A screw-shaped alignment of pyrene using m-calix[3]amide

Article abstract of DOI:10.1016/j.tet.2012.12.015

m-Calix[3]amide bearing three pyrenes (1a) was prepared by the condensation reaction of 3-nonylaminobenzoic acid derivative using Ph₃PCl ₂. Pyrenyl groups were found to be aligned in the screw-like fashion by m-calix[3]amide as confirmed by the X-ray crystallography. Aromatic proton signals observed at the up-field region in the ¹H NMR spectrum at low temperature indicated that pyrenyl groups in 1a are aligned in close proximity in THF solution. UV-vis absorption and fluorescence emission spectra did not show marked peak shift nor concentration fluorescence quenching compared with reference compounds implying no significant electronic interaction between pyrenyl groups. These results can be explained by the steric effect of the m-calix[3]amide platform. On the other hand, an excimer emission was observed for m-calix[3]amide having a flexible spacer between pyrene and m-calix[3]amide (1b).

Full text of DOI:10.1016/j.tet.2012.12.015

Tetrahedron 69 (2013) 1516e1520
Contents lists available at SciVerse ScienceDirect
Tetrahedron
journal homepage: www.elsevier.com/locate/tet
A screw-shaped alignment of pyrene using m-calix[3]amide
,
Ryohei Yamakado a, Shin-ichi Matsuoka a, Masato Suzuki a, Koji Takagi a
,
*
Kosuke Katagiri b, Isao Azumaya b
a Department of Materials Science and Engineering, Nagoya Institute of Technology Gokiso, Showa, Nagoya 466-8555, Japan
b Faculty of Pharmaceutical Sciences at Kagawa Campus, Tokushima Bunri University, 1314-1 Shido, Kagawa 769-2193, Japan
a r t i c l e i n f o
a b s t r a c t
Article history:
m-Calix[3]amide bearing three pyrenes (1a) was prepared by the condensation reaction of 3-
nonylaminobenzoic acid derivative using Ph3PCl2. Pyrenyl groups were found to be aligned in the
screw-like fashion by m-calix[3]amide as confirmed by the X-ray crystallography. Aromatic proton sig-
nals observed at the up-field region in the 1H NMR spectrum at low temperature indicated that pyrenyl
groups in 1a are aligned in close proximity in THF solution. UVevis absorption and fluorescence emission
spectra did not show marked peak shift nor concentration fluorescence quenching compared with
reference compounds implying no significant electronic interaction between pyrenyl groups. These re-
sults can be explained by the steric effect of the m-calix[3]amide platform. On the other hand, an excimer
emission was observed for m-calix[3]amide having a flexible spacer between pyrene and m-calix[3]
amide (1b).
Received 1 November 2012
Received in revised form 4 December 2012
Accepted 5 December 2012
Available online 12 December 2012
Ó 2012 Elsevier Ltd. All rights reserved.
1. Introduction
solution. Pyrene having the high fluorescence quantum yield shows
two characteristic luminescence behaviors,6 namely a monomer
p
-Conjugated molecules play a central role in organic opto-
emission observed in the diluted solution and an excimer emission
derived from the associated dimer in the concentrated solution. The
excimer emission can be also detected when pyrenes are forced
into the confined space even in the diluted condition. Conse-
quently, pyrene is a useful probe as the DNA fluorescence label to
investigate their distance and chain conformation.7 We will herein
describe a novel alignment of three pyrenes using Method 2 and
report optical properties of pyrene-carrying macrocycles in order to
figure out the structureeproperties relationship.
