N-fusion reaction sequence of heptaphyrin(1.1.1.1.1.1.1): Singly, doubly, and quadruply N-fused heptaphyrins

Article abstract of DOI:10.1002/chem.200600671

meso-Heptakis(pentafluorophenyl) heptaphyrin(1.1.1.1.1.1.1) (1) was prepared by a stepwise route in 39% yield and its unique N-fusion reaction (NFR) sequence has been revealed; this reaction leads to singly-, doubly-, and quadruply N-fused heptaphyrins (4

Full text of DOI:10.1002/chem.200600671

FULL PAPER
DOI: 10.1002/chem.200600671
N-Fusion Reaction Sequence of Heptaphyrin(1.1.1.1.1.1.1): Singly, Doubly,
and QuadruplyN-Fused Heptaph yr ins
[
a]
Shohei Saito and Atsuhiro Osuka*
Abstract: meso-Heptakis(pentafluoro-
phenyl) heptaphyrin(1.1.1.1.1.1.1) (1)
was prepared by a stepwise route in
by the inherent conformational distor-
tion of 1 as well as the distorted, folded
conformations of N-fused heptaphyrins
4 and 5. The proximate arrangement of
the three pyrrole units in 6 allowed for
the formation of the tripyrrolylboron-
A
H
R
U
G
39% yield and its unique N-fusion re-
coordination features. Molecules 1, 5,
and 9 were structurally characterized
by X-ray crystallography. In addition,
the boron complexes 7, 8, and 9 dis-
played weak but distinct fluorescence
in the near infrared region.
action (NFR) sequence has been re-
vealed; this reaction leads to singly-,
doubly-, and quadruply N-fused hepta-
phyrins (4, 5, and 6) in good yields.
These transformations are facilitated
Keywords: boron · conjugation ·
macrocycles · N-fusion reaction ·
porphyrinoids
Introduction
has a unique tripyrrolic coordination site that accommodates
boron(III) ion, providing tripyrrolylboron(III) complexes ef-
ficiently.
A
H
R
U
ACHTREUNG
In recent years, expanded porphyrins have emerged as a
new class of interesting conjugated macrocycles in respect of
their unique optical, electrochemical, and coordination
properties that have not been previously reported for por-
Results and Discussion
[1–3]
phyrins.
Some intriguing reactivities of expanded por-
phyrins stem from their conformational flexibilities, which
are in contrast to rigid and planar structures of porphyrins.
Among these, N-fusion reactions (NFR), which are charac-
teristic of medium-size-expanded porphyrins when it re-
Among a series of meso-aryl-substituted expanded porphy-
rins, the chemistry of heptaphyrin(1.1.1.1.1.1.1) 1 has been
left almost unexplored mainly because of the difficult syn-
thetic access to its pure form and its facile N-fusion reaction.
AHCTREUNG
[4–6]
lieves the macrocycle strain,
are synthetically attractive,
because the resultant fused 5,5,6-tricyclic structures cause
substantial influence on the structural and electronic proper-
ties, hence leading to the creation of new porphyrinoids.
meso-Aryl-substituted pentaphyrins exist only as an N-fused
[
3b,5a,b]
pentaphyrin,
are rather stable and need high temperature for their
NFRs.
while meso-aryl-substituted hexaphyrins
[5c]
Here we report NFR sequence of heptaphy-
ACHTREUNG
rin(1.1.1.1.1.1.1) 1, which provides, in a stepwise manner,
singly, doubly, and quadruply N-fused heptaphyrins all in
good yields. In addition, quadruply N-fused heptaphyrin 6
Although 1 was formed in 4–5% in our synthetic protocol
[3c]
of meso-aryl-expanded porphyrins, its isolation was very
difficult, because its elution behavior seriously overlapped
with that of octaphyrin(1.1.1.1.1.1.1.1) on a silica gel or alu-
mina column. Therefore, 1 was prepared by a stepwise route
as shown in Scheme 1. A solution of tripyrrane dicarbinol
[
a] S. Saito, Prof. Dr. A. Osuka
Department of Chemistry, Graduate School of Science
Kyoto University, Sakyo-ku, Kyoto 606–8502 (Japan)
Fax : (+81)75-753-3970
E-mail: osuka@kuchem.kyoto-u.ac.jp
[2f]
[7]
2
and tetrapyrrane 3 was stirred for 15 min under N at-
2
Supporting information for this article is available on the WWW
under http://www.chemeurj.org/ or from the author.
mosphere and treated with p-toluenesulfonic acid for 3h,
Chem. Eur. J. 2006, 12, 9095 – 9102
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
9095

Scheme 1. Synthesis of 1.
and the resulting mixture was oxidized with 2,3-dichloro-5,6-
dicyano-1,4-benzoquinone (DDQ) to afford 1 in 39% yield.
High-resolution electrospray ionization (HR-ESI) mass
spectrometry revealed the parent ion peak at m/z=
+
1
706.1152 (calcd for C H F N [M+H] : m/z=1706.1149)
7
7
19 35
7
1
and the H NMR spectrum exhibits two broad signals at d=
6.59 and 11.82 ppm due to the NH protons, six signals at
1
d=10.49, 7.91, 6.68, 6.23, 5.74, and 5.53 ppm due to the pe-
ripheral b-protons in a integral ratio of 1:1:1:1:2:1 (Figures 1
1
Figure 2. Enlarged H NMR spectra of a) 1, b) 4, and c) 5 in CDCl
d) 6 in [D ]acetone.
3
, and
6
1
Figure 1. H NMR spectra of a) 1, b) 4, and c) 5 in CDCl
3
, and d) 6 in
[
6
D ]acetone.
and 2), suggesting its symmetric structure and delineating its
non-aromatic 32p-electron system. The structure of 1 has
been revealed by single-crystal X-ray diffraction analysis to
[8]
be a distorted figure-of-eight conformation (Figure 3). This
is, to the best of our knowledge, the first X-ray crystal struc-
ture of an intact heptaphyrin(1.1.1.1.1.1.1).
Figure 3. X-ray crystal structure of 1: a) top view and b) side view.
