Selective synthesis of meso-naphthylporphyrins

Article abstract of DOI:10.1021/jo0260488

A series of novel meso-(8-substituted naphth-1-yl)porphyrins has been synthesized creating derivatives with a tight recognition environment above the porphyrin plane. The selective synthesis of single atropisomers is discussed. Condensation of bisnaphthaldehyde 12 with phenyldipyrromethane unexpectedly led to selective synthesis of the α,α-5,10-bridged isomer 14. A mechanism is proposed for this unusual scrambling, and alternative syntheses of α,α-5,15-bisnaphthylporphyrins are described. Synthesis of 5,15-analogues can be achieved by employing (pentafluorophenyl)-dipyrromethane or via presynthesis of a bis(dipyrromethane) derivative 22 (from bisnaphthaldehyde 12) and subsequent condensation with benzaldehyde.

Full text of DOI:10.1021/jo0260488

Selective Syn th esis of m eso-Na p h th ylp or p h yr in s
Andrew N. Cammidge* and Orhan O¨ ztu¨rk
School of Chemical Sciences, University of East Anglia, Norwich NR4 7TJ UK
a.cammidge@uea.ac.uk
Received J une 12, 2002
A series of novel meso-(8-substituted naphth-1-yl)porphyrins has been synthesized creating
derivatives with a tight recognition environment above the porphyrin plane. The selective synthesis
of single atropisomers is discussed. Condensation of bisnaphthaldehyde 12 with phenyldipyr-
romethane unexpectedly led to selective synthesis of the R,R-5,10-bridged isomer 14. A mechanism
is proposed for this unusual scrambling, and alternative syntheses of R,R-5,15-bisnaphthylporphyrins
are described. Synthesis of 5,15-analogues can be achieved by employing (pentafluorophenyl)-
dipyrromethane or via presynthesis of a bis(dipyrromethane) derivative 22 (from bisnaphthaldehyde
12) and subsequent condensation with benzaldehyde.
In tr od u ction
10,20-) on the same face. The two parent compounds are
shown in Figure 1.
The synthesis of porphyrins has been widely studied
since the first synthesis of hemin by Fisher and Ziele in
1929.1 Interest often stems from the wide occurrence of
porphyrin derivatives in nature combined with the ability
of synthetic and natural derivatives to act as models for
biological processes (light harvesting, oxygen transport,
catalysis, molecular recognition).2 For some time we have
been interested in the construction of useful molecular
materials from porphyrins and related macrocycles. As
part of a project aimed at construction of molecular
recognition hosts based on the metalloporphyrin plat-
form, we targeted meso-naphth-1-ylporphyrins3,4 bearing
an additional substituent (suitable for further elabora-
tion) at the 8-position (such naphth-1-ylporphyrins do not
interconvert and so give rise to stable atropisomers5). We
chose to incorporate oxygen at the 8-position (OH) and,
to generate a tight recognition cleft above the porphyrin
central metal ion, we required pairs of hydroxyl groups
located on opposite sides of the porphyrin (5,15- and/or
The synthesis of symmetrical, tetra-meso-substituted
porphyrins typically involves condensation of pyrroles
with aldehydes or their equivalent.2,6 Synthesis of un-
symmetrically substituted porphyrins using this 4 + 4
approach is possible but usually leads to a statistical
distribution of products. A similar statistical distribution
is typically observed when atropisomeric porphyrins are
synthesized in this way.7 In our case we realized that
statistical condensation of pyrrole with 8-hydroxynaphth-
1-aldehyde (or a protected version) would lead to a
mixture that comprised 4 atropisomers (Scheme 1). It can
be seen that the required R,â,R,â-atropisomer is expected
to be formed as a minor component. Nevertheless, we
investigated the statistical synthesis because literature
precedent suggested that separation of the atropisomeric
mixture produced could prove possible (synthesis and
separation of other hydroxynaphthyl porphyrins have
been achieved using this strategy3).
8-Hydroxynaphthaldehyde was synthesized from 1,8-
naphthalic anhydride as shown in Scheme 2.8 Condensa-
tion with pyrrole was attempted using both standard
conditions (hot propionic acid6a) and boron trifluoride
(followed by DDQ),6b but the reaction failed to yield any
porphyrin product. Condensation of acetate derivative 7
with pyrrole also failed to yield any porphyin.
It was therefore decided to protect the hydroxyl
group as its methyl ether (it was known that both
2-methoxy and 7-methoxy-1-naphthaldehyde successfully
formed porphyrin derivatives by condensation with pyr-
role3). 8-Methoxy-1-naphthaldehyde9 was synthesized by
* Corresponding author. Tel/Fax. +(44) 1603 592011.
(1) (a) Fischer, H.; Zeile, K. Liebigs Ann. Chem. 1929, 468, 98. (b)
Fischer, H.; Orth, H. Die Chemie des Pyrrols; Akademische Verlag:
Leipzig, 1934; Vol 1. (c) Fischer, H.; Orth, H. Die Chemie des Pyrrols;
Akademische Verlag: Leipzig, 1937; Vol 2, Part 1. (d) H. Fischer, H.;
Stern, A. Die Chemie des Pyrrols; Akademische Verlag: Leipzig, 1940;
Vol 2, Part 2.
(2) Kadish, K. M.; Smith, K. M.; Guilard, R. (Eds.) The Porphyrin
Handbook; Academic Press: Boston, 2000; Vols. 1-10.
(3) meso-Naphth-1-ylporphyrins bearing hydroxyl substituents at
the 2- and/or 7-positions have been reported: (a) Mizutani, T.;
Kurahashi, T.; Murakami, T.; Matsumi N.; Ogoshi, H. J . Am. Chem.
Soc. 1997, 119, 8991. (b) Hayashi, T.; Miyahara, T.; Koide, N.; Kato,
Y.; Masuda, H.; Ogoshi, H. J . Am. Chem. Soc. 1997, 119, 7281. (c)
Mizutani, T.; Murakami, T.; Ogoshi, H. Tetrahedron Lett. 1996, 37,
5369. (d) Hayashi, T.; Miyahara, T.; Aoyama, Y.; Nonoguchi, M.;
Ogoshi, H. Chem. Lett. 1994, 1749. (e) Hayashi, T.; Miyahara, T.;
Hashizumi, N. Ogoshi, H. J . Am. Chem. Soc. 1993, 115, 2049. (f)
Hayashi, T.; Miyahara, T.; Aoyama, Y.; Ogoshi, H. Pure Appl. Chem.
1994, 66, 797.
(6) (a) Adler, A. D.; Longo, R. F.; Finarelli, J . D.; Goldmacher, J .;
Assour, J .; Korsakoff, L. J . Org. Chem. 1967, 32, 476. (b) Lindsey, J .
S.; Schreiman, I. C.; Hsu, H. C.; Kearney, P. C.; Marguerettaz. A. M.
J . Org. Chem. 1987, 52, 827.
