagano 390-8621, Japan
Received 11 July 2005; revised 18 August 2005; accepted 18 August 2005
Available online 26 September 2005
Abstract—Poly(benzyl ether) dendrimers containing strongly fluorescent distyrylbenzene cores were synthesized, and their fluorescence
and electrochemical properties as well as the action as fluorophores in the chemiluminescence reactions were investigated. While all the
dendrimers exhibited almost the same properties except for their intensities, a characteristic feature due to the dendritic structure was
observed in the electrochemical behaviors. In the peroxyoxalate chemiluminescence reactions using these dendrimers as fluorophores, a
bimolecular interaction between the high-energy intermediates and fluorophores was established, and a decrease in the chemiluminescence
intensity with an increasing generation was observed, which was connected with the insulating effect of the dendritic structures on the core.
q 2005 Elsevier Ltd. All rights reserved.
1. Introduction
quite fascinating, because dendrimers would provide
unusual reaction environments when they act as the
activators in such reactions. In this paper, we describe the
synthesis, fluorescence and electrochemical properties, and
Much attention has been paid to the architecture of
multiform dendrimers,1 that is, molecules with peculiar
structures extending in certain directions from the core, and
each branch radiates like a tree. Of the numerous number of
dendrimers, the photoresponsive ones are of current interest
for chemists because of their unique photochemical proper-
ties. For example, the photon-harvesting ability2,3 and the
insulating effect on some of the physical and chemical
properties of the cores4 are typical of their special functions
due to their peculiar hyperbranched structures. While the
photophysical properties of several dendrimers with
fluorescent cores have been investigated and well
characterized,2c,3,5 only a few studies have described the
chemiluminescent dendrimers6 and there is little study using
the fluorescent dendrimers during the chemiluminescence
reactions.7 Since an interaction between the high-energy
intermediates, usually the cyclic peroxides, and the
fluorophores is the crucial process in the peroxyoxalate
chemiluminescence,8 the use of fluorescent dendrimers is
´
the use of Frechet-type poly(benzyl ether) dendrimers
having strongly fluorescent distyrylbenzene cores in
peroxyoxalate chemiluminescence.9
2. Results and discussion
2.1. Synthesis of the distyrylbenzene core G0 and the
dendrimers G1–G3
The synthetic procedure for the substituted distyrylbenzene
G0 and the dendrimers G1–G3 is shown in Scheme 1.
The fluorescent core, (E,E)-2,5-bis(2-ethylhexyloxy)-1,4-
bis(40-hydroxystyryl)benzene (1), was prepared by the
Horner–Wadsworth–Emmons reaction10,11 of 2,5-bis(2-
ethylhexyloxy)-1,4-bis(ethylphosphonomethyl)benzene
and 4-hydroxybenzaldehyde in the presence of tert-BuOK.
The side chains, the 2-ethylhexyloxy groups attached at
the 2 and 5 positions of the central benzene rings, were
introduced for enhancing the solubility in organic solvents
as well as the electron-donating ability of the fluorescent
moiety.11 The reaction of 1 and benzyl chloride in the
Keywords: Chemiluminescence; Dendrimer; Fluorescence; Insulating
effect; Cyclic voltammetry.
Corresponding author. Fax: C81 268 21 5391;
e-mail: jmotoyo@giptc.shinshu-u.ac.jp
*
0040–4020/$ - see front matter q 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2005.08.108

R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
11021
Scheme 1. Reagents and conditions: (i) EHBr, K2CO3, DMF, 95%; (ii) (CH2O)n, NaBr, H2SO4, CH3COOH, 0 8C, 65%; (iii) P(OEt)3, 100 8C, 99%;
(iv) 4-hydroxybenzaldehyde, tert-BuOK, DMF, rt, 53%; (v) RBr, K2CO3, 18-crown-6, THF, reflux.
presence of K2CO3 and 18-crown-6 gave G0, and a similar
procedure employing 1 and the corresponding dendritic
benzyl bromides produced the dendrimers G1, G2, and G3
with the first, second, and third generation of poly(benzyl
ether) branches, respectively, at the peripheral rings, whose
showed a single peak in a HPLC by monitoring at 385 nm
absorbed by the core.
2.2. Fluorescence property
1
structures were confirmed by H and 13C NMR spectra as
The fluorescence spectra of G0–G3 are shown in Figure 1
and the selected spectral data are collected in Table 1. The
excitation wavelengths were selected, at which the
absorbance was 0.05 in the absorption spectra in THF.
