Synthesis of carbazole-based hetero-core-modified porphyrins

Article abstract of DOI:10.1039/c3ob42564a

Cu(i)-mediated annulation reaction of a 1,1′-(1,3-butadiyne)-8, 8′-(2,5-thiophene)-bridged carbazole dimer 10 with amines provided the N-substituted carbazole-based isophlorines 11a-11c. A similar annulation reaction with selenium in the presence of hydrazine monohydrate afforded hetero-core-modified isophlorine 12. The oxidation of 12 generated the corresponding 21-selena-23-thiaporphyrin 13, which exhibited NIR absorption. The intramolecular charge transfer from Se to S was confirmed by the ¹H NMR results along with DFT calculations. This journal is the Partner Organisations 2014.

Full text of DOI:10.1039/c3ob42564a

Volume 12 Number 17 7 May 2014 Pages 2629–2812
Organic &
Biomolecular
Chemistry
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ISSN 1477-0520
PAPER
Chihiro Maeda, Naoki Yoshioka et al.
Synthesis of carbazole-based hetero-core-modified porphyrins

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Biomolecular Chemistry
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Synthesis of carbazole-based hetero-core-
modified porphyrins†
Cite this: Org. Biomol. Chem., 2014,
12, 2656
Chihiro Maeda,*‡ Motoki Masuda and Naoki Yoshioka*
Cu(I)-mediated annulation reaction of
a 1,1’-(1,3-butadiyne)-8,8’-(2,5-thiophene)-bridged carbazole
dimer 10 with amines provided the N-substituted carbazole-based isophlorines 11a–11c. A similar annu-
lation reaction with selenium in the presence of hydrazine monohydrate afforded hetero-core-modified
isophlorine 12. The oxidation of 12 generated the corresponding 21-selena-23-thiaporphyrin 13, which
Received 23rd December 2013,
Accepted 18th February 2014
1
DOI: 10.1039/c3ob42564a
exhibited NIR absorption. The intramolecular charge transfer from Se to S was confirmed by the H NMR
www.rsc.org/obc
results along with DFT calculations.
co-workers developed calix[4]pyrrole[2]carbazole by replacing
the two methylene moieties of a calix[4]pyrrole by a carbazo-
Introduction
In the past two decades, a variety of porphyrins and porphyri- le.10a Müllen and co-workers synthesized a pyridine-bridged
noids have been synthesized in view of mimicry of the natural carbazole dimer via Suzuki–Miyaura coupling.10b Our group
photosynthetic system and applications to optical devices, reported a double annulation strategy that allows the synthesis
molecular recognitions, and catalyses.1 Both peripheral and of novel fused porphyrinoids from 1,3-butadiyne-bridged
core modifications of porphyrins are intriguing because they carbazole dimer 1 (Scheme 1). Among these porphyrinoids,
can dramatically modify the properties of these compounds. the tetrabenzo-fused dithiaporphyrin 5 and diselenaporphyrin
Peripheral modifications allow tuning of the properties of the 6 exhibited distinct aromaticity as well as NIR absorption due
macrocycles as well as applications to liquid crystal materials2 to the expanded π-conjugation over the entire macrocycles.12a,e
and organic–inorganic hybrid materials.3 In particular, intro- This double annulation reaction represents an alternative por-
duction of acetylene moieties or fusion of additional aromatic phyrin synthesis and is a useful means of obtaining 21,23-
rings at the periphery of the original structures results in homo-core-modified porphyrins, although syntheses of 21,23-
expanded π-conjugation and additional absorption within the hetero-core-modified porphyrins are trivial via this double
near-infrared (NIR) region.4–6 In contrast, core modifications, annulation method. Herein, we report the synthesis of a carba-
namely the replacement of one or more inner nitrogen atoms zole-based 21-modified-23-thiaporphyrin through a stepwise
by other atoms, change the electronic and electrochemical metal-catalyzed strategy.
properties and coordination abilities of the porphyrin base
system.7,8
Carbazole derivatives have also been widely studied because
of their unique properties.9 They can show high emission and
electron conductivity and are readily functionalized or poly-
merized via metal-catalyzed coupling reactions. Since carba-
zole is a benzene-fused pyrrole, its incorporation into fused
porphyrins presents interesting possibilities.10–12 Sessler and
Department of Applied Chemistry, Faculty of Science and Technology,
Keio University, Kohoku-ku, Yokohama 223-8522, Japan
†Electronic supplementary information (ESI) available. CCDC 953495. For
ESI and crystallographic data in CIF or other electronic format see DOI:
10.1039/c3ob42564a
‡Present address: Division of Chemistry and Biotechnology, Graduate School
of Natural Science and Technology, Okayama University, Tsushima, Okayama
700-8530, Japan. E-mail: cmaeda@okayama-u.ac.jp; Fax: +81 86-251-8092;
Tel: +81 86-251-8092.
Scheme 1 Synthesis of carbazole-based porphyrinoids.
2656 | Org. Biomol. Chem., 2014, 12, 2656–2662
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unambiguously provided the structure of 10, shown in Fig. 1.§
The mean plane deviation of the macrocycle is 0.210 Å, indicat-
Results and discussion
The overall synthetic procedure applied in this work is shown ing a highly planar structure. Importantly, 10 could not be
in Scheme 2. The 1,1′-(1,3-butadiyne)-8,8′-(2,5-thiophene)- obtained directly from 1.
bridged carbazole dimer 10 was first synthesized as follows.
