Reaction of β-vinyl-meso-tetraphenylporphyrin with o-quinone methides

Article abstract of DOI:10.1055/s-0030-1260947

The hetero-Diels-Alder reaction of β-vinyl-meso- tetraphenylporphyrinatozinc(II) with quinone methides generated in situ from Knoevenagel reaction of 2-hydroxy-1,4-naphthoquinone, 4-hydroxycoumarin, and 4-hydroxy-6-methylcoumarin with paraformaldehyde and

Full text of DOI:10.1055/s-0030-1260947

LETTER
1841
Reaction of b-Vinyl-meso-tetraphenylporphyrin with o-Quinone Methides
R
eactiono
o
f
b
-Vinyl-
m
s
eso-tetra
p
é
henylporphyrin w
C
ith
o
-Quinone
M
.
ethides J. M. D. S. Menezes,a Ana T. P. C. Gomes,a Artur M. S. Silva,a Maria A. F. Faustino,a Maria G. P. M. S.
Neves,a Augusto C. Tomé,a Fernando de C. da Silva,b Vitor F. Ferreira,b José A. S. Cavaleiro*a
a
QOPNA, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
Fax +351(234)370084; E-mail: jcavaleiro@ua.pt
Departamento de Química Orgânica, Universidade Federal Fluminense, 24020-141 Niterói, Rio de Janeiro, Brazil
b
Received 9 May 2011
Porphyrins have been shown to be versatile reagents in
Diels–Alder reactions wherein a peripheral double bond
acts as a dienophile7 or the b-vinyl substituent of the mac-
rocycle and the neighboring peripheral double bond act as
Abstract: The hetero-Diels–Alder reaction of b-vinyl-meso-
tetraphenylporphyrinatozinc(II) with quinone methides generated
in situ from Knoevenagel reaction of 2-hydroxy-1,4-naphthoqui-
none, 4-hydroxycoumarin, and 4-hydroxy-6-methylcoumarin with
paraformaldehyde and directly from o-hydroxybenzyl alcohol de- a diene.8 We report herein the hetero-Diels–Alder reaction
rivatives is reported.
of several o-quinone methides (o-QM) generated from 2-
hydroxy-1,4-naphthoquinone (1, Lawsone), 4-hydroxy-
coumarin (2a), 4-hydroxy-6-methylcoumarin (2b), o-
hydroxybenzyl alcohol (3a), and 2-hydroxy-3-methoxy-
benzyl alcohol (3b, Figure 1), with b-vinyl-meso-tet-
raphenylporphyrinatozinc(II) (4, Scheme 1).
Key words: porphyrin, o-quinone methide, naphthoquinone, cou-
marin, o-hydroxybenzyl alcohol, hetero-Diels–Alder
Porphyrins demonstrate promising applications in various
scientific fields such as supramolecular chemistry, biomi-
metic models for photosynthesis, catalysis, and medicinal
applications, namely as photosensitizers in the photody-
namic therapy of tumors, in the treatment of age-related
macular degeneration, and in the diagnosis of neoplastic
diseases.1 The modification of a porphyrin macrocycle
leading to new derivatives, using functionalization proce-
dures, especially pericyclic reactions,2 plays a key role in
finding promising compounds with potential use as pho-
todynamic agents. 5,10-Dioxobenzo[g]chromene, 5,6-
dioxobenzo[h]chromene,3a pyrano[3,2-c]coumarin,4 and
benzopyran5 features are found in many natural products
and are associated with antitumor,3a the treatment of
Chagas disease,3b molluscicidal,4a KATP channel open-
ing,5a and myocardial ischemia5b activities. Such motifs
are being incorporated into newer scaffolds using the
domino Knoevenagel hetero-Diels–Alder reaction.6 In
The reaction of b-vinyl-meso-tetraphenylporphyrina-
tozinc(II)9 (4) with the quinone methide 5, generated in
situ from 2-hydroxy-1,4-naphthoquinone (1) and
paraformaldehyde, was performed in refluxing dioxane
until complete disappearance of 4 (monitored by TLC).10
Starting the reaction with one equivalent of 1 and eight
equivalents of paraformaldehyde, it was observed that
gradual addition of another two equivalents of 1 (1 equiv
each time after 12 and 36 h of reaction) and paraformalde-
hyde, in the same ratio, was required for the reaction to
reach completion after 48 hours. On workup of the reac-
tion mixture and its purification by column and prepara-
tive thin-layer chromatography two new compounds were
isolated; these were identified as the porphyrin derivatives
8 and 9 in 44% and 22% yield, respectively (entry 1,
Table 1).