Upon excitation of the distyrylbenzene core at 386.5, 389,
396, and 387 nm for G0, G1, G2, and G3, respectively, all
compounds showed a blue fluorescence at 442–444 nm with
large fluorescence quantum yields (FF), whereas the
fluorescence intensity tends to decrease along with an
increase in the generation. As a fluorescence intensity of
each dendrimer was proportional to the concentration within
well as MALDI-TOF MS. Each fluorescent dendrimers
Table 1. Fluorescence properties for G0–G3
t (ns)b
a
EM lmax
FFl
G0
G1
G2
G3
442
442
443
444
0.97
0.93
0.92
0.89
1.57
1.57
1.63
1.59
Measured in THF (1.0!10K6 M).
a The measured FFls are compared to 9,10-diphenylanthracene (FFlZ
0.95).
Figure 1. The excitation (EX) and fluorescence (FL) spectra of G0–G3 in
THF (1.0!10K6 M).
b The lifetime measurements are carried out at a 392.57 nm irradiation.

11022
R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
a range of the measurements, a decrease in the intensity
depending on the generation is not due to self-quenching or
association, but to the properties of the dendrimers
themselves. Although the reason is unclear at present, a
variation in the fluorescence quantum yields with generation
2.3. Electrochemical behavior
To investigate the electrochemical properties of these
dendritically functionalized distyrylbenzenes, cyclic volt-
ammetry (CV) measurements were carried out and the
results are illustrated in Figure 2. All compounds G0–G3
exhibited three-stage oxidation waves in dichloromethane.
The first step, which might be due to oxidation of the
distyrylbenzene core,11 is almost reversible while the
others are irreversible. Although the first half-wave
potentials (E1/2) for oxidation of the core are almost
constant (0.88 V vs SCE) within the error range, the peak
separation (DEp) showed a slight increase with the
increasing generation (DEp: G0, 70; G1, 80; G2; 110, G3;
130 mV). It might be connected with retardation of the
electron transfer due to encapsulation of the core by the
dendritic moieties toward the electrode.14 On the other
hand, somewhat different electrochemical behaviors were
observed in acetonitrile. While G0 showed reversible redox
waves, others showed a much decrease in reversibility. In
the case of G3, no distinct peak was observable because of
its low solubility. Consequently, these electrochemical
behaviors indicate that the electron transfer from the
´
has been observed in another case of the Frechet-type
dendrimers with the fluorescent pyrrolopyrrole cores.12 In
the fluorescence excitation spectra, the small peaks in the
shorter wavelength region at 285 nm increase with a
generation increase (Fig. 1). This is due to the singlet
energy transfer from the dendron moieties to the core,2,3 and
the efficiency of the energy transfer was estimated to be 0.16
for G3 by comparing the fluorescence quantum yields with
excitation at 285 and 387 nm.
The measurements of the fluorescence decays in THF under
a nitrogen atmosphere revealed that all of them could be
fitted to a mono-exponential model and all compounds G0–
G3 had almost the same fluorescence lifetimes (tZ1.57–
1.63 ns) being much shorter than that for the poly(benzyl
ether) dendrimers having the tristyrylbenzene cores,3c but
comparable with those for the distyrylbenzene structurally
close to G013 and the dendrimers with a stilbene core.3a
Figure 2. Cyclic voltammetry of G0–G3, (a) measured in CH2Cl2, (b) measured in CH3CN.

R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
11023
distyrylbenzene core is affected by the insulating effect of
the dendritic structures.15
presence of hydrogen peroxide and potassium carbonate in
aqueous THF to display a bright blue light emission. The
good agreement of all the emission spectra (lmax 443 nm)
with the fluorescence spectra of the fluorophores indicates
that the light emission was ascribed to the fluorescence from
the excited distyrylbenzene cores. To explore the structural
effect of the dendritic fluorophores, the chemiluminescence
quantum yields of these chemiluminescence reactions were
measured by varying the fluorophore concentration using
the photon-counting method. According to the established
kinetics of the peroxyoxalate chemiluminescence,9b,17 the
double reciprocal plot of FS versus each fluorophore
concentration should give a straight line if the high-energy
intermediates and the fluorophores interact in a bimolecular
reaction fashion. This relationship is expressed by the
following equation:
2.4. Use as the fluorophores during peroxyoxalate
chemiluminescence
Among the many kinds of chemiluminescence reactions, the
peroxyoxalate chemiluminescence reaction is the most
convenient and efficient one,16 where a molecular inter-
action between the fluorophores and the high-energy
intermediates, usually the dioxetanones generated from
the reactive oxalates and hydrogen peroxide, produces
excited fluorophores that emit light corresponding to their
fluorescence (Scheme 2).8,17 Since the environments around
the fluorophores would crucially influence the light forming
efficiency,18 a difference in the chemiluminescence beha-
vior is expected to be presented between the prepared
dendrimers having a common fluorescent core but different
environments around the cores.
