Incorporation of the 1,5-naphthalene subunit into heteroporphyrin structure: Toward helical aceneporphyrinoids

Article abstract of DOI:10.1021/jo4006624

5,10,15,20-Tetraaryl-22-hetero-1,5-naphthiporphyrins, which contain a 1,5-naphthylene moiety instead of one pyrrole embedded in the macrocyclic framework of heteroporphyrins, were obtained by the [3 + 1] approach using the 1,5-naphthylene analogue of tripyrrane (1,5-bis(phenyl(2-pyrolyl)methyl) naphthalene) and 2,5-bis(arylhydroxymethyl)heterocyclopentadiene (heterocyclopentadiene: thiophene, selenophene, tellurophene). The steric constraints, imposed by the substitution mode of the 1,5-naphthylene building block, resulted in the specific helical conformation of 22-hetero-1,5- naphthiporphyrins. The spectroscopic and structural properties of these aceneporphyrinoids indicate a lack of macrocycle aromaticity. Their protonation yielded solely dicationic species.

Full text of DOI:10.1021/jo4006624

Note
pubs.acs.org/joc
Incorporation of the 1,5-Naphthalene Subunit into Heteroporphyrin
Structure: Toward Helical Aceneporphyrinoids
Bartosz Szyszko, Ewa Pacholska-Dudziak, and Lechosław Latos-Grazynski*
́
̇
Department of Chemistry, University of Wrocław, 14 F. Joliot-Curie Street, 50-383 Wrocław, Poland
S
* Supporting Information
ABSTRACT: 5,10,15,20-Tetraaryl-22-hetero-1,5-naphthipor-
phyrins, which contain a 1,5-naphthylene moiety instead of
one pyrrole embedded in the macrocyclic framework of
heteroporphyrins, were obtained by the [3 + 1] approach using
the 1,5-naphthylene analogue of tripyrrane (1,5-bis(phenyl(2-
pyrolyl)methyl)naphthalene) and 2,5-bis(arylhydroxymethyl)-
heterocyclopentadiene (heterocyclopentadiene: thiophene,
selenophene, tellurophene). The steric constraints, imposed
by the substitution mode of the 1,5-naphthylene building
block, resulted in the specific helical conformation of 22-
hetero-1,5-naphthiporphyrins. The spectroscopic and struc-
tural properties of these aceneporphyrinoids indicate a lack of
macrocycle aromaticity. Their protonation yielded solely
dicationic species.
ceneporphyrinoids combine structural features of poly-
cyclic aromatic hydrocarbons and polypyrrolic macro-
spectroscopic properties of 22-hetero-1,5-naphthiporphyrins.
A
An incorporation of a sterically demanding 1,5-linked
naphthalene unit into a porphyrin(1.1.1.1) frame has been
approached. The chosen linker fits to the geometry of
macrocycles and evidently enforces the helical architecture.
The crucial step in the synthesis of 22-hetero-1,5-
naphthiporphyrins is the construction of the condensation
substrate, that is, 1,5-bis(phenylhydroxymethyl)naphthalene 2
(Scheme 2), which is a suitable synthon to introduce the 1,5-
naphthylene ring into a porphyrin-like skeleton.
The method chosen consists of the Friedel−Crafts reaction
between naphthalene and benzoyl chloride, followed by the
reduction of the resulting 1,5-dibenzoylnaphthalene 1 with
lithium aluminum hydride. 1,5-Bis(phenylhydroxymethyl)-
naphthalene 2 was subsequently reacted with an excess of
pyrrole to yield tripyrrane analogue 1,5-bis(phenyl(2-pyrolyl)-
methyl)naphthalene 3.
22-Thia-1,5-naphthiporphyrin has been obtained in a simple
modification of the [3 + 1] synthesis10,15 described for p-
benziporphyrin,3,12 1,4-naphthiporphyrins,7,10 and heterocarba-
porphyrins6,7 (Scheme 3). A condensation of 3 with 2,5-
bis(tolylhydroxymethyl)thiophene 4-S in dichloromethane,
catalyzed by boron trifluoride diethyl etherate and followed
by oxidation with DDQ, resulted in the formation of 22-thia-
1,5-naphthiporphyrin 5-S with 19% yield. Analogous reactions
using 2,5-bis(tolylhydroxymethyl)selenophene 4-Se, 2,5-bis-
(phenylhydroxymethyl)tellurophene 4-Tea, and 2,5-bis(4-
methoxyphenylhydroxymethyl)tellurophene 4-Teb afforded
cycles. A formal concept leading to higher aceneporphyr-
ins(1.1.1.1) is based on an iterative approach involving addition
of benzene units to a prearranged precursor molecule (Scheme
1). Thus, they are derived from benziporphyrins by applying a
fusion of external benzene ring(s) and a built-in phenylene
moiety, conserving the fundamental motive of parent m-
benziporphyrin or p-benziporphyrin.