9096
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Chem. Eur. J. 2006, 12, 9095 – 9102

Heptaphyrins
FULL PAPER
Similarly to the previously reported meso-aryl-substituted
[5a]
heptaphyrin, 1 underwent NFR slowly but quantitatively
to form singly N-fused heptaphyrin 4 just on standing in so-
A
C
H
T
R
E
U
N
G
lution. This conversion was observed in almost all solvents
examined except DMF, in which >95% of 1 was recovered
intact after standing for one month. HR-ESI mass spectros-
A
C
H
T
R
E
U
N
G
copy revealed the elimination of HF during the formation of
+
4
1
(m/z=1686.1079; calcd for C H F N [M+H] : m/z=
77 18 34 7
1
686.1086). The H NMR spectrum of 4 showed three sig-
nals due to the NH protons and fourteen signals due to the
peripheral b-protons, reflecting its nonsymmetric structure.
The structure of 4 has been supported by the similarity of its
1
H NMR and absorption spectra with those of singly N-
[5a]
fused perfluorinated heptaphyrin. Spontaneous NFR pro-
pensity of 1 may be accounted for in terms of the inherent
distortion of the macrocycle, and the proximity of the pyr-
rolic nitrogen atoms of the pyrroles C and F atoms to the 2’-
carbon atoms of the adjacent meso-pentafluorophenyl
groups.
Then, we attempted further NFR by refluxing a toluene
solution of 4 for 12 h and obtained doubly N-fused hepta-
phyrin 5 quantitatively. HR-ESI mass spectroscopy revealed
Figure 4. X-ray crystal structure of 5: a) top view and b) side view.
ingly similar to one another exhibiting two bands around
3
90 and 620 nm (Figure 5a).
To our surprise, further double NFR of 5 proceeded
smoothly upon treatment with NaH in DMF at 608C for
[10]
4
h, providing quadruply N-fused heptaphyrin 6 as green
solids in 71% yield. HR-ESI mass spectroscopy revealed
the parent ion peak of 6 at m/z=1627.0953(calcd for
the parent ion peak of 5 at m/z=1666.1024 (calcd for
+
C H F N [M+H] : m/z=1666.1020), thus indicating fur-
77
17 33
7
1
ther elimination of HF. The H NMR spectrum exhibits two
signals at d=14.97 and 13.14 ppm due to the NH protons
and fourteen signals due to the peripheral b-protons, sug-
gesting its nonsymmetric structure (Figures 1 and 2). The
structure of 5 has been confirmed by single-crystal X-ray
diffraction analysis. Interestingly, the nitrogen atoms of the
pyrroles C and D substitute the adjacent 2- and 3-fluorine
atoms of the same pentafluorophenyl ring to form a fused
pentacyclic structure containing a 1,4-diazepine ring system
[9]
(
Figure 4). Despite differences in the number of N-fusion
structures, the absorption spectra of 1, 4, and 5 are surpris-
Chem. Eur. J. 2006, 12, 9095 – 9102
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
9097

A. Osuka and S. Saito
cle and which are shifted by the
local diatropic ring current of
pyrroles. The absorption spec-
trum of 6 exhibits broad bands
at 702, 884, and 987 nm (Fig-
ure 5b), and are significantly al-
tered from those of 1, 4, and 5.
Quadruple NFR in 6 should
lead to a helically twisted chiral
structure, which has been
proved by actual chiral resolu-
tion through a chiral HPLC
column into optically pure
[11]
enantiomers,
which display
the exactly opposite CD signal
patterns to each other with
prominent Cotton effect around
4
55 and 755 nm (Figure 6). De-
spite many attempts, we could
not obtain nice crystals of 6 for
X-ray diffraction analysis either
from racemic or optically pure
6
. However, the quadruple N-
fusion structure of 6 has been
substantiated from single crys-
tal structure of its boron
complex (see below).
A
C
H
T
R
E
U
N
G
(III)
As shown in Figures 1 and 2,
1
the H NMR spectra become
sharper in the order of 1<4<
5
<6, reflecting increasing ri-
gidity upon the incorporation of
N-fusion structures. Similarly
1
9
the F NMR spectra become
sharper in the order of 1<4<
5
<6 (Supporting Information).
Figure 5. a) Absorption spectra of 1, 4, and 5, and b) those of 6 and 7, and fluorescence spectrum of 7 in
CH Cl
19
In the F NMR spectrum of 6,
2
2
.
+
C H F N
[M] :
m/z=
7
7
16 31
7
1627.0978) indicating the elimi-
nation of two HF units. In line
with the expected C symmetric
2
1
structure, the H NMR spec-
trum of 6 is very simple, exhib-
iting a signal at d=8.89 ppm
due to the two NH protons, a
singlet at d=7.52 ppm due to
the peripheral b-protons, six
doublets at d=7.44, 7.29, 7.11,
6
.62, 5.66, and 4.49 ppm due to
the peripheral b-protons
Figure 2), reflecting its non-ar-
(
omatic 34p-electron system.
The two upfield proton signals
d
e
are assigned due to H and H
situated inside of the macrocy- Figure 6. CD spectra of enantiomers of 6 in CH
2
2
Cl .
9098
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Chem. Eur. J. 2006, 12, 9095 – 9102

Heptaphyrins
FULL PAPER
1
9
the signals due to the para- F nuclei of the five pentafluoro-
phenyl groups are easily differentiated as clear three triplets
in a ratio of 2:2:1 (Figure 7b); starting from these signals, all
19
the F NMR signals have been assigned on the basis of ex-
b1
tensive 2D-COSY experiments. Curiously, signals due to F
1
9
Figure 7. F NMR spectra of 6, a) ortho-F region, b) para-F region, and
c) meta-F region in [D
6
]acetone.
d1
c1
d3
and F , and F and F are mutually coupled with J=
Figure 8. X-ray crystal structure of 9: a) top view and b) side view.
63Hz, despite only very small interactions along the
through-bond network. Therefore, these coupling are as-
signed to through-space direct coupling between spatially
close two F nuclei, which is brought about by the enforced
19
[12]
hinged by the tripyrrolylboronate moiety.
boron
phthalocyanine- or subporphine-like manner,
Curiously, the
structure of 6.