ꢀ
ꢁ
1
FFl
1
k0
1
Z
Z
1 C
Fs
FCL
FrFNS
kss ½Fluꢀ
where Fs is the singlet excitation state quantum yield of the
chemiluminescence, FCL is the total chemiluminescence
quantum yield, Fr is the chemical reaction yield and can be
regarded as unity because all TCPO was completely
consumed during the reactions, FNs is the singlet excitation
state quantum yield at the infinitive fluorophore concen-
tration, FFl is0 the fluorescence quantum yield of the
fluorophores, k is the rate of the unimolecular decompo-
sition of the high-energy intermediates, kss is the rate of
generation of the singlet excited state, and [Flu] is the
concentration of the fluorophores. As shown in Figure 3A,
the reciprocal of FS estimated as FFl/FCL is a linearly
increasing function of the reciprocal of the concentration of
G0–G3, demonstrating that this chemiluminescence
reactions involve the bimolecular interaction process. Of
key interest is a decrease in the FCL when the dendritic
fluorophores with the higher generation were employed at
the higher concentration (Fig. 3B), namely, the FSs for
G0–G3 were almost same at the lower concentration of the
dendrimers, while the difference in the FS increased along
Employing bis(2,4,6-tricholorophenyl) oxalate (TCPO) as a
typical luminophore and G0–G3 as the fluorophores, the
chemiluminescence reactions were carried out in the
Scheme 2. Plausible reaction pathway of peroxyoxalate chemilumi-
nescence.
Figure 3. TCPO chemiluminescence in the presence of G0–G3. Double reciprocal plot of FS versus [dendrimer] (A) and FS at each [dendrimer] (B). The
concentration of the reactants are as follows; [TCPO]Z7.5!10K5 M, [K2CO3]Z7.5!10K5 M, [H2O2]Z7.5!10K3 M, [dendrimer]!106Z0.75, 1.5, 3.75,
7.5, 75 M. The slopes for the reciprocal plots are 0.31 M (R2Z0.998) for G0; 0.32 M (R2Z0.997) for G1; 0.32 M (R2Z0.998) for G2; 0.34 M (R2Z0.997) for
G3.

11024
R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
with an increase in the dendrimer concentration. This
indicates that the insulating effect of the dendritic structures
with larger branches on the core allows the emission
efficiency to decrease. Provided that this chemilumi-
nescence reaction involves a CIEEL (chemically initiated
electron exchange luminescence) or a CT (charge transfer)
process,17b,k,19 the rate of electron transfer or the CT
interaction is significantly influenced by the electron-
donating ability of the core as previously documented in
the chemiluminescence using various distyrylbenzenes.20
The observed variation of FS depending on the structure of
the dendrimers reflects the sensitive situation of the cores
arising from the dendritic encapsulation because an
excitation of the fluorophore needs two electronic process,
an electron transfer from the fluorophore to the dioxetane
intermediate and a back electron transfer from the radical
anion generated by decomposition of the dioxetane to the
fluorophore radical cation if the CIEEL mechanism is
applied. Therefore, the observed decrease in FS can be
related with a decrease in the reversibility of an electron
transfer observed in the CV measurements in the polar
solvent.14c On the other hand, there is also another possible
explanation by the site isolation, that is, the large dendritic
moieties act as obstacles interrupting the approach of the
high-energy intermediate to the fluorescent core, resulting in
a decrease in FS. However, differentiation of these effects,
electronic or steric, is difficult at present, because the steric
hindrance by the large branches retards an electronic
interaction as observed in the CV study. Since the
peroxyoxalate chemiluminescence is very sensitive to the
electronic nature of the fluorophores, there should be much
larger difference in FS than observed if the decrease in FS is
ascribed to inhibition of an electron transfer. Furthermore,
the steric shielding might be insufficient to prevent the
interaction between the high-energy intermediate and
the core in the case of these dendrimers, considering the
ineffective penetration of small quenchers even in the fourth
generation poly(aryl ether) dendrimer with the porphyrin
core.21 Identification of the crucial effect on the chemi-
luminescence efficiency might need architecturally well-
designed dendritic fluorophores that provide much more
definitive insulating effect. Nevertheless, observation of
the structural effect of the fluorescent dendrimers on the
chemiluminescence efficiency in this study is novel and
provides a foothold of the molecular architecture for the
fluorophores useful to control the environment where a light
formation proceeds by a molecular interaction.
generation, which can be explained by the insulating effect
of the dendritic structures on the core.