Such hybrid compounds exemplified by m-benziporphyrin,1,2
p-benziporphyrin,3 oxybenziporphyrins,4,5 24-thia-p-benzipor-
phyrin,6 1,4-naphthiporphyrin,7,8 24-thia-1,4-naphthiporphyr-
in,7 1,3-naphthiporphyrin,8 and its aromatic derivative 1,3-
oxynaphthiporphyrin9 create a unique macrocyclic environment
toward coordination.10,11 These molecules force atypical
intermolecular reactivity,7,12,13 for instance, a contraction of
p-phenylene to cyclopentadiene that is triggered by insertion of
palladium(II) into p-benziporphyrin.12 In more general terms,
aceneporphyrinoids are expected to reveal a broad spectrum of
fundamentally important molecular properties among which are
unexpected optical effects, electron transfer, and redox
chemistry or three-dimensional aromaticity.
In principle, a variety of nontrivial structure-determining
motives can be built into helical porphyrin(1.1.1.1)-like
skeletons which opens a route to a whole class of three-
dimensional helical porphyrinoids, including recently reported
metallocenoporphyrinoids.14 Significantly, the metallocene unit
contributes to metallomacrocyclic aromaticity in a similar
fashion as various commonly incorporated “two-dimensional”
hetero- and carbocyclic rings.
Here, in searching for general routes to helical acenepor-
phyrinoids, we report on the synthesis, structure, and
Received: March 28, 2013
Published: April 24, 2013
© 2013 American Chemical Society
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Note
Scheme 1. Iterative Approach toward Aceneporphyrinoids
Scheme 2. Synthesis of 3
Scheme 3. Synthesis of 22-Hetero-1,5-naphthiporphyrins 5-
X (Anis-4-methoxyphenyl)
Figure 1. Molecular structure of 5-Se (top, perspective view; bottom,
side view). Perimeter hydrogen atoms and meso-aryls are omitted for
clarity. Thermal ellipsoids are at the 50% probability level.
to those of 1,4-thianaphthiporphyrin (1.6°)7 and slightly folded
21-thiaporphyrin (5.8°),16 exceeding even the values reported
for helical ruthenocenothiaporphyrin (13.3°).14 5-S and 5-Se
acquire a helical geometry which is similar to the geometry of
porphyrinoids, which contain an analogous tripyrrane-like
linker and a three-dimensional spacer.14 π-Bonds within the
thia(selena)tripyrrane subunit are largely localized in the
manner indicated by the valence structure of these porphyr-
inoids (Scheme 3). At the same time, the bond lengths in the
naphthalene moiety preserve the pattern of regular naphtha-
lene. The C(20)−C(1) and C(4)−C(5) distances approach the
single-bond limit for C(sp2)−C(sp2).
There is an appreciable effect of the conjugation on the
thiophene and selenophene fragments. The bond distances
within the heterocyclopentadiene rings are altered. Thus the
Cα−Cβ bond lengths (5-S, 1.434(3), 1.432(3) Å; 5-Se,
1.437(3), 1.442(3) Å) are longer than the Cβ−Cβ distances
(5-S, 1.339(3) Å; 5-Se, 1.347(3) Å), whereas the reverse is true
for thiophene17 and selenophene.18
22-selena-1,5-naphthiporphyrin 5-Se (yield 21%) and 22-
tellura-1,5-naphthiporphyrins 5-Tea (yield 16%) and 5-Teb
(yield 21%), respectively.
X-ray analyses have been performed for compounds 5-S and
5-Se. The representative molecular structure of 5-Se is
visualized in Figure 1.
5-S and 5-Se demonstrate the slight tilt of the naphthalene
moiety toward the center of the molecule (Figure 1 and Figure
S1 in Supporting Information). The dihedral angles between
the naphthalene ring and the four meso-carbon atom mean
plane (C4meso) equal ca. 81.7° for 5-S and 82.0° for 5-Se. To
accommodate the 1,5-naphthalene moiety, the dihedral angle
between C(14)C(11)C(5) and C(11)C(14)C(20) planes of
incorporated thiatriphyrin (5-S 17.7°) and selenatriphyrin (5-
Se 16.2°) fragments has to increase considerably as compared
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Note
The UV−vis electronic spectrum of 5-S (Figure 2)
demonstrates three bands at 352 (4.49), 401 (4.53), and 643
position of 1,5-naphthylene with respect to the C4meso mean
plane completely blocks macrocyclic π-delocalization while
retaining unperturbed naphthalene aromaticity. Consequently,
1
the H NMR spectra of 5-X show resonances at positions
consistent with nonaromatic structures (Figure 4). The
macrocyclic aromatic ring current effect is absent for 5-S, 5-
Se, and 5-Te, as clearly illustrated by the positions of pyrrole
and heterocyclopentadiene resonances assigned by two-dimen-
sional experiments. The marked differentiation of H(7,18) and
H(8,17) chemical shifts (5-S, ca. 0.8 ppm; 5-Se, 0.9 ppm; and
5-Tea, 0.8 ppm) is caused by the peculiar orientation of meso-
substituents as shown in the molecular structures (Figure 1 and
Figure S1 in Supporting Information). Because of the unique
conformation of the macrocycle, phenyl rings at positions 5 and
20 acquire conformation characterized by the
CorthoCipsoCmesoCα torsional angle equal to ca. 45°, whereas
the tolyl rings at positions 10 and 15 are nearly orthogonal.