Following the synthesis of 10, its annulation reactions were
The Stille coupling reaction of 2,5-bis(tributylstannyl)thio- examined. A mesitylene solution of 10, aniline (10 equiv.), and
phene with an excess of 3,6-di-tert-butyl-1,8-dibromocarb- CuCl (2 equiv.) was heated at reflux for 21 h. After chromato-
azole13 provided 7. The bromo substituents of 7 were converted graphic separation, N-phenyl substituted isophlorine 11a was
into ethynyl groups via a Stille coupling reaction with tributyl- obtained in 29% yield. HR-MALDI-TOF mass spectral data
(trimethylsilylethynyl)tin and subsequent deprotection of 8 showed the parent ion peak of 11a at an m/z value of 777.4089
with TBAF. The intramolecular Glaser coupling reaction of 9 (calcd for C54H55N3S: 777.4112 [M]+). X-ray diffraction analysis
subsequently provided the cyclic carbazole dimer 10. High- provided a preliminary structure for 11a, shown in Fig. S13
resolution matrix-assisted-laser-desorption-ionization time-of- (ESI).† A similar annulation reaction of 10 with butylamine or
flight (HR-MALDI-TOF) mass spectral data showed the parent 3,4,5-trimethoxybenzylamine resulted in the corresponding
ion peak of 10 at an m/z value of 683.3494 (calcd for 2,5-pyrrolylene-bridged carbazoles 11b and 11c, respectively.14
C48H47N2S: 683.3465 [M − H]−). Slow diffusion of methanol Additionally, reaction of 10 with selenium in the presence of
vapor into a dichloromethane solution of 10 resulted in the hydrazine monohydrate afforded selenophene-bridged carba-
formation of well-defined crystals. X-ray diffraction analysis zole 12.15 The HR-MALDI-TOF mass spectrum of 12 showed
the parent ion peak at an m/z value of 765.2759 (calcd for
C48H49N2SSe: 765.2787 [M − H]−).
The absorption spectra of these isophlorines are shown in
Fig. 2 and summarized in Table 1. The spectra of 11a–11c
exhibit two similar bands at 300 and 380 nm, which are
slightly red-shifted in comparison to those of 2a–2c. On the
other hand, the spectra of dichalcogenaisophlorines 3, 4, and
Scheme 2 Synthesis of 11a–11c and 12.
Fig. 2 UV/vis absorption spectra of (a) 2a–2c and 11a–11c, and (b) 3, 4,
10, and 12 in CH2Cl2.
§Crystallographic data for 10: formula: 2(C46H46N4S2)CHCl3, Mw = 1489.26, tri-
ˉ
clinic, space group P1, a = 15.7704(9), b = 17.0399(9), c = 17.7847(9) Å, α =
82.2120(10), β = 72.642(2), γ = 85.179(2)°, V = 4514.7(4) Å3, Z = 2, ρcalcd = 1.096 g
cm−3, T = –183 °C, 35 820 measured reflections, 15 761 unique reflections (Rint
=
0.0315), R1 = 0.0642 (I > 2σ(I)), wR2 = 0.1934 (all data), GOF = 1.106. CCDC
953495 10 contains the supplementary crystallographic data for this paper. The
contribution to the scattering arising from the presence of disordered solvents
in the crystals was removed by use of the utility SQUEEZE in the PLATON soft-
ware package.19
Fig. 1 X-ray crystal structure of 10. Peripheral substituents are omitted
for clarity. The thermal ellipsoids are at the 50% probability level.
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Table 1 Selected photophysical properties of the carbazole-based por-
phyrinoids in CH2Cl2
b
Compound
λA (nm)
λF a (nm)
ΦF
2a
2b
2c
3
4
10
11a
11b
11c
12
300, 350
298, 368
298, 368
315, 403
315, 396
320, 395, 416
301, 378
299, 383
301, 384
315, 396
424
417
417
448
448
476
451
463
463
455
0.775
0.704
0.573
0.271
0.008c
0.426
0.290
0.289
0.356
0.030c
Fig. 3 UV/vis/NIR absorption spectra of 13 (red), 5 (black), and 6 (blue)
in CH2Cl2.
a Excitation wavelengths are 360 nm. b Absolute fluorescence quantum
yields. c Fluorescence quantum yields of 4 and 12 were determined
with reference to the value of 3 (0.271) in CH2Cl2.
−0.906 V and oxidation waves at 0.326, 0.458, 0.954, and
1.058 V (ESI†). A small electrochemical HOMO–LUMO gap
(0.914 eV) was observed, consistent with the molecule’s optical
HOMO–LUMO gap (1.17 eV).
12 are almost similar. Thus, the spectra of these isophlorines
are exhibited primarily in the UV-region, which reflects non-
aromatic characteristics. Compounds 11a–11c exhibited mod-
erate fluorescent yields of 0.290, 0.289, and 0.356, respectively,
while that of 12 was 0.03 due to the heavy atom effect of the
selenium moiety. Among these, compound 10 showed the
most red-shifted absorption and fluorescence, which might be
ascribed to its planarity.