4. Experimental
Solvents and commercially available compounds were
purchased from standard suppliers and purified by standard
1
methods. H NMR (400 MHz) and 13C NMR (100 MHz)
spectra were recorded in CDCl3 as the solvent, and chemical
shifts (d) were given in ppm relative to tetramethylsilane
(TMS) as the internal standard. Matrix-assisted laser
desporption inonization time-of-flight mass spectral
(MALDI-TOF-MS) measurements were taken on using
dithranol (1,8,9-anthracentriol) as a matrix. Cyclic volt-
ammetry was performed at room temperature with a three-
compartment cell in dry dichloromethane or acetonitrile
solution containing the substrate (ca. 10K4 M) and a
supporting electrolyte(0.1 Mtetrabutylammonium perchlor-
ate). Pt disk, Pt wire, and saturated calomel electrode (SCE)
were used as the working, counter, and reference electrodes,
respectively. The scan rate was 100 mV sK1. Fluorescence
lifetimes were measured in THF solution by means of a time-
wavelength two-dimensional single photon-counting
method coupled with a femtosecond Ti:sapphire regenera-
tive amplifier system. The second harmonics of 392.5 nm of
the laser system at the repetition rate of 3 kHz was used as an
excitation source. Chemiluminescence quantum yields were
measured by a photon-counting method using a Hamamatsu
Photonics R456 photomultiplier connected with a photon-
counting unit (C3866) and a photon-counting board M8784.
The calibration was made by a standard method with the
luminol chemiluminescence in the presence of potassium
tert-butoxide in aerobic DMSO (vide infra).
4.1. Preparation of G0–G3
4.1.1. 2,5-Bis(20-ethylhexyloxy)-1,4-bis(p-hydroxystyryl)
benzene (1). To a suspension of tert-BuOK (4.59 g,
40.94 mmol) in DMF (15 mL) was added a solution
(10 mL) of 2,5-bis(20-ethylhexyloxy)-1,4-bis(diethylphos-
phonomethyl)benzene (3.12 g, 4.91 mmol) in DMF (10 mL)
and stirred for 30 min. at room temperature. To the slurry
was added dropwise a solution of p-hydroxybenzaldehyde
(1.00 g, 8.19 mmol) in DMF (10 mL). After being stirred
for 6 h at room temperature, the solvent was removed by
distillation under a reduced pressure. The residue was
acidified with 1 M HCl and extracted with ethyl acetate. The
organic phase was washed with 1 M HCl twice and brine
and then dried over anhydrous Na2SO4. After removal of the
solvent, the product was recrystallized from ethyl acetate/
hexane to give 1 (2.47 g, 53%). 1H NMR (400 MHz, CDCl3)
d 0.91 (6H, t, JZ7.3 Hz), 0.98 (6H, t, JZ7.3 Hz), 1.32–1.62
(16H, m), 3.94 (4H, d, JZ5.6 Hz), 6.83 (4H, d, JZ8.8 Hz),
7.06 (2H, d, JZ16.4 Hz), 7.09 (2H, s), 7.34 (2H, d, JZ
16.4 Hz), 7.41 (4H, d, JZ8.8 Hz). 13C NMR (100 MHz,
CDCl3) d 11.71, 14.49, 23.50, 24.63, 29.66, 31.34, 40.19,
72.24, 110.59, 115.98, 121.98, 127.14, 128.21, 128.35,
131.55, 151.44, 155.41. HRMS (EI) calcd for C38H50O4
[M]C: 570.3709, found 570.3693.
3. Conclusion
The poly(benzyl ether)dendrimers having strongly fluor-
escent distyrylbenzene cores were synthesized and their
spectral and electrochemical properties were investigated.