(4) An elegant approach to naphth-1-ylporphyrins has recently been
reported: (a) Harmjanz, M.; Scott, M. J . Chem. Commun. 2000, 397.
(b) Harmjanz, M.; Gill, H. S.; Scott, M. J . J . Org. Chem. 2001, 66, 5374.
(5) Gottwald, L. K.; Ullman, E. F. Tetrahedron Lett. 1969, 3071.
(7) Hayashi, T.; Asai, T.; Hokazono, H.; Ogoshi, H. J . Am. Chem.
Soc. 1993, 115, 12210.
(8) (a) Packer, R. J .; Smith, D. C. C. J . Chem. Soc. (C) 1967, 2194.
(b) Elliger, C. A. Org. Prep. Preced. Int. 1985, 17, 419.
10.1021/jo0260488 CCC: $22.00 © 2002 American Chemical Society
Published on Web 09/24/2002
J . Org. Chem. 2002, 67, 7457-7464
7457

Cammidge et al.
separable atropisomers. The porphyrin mixture was
easily isolated (25%) but could not be separated on a
preparative scale. In this case, however, analytical HPLC
clearly showed the presence of all 4 atropisomers in the
mixture.
Sin gle Atr op isom er Syn th esis fr om Dia ld eh yd es.
At this stage it was decided to alter the synthetic
strategy. We reasoned that a less complex mixture of
atropisomeric porphyrins would be produced if we started
from dialdehydes (i.e., if two naphthaldehydes were
linked by a protecting/bridging group). We selected
p-xylyl as linker,11 because a simple molecular model
indicated that it could bridge across the 5,15-positions
easily. Furthermore, we expected its removal (deprotec-
tion) would be straightforward. Diol 4 reacted smoothly
with R,R-dibromo-p-xylene to give bisnaphthyl ether 11,
which was converted to dialdehyde 12 using a Swern
oxidation (Scheme 4). Unfortunately reaction between
dialdehyde 12 and pyrrole [BF3‚OEt2, TCQ, PcFe(II)]
failed to produce any porphyrin product (polymeric tars
and recovered dialdehyde). The conditions were modified
but gave similar disappointing results in all cases.
Due to the difficulties experienced with the synthesis
and isolation of these single-atropisomer 5,10,15,20-
tetranaphth-1-ylporphyrins (which could be elaborated
into porphyrins with two identical recognition faces), we
decided to instead target derivatives which would, when
appropriately modified, bear a single recognition face (i.e.
R,R-5,15-bisnaphth-1-ylporphyrins, Figure 1). Such 5,15-
disubstituted porphyrins are typically synthesized from
a dipyrromethane derivative and an aldehyde.2,12 In our
case, this would be expected to yield a mixture of just
two porphyrins (R,R-5,15- and R,â-5,15-). Using bridged
dialdehyde 12 appeared most attractive, because a single
porphyrin product would be expected (the target R,R-5,-
15-derivative) (Scheme 5).
Phenyldipyrromethane was therefore prepared and
reacted with dialdehyde 12 [both in hot propionic acid
and using BF3‚OEt2, TCQ, PcFe(II)]. A mixture of por-
phyrins was isolated and separated by column chroma-
tography and found to contain a small amount of tet-
raphenylporphyrin along with another porphyrin that we
expected to be the R,R-5,15-bridged porphyrin 13.
However, identification of this major product was not
straightforward. Mass spectrometry gave a molecular ion
consistent with 13, but NMR spectroscopy did not give
the simple spectra that we expected. The 1H NMR
spectrum in fact shows several interesting features
including a broad resonance at 3.9 ppm (which sharpens
somewhat at elevated temperatures) and two doublets
between 3 and 4 ppm, in addition to a complex set of
signals in the aromatic region. The former signal is
attributed to the four protons on the bridging xylyl group,
and the two doublets are from the inequivalent benzylic
protons (geminal coupling). From these data (in conjunc-
tion with COESY and DEPT experiments), the major
product (15%) was identified as the 5,10-bridged porphy-
rin 14 (Scheme 6).13 Crystals suitable for X-ray diffraction
F IGURE 1.
methylation of 8-hydroxy-1-naphthaldehyde using methyl
iodide or dimethyl sulfate. However, its synthesis was
more conveniently achieved from intermediate diol 4 by
methylation of the naphthol followed by oxidation of the
primary alcohol. This latter step could be achieved by
using a J ones oxidation, but it was found that on a large
scale it was more convenient to perform a Swern oxida-
tion (due to simplified workup).
8-Methoxy-1-naphthaldehyde was condensed with pyr-
role in hot propionic acid and gave a modest yield of the
required porphyrins (6%). The reaction was optimized
and a yield of 30% could be obtained using Lindsey’s
conditions10 [BF3‚OEt2, TCQ, PcFe(II)]. The porphyrin
was obtained pure (as a mixture of atropisomers) by
column chromatography. The product is clearly seen to
be a mixture of atropisomers by examination of its 1H
NMR spectrum. A set of singlets (MeO) appear at around
2.1-2.3 ppm. These appear at high field (cf. 4.0 ppm for
8-methoxy-1-naphthaldehyde) due to the porphyrin ring
current, demonstrating their location above the porphyrin
plane. Similarly, a set of signals is clearly observed for
7-H of the meso-naphthalenes. Many attempts were made
to separate the mixture of atropisomers. Careful recrys-
tallization of the solid (various solvent systems) resulted
in product compositions that were essentially unchanged.
The mixture proved inseparable by TLC under all
combinations of stationary phase (silica, alumina) and
mobile phase employed. Analytical HPLC (normal phase)
gave similar disappointing results. It was known from
the literature that the related 2- and 7-substituted
porphyrins could be easily hydrolyzed to give the tet-
rahydroxide mixtures that were separated using column
chromatography. A similar strategy was therefore at-
tempted with 9. However, it was found that hydrolysis
of 9 was extremely difficult in comparison to the other
isomers (no doubt due to the extra constraints imposed
by 8-substitution) with little or no hydrolysis occurring
after treatment with BBr3 at room temperature for 12
h. Hydrolysis was eventually achieved after treatment
for several days with refluxing HBr/glacial acetic acid.
Separation of the atropisomeric mixture was again at-
tempted by TLC and HPLC. Unfortunately, no separation
could be achieved. Tetramethoxide 9 and tetrahydroxide
10 were converted to their zinc complexes (by treatment
with zinc acetate in DMF), but again no separation could
be achieved (Scheme 3).
The synthesis was repeated using a longer chain ether
(hexyloxynaphthaldehyde) in an attempt to prepare
(11) Wang, Q. M.; Bruce, D. W. Tetrahedron Lett. 1996, 37, 7641.
(12) (a) Arsenault, G. P.; Bullock, E.; MacDonald, S. F. J . Am. Chem.
Soc. 1960, 82, 4384. (b) Cavaliero, J . A. S.; Rocha Gonslaves, A. M.
d’A.; Kenner, G. W.; Smith, K. M. J . Chem. Soc., Perkin Trans. 1 1974,
1771.