this context, the synthesis of molecules by coupling enti- Table 1 Products and Yields of Reaction Using Vinyl Porphyrin 4
with o-Quinone Methides 5, 6a,b, and 7a,b
ties containing well-established pharmacological activi-
ties with porphyrins may be a good strategy for the
discovery of new molecules with dual function potential.
Entry Product o-QM Solvent
Time (h) Yields (%)
1
8
9
5
dioxane 48
dioxanea 24
44
22
O
2
8
9
5
50
22
O
O
HO
HO
HO
3
4
5
10a
10b
6a
6b
7a
dioxane
dioxane
1
1
88
95
HO
R1
R1
O
1
3a, R1 = H
2a, R1 = H
2b, R1 = CH3
11a
11c
o-DCBb 26
49
8
3b, R1 = OCH3
Figure 1 Precursors of o-quinone methides
6
11b
7b
o-DCBb
6
86
a Catalytic AcOH.
b o-DCB = o-Dichlorobenzene.
SYNLETT 2011, No. 13, pp 1841–1844
x
x
.x
x
.2
0
1
1
Advanced online publication: 14.07.2011
DOI: 10.1055/s-0030-1260947; Art ID: D14111ST
© Georg Thieme Verlag Stuttgart · New York

1842
J. C. J. M. D. S. Menezes et al.
LETTER
Ph
Zn
Ph
R
2
1
N
N
N
N
N
N
N
o-quinone methide
Ph
Ph
Ph
Ph
Zn
dioxane or o-DCB
reflux
N
O
Ph
8–11
Ph
4
O
O
O
O
O
O
O
5
R1
6a, R1 = H
R1
7a, R1 = H
6b, R1 = CH3
7b, R1 = OCH3
HO
O
12
O
O
O
6'
9'
4'
5'
5'
5'
O
O
6'
2'
b
R =
O
O
7'
O
O
a
10'
R1
10'
11a, R1 = H, 49%
8, 50%
9, 22%
R1
11b, R1 = OCH3, 86%
10a, R1 = H, 88%
11c, R1
=
, 8%
1''
2''
10b, R1 = CH3, 95%
OH
Scheme 1 Reactions of porphyrin 4 with the o-quinone methides
Attempts were carried out to reduce the reaction time of 4 This reaction was extended to 4-hydroxycoumarin (2a)
with 5. It was found that, by addition of a few drops of and 4-hydroxy-6-methylcoumarin (2b). In these cases we
acetic acid6c and also by one addition, after 6 hours, of o- observed that the o-quinone methides (6a and 6b,
quinone methide precursors (1 and paraformaldehyde, Scheme 1) of these coumarins are more reactive than the
1:8), the reaction was completed in 24 hours giving rise to o-quinone methide 5. This is evident from the shorter re-
compounds 8 and 9 in 50% and 22% yields, respectively action times and higher yields (entries 3 and 4, Table 1).
(entry 2, Table 1).