The dendron moieties hardly affected the spectral properties
except for the slight difference in the fluorescence
intensities, while retardation of the electron transfer due to
encapsulation of the core by the dendritic moieties was
detected in the CV measurements. The peroxyoxalate
chemiluminescence of TCPO in the presence of G0–G3
emitted light based on the fluorescent cores, and the
decrease in the chemiluminescence efficiency was observed
when the dendrimers were employed at the higher
4.1.2. Compound G0. To a suspension of K2CO3 (0.194 g,
1.140 mmol) and 18-crown-6 (0.019 g, 0.07 mmol) in THF

R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
11025
(10 mL) was added benzyl chloride (0.089 g, 0.70 mmol)
and a solution of 1 (0.20 g, 0.35 mmol) in THF (30 mL).
After refluxing for 2 days, the solvent was removed under a
reduced pressure. The residue was partitioned between
benzene and saturated NH4Cl solution. The organic phase
was washed with satdurated Na2CO3 solution and brine and
then dried over anhydrous Na2SO4. The solvent was
removed under a reduced pressure. The crude product was
recrystallized from methanol to give G0 (0.24 g, 92%) as a
(1.6 mg, 0.06 mmol) in a manner similar to that describe
above. Reaction time was 5 days. Purification by silica gel
column chromatography (eluent; ethyl acetate/hexane 1:1)
1
gave G3 (26.8 mg, 45%) as a yellow powder. H NMR
(400 MHz, CDCl3) d 0.87–0.91 (6H, m), 0.94–0.98 (6H, m),
1.26–1.42 (16H, m), 1.76–1.82 (2H, m), 3.91 (4H, d, JZ
5.4 Hz), 4.96 (24H, s), 4.98 (4H, s), 5.00 (32H, s), 6.53–6.57
(14H, m), 6.66–6.67 (24H, m), 6.68–6.69 (4H, m), 6.93 (4H,
d, JZ8.8 Hz), 7.06 (2H, d, JZ16.0 Hz), 7.07 (2H, s), 7.29–
7.44 (86H, m). 13C NMR (100 MHz, CDCl3) d 11.34, 14.14,
23.11, 24.25, 29.27, 30.94, 39.79, 70.03, 70.13, 71.81,
101.66, 106.41, 106.49, 110.19, 115.08, 121.67, 127.55,
127.65, 127.99, 128.58, 131.26, 136.80, 139.24, 151.07,
158.27, 160.10, 160.19. MALDI-TOF-MS calcd for
C248H230O32 [MCH]C: 3720.64, found 3721.67.
1
yellow needle crystal. H NMR (400 MHz, CDCl3) d 0.91
(6H, t, JZ7.2 Hz), 0.98 (6H, t, JZ7.2 Hz), 1.32–1.63 (16H,
m), 1.78–1.84 (2H, m), 3.94 (4H, d, JZ5.6 Hz), 5.10 (4H,
s), 6.97 (4H, d, JZ8.6 Hz), 7.08 (2H, d, JZ16.4 Hz), 7.09
(s, 2H), 7.33–7.47 (16H, m). 13C NMR (100 MHz, CDCl3) d
11.34, 14.13, 23.13, 24.26, 29.29, 30.97, 39.82, 70.11,
71.84, 110.18, 115.11, 121.66, 126.78, 127.49, 127.65,
128.00, 128.61, 131.22, 137.01, 151.07, 158.36. MALDI-
TOF-MS calcd for C52H62O4 [M]C: 750.46, found 750.05.
Anal. Calcd for C52H62O4: C, 83.16; H, 8.32. Found: C,
83.47; H, 8.52.
4.2. Measurement of the CL quantum yields
The measurements were carried out according to the
procedure reported previously using the luminol standard
in DMSO for calibration of the photomultiplier tube.22 For a
typical run of G0-activated TCPO-CL, a solution (1.5 mL)
containing TCPO (1.0!10K4 M) and G0 (1.0!10K6 M) in
distilled THF was place in a 1!1 cm quarts cell in front of
the photomultiplier in exactly the same geometry. Photon-
counting was initiated simultaneously with the injection of a
solution (0.5 mL) containing H2O2 (3.0!10K4 M) and
K2CO3 (3.0!10K2 M) into the cuvette, and the data
collection was continued for 500 s. The similar measure-
ments were carried out using the G0 solution of different
concentration, 2.0!10K6, 5.0!10K6, 1.0!10K5, and
1.0!10K4 M in THF. The same procedure was applied to
the measurements of the CL quantum yields for other
dendrimers G1–G3.