(9) Lacy, P. H.; Smith, D. C. C. J . Chem. Soc., Perkin Trans. 1 1975,
419.
(10) Lindsey, J . S.; MacCrum, K. A.; Tyhonas, J . S.; Chuang, Y.-Y.
J . Org. Chem. 1994, 59, 579.
(13) Cammidge, A. N.; O¨ ztu¨rk, O. Tetrahedron Lett. 2001, 42, 355.
7458 J . Org. Chem., Vol. 67, No. 21, 2002

Selective Synthesis of meso-Naphthylporphyrins
SCHEME 1
SCHEME 2
SCHEME 3
were grown from chloroform/methanol. Careful examina-
tion of the products from subsequent reactions allowed
trace quantities (2%) of the expected 5,15-isomer to be
isolated and characterized. As expected, the 1H NMR
spectrum of 13 is uncomplicated and the benzyl and xylyl
protons appear as sharp singlets (3.1 and 3.8 ppm).
Scrambling in porphyrin synthesis is commonly ob-
served,14 but this unprecedented selectivity suggests that
a subtle departure from the usual pathway (usually
interpreted as arising from breakdown of the dipyr-
romethane under the acidic conditions and leading to a
complex mixture of all possible porphyrins) is occurring.
A plausible mechanism is shown in Scheme 7. Following
normal electrophilic aromatic substitution at the 5-posi-
tion of the dipyrromethane, the second aldehyde is added
at the 2-position of the same pyrrole unit to give
intermediate 15. Fragmentation can give cyclic 2,5-
disubstituted pyrrole 16 and pyrrolic carbocation 17.
Reaction of these two components (directly or sequen-
tially) with another equivalent of dipyrromethane leads
to the observed 5,10-bridged isomer 14.
destabilization of this intermediate (leaving group) would
suppress the pathway and favor formation of the 5,15-
isomer. Dipyrro(pentafluorophenyl)methane 1815 was
therefore synthesized and reacted, under the same condi-
tions, with dialdehyde 12 (Scheme 8). This reaction
afforded essentially one porphyrin product, which was
characterized as the expected 5,15-bridged porphyrin 19.
It has been reported that scrambling during porphyrin
synthesis can be reduced if the cyclizations are performed
at lower temperatures in the presence of a metal ion
template (zinc).16 These conditions did indeed increase
the yield of the reaction, and 19Zn was isolated in 37%
yield. However, the 5,10-bridged isomer was still es-
(14) (a) Wallace, D. M.; Leung, S.; Senge, M. O.; Smith, K. M. J .
Org. Chem. 1993, 58, 7245. (b) Litter, B. J .; Ciringh, Y.; Lindsey, J . S.
J . Org. Chem. 1999, 64, 2864. (c) Geier, G. R., III; Lindsey, J . S. J .
Chem. Soc., Perkin Trans. 2 2001, 677. (d) Geier, G. R., III; Lindsey,
J . S. J . Chem. Soc., Perkin Trans. 2 2001, 687. (e) Geier, G. R., III;
Litter, B. J .; Lindsey, J . S. J . Chem. Soc., Perkin Trans. 2 2001, 701.
(f) Geier, G. R., III; Litter, B. J .; Lindsey, J . S. J . Chem. Soc., Perkin
Trans. 2 2001, 712.
It can be seen that this mechanism implicates forma-
tion of carbocation 17. We reasoned, therefore, that
(15) Foxton, S. P.; Lindsay Smith, J . R.; O’Brien, P.; Reginato, G.
J . Chem. Soc., Perkin Trans. 2 2001, 1145.
J . Org. Chem, Vol. 67, No. 21, 2002 7459

Cammidge et al.
SCHEME 4
SCHEME 5. Exp ected Ou tcom e fr om Con d en sa tion of Dip yr r om eth a n e Der iva tives w ith Na p h th a ld eh yd es
SCHEME 6. Un exp ected , Selective Scr a m blin g To
Give 5,10-Bisn a p h th ylp or p h yr in 14
To realize the synthesis of the parent (10,20-diphenyl)
porphyrin 13, an alternative strategy (in which formation
of intermediates 15/16 and hence 14 was avoided) was
devised. Dialdehyde 12 was converted to its bis(dipyr-
romethane) analogue 22. Condensation with benzalde-
hyde proceeded smoothly using Setsune’s conditions to
produce the desired 5,15-bridged porphyrin (as the zinc
derivative). Crystals suitable for X-ray crystallography
were obtained from dichloromethane/methanol. A control
reaction was carried out under identical conditions to
those employed in the synthesis of 14 from dipyrrophe-
nylmethane and 12 (Scheme 10). Compound 13 was the
only observed product and this further implies that an
alternative mechanism to simple scrambling gives rise
to the 5,10-isomer in our previous synthesis.
sentially the only isomer observed from the reaction
employing dipyrrophenylmethane.
Con clu sion s
These observations were mirrored when the syntheses
of bis(methoxynaphthyl) porphyrins were performed by
employing dipyrromethanes and methoxynaphthalde-
hyde 8. When dipyrrophenylmethane was employed, a
complex mixture of all possible scrambled porphyrin
products was obtained (as evidenced by mass spectrom-
etry but not separated). Use of dipyrro(pentafluorophen-
yl)methane resulted in a clean reaction and isolation of
5,15-bisnaphthylporphyrin as a 1:1 mixture of two atro-
pisomers. Careful crystallization permitted a small quan-
tity of crystalline R,R-isomer (20) to be obtained (Scheme
9). Again the yield of (zinc) porphyrin could be improved
(50%) using Setsune’s conditions. The two atropisomers
could be separated by chromatography (as either zinc or
metal-free derivatives).
The controlled synthesis of novel meso-naphthylpor-
phyrins (which are suitable for further elaboration into
molecular recognition hosts) has been achieved. An
unusual “scrambling” mechanism is observed when cer-
tain dialdehydes are condensed with dipyrrophenyl-
methane, leading to essentially exclusive formation of the
5,10-isomer. This scrambling is completely suppressed
when dipyrro(pentafluorophenyl)methane is employed
(destabilized carbocation leaving group). The R,R-5,15-
bridged isomer can be prepared smoothly by conversion
of dialdehyde into bis(dipyrromethane) and condensation
with benzaldehyde.
Exp er im en ta l Section
General methods are detailed in the Supporting Informa-
tion.
(16) Setsune, J .; Hashimoto, M.; Shiozawa, K.; Hayakawa, J .; Ochi,
T.; Masuda, R. Tetrahedron 1998, 54, 1407.
7460 J . Org. Chem., Vol. 67, No. 21, 2002

Selective Synthesis of meso-Naphthylporphyrins
SCHEME 7
the solvents evaporated. The crude product was recrystallized
from methanol to give 8 (0.7 g, 70%).
SCHEME 8
m eso-Tet r a k is(8-m et h oxyn a p h t h -1-yl)p or p h yr in (9).