The reaction of porphyrin 4 with intermediates 6a and 6b
showed complete consumption of 4 in one hour (TLC),
and after workup and column purification the adducts
10a13 (88% yield) and 10b (95% yield) were isolated. In
both cases just one equivalent of the corresponding quino-
ne methide precursor was sufficient for reaction comple-
tion. The 1H NMR spectra show similarities except for the
appearance of a singlet for the methyl group at d = 2.33
ppm in 10b. The analysis of the 13C NMR spectrum of 10a
indicated a peak at d = 163.4 ppm for the coumarin carbo-
nyl group. This shows that the addition occurred selec-
tively at the 3,4-position of the coumarin nucleus. This
was confirmed by HMBC correlation of the H-4¢ protons
with the carbonyl carbon C-5¢ (d = 163.4 ppm), the qua-
ternary carbon C-10¢b (d = 160.7 ppm) and the C-2¢ (d =
75.9 ppm) of the dihydropyran ring.
This result shows that this reaction is highly regioselective
and site-selective, as observed for similar systems.6c,d,11
The structures of the new porphyrin derivatives 8 and 9
were confirmed by NMR and UV/vis spectroscopy and
high-resolution mass spectrometry.12 The mass spectra of
8 and 9 show the same peak at m/z = 889.2143 and
889.2122, respectively, corresponding to the [M + H]+
ion. The 1H NMR of isomer 8 shows multiplets in the re-
gion d = 2.12–2.79 ppm for the H-3¢ and H-4¢ protons and
a doublet at d = 4.95 ppm for the H-2¢ proton. In the HSQC
spectrum, the H-2¢ proton correlates with the resonance at
d = 75.8 ppm which indicates the presence of a dihydro-
pyran ring. The 1H NMR spectrum of isomer 9 shows sim-
ilarities with the one from 8 concerning the porphyrin
macrocycle, pyran ring, and the aromatic signals of naph-
thoquinone part. Detailed analysis of the NMR spectra al-
lowed us to assign the product with higher Rf as being
isomer 8 and the other as the isomer 9. The 2D HMBC
clearly showed correlations of the aromatic protons (H-6¢
and H-9¢) of the naphthalene moiety with the carbonyl
groups (C-5¢ and C-10¢) in 8 and the aliphatic (H-4¢) and
aromatic proton (H-7¢) with the carbonyl groups (C-5¢ and
C-6¢) in 9.
A simple hetero-Diels–Alder reaction wherein the qui-
none methide can be formed in situ from the appropriately
substituted o-hydroxybenzyl alcohols14 was also studied.
The reaction of porphyrin 4 with o-hydroxybenzyl alcohol
(3a), which generates quinone methide 7a (Scheme 1), in
refluxing o-dichlorobenzene (o-DCB) and subsequent
gradual addition of a further equivalent of the alcohol 3a
after 6 and 24 hours showed complete consumption of
starting porphyrin 4 (26 h) and gave two new compounds,
Synlett 2011, No. 13, 1841–1844 © Thieme Stuttgart · New York

LETTER
Reaction of b-Vinyl-meso-tetraphenylporphyrin with o-Quinone Methides
1843
Smith, K. M.; Guilard, R., Eds.; World Scientific Publishing
Company: Singapore, 2010, 193.
(3) (a) Ferreira, V. F.; Ferreira, S. B.; da Silva, F. C. Org.
Biomol. Chem. 2010, 8, 4793; and references cited therein.
(b) Salas, C. O.; Faúndez, M.; Morello, A.; Maya, J. D.;
Tapia, R. A. Curr. Med. Chem. 2011, 18, 144.
(4) (a) Kady, M. M.; Brimer, L.; Furu, P.; Lemmich, S.; Nieslen,
H. M.; Thiilborg, S. T.; Thastrup, O.; Christenesen, S. B.
Planta Med. 1992, 58, 334. (b) Mahmoud, A. A.; Ahmed,
A. A.; Linuma, M.; Tanaka, T. Phytochemistry 1998, 47,
543.
(5) (a) Florence, X.; Sebille, S.; de Tullio, P.; Lebrun, P.;
Pirotte, B. Bioorg. Med. Chem. 2009, 17, 7723.