Eventually this results in deshielding of the 7,18-hydrogen
atoms with respect to the 8,17-hydrogen atoms. The analogous
differentiation of chemical shifts was also reported for tetraaryl-
m-benziporphyrin and tetraaryl-3-aza-m-benziporphyrin.2,19
Consistent with helical structures of 5-X, the frozen rotation
of meso-aryls resulted in differentiation of ortho resonances (see
Figure 2. Electronic spectra (DCM, 298 K) of 5-S (black solid line), 5-
Se (red solid line), 5-Teb (blue solid line), and their dications (dashed
lines of the same color).
(4.32) nm. Spectra of 5-Se and 5-Te resemble the spectrum of
5-S, although the distinctive red shift of the low energy band is
detected for 5-Te. In fact, the spectroscopic features of 5-X
resemble those for nonaromatic 6,11,16,21-tetraphenyl-m-
benziporphyrin or 3-aza-24-thiabenziporphyrin.2,19 The low
extinction coefficients are consistent with the nonaromatic
character of these macrocycles.
1
Figures S8−S10 in Supporting Information). The H chemical
shift values of heterocyclopentadiene and pyrrole β-hydrogens
are in the range determined for other nonaromatic fully
conjugated systems.2,19 The thiophene, selenophene, and
tellurophene moieties embedded in macrocyclic structures
show chemical shifts similar to those seen for 4-S, 4-Se, and 4-
Te, respectively.
The titration of dichloromethane solutions of 5-S, 5-Se, and
5-Te with TFA has been followed by UV−vis electronic
spectroscopy (Figures S27−S30 in Supporting Information),
revealing isosbestic points between the neutral and the
dicationic form. The acid titration is accompanied by the
distinct color change from green to orange. Patterns of UV−vis
1
Results of H NMR spectroscopic titrations carried out by
addition of TFA to solutions of 22-hetero-1,5-naphthiporphyr-
ins 5-X in CDCl3 are shown in Figure 4 (trace D) and Figure
S7 in Supporting Information. Under these conditions
(chloroform-d, 220 or 300 K), proton exchange processes
involving 5-X and (5-X)H22+ (X = S, Se, Te) are fast on the 1H
NMR time scale, and consequently only a smooth change of
the chemical shifts can be observed in the whole titration range.
Addition of more than 2 equiv of TFA does not cause further
changes of chemical shifts affording progressive broadening of
the signals.
2+
electronic spectra of (5-S)H22+, (5-Se)H22+, and (5-Te)H2
resemble that of neutral forms, although remarkable red shifts
have been detected for the low energy band (Figure 2).
Enantiomers of 5-Teb have been separated by HPLC using a
chiral column where two fractions were observed with different
retention times (Figure S31 in Supporting Information). CD
experiments demonstrate the optical activity as complementary
spectra of enantiomers (Figure 3). Once separated, both
enantiomers remain stable and do not show any evidence of
racemization.
In conclusion, in the course of these studies we have
demonstrated that 1,5-naphthylene can be built into a helical
heteroporphyrin(1.1.1.1)-like skeleton, opening a route to
three-dimensional porphyrinoids. The steric constraints reflect-
ing the specific substitution mode of the acene building block
imposed the specific helical conformation of the bridging
heterotripyrrin linker, similar to what has been described for
metallocenoporphyrinoids14 or morpholinochlorins.20 The
nearly orthogonal conformation of 1,5-naphthylene with
respect to the C4meso mean plane blocks efficiently the
macrocyclic π-delocalization, rendering 22-hetero-1,5-naphthi-
porphyrins nonaromatic, which remain in contrast to isomeric
24-thia-1,4-naphthiporphyrin; β-H and NH chemical shifts
resemble these of carbaporphyrinoids in the borderline cases of
porphyrinoid aromaticity.7
Porphyrinoids 5-S, 5-Se, and 5-Te cannot take on the
macrocyclic aromaticity typical of porphyrins because of
structural constraints. In particular, the nearly orthogonal
The chemistry presented herein provides many opportunities
for further study, such as the synthesis of systems with
expanded macrocyclic cores, more extensive π-conjugation, and
metalation which facilitates the specific close spatial metal ion−
1,5-naphthylene proximity.
Figure 3. CD spectra recorded for enantiomers of 5-Teb (DCM, 298
K).
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1
2+
Figure 4. H NMR spectra (chloroform-d, 298 K (traces A, B, and C), 220 K (trace D)) of 5-S (A), 5-Se (B), 5-Teb (C), and (5-Se)H2 (D).
Resonance assignments (obtained from COSY and NOESY experiments) follow the numbering scheme given in Scheme 3. Methyl and methoxyl
peaks are not shown.
then was stirred overnight. The reaction mixture was cooled to room
temperature, and the process was quenched by cautious addition of a
hydrochloric acid/brine solution (100 mL, 2/3 v/v). Subsequently, the
reaction mixture was stirred with 200 mL of dichloromethane for 1 h.