Finally, DFT calculations were performed to assist in eluci-
dating the electronic properties of 13 (Fig. 4).17 Compounds 5,
6, and 13 all showed four orbitals characteristic of typical por-
phyrins. In all three compounds, the electronic coefficients
were well delocalized over the entire macrocycle, while slight
polarization between the thiophene and selenophene was
observed in the case of 13. In addition, the electronic charge
of the S (0.430) in 13 is lower than that in 5 (0.455) while the
Se charge (0.316) in 13 is higher than that in 6 (0.292). These
data, combined with the 1H NMR results, suggest charge trans-
fer from Se to S. Nuclear independent chemical shift (NICS)
values at the center of 5, 6, and 13 were calculated to be −10.8,
−14.1, and −12.2 ppm, respectively, indicating that 5, 6, and
13 are all distinctly aromatic.
The 2,5-pyrrolylene-bridged cyclic carbazole dimers 11a–11c
can be regarded as [20]porphyrins and are expected to become
aromatic after deprotection of the pyrrolic N-substituents and
subsequent oxidation. Attempts to deprotect the pyrrolic
N-substituents have been unsuccessful, however, despite exten-
sive efforts using various acids and oxidants. The oxidation of
12 to the 21-selena-23-thiaporphyrin 13 was accomplished
using MnO2 and was accompanied by a dramatic colour
change from yellow to green (Scheme 3).16 In keeping with the
1
significant transformation of its electronic state, the H NMR
spectrum of 13 exhibits downfield shifts of the peripheral
proton signals, indicating a diatropic ring current in the mole-
cule. Interestingly, the thiophene protons are shifted upfield
(9.74 ppm) while the selenophene protons are shifted down-
field (10.09 ppm) as compared to the corresponding protons
of 5 (9.90 ppm) or 6 (10.07 ppm). The UV/vis/NIR absorption
spectrum of 13 exhibits Q-like bands at 839, 940, and
1064 nm, situated intermediate between the corresponding
bands of 5 and 6 (Fig. 3). In order to confirm such a small
HOMO–LUMO gap, the oxidation and reduction potentials
of 13 were subsequently measured by cyclic voltammetry. The
voltammogram of 13 shows reduction waves at −0.588 and
Fig. 4 Molecular orbital diagrams and selected Mulliken charges of (a)
5, calculated at the B3LYP/6-31G* levels, and (b) 6 and (c) 13, calculated
at the B3LYP/6-31G*/LANL2DZ levels.
Scheme 3 Synthesis of 13.
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Synthesis of 8. A dry toluene (10 mL) solution of 7 (117 mg,
146 μmol), tributyl(trimethylsilylethynyl)tin (206 mg,
Conclusions
In this work, we have synthesized carbazole-based hetero-core- 531 μmol), and Pd(PPh3)4 (10.0 mg, 8.65 μmol) was heated at
modified porphyrins via a stepwise metal-catalyzed strategy. reflux for 20 h under Ar. After the solvent was removed under
The Cu(I)-mediated annulation reaction of the 1,1′-(1,3-buta- reduced pressure, the residue was separated over a silica gel
diyne)-8,8′-(2,5-thiophene)-bridged carbazole dimer 10 with column with CH2Cl2–hexane as an eluent to give 8 (97.5 mg,
1
amines provided the N-substituted thiaporphyrinoids 11a–11c 117 μmol, 80%). H NMR (CDCl3) δ = 8.72 (s, 2H, NH), 8.14 (d,
all of which contain carbazole units. A similar annulation reac- J = 1.8 Hz, 2H, carbazole-H), 8.12 (d, J = 1.4 Hz, 2H, carbazole-
tion of 10 with selenium in the presence of hydrazine mono- H), 7.77 (d, J = 1.7 Hz, 2H, carbazole-H), 7.644 (d, J = 1.7 Hz,
hydrate afforded the hetero-core-modified isophlorine 12. The 2H, carbazole-H), 7.638 (s, 2H, thiophene), 1.55 (s, 18H, t-Bu),
subsequent oxidation of 12 gave the carbazole-based 1.49 (s, 18H, t-Bu), and 0.30 ppm (s, 18H, TMS); 13C NMR
21-selena-23-thiaporphyrin 13. 13 as well as the dichalcogen- (CDCl3) δ = 143.25, 142.72, 141.25, 139.66, 134.85, 126.69,
aporphyrins 5 and 6 exhibit distinct aromaticity and strong 125.12, 124.51, 123.26, 123.02, 117.62, 117.08, 116.61, 105.05,
NIR absorption. In addition, intramolecular charge transfer 101.63, 99.06, 34.81, 34.77, 32.04, 31.94, and 0.16 ppm;
from Se to S was confirmed in the case of 13. Further explora- HR-MALDI-MS: m/z
= 830.4506. calcd for C54H66N2SSi2:
tion of novel carbazole-based porphyrinoids and their metal 830.4480 [M]+; UV/vis (CH2Cl2) λmax (ε) = 280 (30 800), 313
complexes is currently underway in our laboratory.
(30 100), and 375 nm (18 100 mol−1 dm3 cm−1).