4.1.3. Compound G1. This compound was prepared from
3,5-bis(benzyloxy)benzyl bromide (0.108 g, 0.28 mmol),
1 (0.080 g, 0.14 mmol), K2CO3 (0.078 g, 5.6 mmol) and
18-crown-6 (7.4 mg, 0.028 mmol) in a manner similar to
that describe above. Recrystallization from benzene/
1
methanol gave G1 (0.14 g, 83%) as a yellow powder. H
NMR (400 MHz, CDCl3) d 0.91 (6H, t, JZ6.9 Hz), 0.99
(6H, t, JZ7.4 Hz), 1.33–1.63 (16H, m), 1.79–1.84 (2H, m),
3.94 (4H, d, JZ5.3 Hz), 5.03 (4H, s), 5.05 (8H, s), 6.58 (2H,
t, JZ2.0 Hz), 6.69 (4H, d, JZ2.0 Hz), 6.94 (4H, d, JZ
8.6 Hz), 7.08 (2H, d, JZ16.4 Hz), 7.09 (2H, s), 7.30–7.46
(26H, m). 13C NMR (100 MHz, CDCl3) d 11.34, 14.13,
23.12, 24.27, 29.29, 30.96, 39.82, 69.99, 70.17, 71.82,
101.61, 106.35, 110.17, 115.12, 121.67, 126.77, 127.57,
127.65, 128.02, 128.61, 128.75, 131.26, 136.81, 139.49,
160.22. MALDI-TOF-MS calcd for C80H86O8 [M]C:
1174.63, found 1174.33.
Acknowledgements
The authors are grateful to Dr. Musubu Ichikawa and Mr.
Shusuke Kanazawa for the fluorescence lifetime measure-
ments. This work was partially supported by the Grants-in-
aid for the 21st Century COE Research and the CLUSTER
of the Ministry of Education, Culture, Sports, Science and
Technology of Japan. J.M is also grateful for the financial
support by the Grant-in-aid from the Ministry of Education,
Culture, Sports, Science and Technology of Japan.
4.1.4. Compound G2. This compound was prepared from
3,5-bis[30,50-bis(benzyloxy)benzyloxy]benzyl bromide
(0.130 g, 0.16 mmol), 1 (0.045 g, 0.08 mmol), K2CO3
(0.043 g, 0.32 mmol) and 18-crown-6 (4.2 mg,
0.016 mmol) in a manner similar to that describe above.
Purification by silica gel column chromatography (eluent;
1
benzene) gave G2 (0.11 g, 67%) as a yellow powder. H
NMR (400 MHz, CDCl3) d 0.89–0.92 (6H, m), 0.96–0.99
(6H, m), 1.34–1.62 (16H, m), 1.77–1.83 (2H, m), 3.93 (4H,
d, JZ5.5 Hz), 4.98 (8H, s), 5.02 (4H, s), 5.03 (16H, s),
6.54–6.55 (2H, m), 6.57–6.58 (4H, m), 6.68 (12H, d, JZ
2.1 Hz), 6.95 (4H, d, JZ8.8 Hz), 7.07 (2H, d, JZ16.4 Hz),
7.08 (2H, s), 7.27–7.45 (46H, m). 13C NMR (100 MHz,
CDCl3) d 11.33, 14.13, 23.12, 24.26, 29.28, 30.95, 39.81,
70.05, 70.16, 71.82, 101.60, 101.66, 106.43, 108.25, 110.19,
115.11, 121.68, 126.76, 127.56, 127.65, 128.01, 128.60,
131.27, 136.81, 139.24, 139.48, 151.07, 158.26, 160.12,
160.21. MALDI-TOF-MS calcd for C136H134O16 [M]C:
2022.97, found 2023.03.
Supplementary data
Supplementary data associated with this article can be found,
in the online version, at doi:10.1016/j.tet.2005.08.108
References and notes
4.1.5. Compound G3. This compound was prepared from
3,5-bis{30,50-Bis[300,500-bis(benzyloxy)benzyl-loxy]benzyl-
oxy}benzyl bromide (57.7 mg, 0.035 mmol), 1 (9.0 mg,
0.016 mmol), K2CO3 (8.8 mg, 0.063 mmol) and 18-crown-6
¨
1. For reviews: (a) Fischer, M.; Vogtle, F. Angew. Chem., Int. Ed.
´
1999, 38, 885–905. (b) Grayson, S. M.; Frechet, J. M. J. Chem.
Rev. 2001, 101, 3819–3867.

11026
R. Koike et al. / Tetrahedron 61 (2005) 11020–11026
2. (a) Jang, D.-L.; Aida, T. Nature 1997, 388, 454–456. (b) Jang,
D.-L.; Aida, T. J. Am. Chem. Soc. 1998, 120, 10895–10901.