The organic phase was separated, washed with water, and dried over
anhydrous magnesium sulfate. After evaporation of the solvent, the
EXPERIMENTAL SECTION
■
Dichloromethane and pyrrole were distilled over calcium hydride.
Chloroform-d was dried directly before use by being run through a
basic alumina column. Reagents not listed here were used as received.
2,5-Bis(tolylhydroxymethyl)thiophene 4-S, 2,5-bis-
(phenylhydroxymethyl)tellurophene 4-Tea, and 2,5-bis(4-
crude product was washed with acetone on a sintered glass funnel,
1
methoxyphenylhydroxymethyl)tellurophene 4-Teb were synthesized
yielding a yellowish-white, amorphous solid. Yield: 8.5 g (51%). H
according to previously described procedures.21,22
NMR (500 MHz, chloroform-d, 300 K): δ 8.23 (ABC spin system, 2H,
3
2,5-Bis(tolylhydroxymethyl)selenophene 4-Se. Synthesized as
naphthalene), 7.87 (d, 4H, J = 7.8 Hz, o-Ph), 7.62−7.59 (m, 4H,
described in the literature, but p-tolylaldehyde (2.3 mL, 19 mmol) was
naphthalene, p-Ph), 7.52 (ABC spin system, 2H, naphthalene), 7.46 (t,
used instead of benzaldehyde.23 The crude product was chromato-
graphed on silica gel (70−230 mesh) using dichloromethane as eluant
to remove nonpolar impurities and then 5% methanol−dichloro-
methane to elute 4-Se. The solvent was removed under reduced
pressure yielding 4-Se. Recrystallization of 4-Se from dichloro-
methane−hexane afforded 4-Se as a white, crystalline solid. mp: 128
4H, 3J = 7.8 Hz, m-Ph). 13C NMR (126 MHz, chloroform-d, 300 K): δ
197.7, 138.0, 136.9, 133.5, 131.2, 130.4, 128.6, 128.5, 127.9, 126.6.
+
HRMS (ESI-TOF): m/z [M + H]+ calcd for C24H17O2 337.1223;
found 337.1218.
1,5-Bis(phenylhydroxymethyl)naphthalene (2). In a 1000 mL
round-bottomed flask equipped with a magnetic stirring bar and
immersed in an oil bath, 1,5-dibenzoylnaphthalene 1 (6.0 g, 0.018
mol) was dissolved in THF (500 mL) under nitrogen. Solid lithium
aluminum hydride (1.7 g, 2.5 equiv) was then added in small portions
to avoid excessive gas evolution. The reaction mixture was then stirred
for 1 h and then the reaction quenched by cautious addition of water
(3 mL) followed by 2 M aqueous NaOH (5 mL). The reaction
mixture was filtered. The solvent was removed on a rotary evaporator
1
°C. Yield: 702 mg (25%). H NMR (500 MHz, chloroform-d, 300 K,
pair of diastereomers): δ 7.29 and 7.28 (m, 4H, Tol), 7.13 (m, 4H,
Tol), 6.83 (s, 2H, selenophene), 5.87 (m, 2H, CHOH), 2.45 (m, 2H,
CHOH), 2.32 (s, 6H, CH3). 13C NMR (126 MHz, chloroform-d, 300
K, pair of diastereomers): δ 155.9 and 155.8, 140.5 and 140.4, 137.72
and 137.70, 129.2, 126.2, 126.1, 126.0, 74.18 and 74.16, 21.1. HRMS
(ESI-TOF): m/z [M + Na]+ calcd for C20H20NaO2Se+ 395.0521;
found 395.0520.
1
to afford a yellowish, amorphous solid. Yield: 5.7 g (94%). H NMR
1,5-Dibenzoylnaphthalene (1). Synthesized as described, but
with some significant modifications.24 Aluminum chloride (26.7 g, 0.2
mol) was suspended in benzoyl chloride (14.5 mL, 0.12 mol) placed in
a 500 mL round-bottomed flask equipped with a magnetic stirring bar
and immersed in an oil bath. The setup was fitted with a reflux
condenser, and the solution was heated to 70 °C and then cooled to
60 °C. Four portions of naphthalene (6.4 g, 0.05 mol; one portion: 1.6
g) were added every 1 h. The reaction mixture was protected from
moisture (a tube with calcium chloride on the top of a condenser) and
(500 MHz, chloroform-d, 300 K, pair of diastereomers): δ 8.04 and
8.03 (two ABC spin systems, 2H, naphthalene), 7.60 (two ABC spin
systems, 2H, naphthalene), 7.45−7.41 (ABC spin system, 2H,
naphthalene), 7.39−7.38 (m, 4H, o-Ph), 7.33−7.30 (m, 4H, m-Ph),
7.26−7.24 (m, 2H, p-Ph, signal is partially covered with the solvent
3
peak), 6.55−6.53 (m, 2H, CHOH), 2.29 and 2.27 (2d, 2H, J = 4.0
Hz, CHOH). 13C NMR (126 MHz, chloroform-d, 300 K, pair of
diastereomers): δ 143.1, 139.4, 131.24 and 131.21, 128.58 and 128.56,
127.75 and 127.71, 127.1 and 127.0, 125.61 and 125.59, 124.53 and
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124.46, 124.4 and 124.3, 73.9 and 73.8. HRMS (ESI-TOF): m/z [M −
OH]+ calcd for C24H19O+ 323.1430; found 323.1421.
afforded 5-Se as a dark green, crystalline solid. Yield: 164 mg (21%).