Synthesis of 9. Tetrabutylammonium fluoride (260 μL, 1 M
in THF) was added to a CH2Cl2 solution of 8 (97.4 mg,
117 μmol), and the solution was stirred for 20 min. After the
solvents were evaporated, the residue was separated over a
silica gel column with CH2Cl2 to give 9 (76.5 mg, 112 μmol,
Experimental
General
1H and 13C NMR spectra were recorded on a JEOL ECA-500 95%). 1H NMR (CDCl3) δ = 8.72 (s, 2H, NH), 8.15 (d, J = 1.7 Hz,
spectrometer, and chemical shifts were reported as the delta 2H, carbazole-H), 8.11 (d, J = 1.7 Hz, 2H, carbazole-H), 7.73 (d,
1
scale in ppm as an internal reference (δ = 7.260 for H NMR, J = 1.7 Hz, 2H, carbazole-H), 7.67 (d, J = 1.7 Hz, 2H, carbazole-
77.00 for 13C NMR, for CDCl3). UV/vis/NIR absorption spectra H), 7.59 (s, 2H, thiophene), 3.45 (s, 2H, CuCH), 1.53 (s, 18H,
were recorded on a JASCO V-650 spectrometer or on a JASCO t-Bu), and 1.47 ppm (s, 18H, t-Bu); 13C NMR (CDCl3) δ (ppm):
V-570 spectrometer. Fluorescence spectra were recorded on a 143.37, 142.77, 141.10, 139.58, 135.10, 127.37, 125.66, 124.37,
JASCO FP-777W spectrometer. Absolute fluorescence quantum 123.79, 123.29, 117.90, 116.58, 103.86, 81.45, 80.49, 34.83,
yields of 10 and 11a–11c were determined on a Hamamatsu 34.75, 32.01, and 31.92 ppm; HR-MALDI-MS: m/z = 686.3697.
Photonics C9920-02 spectrometer by the photon-counting calcd for C48H50N2S: 686.3690 [M]+; UV/vis (CH2Cl2) λmax (ε) =
method using an integration sphere, and relative fluorescence 311 (28 600) and 373 nm (15 500 mol−1 dm3 cm−1).
quantum yield of 12 was determined with the reference value
Synthesis of 10. To a pyridine (10 mL) suspension of Cu-
of 3 (0.271 in CH2Cl2). MALDI-TOF mass spectra were recorded (OAc)2 (61.5 mg, 323 μmol) was added dropwise a toluene
on a Bruker microTOF. Redox potentials were measured by the (50 mL) solution of 9 (23.0 mg, 33.5 μmol) for 2 h, and the
cyclic voltammetry method using an ALS electrochemical ana- mixture was stirred for further 4 days under air. After the sol-
lyzer model 6102B. Unless otherwise noted, materials obtained vents were removed under reduced pressure, the residue was
from commercial suppliers were used without further purifi- passed through a silica gel column with CH2Cl2 and evapor-
cation. Dry CH2Cl2 and toluene were distilled from CaH2.
ated. The residue was separated by GPC to give 10 (14.4 mg,
Synthesis of 7. A dry toluene (10 mL) solution of 1,8- 21.1 μmol, 63%). 1H NMR (CDCl3) δ = 9.34 (s, 2H, NH), 8.13 (d,
dibromo-3,6-di-tert-butylcarbazole (1.30 g, 2.97 mmol), 2,5-bis- J = 1.7 Hz, 2H, carbazole-H), 8.08 (d, J = 1.5 Hz, 2H, carbazole-
(tributylstannyl)thiophene (251 mg, 379 μmol), and Pd(PPh3)4 H), 7.79 (d, J = 1.8 Hz, 2H, carbazole-H), 7.54 (d, J = 1.8 Hz, 2H,
(45.1 mg, 39.0 μmol) was heated at reflux for 16 h under Ar. carbazole-H), 7.53 (s, 2H, thiophene), 1.53 (s, 18H, t-Bu), and
After the solvent was removed under reduced pressure, the 1.47 ppm (s, 18H, t-Bu); 13C NMR δ = 143.47, 142.89, 142.20,
residue was separated over a silica gel column with CH2Cl2– 140.10, 134.53, 126.52, 124.76, 123.81, 122.85, 122.54, 118.56,
hexane as an eluent to give 7 (117 mg, 146 μmol, 39%). 1H 117.13, 116.98, 103.73, 82.75, 79.79, 34.83, 34.88, 32.02, and
NMR (CDCl3) δ = 8.59 (s, 2H, NH), 8.12 (d, J = 1.4 Hz, 2H, carb- 31.94 ppm; HR-MALDI-MS: m/z
= 683.3494. calcd for
azole-H), 8.10 (d, J = 1.5 Hz, 2H, carbazole-H), 7.77 (d, J = C48H47N2S: 683.3465 [M − H]−; UV/vis (CH2Cl2) λmax (ε) = 320
1.7 Hz, 2H, carbazole-H), 7.68 (d, J = 1.8 Hz, 2H, carbazole-H), (47 900), 395 (20 100), and 416 nm (28 300 mol−1 dm3 cm−1);
7.63 (s, 2H, thiophene), 1.56 (s, 18H, t-Bu), and 1.50 ppm (s, fluorescence (CH2Cl2, λex = 360 nm) λmax = 476 nm, ΦF = 0.426.