(c) Sato, T.; Jang, D.-L.; Aida, T. J. Am. Chem. Soc. 1999, 121,
10658–10659.
17. (a) McCapra, F.; Peering, K.; Hart, R. J.; Hann, R. A.
Tetrahedron Lett. 1981, 22, 5087–5090. (b) Catherall, C. L. R.;
Palmer, T. F.; Cundall, R. B. J. Chem. Soc., Faraday Trans. 2
1984, 80, 823–836. (c) Catherall, C. L. R.; Palmer, R. B.;
Cundall, R. B. J. Chem. Soc., Faraday Trans. 2 1984, 80,
837–849. (d) Alvarez, F. J.; Parekh, N. J.; Matuszewski, B.;
Givens, R. S.; Higuchi, T.; Schowen, R. L. J. Am. Chem. Soc.
1986, 108, 6435–6437. (e) Milofski, R. E.; Birks, J. W. J. Am.
Chem. Soc. 1991, 113, 9715–9723. (f) Prados, P.; Santa, T.;
Homma, H.; Imai, K. Anal. Sci. 1995, 11, 575–580.
(g) Stevani, C. V.; de Arruda Campos, I. P.; Baader, W. J.
J. Chem. Soc., Perkin Trans. 2 1996, 1645–1648. (h) Hohman,
J. R.; Givens, R. S.; Carlson, R. G.; Orosz, G. Tetrahedron
Lett. 1996, 37, 8273–8276. (i) Stevani, C. V.; Baader, W. J.
J. Phys. Org. Chem. 1997, 10, 593–599. (j) Hadd, A. G.;
Seebar, A.; Birks, J. W. J. Org. Chem. 2000, 65, 2675–2683.
(k) Stevani, C. V.; Silva, S. M.; Baader, W. J. Eur. J. Org.
Chem. 2000, 24, 4037–4046. (l) Zhang, Y.; Zheng, X.-R.; You,
X.-Z. J. Chem. Phys. 2000, 113, 7731–7734. (m) Lee, J. H.;
Rock, J. C.; Park, S. B.; Schlautmann, M. A.; Carraway, E. R.
J. Chem. Soc., Perkin Trans. 2 2002, 802–809. (n) Lee, J. H.;
Rock, J. C.; Schlautmann, M. A.; Carraway, E. R. J. Chem.
Soc., Perkin Trans. 2 2002, 1653–1657. (o) Silva, S. M.;
Casallanovo, F.; Oyamaguchi, K. H.; Ciscato, L. F. L. M.;
Stevani, C. V.; Baader, W. J. Luminescence 2002, 17,
313–320. (p) Silva, S. M.; Wagner, K.; Weiss, D.; Beckert,
R.; Stevani, C. V.; Baader, W. J. Luminescence 2002, 17,
362–369. (q) Koike, R.; Motoyoshiya, J.; Takaguchi, Y.;
Aoyama, H. Chem. Commun. 2003, 794–795. (r) Lee, J. H.; Je,
J.; Schlautman, M. A.; Carraway, E. R. Chem. Commun. 2003,
270–271. (s) Bos, R.; Barnett, N. W.; Dyson, G. A.; Lim, K. F.;
Russell, R. A.; Waltson, S. P. Anal. Chim. Acta 2004, 502,
141–147.
3. (a) Mizutani, T.; Ikegami, M.; Nagahata, R.; Arai, T. Chem.
Lett. 2001, 1014–1015. (b) Uda, M.; Mizutani, T.; Hayakawa,
J.; Momotake, A.; Ikegami, M.; Nagahata, R.; Arai, T.
Photochem. Photobiol. 2002, 76, 13–22. (c) Uda, M.;
Momotake, A.; Arai, T. Org. Biomol. Chem. 2003, 1,
1635–1637.
´
4. Hecht, S.; Frechet, J. M. J. Angew. Chem., Int. Ed. 2001, 40,
74–91.
5. (a) Ranasinghe, M. I.; Hager, M. W.; Gorman, C. B.; Goodson,
T., III J. Phys. Chem. B 2004, 108, 8543–8549. (b) Tomoyose,
Y.; Jiang, D. L.; Jin, R. H.; Aida, T.; Yamashita, T.; Horie, K.;
Yashima, E.; Okamoto, Y. Macromolecules 1996, 29,
5236–5238.