(b) Rapposelli, S.; Breschi, M. C.; Calderone, V.;
Digiacomo, M.; Martelli, A.; Testai, L.; Vanni, M.;
Balsamo, A. Eur. J. Med. Chem. 2011, 46, 966.
(6) (a) Rokita, S. E. Quinone Methides; Wiley: Hoboken, 2009.
(b) Tietze, L. F.; Rackelman, N. In Multicomponent
Reactions; Zhu, J.; Bienaymé, H., Eds.; Wiley-VCH:
Weinheim, 2005, 121. (c) da Silva, F. C.; Ferreira, S. B.;
Kaiser, C. R.; Pinto, A. C.; Ferreira, V. F. J. Braz. Chem.
Soc. 2009, 20, 1478. (d) Ferreira, S. B.; da Silva, F. C.;
Bezerra, F. A. F. M.; Lourenco, M. C. S.; Kaiser, C. R.;
Pinto, A. C.; Ferreira, V. F. Arch. Pharm. Chem. Life Sci.
2010, 343, 81. (e) Appendino, G.; Cravotto, G.; Toma, L.;
Annunziata, R.; Palmisano, G. J. Org. Chem. 1994, 59,
5556. (f) Khoshkholgh, M. J.; Lotfi, M.; Balalaie, S.;
Rominger, F. Tetrahedron 2009, 65, 4228. (g) Yadav, J. S.;
Reddy, B. V. S.; Narsimhaswamy, D.; Lakshmi, P. N.;
Narsimulu, K.; Srinivasulu, G.; Kunwar, A. C. Tetrahedron
Lett. 2004, 45, 3493.
which were separated by column and preparative thin-
layer chromatography.15
The major product (with higher Rf) was identified as being
the adduct 11a16 (49% yield). The product with lower Rf
11c17 (8% yield) showed a molecular ion at m/z =
914.2583. Its 1H NMR spectrum shows a multiplet for 4 H
at d = 2.17–2.75 ppm, two doublets at d = 3.79 and 3.92
ppm for 1 H each (J = 14.4 Hz) and a double doublet at
d = 4.97 ppm for 1 H. The aromatic region shows a double
doublet at d = 6.47 ppm (1 H), a double triplet at d = 6.75
ppm (1 H), a triplet at d = 6.84 ppm (1 H), a singlet for a
phenolic proton at d = 6.87 ppm, multiplet at d = 6.93–
6.97 ppm (2 H), and two double doublets at d = 7.12 ppm
and d = 7.20 ppm for 1 H each, indicating there was addi-
tion of a second molecule of 3a.
It was observed by TLC that compound 11c is formed in
the reaction mixture within two hours of reaction time.
Therefore a reaction of compound 11a with excess of al-
cohol 3a was carried out under similar conditions, but it
resulted in total recovery of starting material, thus indicat-
ing that 11a is not a precursor of 11c. Therefore the for-
mation of this compound under the observed experimental
conditions can be justified by the formation of the conden-
sation dimer, 2,2¢-dihydroxy-3-(hydroxymethyl)diphe-
nylmethane, which has been previously identified by GC-
MS analysis18 as a product on heating alcohol 3a above
200 °C. This dimer may form the quinone methide 12 in
situ which can react with porphyrin 4 to give product 11c.
(7) Tomé, A. C.; Lacerda, P. S. S.; Neves, M. G. P. M. S.;
Cavaleiro, J. A. S. Chem. Commun. 1997, 1199.
(8) (a) Faustino, M. A. F.; Neves, M. G. P. M. S.; Tomé, A. C.;
Silva, A. M. S.; Cavaleiro, J. A. S. ARKIVOC 2005, (ix),
332. (b) Oliveira, K. T.; Silva, A. M. S.; Tomé, A. C.; Neves,
M. G. P. M. S.; Neri, C. R.; Garcia, V. S.; Serra, O. A.;
Iamamoto, Y.; Cavaleiro, J. A. S. Tetrahedron 2008, 64,
8709.