18H, t-Bu); 13C NMR (CDCl3) δ = 144.57, 143.62, 141.02,
Synthesis of 11a. A mesitylene (3.0 mL) solution of 10
136.75, 135.03, 126.23, 125.75, 124.69, 124.68, 123.98, 117.43, (69.0 mg, 101 μmol), CuCl (21.1 mg, 213 μmol), and aniline
116.80, 115.66, 104.01, 34.93, 34.86, 32.00, and 31.96 ppm; (0.10 mL, 1.1 mmol) was heated at reflux in a Schlenk tube
HR-MALDI-MS: m/z
= 796.1851. calcd for C44H48N2SBr2: under Ar for 21 h. After the solvent was removed under
796.1879 [M]+; UV/vis (CH2Cl2) λmax (ε) = 303 (40 700) and reduced pressure, the residue was separated over a silica gel
370 nm (24 000 mol−1 dm3 cm−1).
column with CH2Cl2–hexane as an eluent to give 11a (22.9 mg,
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29.4 μmol, 29%). 1H NMR (CDCl3) δ = 8.96 (s, 2H, NH), 8.08 (d, diluted with CH2Cl2, washed with water, and evaporated. The
J = 1.5 Hz, 2H, carbazole-H), 8.05 (d, J = 1.7 Hz, 2H, carbazole- residue was separated over a silica gel column with CH2Cl2–
H), 7.68 (d, J = 1.5 Hz, 2H, carbazole-H), 7.57 (d, J = 1.7 Hz, 2H, hexane to give 12 (13.0 mg, 17.0 μmol, 81%) as a yellow solid.
carbazole-H), 7.37 (d, J = 7.2 Hz, 2H, Ph), 7.32 (s, 2H, thio- 1H NMR (CDCl3) δ = 10.10 (s, 2H, NH), 8.15 (d, J = 1.2 Hz, 2H,
phene), 6.87 (t, J = 7.3 Hz, 2H, Ph), 6.83 (t, J = 7.9 Hz, 1H, Ph), carbazole-H), 8.14 (d, J = 1.2 Hz, 2H, carbazole-H), 7.80 (d, J =
6.48 (s, 2H, pyrrole-H), 1.53 (s, 18H, t-Bu), and 1.47 ppm (s, 1.5 Hz, 2H, carbazole-H), 7.72 (d, J = 1.5 Hz, 2H, carbazole-H),
18H, t-Bu); 13C NMR δ = 143.18, 142.93, 139.96, 138.25, 137.12, 7.47 (s, 2H, thiophene or selenophene), 7.44 (s, 2H, seleno-
136.35, 128.38, 126.84, 126.62, 126.53, 125.81, 125.24, 124.51, phene or thiophene), 1.55 (s, 18H, t-Bu), and 1.54 ppm (s,
122.83, 121.52, 117.41, 117.19, 116.98, 116.73, 113.34, 34.91, 18H, t-Bu); 13C NMR δ = 146.34, 143.16, 143.14, 139.94, 137.09,
34.83, 32.11, and 32.07 ppm; HR-MALDI-MS: m/z = 777.4089. 135.29, 129.47, 125.96, 124.32, 123.75, 121.61, 121.38, 119.62,
calcd for C54H55N3S: 777.4112 [M]+; UV/vis (CH2Cl2) λmax(ε) = 117.22, 117.11, 116.93, 34.99, 34.97, 32.15, and 32.14 ppm;
301 (27 300), and 378 nm (15 600 mol−1 dm3 cm−1); fluo- HR-MALDI-MS: m/z
= 765.2759. calcd for C48H49N2SSe:
rescence (CH2Cl2, λex = 360 nm) λmax = 451 nm, ΦF = 0.290.
765.2787 [M − H]−; UV/vis (CH2Cl2) λmax (ε) = 254 (54 200), 315
Synthesis of 11b. A mesitylene (3.0 mL) solution of 10 (42 300), and 396 nm (27 100 mol−1 dm3 cm−1); fluorescence
(63.2 mg, 92.3 μmol), CuCl (9.50 mg, 96.0 μmol), and butyl- (CH2Cl2, λex = 360 nm) λmax = 455 nm, ΦF = 0.030.
