Template-directed assembly of a macrocyclic porphyrin tetramer using olefin metathesis

Article abstract of DOI:10.1071/CH05262

A macrocyclic porphyrin tetramer was prepared in 52% yield by olefin metathesis employing a 5,10,15,20-tetrapyridylporphyrin template. CSIRO 2005.

Full text of DOI:10.1071/CH05262

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Aust. J. Chem. 2005, 58, 757–761
Template-Directed Assembly of a Macrocyclic Porphyrin Tetramer
Using Olefin Metathesis
Jacinta M. Bakker,A Steven J. Langford,A,B Melissa J. Latter,A Katrina A. Lee,A
and Clint P. WoodwardA
A School of Chemistry, Monash University, Clayton VIC 3800, Australia.
B Corresponding author. Email: steven.langford@sci.monash.edu.au
A macrocyclic porphyrin tetramer was prepared in 52% yield by olefin metathesis employing a 5,10,15,20-
tetrapyridylporphyrin template.
Manuscript received: 24 September 2005.
Final version: 21 October 2005.
A bottom-up approach to the construction of discrete
nanoscaled assemblies has important implications for sev-
eral nanotechnologies.[1,2] Multiporphyrin systems in which
the porphyrin sub-units are interlinked by self-assembly
or covalent means have produced an array of elegant
and geometric[3–5] nanometer-scaled structures designed to
address aspects of photosynthetic mimicry, host–guest com-
plexation, or catalysis.[6–9] We recently reported a strategy
for preparing cubic porphyrin architectures based on the
interplay of Sniv–O and Ruii–N interactions and suggested
that linking meso positions within the heptaporphyrin array
would lead to novel supramolecular hosts.[10] Inspired by the
recent work of Kobuke and coworkers,[11] we embarked on
the synthesis of tetraporphyrinic macrocycles as a pseudo
two-dimensional model to the more complicated cube struc-
ture, by employing olefin metathesis and a coordinative
template-directed strategy to achieve our goal.[12]
The preparation of the 5,15-substituted metalloporphyrin
diene 1 is outlined in Scheme 1. This porphyrin, which
contains heptyl and methyl side chains on alternating
β-pyrrolic positions, was chosen over other candidates to
negate potential problems with solubility within the macro-
cycle and associated supramolecular constructs. A [2+2]
dipyrrolic route was chosen as the synthetic pathway to
1, by adapting the procedures of Sanders and coworkers
and Johnson et al.[13] Alkylation of pentane-2,4-dione with
1-iodoheptane (K2CO3, MeCN) produced the monoalkylated
product 2 in 88% yield after distillation. Reaction of 2
with the oxime 3[13c] under reducing conditions (Zn, HOAc)
yielded the pyrrole 4 as a white solid in 45% yield. Oxidation
of 4 (Pb(OAc)4, Ac2O, HOAc),∗ and the acid-catalyzed
dimerization of 5 gave the dipyrrole 6 in 67% yield on a
gram scale. Catalytic hydrogenation (H2, Pd/C, NEt3) of the
bis(benzyl ester) 6 at ambient temperature yielded the dicar-
boxylic acid 7 in 80% yield. In situ decarboxylation of 7 in
the presence of the butenyl benzaldehyde 8[15] (TFA, MeOH)
gave the corresponding porphyrinogen, which was oxidized
to yield the free base porphyrin 9 in a very acceptable 24%
yield for the final one-pot multi-step process. Metallation
by the standard Zn(OAc)2 method[16] produced the zinc(ii)
analogue 1, the metathesis precursor, in high yield.
Reaction of 1 (millimolar concentration) in the presence
of 0.25 equivalents of 5,10,15,20-tetrapyridylporphyrin 10
with Grubbs’ first generation catalyst (40 mol-%) gave a
new band by thin layer chromatography (TLC) analysis.[12f ]
After further catalyst addition (57 mol-%), reaction comple-
tion (48 h) was indicated by the loss of 1, and the template
was removed by acid workup. The free base tetraporphyrin
macrocycle 11 was isolated by column chromatography in
52% yield (Scheme 2).†
In our hands, olefin metathesis using Grubbs’ first-
generation catalyst seems unaffected by the presence of
10, despite the presence of the four pyridine, two pyrrolic,
and two pyrrolenic nitrogens. This was verified by perform-
ing a ring closure metathesis of diethyl diallyl malonate in
the presence of template 10 under the conditions shown in
Scheme 3. Conversion of the malonate into the corresponding
cyclopentene was achieved in >95% yield.