Cyclic meta-benzamide trimer (m-calix[3]amide) is efficiently
synthesized by the condensation reaction of 3-alkylaminobenzoic
acid derivatives due to the cis preference of the N-alkyl benzani-
lide skeleton.8e13 m-Calix[3]amide has two conformers, in which
the syn conformer has three benzene rings in the same orientation
relative to the amide bond and the anti conformer has one benzene
ring turning in other direction. The syn conformer prefers to the
anti conformer both in the solid phase and solution. As a conse-
quence, appended substituents on the benzene ring are positioned
closely in the syn conformer of m-calix[3]amide. We have reported
the synthesis and characterization of m-calix[3]amides bearing
pyridine14 and bithiophene15 to reveal that m-calix[3]amide is
suitable candidate for assembling functional groups in close prox-
imity. In this paper, m-calix[3]amide was chosen as the platform to
align pyrenes in the screw-like fashion. The synthesis of m-calix[3]
amides having three pyrenes (1a and 1b), m-calix[3]amide having
one pyrene (2), and model compound (3) (Fig. 1) along with the
electronic materials. It is well known that not only the chemical
structure but also the three dimensional alignment structure of
-conjugated molecules contributes largely to the performance of
p
materials. Thus the programmable arrangement of -conjugated
p
molecules in space and the understanding of structureeproperties
relationship are of much importance. However, the three di-
mensional alignment structure is generally governed by the
chemical structure of molecules, as represented by the herringbone
packing of pentacene. One possible strategy to tune-up the align-
ment structure is the chemical modification at the periphery of
conjugated molecules (Method 1). Kobayashi et al. succeeded in the
p-
cofacial packing of bis(methylthio)acenes by using SeS and Se
p
interactions.1,2 Other groups also proposed the molecular design for
the cofacial crystal packing of acene derivatives.3,4 Another tech-
nique to control the alignment structure of p-conjugated molecules
is the utilization of well-defined tethering unit (Method 2). Yoshi-
zawa et al. recently reported a tubular macrocycle containing four
anthracenes covalently connected by the meta-phenylene unit.5
The covalent bond approach (Method 2) would be much reliable
since the three dimensional alignment structure of
molecules can be maintained both in the solid state and diluted
p-conjugated
* Corresponding author. Tel.: þ81 52 735 5264; fax: þ81 52 735 7254; e-mail
address: takagi.koji@nitech.ac.jp (K. Takagi).
0040-4020/$ e see front matter Ó 2012 Elsevier Ltd. All rights reserved.
http://dx.doi.org/10.1016/j.tet.2012.12.015

R. Yamakado et al. / Tetrahedron 69 (2013) 1516e1520
1517
cycloaddition of 10 with 1-azidomethylpyrene in the presence of
copper(I) iodide afforded 1b in 70% yield. The cyclic oligomerization
of 3-alkylaminobenzoic acid carrying the triazole ring with pyrene
using Ph3PCl2 or SiCl4 met with no success probably due to the basic
character of the heterocycle.
C9H19
N
O
R
R
a; R =
b; R =
N
N
O
O
C9H19
N N
N
C9H19
To investigate the optical properties of m-calix[3]amide in
detail, m-calix[3]amide having one pyrene (2) and acyclic model
compound (3) were prepared. The synthesis of 2 was carried out
by the cyclic co-oligomerization of 6 and 3-nonylaminobenzoic
acid using Ph3PCl2 as the condensation reagent, and the purifica-
tion by preparative GPC afforded the desired compound 2 in 6%
yield. On the other hand, 3 was prepared in three steps from 4,
which consists of the benzoylation of the N-nonylamino group, the
estereamide exchange of methyl ester, and the SuzukieMiyaura
cross coupling with pyrene-1-boronic acid. The detailed experi-
mental procedures are described in the Supplementary data.