Reaction of 4 and 2-hydroxy-3-methoxybenzyl alcohol
3b, followed by three additions of one equivalent of that
alcohol after one, three, and five hours gave compound
11b (86% yield) after six hours reaction time.
In conclusion, the hetero-Diels–Alder reaction has been
successfully used in the derivatization of b-vinyl-meso-
tetraphenylporphyrin leading to macrocycles containing
(9) Callot, H. J. Tetrahedron 1973, 29, 899.
(10) General Procedure for Preparing Compounds 8, 9, and
10a,b
5,10-dioxobenzo[g]chromene,
5,6-dioxobenzo[h]-
In a round-bottom flask, equipped with a magnetic stirring
bar, a solution of 2-hydroxy-1,4-naphthoquinone (1, 6.2 mg,
35.5 mmol) [or 4-hydroxycoumarins (2a, 5.7 mg; 2b, 6.2 mg;
35.5 mmol)], 1,4-dioxane (5 mL), paraformaldehyde (8.5
mg, 284 mmol), and porphyrin 4 (25 mg, 35.5 mmol) was
heated at reflux until consumption of the starting porphyrin
4 (1–48 h). Quinone methide precursors were added at
regular intervals. Dioxane was then removed under reduced
pressure, CHCl3 (50 mL) was added to the residue, and the
mixture was washed with sat. aq NaHCO3 (2 × 20 mL). The
organic phase was concentrated under vacuum, and the
residual crude product was purified by column chromatog-
raphy on silica gel and subsequently by preparative TLC
using CHCl3 as the eluent.
chromene, pyrano[3,2-c]coumarin, and benzopyran
motifs at the b-position. Studies on the reaction of these o-
quinone methides with natural vinylporphyrins are under
investigation in our laboratory.
Acknowledgment
Thanks are due to the University of Aveiro, ‘Fundação para a Ciên-
cia e a Tecnologia’ (FCT-Portugal) and FEDER for funding the
QOPNA Research Unit and the Portuguese National NMR network.
JCJMDS Menezes thanks QOPNA for a research grant. Thanks are
also due to the CAPES (Brazil)-FCT (Portugal) Cooperation Agree-
ment 2011/2012.
(11) Wang, H.; Wang, Y.; Han, K. L.; Peng, X. J. J. Org. Chem.
2005, 70, 4910.
(12) Unequivocal proton and carbon assignments for all
compounds were based on two-dimensional COSY, HSQC,
and HMBC experiments.
References and Notes
(1) Handbook of Porphyrin Science, Vol. 4 and 12; Kadish, K.;
Smith, K. M.; Guilard, R., Eds.; World Scientific Publishing
Company: Singapore, 2010.
(2) (a) Tomé, A. C.; Neves, M. G. P. M. S.; Cavaleiro, J. A. S.
J. Porphyrins Phthalocyanines 2009, 13, 408.
Data for {2-(5,10-Dioxo-3,4,5,10-tetrahydro-2H-
benzo[g]chromen-2-yl)-5,10,15,20-
tetraphenylporphyrinato}zinc(II) (8)
1H NMR (300 MHz, CDCl3): d = 2.12–2.32 (m, 2 H, H-3¢
and H-4¢), 2.54–2.79 (m, 2 H, H-3¢ and H-4¢), 4.95 (d, J = 8.3
Hz, 1 H, H-2¢), 7.49–7.54 (m, 1 H, Hp-Ph), 7.65–7.76 (m, 13
(b) Cavaleiro, J. A. S.; Tomé, A. C.; Neves, M. G. P. M. S.
In Handbook of Porphyrin Science, Vol. 2; Kadish, K.;
Synlett 2011, No. 13, 1841–1844 © Thieme Stuttgart · New York

1844
J. C. J. M. D. S. Menezes et al.
LETTER
(4.00) nm. HRMS (ESI+): m/z [M + H]+ calcd for
C56H37N4O3Zn: 877.2152; found: 877.2116.