The 1H NMR spectrum of the macrocycle 11 (Fig. 1b) is
consistent with the expected structure and is clearly different
∗ Oxidation of 4 to form 5 did not occur with Pb(OAc)4 in CH3CO2H as outlined in the procedures of ref. [13]. Upon addition of catalytic quantities of Ac2O
to Pb(OAc)4/CH3CO2H we obtained pyrrole 5 in high yields, as adopted from ref. [14]. We also observed formation of pyrrole 5 in good yield in the absence
of Ac2O however the reaction was heated at 80◦C for 1.5 h to achieve this.
† Attempts to image the free base of square 11 using STM techniques have not been successful. We have attributed this to the more flexible nature of 11 and
the heptyl side chains. This view is supported by ref. [12f ] where STM of a tetraphenylporphyrin analogue on highly ordered pyrolytic graphite was possible
when the template porphyrin was complexed, providing a more rigid structure.
© CSIRO 2005
10.1071/CH05262
0004-9425/05/110757

758
J. M. Bakker et al.
O
O
OBn
(CH2)6CH3
R
O
N
O
3
O
O
OH
Iodoheptane
K2CO3,
MeCN
∆
Zn
CH3CO2H
BnO2C
N
H
(CH2)6CH3
2
4 R ϭ CH3
5 R ϭ CH2OAc
Pb(OAc)4,
CH3CO2H, Ac2O
MeOH, HCl, ∆
(CH2)6CH3
(CH2)6CH3
OHC
(CH2)6CH3
(CH2)6CH3
NH
N
N
N
8
M
N
1. MeOH, TFA
2. DDQ, DCM, TEA
HN
RЈO2C
CO2RЈ
(CH2)6CH3
(CH2)6CH3
6 RЈ ϭ CO2Bn
7 RЈ ϭ CO2H
H2, Pd/C,
THF, TEA
9 M ϭ 2H
1 M ϭ ZnII
Zn(OAc)2, ⌬
CHCl3, MeOH
Scheme 1. Synthesis of trans-functionalized alkenyl porphyrin monomer 1.
H3C(H2C)6
(CH2)6CH3
N
HN
NH
N
(CH2)6CH3
N
H3C(H2C)6
H3C(H2C)6
(CH2)6CH3
N
Zn
PCy3
Ru
PCy3
CH2Cl2, Ar
2. Aq. HCl, CH2Cl2
4
1.
N
N
Cl
Cl
(CH2)6CH3
(CH2)6CH3
Ph
(CH2)6CH3
(CH2)6CH3
H3C(H2C)6
H3C(H2C)6
H3C(H2C)6
(CH2)6CH3
1
H3C(H2C)6
HN
N
N
HN
11
N
N
NH
N
NH
H3C(H2C)6
N
NH
N
N
N
HN
(CH2)6CH3
(CH2)6CH3
H3C(H2C)6
N
HN
NH
N
N
10
H3C(H2C)6
Scheme 2. Template-assisted metathesis to form the tetraporphyrin.
to that seen for the precursor 9.[12f ] Evident within the spec-
trum of 11 are peaks at δ 5.80 and 5.89 of equal intensity,
indicative of E and Z alkenes, respectively.Their approximate
1:1ratioindicateslittlestericinfluenceorringstrainfromthe
supramolecular assembly. Future work aims to hydrogenate
the alkene linkers of 11 to alleviate the cis/trans isomerism
and produce saturated alkyl linkers.
Electrospray ionization mass spectrometry (ESIMS) pro-
vides further evidence for the formation of the macrocyclic
porphyrin tetramer 11 (molecular formula: C280H376N16).
The strong peak within the low-resolution (LR) mass
PCy3
Ru
Cl
Cl
Ph
PCy3
O
O
O
O
10 mol-%
CH2Cl2, Ar
EtO
OEt
EtO
OEt
10 (0.25 eq)
Scheme 3. Verification of the use of 10 as a template.