A
H
R
U
G
[13]
Attempts to put boron
A
H
R
U
G
with bond
failed for the use of BF ·OEt . In the meantime we found
distances of 1.562(8) (B1ÀN1), 1.590(8) (B1ÀN2), 1.606(8)
(B1ÀN7), and 1.433(8) Š (B1ÀO1), which are slightly longer
than those of subphthalocyanine or subporphyrin (NÀB dis-
tances are generally 1.49–1.51 Š for tribenzosubporphyrin
or subphthalocyanine), and bond angles of 104.2(4) (N1-B1-
N2), 122.6(5) (N2-B1-N7), and 101.5(5)8 (N7-B1-N1). These
data suggest loose boron coordination for 9 relative to that
found in subphthalocyanines and subporphyrin. Although
3
2
that boron complexation of 6 was effected upon refluxing a
solution of 6 in CH Cl solution in the presence of BBr and
2
2
3
N-ethyldiisopropylamine. Subsequent aqueous workup pro-
vided hydroxyboron(III) complex 7, which was converted
into alkoxyboron(III) complex 8 (R=methoxy) or 9 (R=
AHCTREUNG
ACHTREUNG
isopropoxy) by refluxing in the presence of methanol or iso-
propyl alcohol. The structure of 9 has been revealed by
some
dipyrrometheneboron
such a tripyrrolylboron
trast to the inertness of subporphyrins towards acid-induced
demetalation, the boron(III) complexes 7, 8, and 9 gradually
examples
have
(III) complexes of porphyrinoids,
(III) complex is quite rare. In con-
been
reported
for
[
14]
AHCTREUNG
AHCTREUNG
AHCTREUNG
underwent demetalation upon treatment with trifluoroacetic
acid. Similar to subphthalocyanines and subporphyrins, the
protons of the axial groups of the complexes show substan-
1
tial upfield shifts in the H NMR spectra, which may be at-
tributed to the local diatropic ring currents of the pyrrole
1
1
rings rather than that of the macrocycle. The B NMR spec-
tra show broad signals at d=À5.2, À5.6, and À5,3ppm for
7, 8, and 9, respectively, which are much less down field
shifted in comparison to those of subphthalocyanines (d=
single-crystal X-ray diffraction analysis as shown in
Figure 8; the two planar pentacyclic frameworks containing
a 1,4-diazepine core are folded in a parallel and helical
manner with an average interplanar distance of 3.0 Š,
[13a]
À17.7 to À19.6 ppm),
À13.7 to À14.6 ppm).
and of tribenzosubporphy
These observations indicate the
A
C
H
T
R
E
U
N
G
rin (d=
[13b]
Chem. Eur. J. 2006, 12, 9095 – 9102
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9099

A. Osuka and S. Saito
lack of diatropic ring current of the macrocycles, in line with
the H NMR analysis.
was purified by silica gel chromatography using a 1:1 mixture of hexane
1
1
and dichloromethane to yield
CDCl
pyrrole-b), 6.15 (m, 2H; pyrrole-b), 5.99 (s, 2H; pyrrole-b), 5.91–5.89 (m,
H; pyrrole-b), 5.85 (s, 2H; meso), 5.79 ppm (s, 1H; meso); FAB-MS:
3
(5.6 g, 73%). H NMR (600 MHz,
3
): d=8.18 (brs, 2H; NH), 8.10–8.06 (br, 2H; NH), 6.72 (m, 2H;
The absorption spectra of the hydroxyboron
becomes much sharper with peaks at 660 and 895 nm (Fig-
ure 5b). Interestingly, the hydroxyboron(III) complex 7
emits weak fluorescence in the near IR range of 900–
A
H
R
U
G
7
4
+
A
H
R
U
G
37 17 15 4
m/z: 802.10 [M] ; m/z calcd for C H F N : 802.12.
meso-Pentafluorophenyl-substituted [32]heptaphyrin(1.1.1.1.1.1.1) 1:
1
6
350 nm as a rare case (Figure 5b), while the fluorescence of
cannot be detected under the same conditions. The ab-
1,14-Bis(pentafluorobenzoyl)-5,10-bis(pentafluorophenyl)tripyrrane
(
1220 mg, 1.29 mmol) was reduced with NaBH
4
(977 mg, 25.8 mmol) in a
1
0:1 mixture of THF and methanol (220 mL). After 30 min, the reaction
sorption and fluorescence spectra of the alkoxyboron(III)
complexes 8 and 9 are similar to those of 7.
A
H
R
U
G
4
was quenched with saturated aqueous NH Cl solution and the products
were extracted with ethyl acetate. The organic phase was washed with
brine and dried over anhydrous Na SO . The solvent was removed under
2
4
reduced pressure to yield dicarbinol 2 quantitatively, which was unstable
at ambient temperature and hence had to be used immediately. The di-
carbinol 2 was added to a solution of 3 (1040 mg, 1.29 mmol) in dry
Conclusion
2 2 2
CH Cl (200 mL). After the resultant solution was stirred under N at-
mosphere for 15 min, p-toluenesulfonic acid monohydrate (25 mg,
0.13mmol) was added and stirring was continued for 3h. DDQ
The unique NFR sequence of the heptaphyrin 1 has been re-
vealed, which provides singly-, doubly-, and quadruply N-
fused heptaphyrins (4, 5, and 6) in good yields. These trans-
formations are facilitated by the inherent conformational
distortion of 1 as well as the distorted, folded conformations
of N-fused heptaphyrins 4 and 5. The proximate arrange-
ment of the three pyrrole units in 6 allowed for the forma-
(
1760 mg, 7.75 mmol) was added and the resulting solution was opened
to the air with constant stirring for further 3h. The reaction mixture was
passed through a basic alumina column followed by evaporation of sol-
vent under reduced pressure. The residue was purified by silica gel chro-
matography using a 3:1 mixture of hexane and dichloromethane. Evapo-
ration of the dark blue fraction to dryness yielded 1 (861 mg, 39%).
Dark blue crystals were obtained by slow vapor diffusion of a pentane
tion of the tripyrrolylboron(III) complex 7. Application of
A
H
R
U
G
1
solution of 1 in a refrigerator. H NMR (600 MHz, CDCl
3
): d=16.59
the NFR strategy in other medium or large size expanded
porphyrins is worthy of further investigations, since it will
allow for the creation of expanded porphyrinoids with novel
photophysical and electrochemical properties.
(
(
5
brs, 2H; NH), 11.82 (brs, 2H; NH), 10.49 (brs, 2H; pyrrole-b), 7.91
brs, 2H; pyrrole-b), 6.68 (brs, 2H; pyrrole-b), 6.23(brs, 2H; pyrrole- b),
1
9
.74 (brs, 4H; pyrrole-b), 5.53ppm (brs, 2H; pyrrole- b); F NMR
(565 MHz, CDCl
3
): d=À135.1 (d, J=16 Hz, 2F; o-F), À136.1 (br, 2F; o-
F), À136.8 (br, 2F; o-F), À137.4 (br, 2F; o-F), À138.4 (d, J=20 Hz, 2F;
o-F), À139.3 (d, J=18 Hz, 2F; o-F), À140.0 (d, J=17 Hz, 2F; o-F)
À152.7 (br, 2F; p-F), À153.1 (br, 4F; p-F), À153.7 (br, 1F; p-F), À161.0
(
br, 2F; m-F), À161.4 (br, 6F; m-F), À162.0 ppm (br, 6F; m-F); ESI-MS:
Experimental Section
+
m/z: 1706.1152 [M+H] ; m/z calcd for C77
19 35 7
H F N : 1706.1149; UV/Vis
À4
(
CH
2
Cl
2
): lmax (e”10 )=394 (5.4), 598 (7.2), 641 (7.6), 827 nm (0.4).