The alignment structure of three pyrenyl groups was determined
by the single crystal X-ray crystallography using m-calix[3]amide
bearing the ethyl substituent on the amide nitrogen (1a0) instead of
1a (Fig. 2).1a0 adopts the syn conformation and three pyrenyl groups
are arranged on the same side of the m-calix[3]amide skeleton. The
tertiary amide bond has the nearly planer structure as judged by the
dihedral angle MeeNeCeO to be 6.0ꢀ on average. The averaged
dihedral angle formed between the benzene ring and the amide
plane is 110.3ꢀ. Owing to the large steric hindrance induced by three
pyrenyl groups, this value is larger than that observed for m-calix[3]
amide bearing three phenyl groups (the corresponding dihedral
angle is 100.0ꢀ).12 The center-to-center distances between adjacent
R
1a, 1b
C9H19
N
O
C9H19
O
N
O
O
C9H19
O
N
CH3
Ph
N
N
C9H19
Ph
2
3
Fig. 1. Structure of m-calix[3]amides (1a, 1b, and 2) and model compound (3).
conformational characteristics of 1a in solid and solution states and
optical properties in solution will be described.
2. Results and discussion
Following to our previous report,15 methyl 3-bromo-5-
nonylaminobenzoate (4) was synthesized in three steps from
3-bromo-5-nitrobenzoic acid. m-Calix[3]amide bearing three pyr-
enes(1a)wassynthesizedfrom4 asshowninScheme1. Thesynthetic
ꢀ
pyrenyl groups are approximately 6.2 A and the dihedral angle be-
tween three pyrenyl groups is about 61ꢀ.
C9H19
HN
O
6
C9H19
HN
O
C9H19
HN
O
C9H19
N
O
(iii)
(ii)
(i)
OH
OCH3
OCH3
3
Br
4
5
1a
Scheme 1. Synthetic route to 1a. Reagents and conditions: (i) pyrene-1-boronic acid, K2CO3, Pd(PPh3)4, THF, H2O, reflux; (ii) NaOH, H2O, THF, MeOH, 40 ꢀC; (iii) Ph3PCl2, (CHCl2)2, reflux.
route consists of the SuzukieMiyaura cross coupling of 4 with pyr-
ene-1-boronic acid, the hydrolysis of methyl ester by NaOH, and the
cyclic oligomerization using Ph3PCl2 as the condensation reagent.
Cyclic trimer 1a was isolated by preparative GPC in 17% yield. The low
yield of the product is likely due to the steric hindrance of the pyrenyl
group. m-Calix[3]amide (1b) having a flexible spacer between pyrene
and m-calix[3]amide was prepared for comparison and the synthetic
route is shown in Scheme 2. Methyl 3-iodo-5-nonylaminobenzoate
The close arrangement of three pyrenyl groups in 1a was also
evident in the 1H NMR spectra (Fig. 3). At 293 K, the 1H NMR
spectrum showed broad signals and the position of aromatic proton
signals was not much different from that of 6 (Supplementary
data). When the spectrum was measured at 233 K, proton signals
become sharp and several new signals were appeared due to the
slow rotation around the carbon(benzene)ecarbon(pyrene) bond
relative to the NMR time scale. The doublet signal at 6.48 ppm can
C9H19
N
O
C9H19
HN
O
C9H19
HN
O
C9H19
N
O
C9H19
HN
O
(i)
(ii)
(iii)
(iv)
3
3
OCH3
OH
OCH3
I
N
N N
TMS
8
9
10
7
1b
Scheme 2. Synthetic route to 1b. Reagents and conditions: (i) trimethylsilylacetylene, CuI, Pd(PPh3)4, Et3N, 50 ꢀC; (ii) NaOH, H2O, THF, MeOH, rt; (iii) SiCl4, pyridine, reflux; (iv) 1-
azidomethylpyrene, CuI, DMF, 90 ꢀC.
(7) was prepared from 3-iodo-5-nitrobenzoic acid. m-Calix[3]amide
bearing three ethynyl groups (10) was obtained in three steps from 7
by the SonogashiraeHagihara cross coupling with trimethylsilyla-
cetylene, the concomitant de-silylation and esterhydrolysis by NaOH,
and the cyclic oligomerization using SiCl4. Finally, the Huisgen
be assigned to the proton derived from the anti conformer.16 Al-
though the complete signal assignment is impossible, the proton
signals observed at the up-field region (6.8e4.5 ppm) seem to be
originated from pyrene protons, which are strongly shielded by
the adjacent pyrenyl group. On the other hand, 1H NMR spectra

1518
R. Yamakado et al. / Tetrahedron 69 (2013) 1516e1520
Fig. 2. Crystal structure of 1a0 depicted as a ball and stick model. (a) Top view and (b) side view. Chloroform molecules are omitted for clarity. One of the pyrene group is disordered
to two positions and the occupancies are refined (about 0.60 and 0.40). Disordered atoms of a pyrene rings, which have minor occupancy are omitted for clarity.