Template-Directed Assembly of a Macrocyclic Porphyrin Tetramer
759
*
Heptyl protons
Inner
peripheral
protons
Aromatics
Terminal
olefin
protons
meso-Protons
Olefin
protons
(a)
10
9
8
7
6
5
4
3
2
1
0
Ϫ1
Ϫ2
Ϫ3 ppm
*
Heptyl protons
Product
olefin
protons
Inner
peripheral
protons
meso-Protons
(b)
Aromatics
8
10
9
7
6
5
4
3
2
1
0
Ϫ1
Ϫ2
Ϫ3 ppm
Fig. 1. 300 MHz 1H NMR spectroscopic comparison of (a) free base porphyrin 9 and (b) square 11. ∗ represents the residual solvent peak.
992.8
R
R
100
N
HN
4ϩ
NH
N
R
R
992.5023
992.7487
993.0048
992.2595
R
R
R
R
R
R
R
R
HN
N
N
N
HN
ϩ 4Hϩ
NH
N
NH
%
R
R
m/z
991 992 993 994 995
N
HN
NH
N
R
R
0
m/z
600
800
1000
1200
1400
1600
Fig. 2. Positive ion LR-ESIMS of 11, inset showing HR-ESIMS expansion of the multiply charged m/z 992 peak.
spectrum at m/z 992.8, is consistent with the formation of
mutiply charged ions but is inconclusive as to which mul-
tiply charged ion is present. High-resolution (HR) ESIMS
(inset, Fig. 2) was necessary to provide diagnostic informa-
tion. The incremental 0.25 amu values found for the isotope
distribution within the signal at m/z 992.8 is only consistent
with the formula [11 + 4H]4+, i.e. the macrocyclic porphyrin
tetramer.
currently underway in our laboratories is exploring the host–
guest possibilities of the metalloporphyrin square, including
rotaxane applications, and a systematic approach to using
Type I and II olefins for more elaborate structures.[17] Such
results will be published in due course.
Experimental
In summary, we have demonstrated a useful method
for preparing a macrocyclic porphyrin tetramer. Research
All chemicals were used as supplied from Aldrich. Solvents were
obtained as AR grade reagents and were used as received. LR-ESIMS

760
J. M. Bakker et al.
were recorded on a Micromass Platform II API QMS-quadrupole elec-
trospray mass spectrometer. HR-ESIMS were recorded on a Bruker
BioApex 47e Fourier-transform mass spectrometer. 1H and 13C NMR
spectra were recorded using a Bruker DPX 300 MHz spectrometer
(300 MHz 1H, 75 MHz 13C) or a Bruker DRX 400 MHz spectrom-
eter (400 MHz 1H, 100 MHz 13C), as solutions in CDCl3. Chemical
shifts (δ) were calibrated against the residual solvent peak. UV-Visible
spectra were recorded on a Varian model Cary 100 Bio UV-Visible
Spectrophotometer in the specified solvent system.
Compounds 2–7 and 9 were prepared by modifying the procedures
reported previously by Sanders and coworkers and Johnson et al.[13] The
major change to that documented was the use of 1-iodoheptane in the
alkylation to achieve dione 2 rather than 1-iodohexane. However, two
other minor differences were the addition of acetic anhydride to assist
in producing the acetoxypyrrole 5[14] and the one-pot decarboxylation,
acid catalyzed condensation, and oxidation from 7 to afford the free
base porphyrin 9.
4H), 5.81 (m, 1H), 5.00 (m, 2H), 2.78 (t, J 8.2, 2H), 2.38 (m, 2H). δC
(75 MHz) 192.0, 149.4, 137.4, 134.8, 130.0, 129.3, 115.6, 35.7, 35.1.
m/z (LR-ESI, +ve, C11H12O) calc. 160.08, found 160.9 [M + H]+.