2
General information: All solvents for reaction were distilled over CaH .
meso-Pentafluorophenyl-substituted singly N-fused [32]heptaphyrin 4: At
room temperature, 1 in dichloromethane was gradually changed to 4, and
wholly changed in three days. This fusion reaction proceeded in all sol-
All reagents were of the commercial reagent grade and were used with-
out further purification except where noted. The spectroscopic grade di-
chloromethane was used as solvent for all spectroscopic studies. Silica gel
column chromatography was performed on Wakogel C-300. UV-visible
vents examined except DMF, in which 1 was recovered in 95% yield
1
1
11
even after one month. H NMR (600 MHz, CDCl
3
): d=15.63(s, 1H;
spectra were recorded on a Shimadzu UV-3100PC spectrometer. H, B,
1
9
NH), 13.61 (s, 1H; NH), 10.91 (s, 1H; NH), 9.65 (s, 1H; pyrrole-b), 9.62
(s, 1H; pyrrole-b), 7.77 (s, 1H; pyrrole-b), 7.46 (s, 1H; pyrrole-b), 7.33 (s,
1H; pyrrole-b), 6.62 (d, J=4.9 Hz, 1H; pyrrole-b) 6.30 (d, J=4.9 Hz,
and F NMR spectra were recorded on a JEOL ECA-600 spectrometer
1
11
(
operating as 600.17 MHz for H, 192.56 MHz for B, and 564.73MHz
1
9
1
for F) using the residual solvent as the internal reference for H (d=
.26 ppm in CDCl and d=2.09 ppm in [D ]acetone), boron trifluoride di-
ethyl etherate as an external reference for B (d=0.0 ppm), and hexa-
1
H; pyrrole-b), 6.25 (d, J=4.2 Hz, 1H; pyrrole-b), 6.00 (d, J=2.4 Hz,
7
3
6
1
1
1H; pyrrole-b), 5.92 (d, J=4.2 Hz, 2H; pyrrole-b), 5.87 (s, 1H; pyrrole-
1
9
1
9
b), 5.83ppm (s, 2H; pyrrole- b); F NMR (565 MHz, CDCl ): d=À132.9
fluorobenzene as an external reference for F (d=À162.9 ppm). Mass
spectra were recorded on a BRUKER microTOF model using positive
mode ESI-TOF method for acetonitrile solutions of samples, or on a
JEOL HX-110 spectrometer using positive mode FAB ionization method
for dichloromethane solutions of samples with accelerating voltage 10 kV
and a 3-nitrobenzylalcohol matrix. CD spectra were recorded on a
JASCO J-720W spectropolarimeter. Fluorescence spectra were recorded
on a HORIBA Jobin Yvon SPEX fluorolog-NIR-K.
3
(
t, J=22 Hz, 1F; C
6
F
4
N), À134.5 (m, 1F; o-F), À135.7 (d, J=22 Hz, 1F;
o-F), À136.1 (d, J=26 Hz, 1F; o-F), À136.8 (br, 1F; C
6
F
4
N), À138.0 (d,
J=22 Hz, 1F; o-F), À138.2 (d, J=22 Hz, 2F; o-F), À139.2 (br, 2F; o-F),
À139.9 (d, J=22 Hz, 1F; o-F), À140.0 (d, J=22 Hz, 1F; o-F), À140.4 (d,
J=22 Hz, 1F; o-F), À151.1 (t, J=22 Hz, 1F; p-F), À151.9 (t, J=22 Hz,
1
F; p-F), À152.6 (t, J=22 Hz, 1F; p-F), À152.7 (t, J=22 Hz, 1F; p-F),
À152.7 (t, J=23Hz, 1F; p-F), À152.8 (t, J=22 Hz, 1F; p-F), À154.3(m,
F; C
N), À159.0 to À159.1 (m, 1F; m-F), À159.9 (m, 1F; m-F),
À160.9 (m, 1F; m-F), À161.2 to À161.8 (m, 9F; m-F), À162.2 (d, J=
8 Hz, 1F; C N); ESI-MS: m/z: 1686.1079
: 1686.1086; UV/Vis (CH Cl
1
6 4
F
5
,10,15-Tris(pentafluorophenyl)tetrapyrrane (3): 1,9-Bis(pentafluoroben-
zoyl)-5-(pentafluorophenyl)dipyrromethane (6,7 g, 9.6 mmol) was re-
duced with NaBH (3.5 g, 93 mmol) in a 10:1 mixture of THF and metha-
nol (220 mL). After 30 min, the reaction was quenched with saturated
aqueous NH Cl solution and the products were extracted with ethyl ace-
tate. The organic phase was washed with brine and dried over anhydrous
Na SO . The solvent was removed under reduced pressure to yield corre-
1
6
F
4
N), À162.5 ppm (m, 1F; C
6 4
F
4
+
[
M+H] ; m/z calcd for C77
H
18
F
34
N
7
2
2
): lmax
À4
(
e”10 )=320 (4.1), 393 (6.3), 617 nm (8.8).