1H NMR (500 MHz, chloroform-d, 300 K): δ 7.87 (ABC spin system,
2H, 11/41-H), 7.77−7.55 (m, 4H, 5,20-o-Ph), 7.51 (d, 2H, 3J = 4.8 Hz,
7,18-H), 7.49−7.44 (m, 6H, 5,20-m,p-Ph), 7.29−7.26 (m, two ABC
spin systems, 4H, 12/42,13/43-H), 7.15 (m, 8H, 10,15-Tol), 6.82 (s,
1,5-Bis(phenyl(2-pyrolyl)methyl)naphthalene (3). In a 250
mL round-bottomed flask equipped with a reflux condenser and
magnetic stirring bar, 1,5-bis(phenylhydroxymethyl)naphthalene 2
(1.21 g, 3.5 mmol) was dissolved in a mixture of dry pyrrole (10 mL,
145 mmol) and chloroform (15 mL). The solution was purged with
nitrogen for 20 min. Subsequently, boron trifluoride diethyl etherate
(250 μL) was added, the setup was fitted with a reflux condenser, and
the solution was refluxed for 48 h in a nitrogen atmosphere. The
solution was neutralized by addition of triethylamine (1−2 mL).
Solvents were removed using a rotary evaporator, and the crude
residue was chromatographed on silica gel (70−230 mesh) using the
solution of 1% triethylamine in dichloromethane as eluant. The
desired product eluted as the first fraction. The solvent was removed
under reduced pressure, yielding 3 as a white, amorphous solid. Yield:
3
2H, 12,13-H), 6.62 (d, 2H, J = 4.8 Hz, 8,17-H), 2.37 (s, 6H, 10,15-
Tol-CH3). 13C NMR (151 MHz, chloroform-d, 280 K): δ 169.7, 157.5,
154.9, 150.0, 140.1, 139.3, 138.2, 137.2, 136.6, 133.9, 132.6, 131.8,
131.4, 131.1, 131.0, 130.4, 129.6, 128.3, 128.7, 127.2, 125.2, 123.4,
21.4. HRMS (ESI-cyclotron): m/z [M + H]+ calcd for C52H37N2Se+
769.2116; found 769.2129. UV−vis (CH2Cl2, 298 K): λmax (log ε) 355
(4.50), 397 (4.53), 643 (4.36).
5,20-Diphenyl-10,15-ditolyl-22-selena-1,5-naphthiporphyr-
in Dication ((5-Se)H22+). 1H NMR (600 MHz, chloroform-d, 220 K):
3
δ 9.33 (b, 2H, 21,23-NH), 7.99 (d, 2H, J = 5.0 Hz, 7,18-H), 7.88 (t,
2H, 3J = 7.5 Hz, 5,20-p-Ph), 7.81 (d, 4H, 3J = 7.5 Hz, 5,20-o-Ph), 7.74
(ABC spin system, 2H, 13/43-H), 7.71 (t, 4H, 3J = 7.5 Hz, 5,20-m-Ph),
7.59 (ABC spin system, 2H, 11/41-H), 7.44 (s, 2H, 12,13-H), 7.38
1
273 mg (18%). H NMR (500 MHz, chloroform-d, 300 K, pair of
diastereomers): δ 7.98 and 7.97 (two ABC spin systems, 2H,
naphthalene), 7.76 (b, 2H, NH), 7.32 (ABC spin system, 2H,
naphthalene), 7.28−7.26 (m, 4H, m-Ph), 7.23−7.20 (m, 2H, p-Ph),
7.18−7.16 (m, 4H, o-Ph), 7.01 (ABC spin system, 2H, naphthalene),
6.67 (m, 2H, pyrrole), 6.22 (2s, 2H, CH), 6.14 (m, 2H, pyrrole), 5.80
(m, 2H, pyrrole). 13C NMR (126 MHz, chloroform-d, 300 K, pair of
diastereomers): δ 142.9, 139.73 and 139.72, 133.4, 132.19 and 132.16,
129.02 and 128.99, 128.6, 126.7, 126.6, 125.7, 123.3, 117.14 and
117.12, 108.42 and 108.40, 108.31 and 108.27, 46.99 and 46.97.
HRMS (ESI-TOF): m/z [M + Na]+ calcd for C32H26N2Na+ 461.1988;
found 461.1983.