Porphyrin 9: Dipyrrole 7 (79.2 mg, 172.7 µmol), aldehyde 8
(27.7 mg, 172.9 µmol), and MeOH (5 mL) were combined and degassed
by three freeze–thaw cycles. Trifluoroacteic acid (TFA) was separately
degassed under the same conditions. In a dark, Ar atmosphere, TFA
(1 mL) was added to the dipyrrole mixture at about −50◦C.The solution
was allowed to warm to ambient temperature and stirring continued for
a further 4 h. 2,3-Dichloro-5,6-dicyano-p-benzoquinone (DDQ; 0.9 g,
3.96 mmol) was added followed by CHCl3 (25 mL), and the mixture was
stirred for 2 h before triethylamine (TEA; 8 mL) was added. The mix-
ture was stirred overnight. The solution was washed with H2O (×3) and
concentrated. Purification by column chromatography (silica, CHCl3)
yielded 9. Recrystallization from CH2Cl2/MeOH gave (20.8 mg, 24%)
of dark red coloured product. δH (400 MHz) 10.21 (s, 2H), 7.96 and 7.54
(ABq, J 7.8, 8H), 6.06 (m, 2H), 5.18 (m, 4H), 3.97 (t, J 7.6, 8H), 3.08
(t, J 7.4, 4H), 2.70 (q, J 7.2, 4H), 2.49 (s, 12H), 2.18 (p, J 7.4, 8H), 1.72
(p, J 7.5, 8H), 1.50 (m, 8H), 1.31 (m, 16H), 0.87 (t, J 6.8, 12H), −2.40
(s, 2H). λmax/nm (ε/M−1 cm−1) (CHCl3) 409 (4.92), 508 (4.01), 541
(3.56), 574 (3.68). m/z (LR-ESI, +ve, C72H98N4) calc. 1018.78, found
1019.8 [M + H]+.
Dione 2: (48.53 g, 88%). δH (300 MHz) 3.51 (t, J 7.2, 1H), 2.06 (s,
3H), 2.02 (s, 3H), 1.73 (q, J 7.4, 2H), 1.16 (s, 10H), 0.79 (t, J 6.05, 3H).
δC (50 MHz) 203.9, 68.5, 31.4, 30.4, 29.1, 28.6, 28.0, 27.2, 13.6. m/z
(LR-ESI, +ve, C12H22O2) calc. 198.2, found 199.0 [M + H]+, 221.0
[M + Na]+, 238.6 [M + K]+.
Oxime 3: (19.6 g, quant.). δH (300 MHz) 9.12 (s, 1H), 7.31 (m, 5H),
5.29 (s, 2H), 2.33 (s, 3H). δC (75 MHz) 194.2, 176.8, 161.7, 134.4,
128.5, 128.4, 128.1, 67.7, 25.1. νmax (nujol)/cm−1 3422m (br), 1728m,
1681m, 1456m. m/z (LR-ESI, +ve, C11H11NO4) calc. 221.1, found
244.1 [M + Na]+.
Zinc porphyrin 1: Zinc(ii) was inserted into free base porphyrin 10
using the acetate method.[16] (38 mg, 84%). δH (400 MHz) 10.15 (s,
2H), 7.96 and 7.53 (ABq, J 7.9, 8H), 6.07 (m, 2H), 5.18 (m, 4H), 3.95
(t, J 7.7, 8H), 3.09 (t, J 7.5, 4H), 2.69 (q, J 7.1, 4H), 2.46 (s, 12H), 2.18
(m, 8H), 1.72 (m, 8H), 1.50 (m, 8H), 1.34 (m, 16H), 0.89 (t, J 6.9, 12H).
δC (100 MHz) 147.9, 146.4, 143.3, 141.7, 141.2, 138.2, 138.0, 133.1,
127.6, 119.4, 115.4, 97.5, 36.2, 35.6, 33.4, 32.0, 30.3, 29.5, 26.8, 22.7,
15.2, 14.1. λmax/nm (ε/M−1 cm−1) (CHCl3) 409 (5.05), 536 (3.91),
572 (3.82). m/z (HR-ESI, +ve, C72H96N4Zn) calc. 1080.692, found
1080.6919 [M]+.
Pyrrole 4: (5.4 g, 45%). δH (300 MHz) 8.51 (s, 1H), 7.37 (m, 5H),
5.28 (s, 2H), 2.33 (t, J 7.5, 2H), 2.27 (s, 3H), 2.18 (s, 3H), 1.28 (m,
10H), 0.87 (t, J 6.6 Hz, 3H). δC (75 MHz) 161.5, 137.0, 130.0, 128.7,
128.3, 128.2, 127.9, 122.8, 116.6, 65.5, 32.1, 31.1, 29.6, 29.4, 24.2,
22.9, 14.3, 11.7, 11.9. νmax (nujol)/cm−1 3290s, 3090w, 1657s. λmax/nm
(ε/M−1 cm−1) (CHCl3) 259 (4.71), 282 (4.58). m/z (LR-ESI, +ve,
C21H29NO2) calc. 327.2, found 328.4 [M + H]+, 350.3 [M + Na]+,
366.6 [M + K]+.