TCQ (0.052 g, 0.215 mmol) and FePc (0.122 g, 0.215 mmol)
were mixed under nitrogen. Dry chloroform (550 mL, 0.75%
ethanol) was added and the mixture stirred for 10 min.
8-Methoxy-1-naphthaldehyde (8) (1.0 g, 5.37 mmol) and pyrrole
(0.36 g, 5.37 mmol) were added, followed by BF3‚OEt2 (1.32
mL, from 2.5 M stock solution in chloroform, 3.3 mmol). The
reaction mixture was stirred for 1 h under nitrogen and an
additional 1 h under air. Water (5 mL) was added, and solvents
were evaporated to dryness. The residue was dissolved in
dichloromethane and purified by flash column chromatography
(neutral alumina, dichloromethane). The fast-moving band was
collected and evaporation of the solvent gave 9 (0.4 g, 32%):
mp >317 °C; λmax (chloroform)/nm (log ꢀ) 427 (5.68), 524 (4.22),
560 (4.02), 601 (3.65), 659 (3.72); δH (270 MHz, CD2Cl2) -2.03
(2H, br s), 2.10-2.29 (12H, 6s), 6.60-6.72 (4H, m), 7.45-7.55
(4H, m), 7.68-7.80 (8H, m), 7.96-8.09 (4H, m), 8.20 (4H, d, J
) 8.2), 8.38 (8H, s); δC (67.9 MHz; CD2Cl2) (most intense peaks)
55.65, 107.8, 121.68, 124.32, 126.89, 128.8, 134.00, 134.10,
135.4, 138.00, 157.60; m/z (FAB) 935 (M+ + 1). Found: C,
81.07; H, 4.49; N, 5.72. C64H46N4O4.0.25 CH2Cl2 requires C,
80.69; H, 4.90; N, 5.86.
8-Met h oxy-1-n a p h t h a ld eh yd e (8). 8-Hydroxy-1-naph-
thaldehyde 58 (1.0 g, 5.8 mmol) and potassium hydroxide (0.32
g, 5.8 mmol) were dissolved in ethanol (50 mL). Methyl iodide
(1.64 g, 11.6 mmol) was added and the mixture stirred for 4
h. The solvent was evaporated and the residue dissolved in
dichloromethane. The solution was washed with water and the
solvent evaporated. The resulting solid was recrystallized from
methanol to give 8 as white crystals (0.3 g, 28%): mp 87-89
°C (lit.9 mp 88-90 °C); δH (270 MHz, CDCl3) 4.01 (3H, s), 6.97
(1H, dd, J ) 7.3, 1.3), 7.42-7.56 (3H, m), 7.91 (1H, dd, J )
7.3, 1.3), 7.96 (1H, dd, J ) 8.2, 1.3), 11.15 (1H, s); δC (67.9
MHz, CDCl3) 55.61, 106.73, 121.45, 123.28, 125.69, 126.46,
127.20, 133.06, 134.98, 135.25, 156.17, 195.61; m/z (EI) 186
(M+).
8-Meth oxy-1-n a p h th a ld eh yd e (8) (Meth od 2). To a
stirred solution of oxalyl chloride (0.63 g, 6.38 mmol) in dry
dichloromethane (30 mL) was added anhydrous DMSO (0.49
g, 6.38 mmol) in dry dichloromethane (20 mL) under nitrogen
at -50 °C. The reaction mixture was stirred for 30 min and
cooled to -78C. After 5 min 8-(hydroxymethyl)naphth-1-yl
methyl ether (6)17 (1.0 g, 5.32 mmol) in dry dichloromethane
(20 mL) was added (dropwise over 5-10 min). After 10 min
TEA (2.15 g, 0.02 mol) was added. The reaction mixture was
stirred a further 5 min and allowed to warm to room temper-
ature. The mixture was diluted with water (60 mL), and the
layers were separated. The aqueous layer was extracted with
dichloromethane. The organic layers were combined and
washed with brine, 1% hydrochloric acid, 5% w/v sodium
carbonate, and water. The extracts were dried (Na2SO4) and
m eso-Tet r a k is(8-m et h oxyn a p h t h -1-yl)p or p h yr in a t o
Zin c (9Zn ). meso-Tetrakis(8-methoxynaphth-1-yl)porphyrin
(9) (0.5 g, 0.534 mmol) was dissolved in chloroform (50 mL)
and zinc acetate dihydrate (excess) added. The reaction
mixture was refluxed for 3 h. Water (50 mL) was added and
the mixture was extracted with dichloromethane, washed with
water, and dried (Na2SO4). The solvents were evaporated to
give crude compound, which was purified by column chroma-
tography (silica gel, dichloromethane/ethyl acetate, 4:1) to give
9Zn (0.45 g, 84%): mp >300 °C; λmax (dichloromethane:THF
4:1)/nm (log ꢀ) 432 (5.67), 561 (4.27), 604 (3.94); δH (270 MHz,
CDCl3) 1.89-2.10 (12H, 5s), 6.42-6.55 (4H, m), 7.33-7.43 (4H,
m), 7.65-7.70 (8H, m), 8.01-8.13 (8H, m), 8.42 (8H, d, J )
4.6); δC (75.4 MHz, CDCl3) 55.34, 55.63, 107.27, 107.69, 121.36,
121.51, 123.07, 123.82, 123.88, 123.98, 126.12, 126.18, 126.21,
126.28, 127.61, 127.74, 128.15, 130.33, 130.36, 130.47, 130.62,
130.74, 133.17, 133.63, 133.69, 134.82, 134.86, 134.89, 138.61,
149.82, 157.43; m/z (FAB) 996 (M+); Acc Mass (FAB) found
996.2897 (C64H44N4O4Zn ) 996.2654). Found: C, 76.80; H,
4.50, N, 5.60. C64H44N4O4Zn‚0.5CH2Cl2 requires C, 76.98; H,
4.44; N, 5.61.
(17) (a) Berry, D.; Smith, D. C. C. J . Chem. Soc., Perkin Trans. 1
1972, 699. (b) Kleinfelter, D. C.; Chen, P. H. J . Org. Chem. 1969, 34,
1741.
8-(H yd r oxym et h yl)n a p h t h -1-yl H exyl E t h er . 8-(Hy-
droxymethyl)-1-naphthol (4) (4.75 g, 27.3 mmol), 1-bromohex-
J . Org. Chem, Vol. 67, No. 21, 2002 7461

Cammidge et al.