4
meso-Pentafluorophenyl-substituted doubly N-fused [32]heptaphyrin 5:
Refluxing a solution of 4 (30 mg, 0.018 mmol) in toluene (100 mL) for
2
4
sponding dipyrromethane dicarbinol quantitatively, which was unstable at
ambient temperature and hence had to be used immediately. The dicarbi-
nol was dissolved in pyrrole (54 mL, 780 mmol), and trifluoroacetic acid
12 h gave 5 quantitatively. Recrystallization from a hexane/isopropyl al-
1
cohol solution of 5 gave dark blue crystals. H NMR (600 MHz, CDCl
3
):
d=14.97 (brs, 1H; NH), 13.14 (brs, 1H; NH), 8.23(d, J=5.5 Hz, 1H; pyr-
role-b), 7.79 (d, J=5.5 Hz, 1H; pyrrole-b), 7.57 (d, J=4.6 Hz, 1H; pyr-
role-b), 6.80 (d, J=4.6 Hz, 1H; pyrrole-b), 6.78 (m, 1H; pyrrole-b), 6.74
(m, 1H; pyrrole-b), 6.64 (d, J=4.6 Hz, 1H; pyrrole-b), 6.63(d, J=
(
0.74 mL, 9.6 mmol) was added to the solution, which was stirred under
atmosphere for 1 h. The reaction was quenched with triethylamine,
and unreacted pyrrole was distilled under reduced pressure. The residue
N
2
9100
www.chemeurj.org
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Chem. Eur. J. 2006, 12, 9095 – 9102

Heptaphyrins
FULL PAPER
1
9
4
.6 Hz, 1H; pyrrole-b), 6.52 (br, 2H; pyrrole-b), 6.46 (d, J=4.6 Hz,1H;
(brs, 1H; OH); F NMR (565 MHz, CDCl
3
): d=À136.6 (dd, J=58,
pyrrole-b), 6.17 (d, J=4.6 Hz, 1H; pyrrole-b), 6.07 (br, 1H; pyrrole-b),
20 Hz, 1F; C F N ), À137.5 (dd, J=26, 5.4 Hz, 1F; o-F), À137.7 (dd, J=
6
3
2
1
9
6
(
.04 ppm (br, 1H; pyrrole-b); F NMR (565 MHz, CDCl
dd, J=75, 25 Hz, 1F; o-F), À133.3 (dd, J=76, 19 Hz, 1F; C
À133.5 (d, J=26 Hz, 1F; o-F), À134.4 (dd, J=75, 23Hz, 1F; o-F),
À135.3 (d, J=24 Hz, 1F; o-F), À136.1 (dd, J=45, 20 Hz, 1F; C ),
À136.6 to À136.8 (m, 4F; o-F), À137.5 (d, J=25 Hz, 1F; o-F), À138.6
dd, J=48, 23Hz, 2F; o-F), À140.3(d, J=22 Hz, 1F; o-F), À150.3(t, J=
3
): d=À128.0
25, 6.0 Hz, 1F; o-F), À137.8 to À137.9 (m, 2F; o-F), À138.0 (dd, J=25,
6.6 Hz, 1F; o-F), À138.1 (dd, J=25, 6.0 Hz, 1F; o-F), À138.8 (m, 3F; o-
F, C F N ), À139.1 (dd, J=61, 30 Hz, 1F; C F N ), À139.5 (dd, J=51,
6 3 2
F N
),
6
3
2
6
3
2
6
F
3
N
2
24 Hz, 1F; o-F), À139.7 (dd, J=57, 28 Hz, 1F; C F N ), À139.8 (dd, J=
6
3
2
55, 35 Hz, 1F; o-F), À152.3(t, J=22 Hz, 1F; p-F), À152.5 (t, J=22 Hz,
1F; p-F), À152.6 (t, J=23Hz, 1F; p-F), À153.0 (t, J=22 Hz, 1F; p-F),
À153.2 (t, J=22 Hz, 1F; p-F), À161.6 to À162.2 (m, 10F, m-F), À168.3
(
2
2 Hz, 1F; p-F), À151.2 (t, J=22 Hz, 1F; p-F), À151.6 (t, J=22 Hz, 1F;
1
1
p-F), À151.8 (t, J=22 Hz, 1F; p-F), À152.1 (t, J=22 Hz, 1F; p-F),
À152.7 (t, J=22 Hz, 1F; p-F), À159.0 (m, 1F; m-F), À160.0 (m, 2F; m-
(m, 1F; C F N ), À168.7 ppm (m, 1F; C F N ); B NMR (193MHz,
6
3
2
6
3
2
+
CDCl ): d=À5.2 ppm (brs); ESI-MS: m/z (%): 1653.0918 [M] (100),
3
+
À4
F), À160.3to À160.7 (m, 9F; m-F), À164.0 ppm (m, 1F; C
6
F
3
N
2
); ESI-
1636.0945 [MÀOH] (7); UV/Vis (CH Cl ): l
max
(e”10 )=375 (4.4),
2
2
+
MS: m/z: 1666.1020 [M+H] ; m/z calcd for C77
H
17
F
33
N
7
: 1666.1024; UV/
2 2 ex
419 (3.8), 450 (6.1), 660 (11.0), 895 nm (2.7); fluorescence (CH Cl , l =
À4
Vis (CH
2
Cl
2
): lmax (e”10 )=316 (4.0), 378 (5.5), 614 nm (8.1).
895 nm): lmax =1068, 1214 nm.
meso-Pentafluorophenyl-substituted quadruply N-fused [34]heptaphyrin
: NaH (60% purity, dispersion in paraffin liquid, 35 mg) was added to a
solution of 5 (240 mg, 0.14 mmol) in dry DMF (30 mL) and the mixture
was stirred under N atmosphere at 608C for 4 h. After the reaction was
quenched by the addition of water (20 mL), the products were extracted
with diethyl ether (200 mL). The organic phase was washed with 0.5m
Methoxyboron complex of meso-pentafluorophenyl-substituted quadru-
plyN-fused [34]heptaph yr in 8 : Methanol (30 mL) was added to a solu-
tion of 7 (28 mg, 17 mmol) in ethyl acetate (10 mL), and the solution was
6
2
refluxed for 12 h to provide 8 (17 mg, 60%) with the recovery of 7
1
(
11 mg, 39%). H NMR (600 MHz, CDCl
3
): d=8.11 (m, 1H; pyrrole-b),
8
7
7
7
.08 (d, J=4.6 Hz, 1H; pyrrole-b), 7.99 (d, J=4.6 Hz, 1H; pyrrole-b),
HCl (3”200 mL) and dried over anhydrous Na
2 4
SO . After the removal
.98 (d, J=4.1 Hz, 1H; pyrrole-b), 7.86 (d, J=3.7 Hz, 1H; pyrrole-b),