form the face-to-face stacked structure. In contrast, the fluores-
cence emission of 1b appeared as a broad featureless band at the
longer wavelength region (476 nm) having the quantum yield of
0.06. The flexible methylene spacer reduces the steric hindrance to
permit the excimer emission. The fluorescence quantum yield of 3
was quite low (Ffl¼0.04), which might be resulted from the twisted
intramolecular charge transfer (TICT) by the rotation of the amide
bonds.17 On the other hand, the quantum yields of 1a (Ffl¼0.36)
and 2 (Ffl¼0.34) were high probably because the cyclic structure
suppresses the rotation of the amide bond. It should be noted that
the fluorescence quantum yield of 1a and 2 are almost similar even
though the chromophores are closely located in 1a. This is also
a consequence of the tilted alignment of three pyrenes in the m-
calix[3]amide platform.
3. Conclusion
Fig. 3. 1H NMR spectra of 1a in THF-d8 at 293 K (top) and 233 K (bottom).
m-Calix[3]amides bearing three pyrenes (1a and 1b), m-calix[3]
amide having one pyrene (2), and model compound (3) were syn-
thesized. The structure was investigated in the solid and solution
of 2 and 3 showed no proton signals around the same region
states by the single crystal X-ray crystallography and 1H NMR spec-
(Supplementary data). These results indicate that m-calix[3]amide
troscopy to find out that three pyrenyl groups in 1a are arranged
is a suitable platform to realize the screw-like arrangement of three
closely in space by the m-calix[3]amide platform. Optical properties
pyrenyl groups.
in THF solution were investigated by UVevis and fluorescence
The UVevis absorption and fluorescence emission spectra were
spectroscopy. The absorption and emission maximum wavelengths
measured in THF solution. Prior to the measurement, the solution
were similar between 1a, 2, and 3. In contrast to 1b having the
was purged with nitrogen in order to avoid the fluorescence
flexible spacer between pyrene and m-calix[3]amide, 1a showed
quenching by oxygen. The concentration of the solution are kept
monomer emission and no excimer emission was observed. 1a had
low (<10ꢁ5 M) to prevent the intermolecular interaction. As shown
a high fluorescence quantum yield compared to 3 and the concen-
in Fig. 4a, the absorption maximum wavelengths were similar
tration quenching did not occur. These results indicate that m-calix
between 1a, 2, and 3, which indicates that they have comparable
[3]amide is an excellent platform to align conjugated molecules in
effective conjugation length. In our previous report,15 the absorp-
close proximity and screw-like fashion. We believe that this new
tion maximum wavelength of m-calix[3]amide bearing three
strategy for the programmable arrangement of
cules in space leads to the better understanding of structur-
eeproperties relationship of p-conjugated molecules.
p-conjugated mole-
bithiophenes was blue-shifted by 9 nm from that of acyclic model
compound to imply the intramolecular electronic interaction be-
tween bithiophenes. Hence three pyrenes included in 1a have
negligible interaction in the ground state. The absorption spectrum
of 1b showed the vibronic fine structure characteristic to pyrene
(Fig. 4b). Fluorescence maximum wavelength of 1a was red-shifted
by 3e5 nm from those of 2 and 3, and the tailing to the longer
wavelength region was observed (Fig. 4c). The fluorescence emis-
sion from the associated state (excimer emission) was not observed
from 1a. These results indicate that three pyrenes in 1a have very
weak electronic interaction in the excited state because they cannot
4. Experimental section
4.1. Synthesis of 5
To a mixture of methyl 3-bromo-5-nonylaminobenzoate (4)15
(0.70 g, 2.0 mmol) and pyrene-1-boronic acid (0.50 g, 2.0 mmol)
in THF (20 mL) were added 2 M aq K2CO3 (8.0 mL) and Pd(PPh3)4

R. Yamakado et al. / Tetrahedron 69 (2013) 1516e1520
1519
Fig. 4. Normalized absorption and emission spectra of 1a, 1b, 2, and 3 in THF solution (lex labs, room temperature).