SCHEME 9
SCHEME 10
ane (5.407 g, 32.7 mmol), potassium carbonate (5.65 g, 40.9
mmol), and TBAI (1.0 g, 2.73 mmol) were mixed in MEK (300
mL). The reaction mixture was refluxed under nitrogen for 4
h. The mixture was cooled to room temperature, inorganic
materials were removed by filtration, and water (200 mL) was
added. The mixture was extracted with dichloromethane and
dried (Na2SO4). The solvents were evaporated to give crude
compound, which was purified by recrystallization from metha-
nol to give the title compound as a white solid (4.0 g, 57%):
mp 59-60 °C; δH (270 MHz, CDCl3) 0.90 (3H, t, J ) 7.1), 1.37-
1.43 (4H, m, -CH2CH2-), 1.45-1.61 (2H, m, -CH2), 4.18 (2H,
t, J ) 6.5, -OCH2), 5.07 (2H, s), 6.92 (1H, d, J ) 7.6), 7.35-
naphthaldehyde (1.0 g, 3.9 mmol) and pyrrole (0.26 g, 3.9
mmol) were added, followed by BF3‚OEt2 (2.6 mL, from 2.5 M
stock solution in chloroform, 6.3 mmol). The reaction mixture
was stirred for 1 h under nitrogen and an additional 1 h under
air. Water (5 mL) was added, and solvents were evaporated
to dryness. The residue was dissolved in dichloromethane and
purified by flash column chromatography (neutral alumina,
dichloromethane). The fast-moving band was collected and
evaporation of the solvent gave the title porphyrin (0.3 g,
25%): mp 198-200, 239-240, 245-250, 265-268 °C; λmax
(dichloromethane)/nm (log ꢀ) 427 (5.31), 522 (4.32), 558 (4.13),
601 (3.76), 659 (3.90); δH (270 MHz, CDCl3) -2.01 (2H, s),
-1.5-0.16 (32H, m), -0.13 (12H, t, J ) 6.9), 2.57-2.89 (8H,
m), 6.55 (4H, 2d, J ) 6.9, 8.3), 7.40 (4H, t, J ) 8.0), 7.57-7.72
(8H, m), 7.87 (4H, dd, J ) 7.3, 1.3), 8.12 (4H, dd, J ) 8.2, 1.3),
8.22 (8H, m); δC (67.4 MHz, CDCl3) 12.14-12.85, 20.72-22.67,
23.75-24.60, 26.52-27.02, 29.59-30.85, 67.18-67.69, 107.00-
107.38, 121.09-121.18, 122.64, 123.98-124.29, 126.84, 127.63,
127.70, 128.66, 128.75, 130.13, 133.69, 133.94, 134.12, 134.46,
134.75, 135.43, 138.85, 156.80. m/z FAB 1216 (M+ ). Found:
C, 82.66; H, 7.18, N, 4.53. C84H86N4O4 requires C, 82.99; H,
7.13; N, 4.60.
5,15-Bis(8-m et h oxy-1-n a p h t h yl)-10,20-b is(p en t a flu o-
r op h en yl)p or p h yr in (20, 21). TCQ (0.0196 g, 0.096 mmol)
and PcFe(II) (0.045 g, 0.096 mmol) were mixed under nitrogen
and degassed for 10 min. Dry chloroform (100 mL 0.75%
ethanol) was added and the solution stirred for 10 min.
8-Methoxy-1-naphthaldehyde 8 (0.178 g, 0.95 mmol) in dry
chloroform (10 mL) and dipyrro(pentafluorophenyl)methane
(0.30 g, 0.95 mmol) in dry chloroform (10 mL) were added.
After 15 min, BF3‚OEt2 (0.1 mL, from 2.5 M stock solution in
chloroform, 0.25 mmol) was added and the reaction mixture
stirred for a further 1 h under nitrogen. Air was bubbled
through the mixture for an additional 1 h. The reaction was
quenched with water and evaporated to dryness. The crude
7.49 (4H, m), 7.74 (1H, dd, J ) 8.3, 1.3); m/z (EI) 259 (M+
+
1). Found: C, 79.09; H, 8.55. C17H22O2 requires C, 79.03; H,
8.58.
8-Hexyloxy-1-n a p h th a ld eh yd e. Pyridinium chlorochro-
mate (3.57 g, 16.5 mmol) was dissolved in dry dichloromethane
(300 mL). 8-(Hydroxymethyl)naphth-1-yl hexyl ether (3.57 g,
13.8 mmol) was added and the mixture stirred for 4 h under
nitrogen. The reaction mixture was diluted with ether (300
mL), and inorganic residues were removed by filtration. The
solvents were evaporated to give crude product, which was
recrystallized from methanol to give the title compound (3.0
g, 85%): mp 34-35 °C; δH (270 MHz, CDCl3) 0.86 (3H, t, J )
7.0), 1.32-1.40 (4H, m), 1.43-1.53 (2H, m), 1.85-1.95 (2H,
m), 4.12 (2H, t, J ) 6.6), 6.94 (1H, dd, J ) 7.4, 1.2), 7.39-7.54
(3H, m), 7.87 (1H, dd, J ) 7.0, 1.2), 7.94 (1H, dd, J ) 8.3, 1.3),
11.11 (1H, s); δH (67.8 MHz, CDCl3) 13.91, 22.46, 25.80, 29.05,
31.41, 69.04, 107.27, 121.15, 125.53, 126.45, 127.00, 132.92,
135.16, 135.23, 155.52, 195.39; m/z (EI) 256 (M+). Found: C,
79.61; H, 7.95. C17H20O2 requires C, 79.65; H, 7.86.
m eso-Tetr a k is(8-h exyloxyn a p h th -1-yl)p or p h yr in . TCQ
(0.038 g, 0.156 mmol) and PcFe(II) (0.088 g, 0.156 mmol) were
mixed under nitrogen. Dry chloroform (390 mL 0.75% ethanol)
was added and the mixture stirred for 10 min. 8-Hexyloxy-1-
7462 J . Org. Chem., Vol. 67, No. 21, 2002

Selective Synthesis of meso-Naphthylporphyrins
residue was purified (as a mixture) by column chromatography
(silica gel, pet. ether/dichloromethane 50:50, then 100% dichlo-
romethane). The major components were isolated as a mixture
of R,R- and R,â-isomers (0.2 g, 43%). This mixture was
recrystallized (from dichloromethane/methanol) to give powder
and crystals. A crystal was carefully removed and X-ray
analysis proved it to be the R,R-isomer 20. See below for
characterization data for each isomer.