.78 (d, J=4.6 Hz, 1H; pyrrole-b), 7.50 (d, J=5.0 Hz, 1H; pyrrole-b),
.40 (d, J=5.0 Hz, 1H; pyrrole-b), 7.32 (dd, J=9.2, 4.6 Hz, 1H; pyrrole-
of the solvent, recrystallization from dichloromethane/hexane afforded 6
1
as
a
green solid (166 mg, 0.10 mmol, 71%). H NMR (600 MHz,
[
6
D ]acetone): d=8.89 (brs, 2H; NH), 7.52 (s, 2H; pyrrole-b), 7.44 (d, J=
b), 7.20 (d, J=3.7 Hz, 1H; pyrrole-b), 7.03(d, J=5.0 Hz, 1H; pyrrole-b),
4
4
.6 Hz, 2H; pyrrole-b), 7.29 (d, J=3.7 Hz, 2H; pyrrole-b), 7.11 (dd, J=
.6, 1.8 Hz, 2H; pyrrole-b), 6.62 (d, J=5.5 Hz, 2H; pyrrole-b), 5.66 (d,
6
3
1
.31 (m, 2H; pyrrole-b), 3.79 (d, J=4.6 Hz, 1H; pyrrole-b), 1.10 ppm (s,
19
H; OMe); F NMR (565 MHz, CDCl
F; C
), À137.7 to À137.9 (m, 4F; o-F, C
), À139.0 (dd, J=25, 6.5 Hz,
F; o-F), À139.0 (dd, J=59, 28 Hz, 1F; o-F), À139.4 (dd, J=56, 23Hz,
3
): d=À136.8 (dd, J=56, 19 Hz,
J=4.6 Hz, 2H; pyrrole-b), 4.49 ppm (d, J=5.5 Hz, 2H; pyrrole-b);
6
F
3
N
2
6 3 2
F N
), À138.2 (m, 2F; o-
1
9
F NMR (565 MHz, [D
6
]acetone): d=À135.9 (dd, J=63, 19 Hz, 2F;
F), À138.6 to À138.9 (m, 2F; o-F, C
6 3 2
F N
C
6
F
3
N
2
), À139.0 (dd, J=63, 19 Hz, 2F; C
6
F
3
N
2
), À140.0 (dd, J=64,
1
1
1
2
2
9 Hz, 2F; o-F), À140.8 (dd, J=26, 7.3Hz, 2F; o-F), À141.5 (d, J=
4 Hz, 2F; o-F), À141.7 (dd, J=25, 7.3Hz, 2F; o-F), À143.0 (dd, J=63,
5 Hz, 2F; o-F), À157.0 (t, J=22 Hz, 2F; p-F), À157.4 (t, J=22 Hz, 2F;
F; o-F), À139.7 (m, 2F; o-F, C
6
F
3
N
2
), À152.3(t, J=22 Hz, 1F; p-F),
À152.6 (t, J=22 Hz, 1F; p-F), À152.7 (t, J=22 Hz, 1F; p-F), À153.1 (t,
J=22 Hz, 1F; p-F), À153.4 (t, J=22 Hz, 1F; p-F), À161.6 (m, 2F; m-F),
p-F), À158.3(t, J=22 Hz, 1F; p-F), À164.4 (dt, J=23, 7.3 Hz, 2F; m-F),
À165.1 (dt, J=25, 8.8 Hz, 2F; m-F), À165.2 (dt, J=26, 8.8 Hz, 2F; m-F),
À161.8 to À162.3(m, 8F; m-F), À168.3(m, 1F; C
6
F
3
N
2
), À168.7 ppm (m,
11
1
F; C
6
F
3
N
2
); B NMR (193MHz, CDCl
3
): d=À5.6 ppm (brs); ESI-MS:
À165.3(dd, J=22, 8.8 Hz, 2F; m-F), À165.6 (dt, J=22, 7.2 Hz, 2F; m-F),
+
+
m/z (%): 1667.1043[ M]
(100), 1636.0876 [MÀOMe] ; UV/Vis
1
À168.2 ppm (dt, J=21, 7.3Hz, 2F;
C
6
F
3
N
2
); H NMR (600 MHz,
À4
(
CH
2
Cl
2
): lmax (e”10 )=374 (3.7), 450 (4.9), 660 (8.5), 892 nm (2.1); flu-
3
CDCl ): d=8.87 (brs, 2H; NH), 7.20 (s, 2H; pyrrole-b), 7.03(d, J=
orescence (CH
2
2
Cl , lex =892 nm): lmax =1069, 1233 nm.
2
3
5
.8 Hz, 2H; pyrrole-b), 6.99 (d, J=4.6 Hz, 2H; pyrrole-b), 6.86 (d, J=
.7 Hz, 2H; pyrrole-b), 6.08 (d, J=2.8 Hz, 2H; pyrrole-b), 5.20 (d, J=
Isopropoxyboron complex of meso-pentafluorophenyl-substituted quad-
ruplyN-fused [34]heptaph yr in 9 : Isopropyl alcohol (25 mL) was added
to a solution of 7 (104 mg, 63 mmol) in ethyl acetate (25 mL), and the sol-
ution was refluxed for 12 h to provide 9 (73mg, 68%) with the recovery
1
9
.5 Hz, 2H; pyrrole-b), 4.32 ppm (d, J=4.6 Hz, 2H; pyrrole-b); F NMR
): d=À133.9 (dd, J=63, 22 Hz, 2F; C ), À137.3 to
), À137.5 to À137.7 (m, 4F; o-F),
(
565 MHz, CDCl
3
6 3 2
F N
À137.5 (dd, J=65, 22 Hz, 2F; C
6
3 2
F N
of 7 (22 mg, 21%). Recrystallization from 1,2-dichloroethane/isopropyl
À137.8 (dd, J=26, 7.7 Hz, 2F; o-F), À138.7 (dd, J=25, 7.7 Hz, 2F; o-F),
À140.8 to À141.0 (m, 2F; o-F), À152.7 (t, J=23Hz, 2F; p-F), À153.4 (t,
J=22 Hz, 2F; p-F), À154.1 (t, J=23Hz, 1F; p-F), À161.1 (dt, J=22,
1
alcohol gave purple crystals. H NMR (600 MHz, CDCl
3
): d=8.12 (d, J=
4
4
4
.8 Hz, 1H; pyrrole-b), 8.11 (d, J=4.8 Hz, 1H; pyrrole-b), 8.01 (d, J=
.9 Hz, 1H; pyrrole-b), 7.99 (d, J=5.5 Hz, 1H; pyrrole-b), 7.86 (d, J=
.9 Hz, 1H; pyrrole-b), 7.77 (d, J=4.8 Hz, 1H; pyrrole-b), 7.53(d, J=
8
9
2
1
.4 Hz, 2F; m-F), À161.3(dt, J=22, 9.0 Hz, 2F; m-F), À161.9 (dt, J=22,
.0 Hz, 2F; m-F), À162.2 (m, 4F; m-F), À166.2 ppm (dt, J=20, 6.6 Hz,
+
5.5 Hz, 1H; pyrrole-b), 7.42 (d, J=5.5 Hz, 1H; pyrrole-b), 7.36 (dd, J=
8.9, 4.9 Hz, 1H; pyrrole-b), 7.22 (d, J=2.8 Hz, 1H; pyrrole-b), 7.08 (d,
J=4.8 Hz, 1H; pyrrole-b), 6.54 (d, J=5.5 Hz, 1H; pyrrole-b), 6.32 (d, J=
F; C
6
F
3
N
2
); ESI-MS: m/z: 1627.0953[ M] ; m/z calcd for C77
H
16
F
31
N
7
:
À4
627.0978; UV/Vis (CH
2
Cl
2
): lmax (e”10 )=419 (4.3), 454 (5.5), 702
(
5.4), 884 (1.2), 987 nm (1.2).