amine (0.10 mL, 1.0 mmol) was heated at reflux in a Schlenk
Synthesis of 13. To a dry CH2Cl2 (20 mL) solution of 12
tube under Ar for 16 h. After the solvent was removed under (39.2 mg, 51.2 μmol) was added MnO2 (178 mg 2.04 mmol)
reduced pressure, the residue was separated over a silica gel and the resulting suspension was stirred for 3 days, in the
column with CH2Cl2–hexane as an eluent to give 11b (21.8 mg, period of which the second and third addition of MnO2
28.8 μmol, 31%). 1H NMR (CDCl3) δ = 9.06 (s, 2H, NH), 8.13 (d, (100 mg) was done after 1 day and 2 days, respectively. The
J = 1.7 Hz, 2H, carbazole-H), 8.12 (d, J = 1.8 Hz, 2H, carbazole- mixture was passed through a pad of celite. Evaporation of the
H), 7.69 (d, J = 1.8 Hz, 2H, carbazole-H), 7.64 (d, J = 1.7 Hz, 2H, solvent and recrystallization of the residue with CHCl3 pro-
carbazole-H), 7.36 (s, 2H, thiophene), 6.46 (s, 2H, pyrrole-H), vided 13 (9.26 mg, 12.1 μmol, 24%) as a green solid.18 1H NMR
4.10 (t, J = 6.7 Hz, 2H, CH2), 1.53 (s, 18H, t-Bu), 1.52 (s, 18H, (CDCl3) δ = 10.09 (s, 2H, selenophene), 9.74 (s, 2H, thiophene),
t-Bu), 1.11 (m, 2H, CH2), 0.74 (m, 2H, CH2), and 0.40 ppm (t, 9.50 (s, 2H, carbazole-H), 9.32 (s, 2H, carbazole-H), 8.86 (s, 4H,
J = 7.5 Hz, 3H, CH3); 13C NMR δ = 143.52, 143.30, 139.97, carbazole-H), 1.87 (s, 18H, t-Bu), and 1.85 ppm (s, 18H, t-Bu);
136.48, 135.99, 132.08, 125.73, 124.90, 124.43, 123.30, 121.63, 13C NMR δ = 154.55, 153.49, 149.53, 148.38, 142.64, 132.90,
117.17, 117.00, 116.90, 116.19, 111.76, 46.33, 34.93, 34.91, 131.99, 130.42, 127.78, 125.95, 124.99, 124.18, 122.57, 121.69,
33.67, 32.10, 31.95, 18.98, and 13.34 ppm; HR-MALDI-MS: m/z 120.45, 119.80, 38.47, 36.26, 32.12, and 31.59 ppm; HR-MALDI-
= 756.4350. calcd for C52H58N3S: 756.4356 [M − H]−; UV/vis MS: m/z = 764.2683. calcd for C48H48N2SSe: 764.2708 [M]−;
(CH2Cl2) λmax (ε) = 299 (27 400), and 383 nm (13 200 mol−1 UV/vis/NIR (CH2Cl2) λmax (ε) = 261 (47 200), 294 (26 900), 321
dm3 cm−1); fluorescence (CH2Cl2, λex = 360 nm) λmax = 463 nm, (31 500), 353 (42 200), 391 (45 500), 839 (44 800), 940 (18 300),
ΦF = 0.289.
and 1064 nm (45 500 mol−1 dm3 cm−1).
Synthesis of 11c. A mesitylene (5.0 mL) solution of 10
(102 mg, 149 μmol), CuCl (36.4 mg, 368 μmol), and trimeth-
oxybenzylamine (197 mg, 1.00 mmol) was heated at reflux in a
Schlenk tube under Ar for 20 h. After the solvent was removed
under reduced pressure, the residue was separated over a silica
gel column with CH2Cl2 as an eluent to give 11c (74.9 mg,
84.9 μmol, 57%). 1H NMR (CDCl3) δ = 9.17 (s, 2H, NH), 8.16 (d,
J = 1.5 Hz, 2H, carbazole-H), 8.15 (d, J = 1.5 Hz, 2H, carbazole-
H), 7.72 (d, J = 1.5 Hz, 2H, carbazole-H), 7.51 (d, J = 1.5 Hz, 2H,
carbazole-H), 7.38 (s, 2H, thiophene), 6.49 (s, 2H, pyrrole-H),
5.63 (s, 2H, Ph), 5.19 (s, 2H, CH2), 3.69 (s, 3H, OMe), 3.50 (s,
6H, OMe), 1.56 (s, 18H, t-Bu), and 1.50 ppm (s, 18H, t-Bu); 13C
NMR δ = 152.70, 143.85, 143.67, 140.08, 137.34, 136.80, 136.77,
136.17, 133.30, 125.74, 124.81, 124.68, 123.87, 121.64, 117.44,
117.21, 117.02, 116.46, 113.01, 104.85, 60.57, 55.84, 50.99,
34.99, 34.90, and 32.14 ppm; HR-MALDI-MS: m/z = 880.4510.
calcd for C58H62N3O3S: 880.4517 [M − H]−; UV/vis (CH2Cl2)
λmax (ε) = 301 (40 100), and 384 nm (19 300 mol−1 dm3 cm−1);
fluorescence (CH2Cl2, λex = 360 nm) λmax = 463 nm, ΦF = 0.356.
Synthesis of 12. A DMSO (15 mL) solution of 10 (14.4 mg,
21.1 μmol), selenium powder (10.4 mg, 132 μmol), N2H4·H2O
(43.2 mg, 853 μmol), and KOH (19.2 mg, 343 μmol) was heated
at 100 °C for 20 h under Ar. After cooling to rt, the mixture was
Acknowledgements
This work was supported by a Grant-in-Aid for Young Scientists
[no. 23750231] from MEXT, Japan. We thank Prof. A. Osuka,
Dr T. Tanaka, and Mr H. Mori (Kyoto University) for X-ray diffr-
action analysis and measurements of the absolute fluo-
rescence quantum yields. C.M. also thanks the Casio Science
Promotion Foundation for its support.
Notes and references
1 (a) K. M. Smith, in The Porphyrin Handbook, ed.