Square 11: Zinc porphyrin 1 (13.4 mg, 12.4 µmol) and template por-
phyrin 10 (2 mg, 3.2 µmol) were stirred in CH2Cl2 (15 mL, degassed)
in the dark under an Ar atmosphere. Grubbs first-generation catalyst
(4.1 mg, 4.98 µmol) was added and the reaction was monitored byTLC.
Further catalyst additions were made (5.8 mg, 7.05 µmol) and stirring
was maintained. When TLC analysis showed that 1 was predominately
consumed, the solution was washed consecutively with 30 mL HCl
(3 M), H2O (×2), NaHCO3 (sat. soln.), H2O (×2), and dried (MgSO4).
After the sample was concentrated, it was purified by column chro-
matography (silica, CHCl3) and residual solvent was removed under
high vacuum to obtain the square 11 as a purple-red solid (6.4 mg, 52%).
δH (300 MHz) 10.18 (br m, 8H), 8.01 (br m, 16H), 7.64 (br m, 16H),
5.87 (br m, 4H), 5.81 (br m, 4H), 3.94 (br m, 32H), 3.15–0.82 (br m,
288H), −2.38 (br s, 8H). λmax/nm (ε/M−1 cm−1) (CHCl3) 413 (5.56),
Acetoxypyrrole 5: (1.1 g, 85%). δH (300 MHz) 8.97 (s, 1H), 7.38 (m,
5H), 5.31 (s, 2H), 5.00 (s, 2H), 2.42 (t, J 11.0, 2H), 2.28 (s, 3H), 2.06 (s,
3H), 1.43 (m, 2H), 1.28 (m, 8H), 0.88 (t, J 9.6, 3H). δC (100 MHz) 171.1,
162.4, 136.7, 128.8, 128.4, 128.3, 127.4, 125.7, 123.7, 119.1, 65.9, 57.3,
32.1, 31.5, 29.6, 29.4, 24.1, 22.9, 21.1, 14.3, 10.7. νmax (nujol)/cm−1
3301m, 1670s, 1464m, 1377m. λmax/nm (ε/M−1 cm−1) (CHCl3) 259
(4.82), 276 (4.69). m/z (LR-ESI, +ve, C23H31NO4) calc. 385.23, found
386.3 [M + H]+, 408.3 [M + Na]+.
Dipyrrole 6: (1.7 g, 67%). δH (300 MHz) 8.54 (s, 2H), 7.34 (m, 10H),
5.28 (s, 4H), 3.82 (s, 2H), 2.34 (t, J 5.85, 4H) 2.27 (s, 6H), 1.34 (m, 4H),
1.27 (s, 16H), 0.87 (m, 6H). δC (100 MHz) 161.7, 136.7, 129.7, 128.7,
128.4, 128.2, 128.1, 123.3, 117.8, 65.8, 32.1, 31.2, 29.8, 29.5, 24.2,
22.8, 14.5, 11.6, 11.0. m/z (LR-ESI, +ve, C41H54N2O4) calc. 638.41,
found 661.5 [M + Na]+.
509 (4.46), 542 (4.06), 575 (4.09). m/z (LR-ESI, +ve, C280H376N16
)
calc. 3966.2, found 992.8 [M + 4H]4+
.
Dicarboxylic acid dipyrrole 7: (0.61 g, 80%). δH (300 MHz) 11.27
(s, 2H), 9.74 (s, 2H), 3.83 (s, 2H), 3.02 (m, 6H), 2.44 (t, J 7.3, 4H),
2.27 (s, 6H), 1.32 (m, 16H), 0.88 (m, 6H). δC (100 MHz) 160.1, 130.4,
125.2, 121.6, 120.8, 32.2, 31.7, 30.2, 29.5, 24.9, 22.9, 14.3, 10.9, 8.9.
m/z (LR-ESI, +ve, C27H42N2O4) calc. 458.31, found 481.5 [M + Na]+,
497.5 [M + K]+.
Accessory Materials
A scheme describing the template-directed assembly of four
equivalents of alkenyl porphyrin 1 with the free base por-
phyrin 10 to give the desired square geometry in preparation
for metathesis, and the corresponding time-averaged 1H
NMR spectroscopic changes of 1 and 10 during the assem-
bly are available from the author or, until November 2010,
the Australian Journal of Chemistry.