¼
(26 mg, 20
mmol), and the system was heated to reflux overnight.
31.8, 29.5, 29.3, 29.2, 29.1, 27.0, 22.6, 14.0. IR (
n
, cmꢁ1) 3734, 3628,
After an aqueous phase was extracted with DCM, the combined
organic phase was washed with saturated aq Na2CO3. After drying
over MgSO4, solvents were removed by rotary evaporator. The
crude product was purified by recrystallization from DCM/hexane
to obtain yellow crystal in 0.55 g (57% yield). Mp 102e103 ꢀC. 1H
3422, 3275, 2925, 2850, 1682, 1597, 1506, 1429, 1344, 1305, 1270,
873, 773, 654.
4.3. Synthesis of 1a
NMR (d, 200 MHz, ppm, CDCl3) 8.47e7.91 (9H), 7.62 (s, 1H), 7.37 (s,
To a solution of 6 (0.27 g, 0.74 mmol) in (CHCl2)2 (30.0 mL) was
added Ph3PCl2 (0.87 mL, 2.6 mmol), and the mixture was heated to
reflux for 12 h. After removal of (CHCl2)2, ethylacetate was added
and washed with water. The organic phase was dried over MgSO4
and solvents were removed by rotary evaporator. The crude prod-
uct was purified by the preparative GPC (CHCl3 as an eluent) to
1H), 6.95 (s, 1H), 3.90 (s, 3H), 3.14 (t, J¼7.0 Hz, 2H), 1.60 (m, 2H),
1.40e1.20 (12H), 0.87 (t, J¼6.8 Hz, 3H). 13C NMR (
d, 50 MHz, ppm,
CDCl3) 167.5, 148.5, 142.2, 137.3, 131.4, 131.1, 130.9, 130.6, 128.4,
127.5, 127.5, 127.4, 127.3, 127.3, 125.9, 125.2, 125.1, 124.8, 124.8,
124.5, 120.4, 119.2, 112.2, 52.0, 44.0, 31.8, 29.5, 29.4, 29.4, 29.2, 27.1,
22.6, 14.1. IR (n
, cmꢁ1) 3395, 2921, 2847,1708, 1597,1523,1435,1352,
obtain white solid (72 mg, 17%). Mp>300 ꢀC. 1H NMR (
ppm, CDCl3) 8.40e6.81 (br m, 36H), 4.15e3.62 (br m, 6H), 1.84e1.60
(br s, 6H), 1.50e1.10 (br m, 36 H), 0.94e0.73 (br s, 9H). 13C NMR (
d, 600 MHz,
1307, 1239, 1187, 1104, 987, 840, 772, 722. Anal. Calcd for
C33H35NO2: C, 82.98; H, 7.39; N, 2.93. Found: C, 81.89; H, 7.65; N,
2.85.
d
,
150 MHz, ppm, CDCl3) 170.2, 142.7, 134.3, 131.0, 128.7, 128.3, 127.9,
127.8, 127.6, 127.1, 126.0, 125.3, 124.8, 31.8, 29.5, 29.4, 29.2, 27.8,
26.9, 22.6, 14.1. IR (n
, cmꢁ1) 2923, 2853, 1651, 1586, 1456, 843, 721.
4.2. Synthesis of 6
HR MALDI-TOF-MS calcd for C96H94N3O3 (MþHþ): 1336.7295.
Found: 1336.8346.