(14) Van de Waters, R. W.; Pettus, T. R. R. Tetrahedron 2002,
58, 5367; and references cited therein.
H, Hm,p-Ph, H-7¢ and H-8¢), 8.07–8.11 (m, 2 H, H-6¢ and H-
9¢), 8.14–8.23 (m, 8 H, Ho-Ph), 8.73 (d, J = 4.8 Hz, 1 H, H-
b), 8.89 (d, J = 4.8 Hz, 1 H, H-b), 8.92 (d, J = 4.8 Hz, 1 H,
H-b), 8.93 (s, 2 H, H-12 and H-13), 8.95 (d, J = 4.8 Hz, 1 H,
H-b), 9.12 (s, 1 H, H-3). 13C NMR (75 MHz, CDCl3):
d = 20.2 (C-4¢), 29.4 (C-3¢), 75.8 (C-2¢), 120.4, 121.1, 121.2,
121.5, 121.7 (C-4¢a and 2 C-quat), 126.0, 126.2, 126.3,
126.4, 126.6, 126.65, 126.7, 127.5, 128.3 (Co-Ph, Cm,p-Ph,
C-6¢, C-9¢), 131.1; 131.6, 132.0, 132.2, 132.2, 132.5 (C-b),
132.9 (Co-Ph, C-3), 133.0, 133.3, 133.8, 134.4, 134.42,
134.7 (C-7¢, C-8¢, Co-Ph, Cm,p-Ph), 142.5, 142.6,
142.7,143.3 (C-1), 145.8, 147.9, 150.3, 150.4, 150.5, 150.6,
150.9, 156.2 (C-10a¢), 179.5 (C-5¢), 184.5 (C-10¢); UV/vis
(CHCl3): lmax (log e) = 424 (4.94), 554 (4.57), 597 (3.96)
nm. HRMS (ESI+): m/z [M + H]+ calcd for C57H37N4O3Zn:
889.2152; found: 889.2143.
(15) General Procedure for Preparing 11a–c
A mixture of porphyrin 4 (10 mg, 14.2 mmol) and
appropriate benzyl alcohol (3a, 1.7 mg; 3b, 2.2 mg; 14.2
mmol) was refluxed in o-dichlorobenzene (3 mL) in a sealed
tube until consumption of starting porphyrin 4 (monitored by
TLC) with addition of quinone methide precursors at regular
intervals. After completion of reaction (6–26 h) the mixture
was loaded on a silica column or preparative TLC plate and
eluted with PE. Further elution with CHCl3 gave the
corresponding adducts.
(16) Data for [2-(Chroman-2-yl)-5,10,15,20-
tetraphenylporphyrinato]zinc(II) (11a)
Data for {2-(5,6-Dioxo-3,4,5,6-tetrahydro-2H-
benzo[h]chromen-2-yl)-5,10,15,20-
tetraphenylporphyrinato}zinc(II) (9)
1H NMR (300 MHz, CDCl3): d = 2.14–2.26 (m, 1 H, H-3¢),
2.43–2.55 (m, 1 H, H-3¢), 2.56–2.74 (m, 2 H, H-4¢), 4.95 (d,
J = 9.6 Hz, 1 H, H-2¢), 6.85–6.94 (m,2 H, H-6¢ and H-8¢),
7.07–7.21 (m, 2 H, H-5¢ and H-7¢), 7.53–7.59 (m, 1 H, Hp-
Ph), 7.68–7.80 (m, 11 H, Hm,p-Ph), 8.15–8.23 (m, 8 H, Ho-
Ph), 8.73 (d, J = 4.7 Hz, 1 H, H-b), 8.89 (d, J = 4.7 Hz, 1 H,