(400 mL) and refluxed for 5 h in the dark under nitrogen. The
reaction mixture was cooled to room temperature. Water (200
mL) was added and the mixture was extracted with dichlo-
romethane and then dried (Na2SO4). The solvents were
evaporated to give crude product, which was recrystallized
(dichloromethane/hexane) to give 11 (4.0 g, 60%): mp 222-
223 °C; δH (270 MHz; CDCl3) 3.69 (2H, br s), 4.98 (4H, s), 5.27
(4H, s), 7.02 (2H, dd, J ) 7.6, 1.0), 7.38-7.53 (8H, m), 7.60
(4H, s), 7.47-7.78 (2H, dd, J ) 7.9, 1.7), δC (75.4 MHz, CDCl3)
66.67, 71.42, 121.57, 122.73, 124.30, 125.26, 125.76, 126.42,
127.10, 128.70, 130.51, 133.64, 136.74, 153.43; m/z Acc Mass
(EI) (calcd M+) 450.1831, (found) 450.1828.
r,r′-Bis(8-for m yln a p h th -1-yloxy)-p-xylen e (12). Pyri-
dinium chlorochromate (5.746 g, 26.6 mmol) was dissolved in
dry dichloromethane (300 mL). Compound 11 (4.0 g, 8.88
mmol) was added and the mixture was stirred for 24 h under
nitrogen. The reaction mixture was diluted with dry ether (600
mL), and the inorganic salts were removed by filtration. The
solvents were evaporated to give crude product, which was
purified by column chromatography (silica gel, dichloromethane)
and recrystallization from dichloromethane/pet. ether to give
12 (3.0 g, 76%): mp 242-244 °C; δH (300 MHz, CDCl3) 5.32
(4H, s), 7.07 (2H, d, J ) 7.9), 7.43 (2H, t, J ) 7.9), 7.50 (4H,
s), 7.53-7.58 (4H, m), 7.93 (2H, dd, J ) 7.2, 1.3), 7.99 (2H,
dd, J ) 8.9, 1.2), 11.10 (2H, s); δC (75.4 MHz, CDCl3) 70.89,
108.30, 121.92, 125.80, 126.48, 127.47, 128.01, 133.13, 135.11,
135.43, 136.19, 155.14, 195.47; m/z (EI) 446 (M+). Found: C,
80.47; H, 4.82. C30H22O4 requires C, 80.70; H, 4.96.
Xylyl-Br id ged P or p h yr in s 13, 14. TCQ (0.015 g, 0.063
mmol) and PcFe(II) (0.035 g, 0.063 mmol) were mixed under
nitrogen. Dry chloroform (400 mL 0.75% ethanol) was added
and the mixture stirred for 10 min. Compound 12 (0.35 g,
0.7838 mmol) and dipyrrophenylmethane (0.348 g, 1.56 mmol)
were added, followed by BF3‚OEt2 (1.3 mL, from 2.5 M stock
solution in chloroform, 3.3 mmol). The reaction mixture was
stirred for 1 h under nitrogen and an additional 1 h under
air. Water (5 mL) was added, and the solvents were evaporated
to dryness. The black residue was dissolved in dichlo-
romethane. TLC analysis indicated that at least three por-
phyrins were present. Separation by column chromatography
(silica gel, dichloromethane/pet. ether 5:1) gave 14 (0.1 g, 15%),
TPP (0.02 g, 4%), 13 (0.015 g, 2%). 14: mp> 300 °C; λmax
(dichloromethane)/nm (log ꢀ) 425 (5.79), 520 (4.41), 557 (4.18),
597 (3.81), 653 (3.78); δH (270 MHz, CDCl3)(at 24 °C) -2.49
(2H, br s), 3.52 (2H, d, J ) 10.2), 3.91-3.94 (4H, br s), 4.13
(2H, d, J ) 10.2), 6.79 (2H, d, J ) 7.6), 7.53 (2H, t, J ) 7.6),
7.62-7.79 (10H, m), 7.93 (2H, d, J ) 6.9), 8.07 (2H, m), 8.17
(2H, d, J ) 4.6), 8.33 (2H, m), 8.55 (2H, s), 8.59 (2H, d, J )
4.6), 8.85 (2H, s); δC (67.4 MHz, CDCl3) 69.63, 106.27, 119.19,
120.70, 123.16, 124.18, 126.36, 126.55, 127.45, 127.96, 128.28,
129.56, 133.76, 134.41, 134.62, 0.134.96, 137.80, 142.55,
156.04; m/z Acc Mass (calcd) 848.315127 (M+), (found) 848.3171
(M+). 13: mp >300 °C, λmax (dichloromethane)/nm (log ꢀ) 426
(5.78), 521 (4.40), 556 (4.17), 598 (3.80), 654 (3.77); δH (270
MHz, CDCl3) -3.11 (2H, s,), 3.16 (4H, s), 3.63 (4H, s), 6.48
(2H, d, J ) 7.6), 7.34 (2H, t, J ) 7.9), 7.61 (6H, m), 7.73 (2H,
d, J ) 8.3), 7.81 (2H, t, J ) 7.6), 8.04 (2H, m), 8.10 (2H, m),
8.20 (2H, d, J ) 8.3), 8.45 (2H, d, J ) 7.9), 8.48 (4H, s, d, J )
4.62), 8.56 (4H, d, J ) 4.62); δC (67.4 MHz, CDCl3) 69.34, 77.19,
109.57, 120.18, 122.30, 123.32, 124.09, 126.48, 127.20, 128.50,
128.89, 130.99, 131.44, 132.95, 134.28, 134.93, 138.38, 143.16,
149.21, 149.86, 155.81.
5,15-Bis(8-m e t h oxyn a p h t h -1-yl)-10,20-b is(p e n t a flo-
r op h en yl)p or p h yr in a to Zin c (20Zn a n d 21Zn ). Dipyrro-
(pentafluorophenyl)methane (0.335 g, 1.07 mmol) and an
excess of zinc acetate dihydrate were added to stirring propi-
onic acid (50 mL) and cooled to 0 °C. 8-Methoxy-1-naphthyl-
dehyde 8 (0.20 g, 1.07 mmol) in dry dichloromethane (20 mL)
was added (dropwise over 1 h) and the mixture stirred for 2 h
at 0 °C then 12 h at room temperature. The reaction mixture
was refluxed for 2 h, and the solvents were evaporated. The
crude was dissolved in dichloromethane (100 mL), and the zinc
salts were removed by filtration, neutralized by excess aqueous
ammonia, and dried (Na2SO4). TLC analysis showed that two
porphyrin products were present. The mixture was purified
by flash column chromatography (neutral alumina, dichlo-
romethane) to give 20Zn and 21Zn (0.26 g, 48%) as a mixture
of isomers. These isomers were separated by careful column
chromatography (silica gel, dichloromethane/pet. ether 70:30);
first fraction (20Zn ) (0.15 g): mp >300 °C; λmax (dichlo-
romethane)/nm (log ꢀ) 420 (5.61), 545 (4.20), 600 (3.77); δH (270
MHz; CDCl3) 2.22 (6H, s), 6.67 (2H, d, J ) 7.9), 7.52 (2H, t, J
) 7.9), 7.73 (2H, d, J ) 8.3), 7.79 (2H, t, J ) 7.8), 7.98 (2H,
dd, J ) 6.9, 1.0), 8.25 (2H, d, J ) 8.3), 8.72-8.78 (8H, dd, J )
4.6, 1.3); δC (69.7 MHz; CDCl3) 55.50, 107.44, 121.45, 124.00,
125.21, 126.70, 127.26, 128.78, 129.47, 133.06, 134.25, 134.91,
137.28, 148.78, 151.14, 157.01; m/z (FAB) 1018 (M+). Second
fraction (21Zn ) (0.1 g): mp >300 °C; λmax (dichloromethane)/
nm (log ꢀ) 420 (5.57), 545 (4.19), 600 (3.77); δH (270 MHz;
CDCl3) 2.04 (6H, s), 6.60 (2H, d, J ) 7.3), 7.50-7.57 (2H, t, J
) 7.8), 7.75 (2H, d, J ) 7.6), 7.80 (2H, d, J ) 8.3), 8.03 (2H, t,
J ) 7.3), 8.26 (2H, d, J ) 8.3), 8.72-8.81 (8H, m); δC (69.7
MHz; CDCl3) 54.93, 107.13, 116.71, 121.34, 126.90, 127.33,
127.45, 128.76, 129.00, 130.02, 131.10, 131.55, 133.71, 149.29,
149.55, 149.90, 151.44, 156.85; m/z (FAB) 1018 (M+).