To a solution of 5 (0.40 g, 0.84 mmol) in THF/MeOH (4 mL/4 mL)
was added 2 M aq NaOH (4 mL), and the system was stirred for 10 h
at 40 ꢀC. The solution was acidified to pH 3e4 with 1 M aq HCl and
the precipitate was collected to obtain yellow powder in 0.36 g (93%
4.4. Synthesis of 8
yield). 1H NMR (
d, 200 MHz, ppm, CDCl3) 7.56 (s, 1H), 7.30 (s, 1H),
To a mixture of methyl 3-iodo-5-nonylaminobenzoate (7)15
(0.40 g, 1.0 mmol), CuI (12 mg, 0.06 mmol), and Pd(PPh3)4
(34 mg, 0.03 mmol) in Et3N (10 mL) was added trimethylsilylace-
tylene (0.28 mL, 2.0 mmol), and the system was heated to 50 ꢀC for
6.94 (s, 1H), 3.14 (t, J¼7.1 Hz, 2H), 3.06 (s, 1H), 1.63 (br m, 2H),
1.43e1.21 (12H), 0.89 (t, J¼6.7 Hz, 3H). 13C NMR (
d, 50 MHz, ppm,
CDCl3) 171.1, 147.7, 130.6, 123.3, 123.2, 121.1, 115.2, 83.1, 77.2, 44.4,

1520
R. Yamakado et al. / Tetrahedron 69 (2013) 1516e1520
6 h. After removal of solvents, DCM was added and washed with
1 M aq HCl. The organic phase was dried over MgSO4 and solvents
were removed by rotary evaporator. The crude product was purified
by SiO2 chromatography (DCM, Rf¼0.7) followed by re-
crystallization from DCM/hexane to obtain yellow powder in 0.27 g
0.01 mmol), and the system was stirred for 6 h at 90 ꢀC. After re-
moval of solvents, DCM was added and washed with brine. The
organic phase was dried over MgSO4 and solvents were removed by
rotary evaporator. The crude product was purified by SiO2 chro-
matography (DCM then ethylacetate (Rf¼0.9)) to obtain brown
(73% yield). Mp 112e113 ꢀC. 1H NMR (
d, 200 MHz, ppm, CDCl3) 7.44
solid (23 mg, 70%). 1H NMR (
d, 600 MHz, ppm, CDCl3) 8.16e7.76
(s, 1H), 7.20 (s, 1H), 6.83 (s, 1H), 3.88 (s, 3H), 3.73 (s, 1H), 3.11 (t,
(24Hꢂ0.75, 27Hꢂ0.25), 7.71e7.66 (6Hꢂ0.25), 7.64 (s, 3Hꢂ0.75),
7.49 (s, 3Hꢂ0.25), 7.46 (3Hꢂ0.75), 7.19 (s, 3Hꢂ0.75), 7.13 (d,
J¼8.1 Hz, 3Hꢂ0.75), 6.69 (s, 3Hꢂ0.75), 6.23 (s, 3Hꢂ0.25), 5.85 (s,
6Hꢂ0.25), 5.55 (d, J¼15.0 Hz, 3Hꢂ0.75), 5.38 (d, J¼15.0 Hz,
3Hꢂ0.75), 3.77 (s, 3Hꢂ0.75), 3.67 (6Hꢂ0.25), 3.54(3Hꢂ0.75),
J¼7.4, 2H), 1.60 (br m, 2H), 1.41e1.23 (12H), 0.88 (t, J¼6.7 Hz, 3H),
0.24 (s, 9H). 13C NMR (
d, 50 MHz, ppm, CDCl3) 166.8, 148.3, 131.0,
123.9, 121.8, 119.3, 113.9, 104.8, 93.9, 52.1, 43.8, 31.8, 29.5, 29.4, 29.3,
29.2, 27.0, 22.6, 14.1, ꢁ0.09. IR (
n
, cmꢁ1) 3396, 2954, 2923, 2849,
2149, 1706, 1595, 1518, 1436, 1344, 1308, 1237, 1178, 1105, 996, 843,
771. Anal. Calcd for C22H35NO2Si: C, 70.73; H, 9.44; N, 3.75. Found:
C, 70.42; H, 9.57; N, 3.62.