K. M. Kadish, K. M. Smith and R. Guilard, Academic Press,
San Diego, 1999, ch. 1, vol. 1, p. 1; (b) J. S. Lindsey, in The
Porphyrin Handbook, ed. K. M. Kadish, K. M. Smith and
R. Guilard, Academic Press, San Diego, 1999, ch. 2, vol. 1,
p. 45; (c) K. M. Smith, in The Porphyrin Handbook, ed.
K. M. Kadish, K. M. Smith and R. Guilard, Academic Press,
San Diego, 1999, ch. 3, vol. 1, p. 119.
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Paper
2 (a) T. Sakurai, K. Tashiro, Y. Honsho, A. Saeki, S. Seki,
A. Osuka, A. Muranaka, M. Uchiyama, J. Kim, S. Ha,
K. Kato, M. Takata and T. Aida, J. Am. Chem. Soc.,
2011, 133, 6537; (b) C. Xue, Y. Xu, Y. Pang, D. Yu,
L. Dai, M. Gao, A. Urbas and Q. Li, Langmuir, 2012,
28, 5956.
3 (a) G. Sedghi, K. Sawada, L. J. Esdaile, M. Hoffmann,
H. L. Anderson, D. Bethell, W. Haiss, S. J. Higgins and
R. J. Nichols, J. Am. Chem. Soc., 2008, 130, 8582;
(b) A. Yella, H.-W. Lee, H. N. Tsao, C. Yi, A. K. Chandiran,
M. K. Nazeeruddin, E. W.-G. Diau, C.-Y. Yeh,
S. M. Zakeeruddin and M. Grätzel, Science, 2011, 334, 629;
(c) T. Ema, Y. Miyazaki, T. Taniguchi and J. Takada, Green
Chem., 2013, 15, 2485.
and T. K. Chandrashekar, Acc. Chem. Res., 2008, 41, 265;
(f) Y. Matano and H. Imahori, Acc. Chem. Res., 2009, 42,
1193.
8 (a) J. Mack, M. Bunya, Y. Shimizu, H. Uoyama,
N. Komobuchi, T. Okujima, H. Uno, S. Ito, M. J. Stillman,
N. Ono and N. Kobayashi, Chem.–Eur. J., 2008, 14, 5001;
(b) M. Kon-no, J. Mack, N. Kobayashi, M. Suenaga, K. Yoza
and T. Shinmyozu, Chem.–Eur. J., 2012, 18, 13361;
(c) H.-J. Xu, J. Mack, D. Wu, Z.-L. Xue, A. B. Descalzo,
K. Rurack, N. Kobayashi and Z. Shen, Chem.–Eur. J., 2012,
18, 16844.
9 (a) J. V. Grazulevicius, P. Strohriegl, J. Pielichowski and
K. Pielichowski, Prog. Polym. Sci., 2003, 28, 1297;
(b) J. F. Morin, M. Leclerc, D. Ades and A. Siove, Macromol.
Rapid Commun., 2005, 26, 761; (c) N. Blouin and M. Leclerc,
Acc. Chem. Res., 2008, 41, 1110.
4 (a) V. S.-Y. Lin, S. G. DiMagno and M. J. Therine, Science,
1994, 264, 1105; (b) T. E. O. Screen, K. B. Lawton,
G. S. Wilson, N. Dolney, R. Ispasoiu, T. Goodson III, 10 (a) P. Piatek, V. M. Lynch and J. L. Sessler, J. Am. Chem.
S. J. Martin, D. D. C. Bradley and H. L. Anderson, J. Mater.
Chem., 2001, 11, 312; (c) T. Chandra, B. J. Kraft,
J. C. Huffman and J. M. Zaleski, Inorg. Chem., 2003, 42,
5158; (d) T. V. Duncan, K. Susumu, L. E. Sinks and
M. J. Therien, J. Am. Chem. Soc., 2006, 128, 9000.
5 (a) S. Fox and R. W. Boyle, Tetrahedron, 2006, 62, 10039;
(b) J. P. Lewtak and D. T. Gryko, Chem. Commun., 2012,
10069; (c) V. V. Roznyatovskiy, C.-H. Lee and J. L. Sessler,
Chem. Soc. Rev., 2013, 42, 1921; (d) H. Mori, T. Tanaka and
A. Osuka, J. Mater. Chem. C, 2013, 1, 2500.
Soc., 2004, 126, 16073; (b) L. Arnold, H. Norouzi-Arasi,
M. Wagner, V. Enkelmann and K. Müllen, Chem. Commun.,
2011, 970; (c) L. Arnold, M. Baumgarten and K. Müllen,
Chem. Commun., 2012, 9640.
11 Carbazole-based porphyrins were formed as a consequence
of Bergman cyclization of β,β′-diethynylated porphyrins;
(a) H. Aihara, L. Jaquinod, D. J. Nurco and K. M. Smith,
Angew. Chem., Int. Ed., 2001, 40, 3439; (b) M. Nath,
J. C. Huffman and J. M. Zaleski, J. Am. Chem. Soc., 2003,
125, 11484; (c) M. Nath, M. Pink and J. M. Zaleski, J. Am.
Chem. Soc., 2005, 127, 478.