5,15-Bis(8-m e t h oxyn a p h t h -1-yl)-10,20-b is(p e n t a flo-
r oph en yl)por ph yr in (20 an d 21). 5,15-Bis(8-methoxynaphth-
1-yl)-10,20-bis(pentaflorophenyl)porphyrinato zinc (20Zn and
21Zn ) (0.01 g, 1 × 10-6 mol) was dissolved in dichloromethane
(50 mL) and concentrated hydrochloric acid (5 mL) added. The
solution was stirred vigorously for 4 h at room temperature.
The organic layer was separated, washed with excess aqueous
ammonia, and dried (Na2SO4), and the solvent was evaporated
under reduced pressure. The crude product was purified by
column chromatography (silica gel, dichloromethane) to give
20 (0.0054 g, 57%) and 21 (0.0035 g, 37%). 20: λmax (dichlo-
romethane)/nm (log ꢀ) 420 (5.39), 515 (4.25), 550 (3.87), 594
(3.66), 650 (3.87); δH (270 MHz; CDCl3) -2.42 (2H, s), 2.24 (6H,
s), 6.66 (2H, d, J ) 7.6), 7.51 (2H, t, J ) 8.1), 7.70 (2H, d, J )
7.3), 7.76 (2H, t, J 7.3), 7.92 (2H, dd, J ) 8.3, 1.2), 8.23 (2H,
d, J ) 7.9), 8.59-8.65 (8H, dd, J ) 4.6, 1.3); δC (75.3 MHz;
CDCl3) 54.31, 106.41, 120.58, 123.32, 123.45, 126.03, 126.39,
128.19, 133.53, 134.18, 135.82, 156.15; m/z Acc Mass (calcd
M+ + 1) (FAB) 955.2131, (found), 955.2172. 21: λmax (dichlo-
romethane)/nm (log ꢀ) 419 (5.21), 515 (4.23), 550 (3.87), 594
(3.60), 650 (3.91); δH (270 MHz; CDCl3) -2.65 (2H, br s), 2.08
(6H, s), 6.59 (2H, d, J ) 7.9), 7.49-7.56 (2H, m), 7.73-7.81
(4H, m), 7.97 (2H, d, J ) 5.9,), 8.24 (2H, d, J ) 7.6),
8.60-8.69 (8H, m); δC (69.7 MHz; CDCl3) 54.77, 54.82,
106.97, 121.15, 121.22, 124.06, 124.27, 126.73, 126.86, 127.00,
128.98, 129.21, 133.89, 134.89, 136.53, 156.63; m/z FAB 955
(M+ + 1).
Bis(d ip yr r om eth a n e) Der iva tive 22. Compound 12 (0.5
g, 0.73 mmol) in dry dichloromethane (100 mL) was added to
stirring pyrrole (1.96 g, 29.28 mmol) at room temperature
under nitrogen. BF3‚OEt2 (0.0157 g, 0.222 mmol) was added
and the reaction mixture stirred for 45 min. The mixture was
diluted with dichloromethane (50 mL), washed with 0.1 N
sodium hydroxide and water, and then dried (Na2SO4). The
solvent and pyrrole were removed by vacuum distillation to
give a sticky brown solid, which was purified by column
chromatography (silica gel, dichloromethane) to give 22 as an
r,r′-Bis(8-hydroxymethylnaphth-1-yloxy)-p-xylene (11). 8-(Hy-
droxymethyl)-1-naphthol 4 (5.19 g, 29.8 mmol), R,R′-dibromo-
p-xylene (3.983 g, 15.0 mmol), potassium carbonate (10.36 g,
74.9 mmol), and TBAI (1.108 g, 3.0 mmol) were stirred in MEK
J . Org. Chem, Vol. 67, No. 21, 2002 7463

Cammidge et al.
off white solid (0.45 g, 56%): mp 208-210 °C; δH (270 MHz,
CDCl3) 5.05 (4H, s), 5.67 (4H, s), 6.04 (4H, m), 6.48 (4H, d, J
) 1.3), 6.86 (2H, d, J ) 7.6), 7.01 (2H, s), 7.06 (2H, d, J ) 7.3),
7.20 (4H, s), 7.28-7.35 (4H, m), 7.43 (2H, d, J ) 8.3), 7.51
(4H, br s), 7.67 (2H, d, J ) 8.2); δC (75.4 MHz, CDCl3) 41.63,
70.60, 106.97, 107.51, 108.16, 116.29, 116.47, 122.24, 124.06,
125.28, 125.91, 127.65, 128.66, 134.33, 136.40, 136.72, 139.37,
156.11; m/z Acc Mass (EI) (calcd M+) 678.2995, (found)
678.2993.
solution was cooled to 0 °C under nitrogen. Compound 12 (0.20
g, 0.448 mmol) in dry dichloromethane (50 mL) was added
dropwise over 1 h and the mixture stirred a further 2 h at 0
°C. Air was then bubbled through the reaction mixture
overnight at room temperature. The mixture was refluxed for
2 h, and the solvents were evaporated. The crude solid was
dissolved in dichloromethane, and zinc acetate was removed
by filtration, washed with aqueous ammonia and water, and
dried (Na2SO4). The solvents were evaporated to give crude
product, which was purified by column chromatography (neu-
tral alumina, dichloromethane) to give 19Zn as red/purple
solid (0.12 g, 37%): mp >310 °C; λmax (dichloromethane)/nm
(log ꢀ) 423 (5.38), 550 (4.16), 596 (3.72); δH (300 MHz, CDCl3)
3.04 (4H, s), 3.69 (4H, s), 6.54 (2H, d, J ) 7.6), 7.44 (2H, t, J
) 7.9), 7.84 (2H, d, J ) 8.5), 7.92 (2H, t, J ) 7.7), 8.32 (2H, d,
J ) 8.2), 8.52 (2H, d, J ) 7.0), 8.70-8.77 (8H, dd, J ) 4.7,
4.1); δC (75.3 MHz, CDCl3) 69.04, 77.18, 109.27, 122.21, 123.52,
124.07, 124.43, 126.55, 128.75, 128.84, 129.23, 131.32, 132.63,
132.75, 134.87, 137.52, 148.46, 150.63, 155.47; m/z Acc Mass
(FAB) (calcd M++1) 1091.1422, (found) 1091.1425.