Hydroxyboron complex of meso-pentafluorophenyl-substituted quadru-
plyN-fused [34]heptaph yr in 7 : BBr (2.9 mL, 31 mmol) was added to a
4
.8 Hz, 1H; pyrrole-b), 3.77 (d, J=4.8 Hz, 1H; pyrrole-b), 1.19 (m, 1H;
BOCH(CH (CH ), À0.29 ppm (d,
), À0.22 (d, J=6.2 Hz, 3H; BOCH
J=6.2 Hz, 3H; BOCH(CH ); F NMR (565 MHz, CDCl
): d=À135.7
to À135.9 (m, 2F; C ), À136.1 (dd, J=26, 7.3Hz, 1F; o-F), À136.3
dd, J=26, 7.3Hz, 1F; o-F), À136.6 (d, J=21 Hz, 1F; o-F), À136.9 (dd,
J=25, 5.9 Hz, 1F; o-F), À137.1 (dd, J=25, 5.8 Hz, 1F; o-F), À137.5 (br,
F; o-F), À137.6 (d, J=21 Hz, 1F; o-F), À137.8 to À137.9 (m, 2F; o-F,
A
H
R
U
G
3
)
2
A
H
R
U
G
3 2
)
3
1
9
A
H
R
U
G
3
)
2
3
solution of 6 (380 mg, 0.23 mmol) in dichloromethane (250 mL) in the
presence of distilled ethyldiisopropylamine (EDIPA; 6.1 mL, 35 mmol),
and the reaction mixture was refluxed for 28 h under N atmosphere.
2
After the reaction was quenched by the addition of water (50 mL), the
products were extracted with diethyl ether (500 mL). The organic phase
6
3 2
F N
(
1
C
6
F
3
N
2
), À138.1 to À138.4 (m, 3F; o-F, C
6
F
3
N
2
), À151.3(t, J=22 Hz, 1F;
was washed with 3m HCl (3”200 mL), neutralized by aqueous NaHCO
and then dried over anhydrous Na SO . After the removal of the solvent,
the residue was subjected to silica gel column chromatography by using a
3
,
p-F), À151.4 (t, J=23Hz, 1F; p-F), À151.5 (t, J=22 Hz, 1F; p-F),
À151.9 (t, J=23Hz, 1F; p-F), À152.2 (t, J=23Hz, 1F; p-F), À160.4 to
2
4
À161.1 (m, 10F; m-F), À167.2 (m, 1F; C
6
F
3
N
2
), À167.6 ppm (m, 1F;
1
0:1 mixture of hexane and ethyl acetate. Evaporation of the last green
1
1
1
C F N ); B NMR (193MHz, CDCl ): d=À5.3ppm (brs); ESI-MS: m/z
fraction to dryness yielded
7
(262 mg, 68%). H NMR (600 MHz,
6
3
2
3
+
+
(
(
%): 1695.1427 [M]
CH Cl ): lmax (e”10 )=374 (4.4), 450 (6.3), 659 (11.1), 890 nm (2.7);
2 2
(92), 1636.0954 [MÀOiPr]
(100); UV/Vis
3
CDCl ): d=8.10 (d, J=3.7 Hz, 1H; pyrrole-b), 8.09 (d, J=4.6 Hz, 1H;
À4
pyrrole-b), 7.99 (d, J=5.5 Hz, 1H; pyrrole-b), 7.98 (d, J=3.7 Hz, 1H;
pyrrole-b), 7.86 (d, J=4.6 Hz, 1H; pyrrole-b), 7.79 (d, J=4.6 Hz, 1H;
pyrrole-b), 7.49 (d, J=4.6 Hz, 1H; pyrrole-b), 7.40 (d, J=4.6 Hz, 1H;
pyrrole-b), 7.30 (m, 1H; pyrrole-b), 7.20 (m, 1H; pyrrole-b), 7.06 (d, J=
fluorescence (CH
2
Cl
2
, lex =890 nm); lmax =1069, 1216 nm.
X-rayc rs yt allography
:
CCDC-604429 (1),CCDC-604430 (5), CCDC-
604431 (9) contain the supplementary crystallographic data for this
paper. These data can be obtained free of charge from The Cambridge
Crystallographic Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
4
4
.6 Hz, 1H; pyrrole-b), 6.52 (d, J=5.5 Hz, 1H; pyrrole-b), 6.31 (d, J=
.6 Hz, 1H; pyrrole-b), 3.71 (d, J=4.6 Hz, 1H; pyrrole-b), À1.6 ppm
Chem. Eur. J. 2006, 12, 9095 – 9102
ꢀ 2006 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.chemeurj.org
9101

A. Osuka and S. Saito
Acknowledgements
J.-Y. Shin, S. Shimizu, F. Ishikawa, H. Furuta, A. Osuka, Chem. Eur.
J. 2005, 11, 2417; c) M. Suzuki, R. Taniguchi, A. Osuka, Chem.
Commun. 2004, 2682.
6] C.-H. Hung, J.-P. Jong, M.-Y. Ho, G.-H. Lee, S.-M. Peng, Chem. Eur.
J. 2002, 8, 4542.
This work was partly supported by Grant-in-Aid from the Ministry of
Education, Culture, Sports, Science and Technology of Japan (No.
7350017), CREST (Core Research for Evolutional Science and Technol-
ogy) of Japan Science and Technology Agency (JST), and 21st Century
COE on Kyoto University Alliance for Chemistry. We thank Prof. Hi-
toshi Tamiaki of Ritsumeikan University for CD spectroscopy.
[
[
[
1
7] R. Guilard, D. T. Gryko, G. Canard, J.-M. Barbe, B. Koszarna, S.
Brandes, M. Tasior, Org. Lett. 2002, 4, 4491.