1.60e1.50 (6H), 1.30e1.05 (36H), 0.84 (t, J¼7.3 Hz, 9H). 13C NMR (
d,
150 MHz, ppm, CDCl3) 169.5, 145.6, 142.9, 139.3, 131.4, 130.9, 130.3,
128.6, 128.3, 127.9, 127.2, 127.0, 126.7, 126.2, 126.0, 125.7, 125.6,
124.7, 124.4, 124.1, 121.5, 107.9, 67.6, 51.5, 49.6, 31.7, 29.7, 29.4, 29.2,
4.5. Synthesis of 9
29.1, 27.5, 26.7, 23.9, 22.6, 14.1. IR (n
, cmꢁ1) 3868, 3044, 2922, 2851,
1651,1590,1453,1391, 1304,1185, 1129,1044, 881, 845, 756, 706. HR
MALDI-TOF-MS calcd for C105H102N12NaO3 (MþNaþ): 1602.8129.
Found: 1602.8812.
To a solution of 8 (0.20 g, 0.48 mmol) in THF/MeOH (2 mL/2 mL)
was added 2 M aq NaOH (2 mL), and the system was stirred for 48 h
at room temperature. The solution was acidified to pH 3e4 with
1 M aq HCl and the precipitate was collected to obtain white
powder in 0.14 g (93% yield). Mp 112e113 ꢀC. 1H NMR (
d, 200 MHz,
Supplementary data
ppm, CDCl3) 7.56 (s, 1H), 7.30 (s, 1H), 6.94 (s, 1H), 3.14 (t, J¼7.1 Hz,
Experimental procedure, 1H and 13C NMR spectral data, and
crystal data. Supplementary data related to this article can be found
online at http://dx.doi.org/10.1016/j.tet.2012.12.015.
2H), 3.06 (s, 1H), 1.63 (br m, 2H), 1.43e1.21 (12H), 0.89 (t, J¼6.7 Hz,
3H). 13C NMR (
d, 50 MHz, ppm, CDCl3) 171.1, 147.7, 130.6, 123.3,
123.2, 121.1, 115.2, 83.1, 77.2, 44.4, 31.8, 29.5, 29.3, 29.2, 29.1, 27.0,
22.6, 14.0. IR (
n
, cmꢁ1) 3734, 3628, 3422, 3276, 2925, 2850, 1682,
1597, 1506, 1429, 1344, 1305, 1270, 873, 773, 654.
References and notes
4.6. Synthesis of 10
1. Kobayashi, K.; Masu, H.; Shuto, A.; Yamaguchi, K. Chem. Mater. 2005, 17, 6666.
2. Kobayashi, K.; Shimaoka, R.; Kawahata, M.; Yamanaka, M.; Yamaguchi, K. Org.
Lett. 2006, 8, 2385.
3. Anthony, J. E.; Brooks, J. S.; Eaton, D. L.; Parkin, S. R. J. Am. Chem. Soc. 2001, 123,
9482.
4. Sundar, V. C.; Zaumeil, J.; Podzorov, V.; Menard, E.; Willett, R. L.; Someya, T.;
Gershenson, M. E.; Rogers, J. A. Science 2004, 303, 1644.
5. Hagiwara, K.; Sei, Y.; Akita, M.; Yoshizawa, M. Chem. Commun. 2012, 7678.
6. Winnik, F. M. Chem. Rev. 1993, 93, 587.
7. Isied, S. S.; Ogawa, M. Y.; Wishart, J. F. Chem. Rev. 1992, 92, 381.
8. Azumaya, I.; Kagechika, H.; Yamaguchi, K.; Shudo, K. Tetrahedron 1995, 51, 5277.
9. Azumaya, I.; Kagechika, H.; Yamaguchi, K.; Shudo, K. Tetrahedron Lett. 1996, 37,
5003.