Aldehyde 8: prepared by adapting the reported method of Wilcox
andcoworkers.[15a] The4-(4-bromophenyl)but-1-eneprecursorwaspre-
pared as per the procedure described by Kabalka and coworkers.[15b] A
solution of 4-(4-bromophenyl)but-1-ene (10 g, 47.4 mmol) in tetrahy-
drofuran (THF) (100 mL) was cooled to −78◦C and n-butyllithium
(2.5 M solution in hexane, 20.4 mL, 52.2 mmol) was added slowly to
maintain a temperature below −70◦C. The solution was stirred for
30 min and N,N-dimethylformamide (DMF) (8.8 mL, 111.8 mmol) was
added at −78◦C followed by a further 30 min stirring. The solution was
then warmed to 0◦C, quenched with H2O (150 mL), extracted with Et2O
(3 × 100 mL), washedwithH2O(3 × 100 mL), dried(MgSO4), andcon-
centrated under reduced pressure to give a crude yellow residue. Column
chromatography (silica, 8/1 hexane/EtOAc) gave 8 (5.23 g, 69%) as a
colourless liquid. δH (300 MHz) 9.95 (s, 1H), 7.78 & 7.32 (ABq, J 8.4,
Acknowledgements
This work was supported by the Australian Research Coun-
cil, Discovery Project Scheme through award to S.J.L.
(DP0556313), which is greatfully acknowledged. We thank
Dr P. Nichols and S. Duck for their help in obtaining NMR
and mass spectra, respectively.

Template-Directed Assembly of a Macrocyclic Porphyrin Tetramer
761
References
[10] S. J. Langford, C. P. Woodward, Coll. Czech. Chem. Commun.
2004, 69, 996. doi:10.1135/CCCC20040996
[1] A. H. Flood, R. J. A. Ramirez, W.-Q. Deng, R. P. Muller,
W. A. Goddard, J. F. Stoddart, Aust. J. Chem. 2004, 57, 301.
doi:10.1071/CH03307
[2] V. Balzani, M. Venturi, A. Credi, Molecular Devices and
Machines—A Journey into the Nanoworld 2003 (Wiley-VCH:
Wienheim).
[11] (a) D. Furutsu, A. Satake, Y. Kobuke, Inorg. Chem. 2005, 44,
4460. doi:10.1021/IC050029+
(b) O. Shoji, H. Tanaka, T. Kawai, Y. Kobuke, J. Am. Chem. Soc.
2005, 127, 8598. doi:10.1021/JA051344Y
(c) C. Ikeda, A. Satake, Y. Kobuke, Org. Lett. 2003, 5, 4935.
doi:10.1021/OL0357191
(d) R. Takahashi, Y. Kobuke, J. Am. Chem. Soc. 2003, 125, 2372.
doi:10.1021/JA028325Y
[3] (a) R. V. Slone, J. T. Hupp, Inorg. Chem. 1997, 36, 5422.
doi:10.1021/IC9703991
(b) F. K. Czaplewski, J. T. Hupp, R. Q. Snurr, Adv. Mater.
2001, 13, 1895. doi:10.1002/1521-4095(200112)13:24<1895::
AID-ADMA1895>3.0.CO;2-C
[12] Recent examples of template-assisted olefin-metathesis to pre-
pare macrocyclic compounds include:
(a) T. Inomata, K. Konishi, Chem. Commun. 2003, 11, 1282.
doi:10.1039/B302609D
(c) M. L. Merlau, M. P. Meija, S. T. Nguyen, J. T. Hupp,
Angew. Chem. Int. Ed. 2001, 40, 4239. doi:10.1002/1521-3773
(20011119)40:22<4239::AID-ANIE4239>3.3.CO;2-5
[4] (a) N. Fujita, K. Biradha, M. Fujita, S. Sakamoto, K.Yamaguchi,
Angew. Chem. Int. Ed. 2001, 40, 1718. doi:10.1002/1521-3773
(20010504)40:9<1718::AID-ANIE17180>3.3.CO;2-Z
(b) K. Sugiura, Y. Fujimoto, Y. Sakata, Chem. Commun. 2000,
1105. doi:10.1039/B002699I
(b) M. O. Vysotsky, A. Bogdan, L. Wang, V. Böhmer, Chem.