Synthesis of 5-X: A General Protocol for Condensation. 3
(876 mg, 2 mmol in the case of 5-S; 438 mg, 1 mmol in the case of 5-
Se, 5-Tea, and 5-Teb) and 4-S (648 mg, 2 mmol), 4-Se (371 mg, 1
mmol), 4-Tea (394 mg, 1 mmol), or 4-Teb (454 mg, 1 mmol) were
added to dry dichloromethane (900 mL) under nitrogen. Boron
trifluoride diethyl etherate (150 μL in the case of 5-S, 100 μL in other
cases) was then added, and the reaction mixture was protected from
light and stirred for 2 h. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone
(DDQ; 1362 mg, 6 mmol in the case of 5-S and 681 mg, 3 mmol in
other cases) was subsequently added, and the reaction mixture was
stirred for an additional 0.5 h. The solvent was evaporated under
reduced pressure, and the dark residue was subjected to chromatog-
raphy (grade II alumina, dichloromethane). The desired product was
eluted as a green band. Next steps of separation are described
specifically for 5-S, 5-Se, 5-Tea, and 5-Teb.
3
(ABC spin system, 2H, 12/42-H), 7.31 (d, 4H, J = 8.1 Hz, 10,15-m-
Tol), 7.23−7.20 (m partially covered with solvent signal, 4H, 10,15-o-
Tol), 7.10 (d, 2H, 3J = 5.0 Hz, 8,17-H), 2.43 (s, 6H, 10,15-Tol-CH3).
UV−vis (CH2Cl2, 298 K): λmax (log ε) 302 (4.36), 348 (4.38), 437
(4.71), 559 (4.01), 809 (4.44).
5,10,15,20-Tetraphenyl-22-tellura-1,5-naphthiporphyrin (5-
Tea). 5-Tea has been isolated using column chromatography (grade II
alumina) with dichloromethane−hexane as eluant (v/v 4/1).
Subsequently, the recrystallization from dichloromethane−methanol
afforded 5-Tea as a dark green, crystalline solid. Yield: 125 mg (16%).
1H NMR (600 MHz, chloroform-d, 298 K): δ 7.88 (ABC spin system,
2H, 11/41-H), 7.79−7.77 (m, 4H, 5,20-o-Ph), 7.51 (d, 2H, 3J = 4.8 Hz,
7,18-H), 7.49−7.44 (m, 6H, 5,20-m,p-Ph), 7.41 (ABC spin system,
2H, 12/42-H), 7.38−7.35 (m, 4H, 10,15-Ph), 7.33−7.30 (m, 2H,
10,15-Ph), 7.29 (ABC spin system, 2H, 13/43-H), 7.26 (d, 3J = 7.4 Hz,
3
4H, 10,15-Ph), 7.11 (s, 2H, 12,13-H), 6.69 (d, 2H, J = 4.8 Hz, 8,17-
H). 13C NMR (151 MHz, chloroform-d, 298 K): δ 170.7, 156.2, 152.9,
149.1, 142.5, 139.9, 139.3, 139.0, 137.6, 134.5, 131.5, 131.4, 130.9 (b),
130.7, 130.2 (b), 129.5, 128.7, 127.9, 127.2, 126.9, 126.7, 124.4.
HRMS (ESI-cyclotron): m/z [M + H]+, calcd for C50H33N2Te+
791.1700; found 791.1720. UV−vis (CH2Cl2, 298 K): λmax (log ε)
373 (4.45) sh, 420, 672 (4.31).
5,10,15,20-Tetraphenyl-22-tellura-1,5-naphthiporphyrin Di-
cation ((5-Tea)H22+). H NMR (600 MHz, chloroform-d, 298 K): δ
1
3
7.88 (d, 2H, J = 5.0 Hz, 7,18-H), 7.79−7.78 (m, 6H, 5,20-o-Ph and
11/41-H or 13/43-H), 7.69 (t, 2H, 3J = 7.7 Hz, 5,20-p-Ph), 7.61 (t, 4H,
3J = 7.7 Hz, 5,20-m-Ph), 7.56 (ABC spin system, 2H, 11/41-H or 13/43-
H), 7.49−7.47 (m, 8H, 10,15-Ph, 12/42-H), 7.46 (s, 2H, 12,13-H),
5,20-Diphenyl-10,15-ditolyl-22-thia-1,5-naphthiporphyrin
(5-S). 21,23-Dithiaporphyrin formed also in the course of con-
densation has been separated from 5-S using column chromatography
(silica gel 70−230 mesh) with dichloromethane as eluant. The second
band eluted with 5% methanol−dichloromethane that contained 5-S.
Two following column chromatographies (grade II alumina) using
dichloromethane−hexane as eluant (v/v 3/2 then 7/3) and the
subsequent recrystallization from dichloromethane-methanol afforded
3
7.27−7.26 (m, 4H, 10,15-Ph), 6.95 (d, 2H, J = 5.0 Hz, 8,17-H).