6. (a) Nakazono, M.; Ma, L.; Zaitsu, K. Tetrahedron Lett. 2002,
43, 8185. (b) Adamczyk, M.; Fishpaugh, J.; Mattingly, P. G.;
Shreder, K. Bioorg. Med. Chem. Lett. 1998, 8, 3595.
7. Lehman, M.; Schartel, B.; Hennecke, M.; Meier, H.
Tetrahedron 1999, 8, 3595.
8. Adan, w. Four-membered Ring Peroxides. 1,2-Dioxetanes and
a-Peroxylactones. In The Chemistry of Peroxides; Patti, S.,
Ed.; Wiley: New York, 1983; pp 829–920.
9. (a) Chandross, E. A. Tetrahedron Lett. 1963, 12, 761–765.
(b) Rauhut, M. M. Acc. Chem. Res. 1969, 2, 80–87.
10. Nakatsuji, S.; Matsuda, K.; Uesugi, Y.; Nakashima, K.;
Akiyama, S.; Katzer, G.; Fabian, W. J. Chem. Soc., Perkin
Trans. 2 1991, 861–867.
¨
11. Pfeifer, S.; Horhold, H. H. Macromol. Chem. Phys. 1999, 200,
1870–1878.
12. Verheijen, W.; Hofkens, J.; Metten, B.; Vercammen, J.;
Shukla, R.; Smet, M.; Dehaen, W.; Engelborghs, Y.; Schryver,
F. D. Macromol. Chem. Phys. 2005, 206, 25–32.
13. Schweikart, K.-H.; Hanack, M.; Lu¨er, L.; Oelkrug, D. Eur.
J. Org. Chem. 2001, 293–302.
18. (a) Yuan, D.-Q.; Kishikawa, N.; Yang, C.; Koga, K.; Kuroda,
N.; Fujita, K. Chem. Commun. 2003, 416–417. (b) For the
other chemiluminescence systems: (i) Teranishi, K.;
Nishiguchi, T. Anal. Biochem. 2004, 325, 185–195.
(ii) Matsumoto, M.; Hamaoka, K.; Takashima, Y.; Yokokawa,
M.; Yamada, K.; Watanabe, N.; Ijuin, H. K. Chem. Commun.
2005, 808–810.
14. (a) Cardona, C. M.; Kaifer, A. E. J. Am. Chem. Soc. 1998, 120,
4023–4024. (b) Smith, D. K. J. Chem. Soc., Perkin Trans. 2
1999, 1563–1565. (c) Gorman, C. B.; Smith, J. C.; Hager,
M. W.; Parkhurst, B. L.; Sierzputowska-Gracz, H.; Haney, C.
J. Am. Chem. Soc. 1999, 121, 9958–9966.
19. Schuster, G. B. Acc. Chem. Res. 1979, 12, 366–373.
20. Motoyoshiya, J.; Sakai, N.; Imai, Y.; Yamaguchi, Y.; Koike,
R.; Takaguchi, Y.; Aoyama, H. J. Org. Chem. 2002, 67,
7314–7318.
´
15. (a) Hawker, C. J.; Wooley, K. L.; Frechet, J. M. J. J. Chem.
Soc., Chem. Commun. 1994, 925–926. (b) Boulas, P. L.;
´
Comez-Kaifer, M.; Echegoyen, L. Angew. Chem., Int. Ed.
¨
1998, 37, 216–247. (c) Vogtle, F.; Plevoets, M.; Nieger, M.;
21. (a) Jin, R. H.; Aida, T.; Inoue, S. J. Chem. Soc., Chem.
Commun. 1993, 1260–1262. (b) Pollak, K. W.; Leon, J. W.;
´
Frechet, J. M. J.; Maskus, M.; Abruna, H. Chem. Mater. 1998,
Azzellini, G. C.; Credi, A.; Cola, L. D.; Marchis, V. D.;
Venturi, M.; Balzani, V. J. Am. Chem. Soc. 1999, 121,
6290–6298. (d) Armaroli, N.; Barigelletti, F.; Ceroni, P.;
Eckert, J.-F.; Nicoud, J. F.; Nierengarten, J.-F. Chem.
Commun. 2000, 599–600.
10, 30–38.
22. Lee, J.; Wesley, A. S.; Ferguson, J. F., III; Seliger, H. H. In
Bioluminescence in progress; Johnson, F. H., Haneda, Y.,
Eds.; Princeton: Princeton, 1966; p 35.
16. Catherall, C. L. R.; Palmer, T. F.; Cundall, R. B. J. Biolumin.
Chemilumin. 1989, 3, 147–154.