6 (a) H. J. Callot, E. Schaeffer, R. Cromer and F. Metz, Tetra-
hedron, 1990, 46, 5253; (b) L. Barloy, D. Dolphin, D. Dupre 12 (a) C. Maeda, T. Yoneda, N. Aratani, M.-C. Yoon,
and T. Wijesekera, J. Org. Chem., 1994, 59, 7976;
(c) S. Richeter, C. Jeandon, J.-P. Gisselbrecht, R. Ruppert
and H. J. Callot, J. Am. Chem. Soc., 2002, 124, 6168;
(d) H. S. Gill, M. Harmjanz, J. Santamaría, I. Finger and
M. J. Scott, Angew. Chem., Int. Ed., 2004, 43, 485;
(e) O. Yamane, K. Sugiura, H. Miyasaka, K. Nakamura,
T. Fujimoto, K. Nakamura, T. Kaneda, Y. Sakata and
M. Yamashita, Chem. Lett., 2004, 33, 40; (f) S. Fox and
J. M. Lim, D. Kim, N. Yoshioka and A. Osuka, Angew.
Chem., Int. Ed., 2011, 50, 5691; (b) C. Maeda and
N. Yoshioka, Org. Lett., 2012, 14, 2122; (c) C. Maeda and
N. Yoshioka, Org. Biomol. Chem., 2012, 10, 5153;
(d) M. Masuda and C. Maeda, Chem.–Eur. J., 2013, 19,
2971; (e) M. Masuda, C. Maeda and N. Yoshioka, Org.
Lett., 2013, 15, 578; (f) C. Maeda, M. Masuda and
N. Yoshioka, Org. Lett., 2013, 15, 3566.
R.
(g) A. N. Cammidge, P. J. Scaife, G. Berber and
D. L. Hughes, Org. Lett., 2005, 7, 3413; (h) D. Shen, C. Liu 14 The low yields of 11a and 11b were due to the
and Q. Chen, Chem. Commun., 2005, 4982; (i) E. Hao, unstability.
F. R. Fronczek and M. G. H. Vicente, J. Org. Chem., 2006, 15 For the transformation of 1,3-butadiyne to selenophene,
W.
Boyle,
Chem.
Commun.,
2004,
1322; 13 M. S. Mudadu, A. N. Singh and R. P. Thummel, J. Org.
Chem., 2008, 73, 6513.
71, 1233; ( j) K. Kurotobi, K. S. Kim, S. B. Noh, D. Kim and
A. Osuka, Angew. Chem., Int. Ed., 2006, 45, 3944;
(k) S. Tokuji, Y. Takahashi, H. Shinmori, H. Shinokubo and
A. Osuka, Chem. Commun., 2009, 1028; (l) N. K. S. Davis,
A. L. Thompson and H. L. Anderson, J. Am. Chem. Soc.,
see: (a) V. A. Potapov, S. V. Amosova, I. V. Dorońkina and
S. V. Zinchenko, Sulfur Lett., 2001, 24, 275; (b) K. J. Lie,
S. F. Marcel and Y. K. Cheung, J. Chem. Res., Synop., 1993,
392; (c) S. Inoue, T. Jigami, H. Nozoe, Y. Aso, F. Ogura and
T. Otsubo, Heterocycles, 2000, 52, 159.
2011, 133, 30; (m) T. Ishizuka, Y. Saegusa, Y. Shiota, 16 For examples of 21-selena-23-thiaporphyrins, see:
K. Ohtake, K. Yoshizawa and T. Kojima, Chem. Commun.,
2013, 5939.
(a) A. Ulman, J. Manassen, F. Frolow and D. Rabinovich,
J. Am. Chem. Soc., 1979, 101, 7055; (b) L. Latos-Grażyński,
E. Pacholska, P. J. Chmielewski, M. M. Olmstead and
A. L. Balch, Inorg. Chem., 1996, 35, 566; (c) D. G. Hilmey,
M. Abe, M. I. Nelen, C. E. Stilts, G. A. Baker, S. N. Baker,
F. V. Bright, S. R. Davies, S. O. Gollnick, A. R. Oseroff,
S. L. Gibson, R. Hilf and M. R. Detty, J. Med. Chem., 2002,
45, 449.
7 (a) L. Latos-Grażyński, in The Porphyrin Handbook, ed.
K. M. Kadish, K. M. Smith and R. Guilard, Academic Press,
San Diego, 2000, ch. 14, vol. 2, p. 361; (b) A. Jasat and
D. Dolphin, Chem. Rev., 1997, 97, 2267; (c) I. Gupta and
M. Ravikanth, Coord. Chem. Rev., 2006, 250, 468;
(d) T. D. Lash, Eur. J. Org. Chem., 2007, 5461; (e) R. Misra
This journal is © The Royal Society of Chemistry 2014
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17 M. J. Frisch, et al., GAUSSIAN 9 (Revision C.01), Gaussian, 19 (a) A. L. Spek, PLATON, A Multipurpose Crystallographic
Inc., Wallingford CT, PA, 2009.
18 The solubility of 13 is much lower than that of 12, and
unreacted 12 was removed by recrystallization.
Tool, Utrecht, The Netherlands, 2005; (b) P. van der Sluis
and A. L. Spek, Acta Crystallogr., Sect. A: Fundam. Crystal-
logr., 1990, 46, 194.
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