5,20-Diphenyl-10,15-dianisyl-22-tellura-1,5-naphthipor-
phyrin (5-Teb). 5-Teb has been isolated in two following
chromatographies on alumina (active alumina) with dichloromethane
and then grade II alumina with dichloromethane−hexane as eluant (v/
v 4/1). Subsequently, the recrystallization from dichloromethane−
methanol afforded 5-Teb as a dark green, crystalline solid. Yield: 181
mg (21%).
1
5-S as a dark green, crystalline solid. Yield: 277 mg (19%). H NMR
(500 MHz, chloroform-d, 300 K): δ 7.85 (ABC spin system, 2H, 11/
41-H), 7.78−7.76 (m, 4H, 5,20-o-Ph), 7.50−7.44 (m, 6H, 5,20-m,p-
3
Separation of enantiomers 5-Teb and 5-Teb′ was accomplished
using the HPLC system equipped with an analytical column (25 cm
length, 4.6 mm i.d.) packed with 5 μm silica gel coated with covalently
bound (S)-valine and dinitroaniline. The eluant system was dichloro-
Ph), 7.48 (d, 2H, J = 4.8 Hz, 7,18-H), 7.31 (ABC spin system, 2H,
13/43-H), 7.19 (ABC spin system, 2H, 12/42-H), 7.16−7.09 (m, 8H,
3
10,15-Tol), 6.66 (s, 2H, 12,13-H), 6.56 (d, 2H, J = 4.8 Hz, 8,17-H),
2.37 (s, 6H, 10,15-Tol-CH3). 13C NMR (151 MHz, chloroform-d, 298
K): δ 168.7, 158.1, 153.3, 150.1, 140.2, 139.5, 137.2, 137.0, 136.4,
133.4, 131.9, 131.6, 131.1, 131.0, 130.6, 129.4, 129.3, 128.6, 128.5,
127.3, 124.3, 122.5, 21.2. HRMS (ESI-cyclotron): m/z [M + H]+ calcd
for C52H37N2S+ 721.2672; found 721.2664. UV−vis (CH2Cl2, 298 K):
λmax (log ε) 352 (4.49), 401 (4.53), 643 (4.32).
1
methane−hexane (v/v 1/5). H NMR (600 MHz, chloroform-d, 298
K): δ 7.88 (ABC spin system, 2H, 11/41-H), 7.79−7.78 (m, 4H, 5,20-
o-Ph), 7.57 (d, 2H, 3J = 4.8 Hz, 7,18-H), 7.49−7.44 (m, 6H, 5,20-m,p-
Ph), 7.40 (ABC spin system, 2H, 12/42-H), 7.29 (ABC spin system,
2H, 13/43-H), 7.19 (d, 4H, 3J = 8.6 Hz, 10,15-o/m-anisyl), 7.16 (s, 2H,
3
12,13-H), 6.91 (m, 4H, 10,15-o/m-anisyl), 6.72 (d, 2H, J = 4.8 Hz,
5,20-Diphenyl-10,15-ditolyl-22-thia-1,5-naphthiporphyrin
8,17-H), 3.83 (s, 6H, 10,15-CH3-anisyl). 13C NMR (151 MHz,
chloroform-d, 298 K): δ 171.0, 158.8, 156.2, 152.9, 148.9, 142.4, 140.0,
139.0, 137.2, 134.4, 132.2 (b), 132.8, 131.5, 131.4, 130.8, 129.5, 128.7,
126.9, 126.7, 124.4, 113.3, 55.3. HRMS (ESI-cyclotron): m/z [M +
2+
Dication (5-S). H2 UV−vis (CH2Cl2, 298 K): λmax (log ε) 354
(4.34), 434 (4.66), 569 (3.98), 797 (4.44).
5,20-Diphenyl-10,15-ditolyl-22-selena-1,5-naphthiporphyr-
in (5-Se). 5-Se has been isolated by column chromatography (grade II
alumina) with dichloromethane−hexane as eluant (v/v 7/3 then 3/2).
Subsequently, the recrystallization from dichloromethane−methanol
+
H]+ calcd for C52H37N2TeO2 851.1912; found 851.1929. UV−vis
(CH2Cl2, 298 K): λmax (log ε) 378 (4.55), 444 (4.30), 681 (4.39).
5094
dx.doi.org/10.1021/jo4006624 | J. Org. Chem. 2013, 78, 5090−5095

The Journal of Organic Chemistry
Note
5,20-Diphenyl-10,15-dianisyl-22-tellura-1,5-naphthipor-
phyrin Dication ((5-Teb)H22+). UV−vis (CH2Cl2, 298 K): λmax (log
ε) 363 (4.36), 448 (4.64), 853 (4.46).
(19) Mysl
5039−5048.
(20) Bruckner, C.; Gotz, D. C.; Fox, S. P.; Ryppa, C.; McCarthy, J.
R.; Bruhn, T.; Akhigbe, J.; Banerjee, S.; Daddario, P.; Daniell, H. W.;
Zeller, M.; Boyle, R. W.; Bringmann, G. J. Am. Chem. Soc. 2011, 133,
8740−8752.
(21) Ulman, A.; Manassen, J. J. Chem. Soc., Perkin Trans. 1 1979,
1066−1069.