5,15-Xylyl-Br id ged 10,20-Bis(p en ta flu or op h en yl)p or -
p h yr in a to Zin c(II)19Zn (Meth od 2). Compound 22 (0.10 g,
0.147 mmol) and zinc acetate dihydrate (excess) were mixed
in propionic acid (50 mL) and cooled to 0 °C under nitrogen.
To the mixture was added pentafluorobenzaldehyde (0.057 g,
0.294 mmol) in dry dichloromethane (50 mL) (dropwise over
1 h). The mixture was stirred for 2 h at 0 °C then at room
temperature for an additional 12 h under air. The reaction
mixture was refluxed for 2 h, and solvents were evaporated
to dryness. The residue was dissolved in dichloromethane,
treated with aqueous ammonia, washed with water, and dried
(Na2SO4). The solvents were evaporated to give crude product,
which was purified by column chromatography (neutral alu-
mina, dichloromethane). The fast-moving dark red band was
collected, and evaporation of the solvent gave 19Zn as red/
purple solid (0.04 g, 25%).
5,15-Xylyl-Br idged 10,20-Diph en ylpor ph yr in 13Zn . Com-
pound 22 (0.2 g, 0.294 mmol) was dissolved in propionic acid
(50 mL), and zinc acetate dihydrate (excess) was added. The
mixture was cooled to 0 °C under nitrogen. Benzaldehyde
(0.078 g, 0.73 mmol) in dichloromethane (50 mL) was added
dropwise over 1 h and the mixture stirred for a further 2 h at
0 °C under nitrogen and then 12 h at room temperature. The
reaction mixture was refluxed for 2 h, then the solvents were
evaporated. The black solid was dissolved in dichlorometh-
ane, and inorganic salts were removed by filtration. The
solution was treated with aqueous ammonia and water and
dried (Na2SO4). The solvents were removed in vacuo. The crude
product was purified by column chromatography (neutral
alumina, dichloromethane). The fast-moving dark red fraction
was collected, and the solvents were evaporated to give 13Zn
(0.1 g 37%): mp >300 °C; λmax (dichloromethane)/nm (log ꢀ)
426 (5.37), 553 (3.92), 595 (3.34); δH (270 MHz, CDCl3) 3.07
(4H, s), 3.68 (4H, s), 6.51 (2H, d, J ) 7.6), 7.38 (2H, t, J )
8.1), 7.68 (6H, m), 7.79 (2H, d, J ) 8.6), 7.87 (2H, t, J ) 7.8),
8.15 (4H, m), 8.25 (2H, d, J ) 8.3), 8.51 (2H, d, J ) 6.9), 8.62
(4H, d, J ) 4.6), 8.74 (4H, d, J ) 4.6); δC (75.4 MHz, CDCl3)
69.34, 77.19, 109.57, 120.18, 122.30, 123.07, 123.32, 124.09,
126.28, 126.48, 127.20, 128.50, 128.89, 130.99, 131.44, 132.95,
134.28, 134.93, 138.38, 143.16, 149.21, 149.86, 155.81; m/z
(FAB) 912 (M+). 13Zn was recrystallized from dichloromethane/
methanol to obtain crystals for X-ray diffraction.
5,15-Xylyl-Br id ged 10,20-Bis(p en ta flu or op h en yl)p or -
p h yr in 19. TCQ (0.0196 g, 0.08 mmol) and PcFe(II) (0.045 g,
0.08 mmol) were mixed under nitrogen for 10 min. Dry
chloroform (300 mL, 0.75% ethanol) was added and the
mixture was stirred for 10 min. 12 (0.178 g, 0.4 mmol) and
dipyrro(pentafluorophenyl)methane (0.25 g, 0.8 mmol) were
added, followed by BF3‚OEt2 (0.2 mL, from 2.5 M stock solution
in chloroform, 0.5 mmol). The reaction mixture was stirred
for 1 h under nitrogen and an additional 1 h under air. Water
(5 mL) was added and the solvents were evaporated to dryness.
The residue was separated by column chromatography (silica
gel, dichloromethane/cyclohexane, 40:60) to give 19 (0.025 g,
6.1%): mp >320 °C; λmax (dichloromethane)/nm (log ꢀ) 422
(5.37), 516 (4.16), 551 (3.79), 595 (3.68), 652 (3.69); δH (270
MHz, CDCl3) -3.33 (2H, s), 3.06 (4H, s), 3.67 (4H, s), 6.48 (2H,
d, J ) 7.6), 7.37 (2H, t, J ) 7.9), 7.75 (2H, d, J ) 7.9), 7.85
(2H, t, J ) 7.6), 8.23 (2H, d, J ) 7.8), 8.43 (2H, d, J ) 6.9),
8.50 (8H, dd, J ) 4.6, 4.3); δC (67.4 MHz, CDCl3) 69.27, 77.20,
108.78, 122.03, 123.55, 123.73, 124.09, 126.66, 128.42, 129.03,
131.71, 131.93, 134.93, 136.92, 155.50; m/z Acc Mass (FAB)
(calcd M+) 1028.2209, (found) 1028.2201.
5,15-Xylyl-Br id ged 10,20-Bis(p en ta flu or op h en yl)p or -
p h yr in 19. Compound 19Zn (0.01 g, 0.0091 mmol) was
dissolved in dichloromethane (50 mL), and concentrated
hydrochloric acid (5 mL) was added. The mixture was stirred
at room temperature for 4 h. Water (100 mL) was added, and
the layers were separated. The organic phase was washed with
aqueous ammonia and water and then dried (Na2SO4). The
solvents were evaporated to give crude product, which was
purified by column chromatography (silica gel, dichloromethane)
to give 19 (0.008 g, 85%).
Ack n ow led gm en t. We thank the EPSRC mass
spectrometry service center at Swansea, UK, for mass
spectra, and Drs P. Wood, S. Wocadlo, A. Mandel and
D. Hughes, for X-ray diffraction.
Su p p or tin g In for m a tion Ava ila ble: Further experimen-
tal details and comparison of synthetic methods, synthesis of
starting materials, MS, NMR spectra, HPLC profile for meso-
tetrakis(8-hexyloxynaphth-1-yl)porphyrin, and X-ray crystal-
lographic details for 14, 13Zn , and 20. This information is
available free of charge via the Internet at http://pubs.acs.org.
5,15-Xylyl-Br id ged 10,20-Bis(p en ta flu or op h en yl)p or -
p h yr in a to Zin c(II) 19Zn (Meth od 1). Dipyrro(pentaflo-
rophenyl)methane (0.28 g, 0.896 mol) and zinc acetate dihy-
drate (excess) were mixed in propionic acid (50 mL), and the
J O0260488
7464 J . Org. Chem., Vol. 67, No. 21, 2002