Commun. 2004, 11, 1268. doi:10.1039/B402719A
(c) S. J. Cantrill, R. H. Grubbs, D. Lanari, K. C.-F. Leung,
A. Nelson, K. G. Poulin-Kerstein, S. P. Smidt, J. F. Stoddart,
D. A. Tirrell, Org. Lett. 2005, 7, 4213. doi:10.1021/OL051599G
(d) X.-Z. Zhu, C.-F. Chen, J. Am. Chem. Soc. 2005, 127, 13158.
doi:10.1021/JA0546020
(e) E. N. Guidry, S. J. Cantrill, J. F. Stoddart, R. H. Grubbs, Org.
Lett. 2005, 7, 2129. doi:10.1021/OL050463F
(f ) P. C. M. van Gerven, J. A. A. W. Elemans, J. W. Gerritsen,
S. Speller, R. J. M. Nolte, A. E. Rowan, Chem. Commun. 2005,
28, 3535. doi:10.1039/B503619D
(c) J. Fan, J. A. Whiteford, B. Olenyuk, M. D. Levin,
P. J. Stang, E. B. Fleischer, J. Am. Chem. Soc. 1999, 121,
2741. doi:10.1021/JA9839825
[5] (a) A. Satake, Y. Kobuke, Tetrahedron 2005, 61, 13.
doi:10.1016/J.TET.2004.10.073
(b) F. Würthner, C.-C. You, C. R. Saha-Möller, Chem. Soc. Rev.
2004, 33, 133. doi:10.1039/B300512G
[6] Z. Clyde-Watson, A. Vidal-Ferran, L. J. Twyman, C. J. Walter,
D. W. J. McCallien, S. Fanni, N. Bampos, R. S. Wylie,
J. K. M. Sanders, New J. Chem. 1998, 493. doi:10.1039/
A709199K
[7] J. Li, A. Ambrose, S. I. Yang, J. R. Dier, J. Seth, C. R. Wack,
D. F. Bocian, D. Holten, J. S. Lindsay, J. Am. Chem. Soc. 1999,
121, 8927. doi:10.1021/JA991730D
[8] (a) E. Alessio, M. Macchi, S. Heath, L. G. Marzilli, Chem.
Commun. 1996, 12, 1411. doi:10.1039/CC9960001411
(b) E. Iengo, E. Zangrando, E. Alessio, J.-C. Chambron,
V. Heitz, L. Flamigni, J.-P. Sauvage, Chem. Eur. J. 2003, 9,
5879. doi:10.1002/CHEM.200304795
[13] (a) A. Vidal-Ferran, N. Bampos, J. K. M. Sanders, Inorg. Chem.
1997, 36, 6117. doi:10.1021/IC971235N
(b) L. J. Twyman, J. K. M. Sanders, Tetrahedron Lett. 1999, 40,
6681. doi:10.1016/S0040-4039(99)01375-1
(c) A. W. Johnson, I. T. Kay, E. Markham, R. Price, K. B. Shaw,
J. Chem. Soc. 1959, 3416. doi:10.1039/JR9590003416
[14] W. Jiao, T. D. Lash, Org. Lett. 2003, 68, 3896.
[15] (a) T. Bosanac, Y. Jaemoon, C. S. Wilcox, Angew. Chem. Int.
Ed. 2001, 40, 1875. doi:10.1002/1521-3773(20010518)40:10
<1875::AID-ANIE1875>3.0.CO;2-5
(b) R. R. Srivastava, R. R. Singhaus, G. W. Kabalka, J. Org. Chem.
1999, 64, 8495. doi:10.1021/JO990878C
[16] J. W. Buchler, in The Porphyrins (Ed. D. Dolphin) 1978, Vol. 1A,
p. 389 (Academic: New York, NY).
(c) D. M. Guldi, T. Da Ros, P. Braiuca, M. Prato, E. Alessio,
J. Mater. Chem. 2002, 12, 2001. doi:10.1039/B202116A
[9] P. Thordarson, R. J. M. Nolte, A. E. Rowan, Aust. J. Chem. 2004,
57, 323. doi:10.1071/CH03302
[17] A. K. Chatterjee, T.-L. Choi, D. P. Sanders, R. H. Grubbs, J. Am.
Chem. Soc. 2003, 125, 11360. doi:10.1021/JA0214882