42 35 7 w
8] Crystallographic data for 1: C87H F N , M =1850.28, monoclinic,
space group P2 /n (No.14), a=14.559(3), b=24.596(7), c=
1
3
À3
2
4
2
2.022(5) Š, b=96.233(9)8, V=7839(3) Š , 1calcd =1.568 gcm , Z=
, R =0.0760 [I>2.0s(I)], R =0.2235 (all data), GOF=1.186 [I>
.0s(I)].
[
1] a) A. Jasat, D. Dolphin, Chem. Rev. 1997, 97, 2267; b) J. L. Sessler,
A. Gebauer, S. J. Weghorn, in The Porphyrin Handbook, Vol. 2
Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic Press, San
Diego, 2000, pp. 55–124; c) T. D. Lash, Angew. Chem. 2000, 112,
833; Angew. Chem. Int. Ed. 2000, 39, 1763; d) H. Furuta, H.
Maeda, A. Osuka, Chem. Commun. 2002, 1795; e) J. L. Sessler, D.
Seidel, Angew. Chem. 2003, 115, 5292; Angew. Chem. Int. Ed. 2003,
2, 5134; f) T. K. Chandrashekar, S. Venkatraman, Acc. Chem. Res.
003, 36, 676; g) S. Shimizu, A. Osuka, Eur. J. Inorg. Chem. 2006,
319.
1
w
[
30 33 7 w
9] Crystallographic data for 5: C86H F N , M =1788.17, monoclinic,
(
space group P2 /n (No.14), a=13.528(2), b=12.225(2), c=
1
3
À3
4
4
2
4.328(8) Š, b=96.543(3)8, V=7283(2) Š , 1calcd =1.631 gcm , Z=
, R =0.1081 [I>2.0s(I)], R =0.2558 (all data), GOF=1.154 [I>
.0s(I)].
1
1
w
[
10] This reaction conditions were used for the preparations of hexapyr-
rolylbenzene: H. A. M. Biemans, C. Zhang, P. Smith, H. Kooijman,
W. J. J. Smeets, A. L. Spek, E. W. Meijer, J. Org. Chem. 1996, 61,
4
2
1
9
012.
11] A. Werner, M. Michels, L. Zander, J. Lex, E. Vogel, Angew. Chem.
999, 111, 3866; Angew. Chem. Int. Ed. 1999, 38, 3650.
12] Crystallographic data for 9: C89 O, M =2141.13, triclin-
ic, space group P1 (No.2), a=14.628(6), b=15.369(6), c=
[
2] a) E. Vogel, M. Michels, L. Zander, J. Lex, N. S. Tuzun, K. N. Houk,
Angew. Chem. 2003, 115, 2964; Angew. Chem. Int. Ed. 2003, 42,
[
[
1
2
857; b) Y. Tanaka, W. Hoshino, S. Shimizu, K. Youfu, N. Aratani,
N. Maruyama, S. Fujita, A. Osuka, J. Am. Chem. Soc. 2004, 126,
046; c) S. Shimizu, V. G. Anand, R. Taniguchi, K. Furukawa, T.
Kato, T. Yokoyama, A. Osuka, J. Am. Chem. Soc. 2004, 126, 12280;
d) S. Shimizu, Y. Tanaka, K. Youfu, A. Osuka, Angew. Chem. 2005,
H
39BCl
9
F
31
N
7
w
¯
3
1
4
0
9.229(9) Š, a=72.913(15), b=87.450(16), g=86.269(15)8, V=
3
À3
122(3) Š , 1calcd =1.725 gcm , Z=2, R
1 w
=0.0915 [I>2.0s(I)], R =
.2969 (all data), GOF=1.026 [I>2.0s(I)].
1
17, 3792; Angew. Chem. Int. Ed. 2005, 44, 3726; e) S. Mori, A.
[
[
13] a) C. G. Claessens, D. Gonzµlez-Rodríguez, T. Torres, Chem. Rev.
002, 102, 835; b) Y. Inokuma, J. H. Kwon, T. K. Ahn, M.-C. Yoo, D.
Osuka, J. Am. Chem. Soc. 2005, 127, 8030; f) V. G. Anand, S. Saito,
S. Shimizu, A. Osuka, Angew. Chem. 2005, 117, 7410; Angew. Chem.
Int. Ed. 2005, 44, 7244.
3] a) M. G. P. M. S. Neves, R. M. Martins, A. C. TomØ, A. J. D. Silves-
tre, A. M. S. Silva, V. FØlix, M. G. B. Drew, J. A. S. Cavaleiro, Chem.
Commun. 1999, 385; b) J.-Y. Shin, H. Furuta, A. Osuka, Angew.
Chem. 2001, 113, 63 9;Angew. Chem. Int. Ed. 2001, 40, 619; c) J.-Y.
Shin, H. Furuta, K. Yoza, S. Igarashi, A. Osuka, J. Am. Chem. Soc.
2
Kim, A. Osuka, Angew. Chem. 2006, 118, 975; Angew. Chem. Int.
Ed. 2006, 45, 961.
[
14] a) W. J. Belcher, P. D. W. Boyd, P. J. Brothers, M. J. Liddell, C. E. F.
Rickard, J. Am. Chem. Soc. 1994, 116, 8416; b) W. J. Belcher, M.
Breede, P. J. Brothers, C. E. F. Rickard, Angew. Chem. 1998, 110,
1
133; Angew. Chem. Int. Ed. 1998, 37, 1112; c) A. Weiss, H. Pritz-
kow, P. J. Brothers, W. Siebert, Angew. Chem. 2001, 113, 4311;
Angew. Chem. Int. Ed. 2001, 40, 4182; d) T. Kçhler, M. C. Hodgson,
D. Seidel, J. M. Veauthier, S. Meyer, V. Lynch, P. D. W. Boyd, P. J.
Brothers, J. L. Sessler, Chem. Commun. 2004, 1060.
2
001, 123, 7190.
4] a) H. Furuta, T. Ishizuka, A. Osuka, T. Ogawa, J. Am. Chem. Soc.
999, 121, 2945; b) H. Furuta, T. Ishizuka, A. Osuka, T. Ogawa, J.
[
[
1
Am. Chem. Soc. 2000, 122, 5748; c) A. Srinivasan, T. Ishizuka, H.
Furuta, Angew. Chem. 2004, 116, 894; Angew. Chem. Int. Ed. 2004,
4
3, 876.
5] a) S. Shimizu, J.-Y. Shin, H. Furuta, R. Ismael, A. Osuka, Angew.
Chem. 2003, 115, 82; Angew. Chem. Int. Ed. 2003, 42, 78; b) S. Mori,
Received: May 15, 2006
Published online: September 22, 2006
9102
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