́
iborski, R.; Latos-Grazynski, L. Eur. J. Org. Chem. 2005,
́
̇
̈
̈
ASSOCIATED CONTENT
* Supporting Information
■
S
Tables of crystal data, bond lengths, angles, anisotropic thermal
parameters (cif file), a full set of NMR and UV−vis electronic
spectra, and HRMS data. This material is available free of
charge via the Internet at http://pubs.acs.org.
(22) Pacholska-Dudziak, E.; Szterenberg, L.; Latos-Grazyn
ski, L.
̇
Chem.Eur. J. 2011, 17, 3500−3511.
(23) Narayanan, S. J.; Sridevi, B.; Chandrashekar, T. K.; Vij, A.; Roy,
R. J. Am. Chem. Soc. 1999, 121, 9053−9068.
(24) Yoshida, S. Design, Synthesis and Characterization of Novel
Heterocyclic Polymers. Ph.D. Thesis, Department of Chemistry,
McGill University, Montreal, 1997.
AUTHOR INFORMATION
Corresponding Author
■
*E-mail, lechoslaw.latos-grazynski@chem.uni.wroc.pl; tel, +48
71 3757256; fax, +48 71 3282348; homepage, http://llg.chem.
uni.wroc.pl.
Notes
The authors declare no competing financial interest.
ACKNOWLEDGMENTS
■
Financial support from the National Science Centre (Grants
2011/01/N/ST5/02557 and 2012/04A/ST5/00593) is kindly
acknowledged.
REFERENCES
■
(1) Berlin, K.; Breitmaier, E. Angew. Chem., Int. Ed. Engl. 1994, 33,
1246−1247.
(2) Stępien
5117.
, M.; Latos-Grazyn
ski, L. Chem.Eur. J. 2001, 7, 5113−
̇
(3) Stępien
3838−3839.
́ ́
, M.; Latos-Grazynski, L. J. Am. Chem. Soc. 2002, 124,
̇
(4) Lash, T. D. Angew. Chem., Int. Ed. Engl. 1995, 34, 2533−2535.
(5) Liu, D. C.; Ferrence, G. M.; Lash, T. D. J. Org. Chem. 2004, 69,
6079−6093.
(6) Hung, C. H.; Lin, C. Y.; Lin, P. Y.; Chen, Y. J. Tetrahedron Lett.
2004, 45, 129−132.
(7) Szyszko, B.; Latos-Grazyn
ski, L. Organometallics 2011, 30, 4354−
̇
4363.
(8) Lash, T. D.; Young, A. M.; Rasmussen, J. M.; Ferrence, G. M. J.
Org. Chem. 2011, 76, 5636−5651.
(9) Lash, T. D.; Rasmussen, J. M.; Bergman, K. M.; Colby, D. A. Org.
Lett. 2004, 6, 549−552.
́
(10) Pawlicki, M.; Latos-Grazynski, L. Carbaporphyrinoids−Syn-
̇
thesis and Coordination Properties. In Handbook of Porphyrin Science:
With Applications to Chemistry, Physics, Materials Science, Engineering,
Biology and Medicine; Kadish, K. M., Smith, K. M., Guilard, R., Eds.;
World Scientific Publishing: Singapore, 2010; Vol. 2, pp 104−192.
(11) Toganoh, M.; Furuta, H. Synthesis and Metal Coordination of
N-Confused and N-Fused Porphyrinoids. In Handbook of Porphyrin
Science: With Applications to Chemistry, Physics, Materials Science,
Engineering, Biology and Medicine; Kadish, K. M., Smith, K. M., Guilard,
R., Eds.; World Scientific Publishing: Singapore, 2010; Vol. 2, pp 295−
367.
(12) Szyszko, B.; Latos-Grazyn
ski, L.; Szterenberg, L. Angew. Chem.,
̇
Int. Ed. 2011, 50, 6587−6591.
́
(13) Szyszko, B.; Latos-Grazynski, L.; Szterenberg, L. Chem.
̇
Commun. 2012, 48, 5004−5006.
́
(14) Grocka, I.; Latos-Grazynski, L.; Stępien, M. Angew. Chem., Int.
́
̇
Ed. 2013, 52, 1044−1048.
(15) Lash, T. D. Eur. J. Org. Chem. 2007, 5461−5481.
(16) Latos-Grazyn
ski, L.; Lisowski, J.; Szterenberg, L.; Olmstead, M.
̇
M.; Balch, A. L. J. Org. Chem. 1991, 56, 4043−4045.
(17) Pouzet, P.; Erdelmeier, I.; Ginderow, D.; Mornon, J. P.;
Dansette, P. M.; Mansuy, D. J. Heterocycl. Chem. 1997, 34, 1567−1574.
(18) Hua, G.; Henry, J. B.; Li, Y.; Mount, A. R.; Slawin, A. M.;
Woollins, J. Org. Biomol. Chem. 2010, 8, 1655−1660.
5095
dx.doi.org/10.1021/jo4006624 | J. Org. Chem. 2013, 78, 5090−5095