To a solution of 9 (0.17 g, 0.60 mmol) in dry pyridine (4.0 mL)
was added dropwise SiCl4 (0.12 mL, 0.90 mmol) at 0 ꢀC, and the
mixture was heated to reflux for 12 h. After removal of pyridine,
DCM was added and washed with 1 M aq HCl. The organic phase
was dried over MgSO4 and solvents were removed by rotary
evaporator. The crude product was purified by the preparative GPC
(CHCl3 as an eluent) to obtain brown solid (16 mg, 10%).
Mp>300 ꢀC. 1H NMR (
d, 600 MHz, ppm, CDCl3) 7.62 (s, minor
3Hꢂ0.25), 7.35 (s, minor 3Hꢂ0.25), 7.15 (s, major 3Hꢂ0.75), 7.02 (s,
major 3Hꢂ0.75), 6.84 (s, major 3Hꢂ0.75), 6.32 (s, minor 3Hꢂ0.25),
3.77 (m, major 3Hꢂ0.75 and minor 6Hꢂ0.25), 3.60 (m, major
3Hꢂ0.75), 3.12 (s, major and minor 3H), 1.60e1.48 (6H), 1.36e1.14
10. Imabeppu, F.; Katagiri, K.; Masu, H.; Kato, T.; Tominaga, M.; Therrien, B.; Ta-
kayanagi, H.; Kaji, E.; Yamaguchi, K.; Kagechika, H.; Azumaya, I. Tetrahedron Lett.
2006, 47, 413.
11. Azumaya, I.; Okamoto, T.; Imabeppu, F.; Takayanagi, H. Tetrahedron 2003, 59,
2325.
(36H), 0.88 (t, J¼7.1 Hz, 9H). 13C NMR (
d, 150 MHz, ppm, CDCl3),
12. Kakuta, H.; Azumaya, I.; Masu, H.; Matsumura, M.; Yamaguchi; Kagechika, H.;
Tanatani, A. Tetrahedron 2010, 66, 8254.
13. Katagiri, K.; Furuyama, T.; Masu, H.; Kato, T.; Matsumura, M.; Uchiyama, M.;
Tanatani, A.; Tominaga, M.; Kagechika, H.; Yamaguchi, K.; Azumaya, I. Supramol.
Chem. 2011, 23, 125.
168.9, 142.3, 139.2, 133.0, 130.1, 127.1, 124.0, 81.1, 79.7, 50.1, 31.8,
29.5, 29.2, 29.1, 27.4, 26.7, 22.6, 14.1. IR (n
, cmꢁ1) 3734, 3306, 3235,
2924, 2853, 1648, 1581, 1433, 1389, 1328, 1261, 1127, 887, 802, 703,
652. HR MALDI-TOF-MS calcd for C54H70N3O3 (MþHþ): 808.5417.
Found: 808.5050.
14. Yamakado, R.; Sugimoto, S.; Matsuoka, S.; Suzuki, M.; Funahashi, Y.; Takagi, K.
Chem. Lett. 2012, 41, 249.
15. Takagi, K.; Sugimoto, S.; Yamakado, R.; Nobuke, K. J. Org. Chem. 2011, 76,
2471.
16. The syn/anti ratio in 1a could not be determined due to the complicated NMR
signals.
4.7. Synthesis of 1b
17. Azumaya, I.; Kagechika, H.; Fujiwara, Y.; Itoh, M.; Yamaguchi, K.; Shudo, K. J. Am.
Chem. Soc. 1991, 113, 2833.
18. Wang, X.-N.-S.; Tao, X.-Z.-Z.; Yamamoto, T. Org. Lett. 2011, 13, 552.
To a solution of 10 (16 mg, 0.02 mmol) and 1-azidomethylpyr-
ene18 (30 mg, 0.12 mmol) in DMF (2 mL) was added CuI (2.0 mg,