H-b), 8.91 (d, J = 4.7 Hz, 1 H, H-b), 8.92 (s, 2 H, H-12 and
1H NMR (500 MHz, CDCl3): d = 2.16–2.24 (m, 2 H, H-3¢
and H-4¢), 2.58–2.61 (m, 1 H, H-3¢), 2.71–2.75 (m, 1 H, H-
4¢), 5.08 (d, J = 10.2 Hz, 1 H, H-2¢), 7.47–7.51 (m, 2 H, H-
8¢, 1 Hp-Ph), 7.55 (dt, J = 7.6, 1.6 Hz, 1 H, H-9¢), 7.71–7.81
(m, 12 H, Hm,p-Ph, H-10¢), 8.09 (dd, J = 7.6, 1.3 Hz, 1 H, H-
7¢), 8.16–8.24 (m, 8 H, Ho-Ph), 8.76 (d, J = 4.6 Hz, 1 H, H-
b), 8.91 (d, J = 4.6 Hz, 1 H, H-b), 8.95 (s, 2 H, H-12 and H-
13), 8.96 (d, J = 4.6 Hz, 1 H, H-b), 8.97 (d, J = 4.6 Hz, 1 H,
H-b), 9.14 (d, J = 0.7 Hz, 1 H, H-3). 13C NMR (125 MHz,
CDCl3): d = 19.8 (C-4¢), 29.8 (C-3¢), 76.9 (C-2¢), 114.2 (C-
4¢a), 120.4, 121.1, 121.4, 121.7, 124.2 (C-10¢), 126.4, 126.5,
126.6, 126.7, 127.6, 127.7 (Cm,p-Ph), 128.6, 128.7 (Cm,p-
Ph, C-7¢), 129.9 (C-6¢a), 130.6 (C-8¢), 131.8, 132.27, 132.30,
132.33, 132.4, 132.43 (C-b), 132.6 (C-3, C-10¢a), 133.4,
133.5, 134.36, 134.4, 134.42; 134.5 (C-o), 134.75 (C-9¢),
142.3, 142.5, 142.7, 143.2 (C-1), 145.5, 147.7, 150.21,
150.4, 150.57, 150.6, 150.7, 150.8, 163.6 (C-10b¢), 178.7
(C-5¢), 179.7 (C-6¢); UV/vis (CHCl3): lmax (log e): 424
(4.85), 552 (4.52), 596 (3.96) nm. HRMS (ESI+): m/z [M +
H]+ calcd for C57H37N4O3Zn: 889.2152; found: 889.2122.
H-13), 8.95 (d, J = 4.7 Hz, 1 H, H-b), 9.16 (s, 1 H, H-3). 13
C
NMR (75 MHz, CDCl3): d = 26.2 (C-4¢), 31.7 (C-3¢), 74.2
(C-2¢), 117.1 (C-8¢), 120.0 (C-6¢), 120.6, 120.9, 121.1, 121.5,
122.1 (C-4¢a), 126.1, 126.5, 126.55, 127.0, 127.5, 128.1 (C-
7¢, Cm,p-Ph), 129.5 (C-5¢), 131.5, 131.9, 132.0, 132.1,
132.4, 132.5 (C-b), 133.3, 133.7, 134.3, 134.4, 134.42, 134.6
(Co-Ph), 142.6, 142.7, 142.8, 145.9, 146.5 (C-1), 148.4,
150.0, 150.2, 150.3, 150.5, 150.9, 155.6 (C-8¢a). UV/vis
(CHCl3): lmax (log e): 420 (4.98), 548 (4.59) nm. HRMS
(ESI+): m/z [M + H]+ calcd for C53H37N4Ozn: 809.2253;
found: 809.2273.
(17) Data for {2-[8-(2-Hydroxybenzyl)chroman-2-yl)]-
5,10,15,20-tetraphenylporphyrinato}zinc(II) (11c)
1H NMR (300 MHz, CDCl3): d = 2.17–2.75 (m, 4 H, H-
3¢and H-4¢), 3.79 (d, J = 14.4 Hz, 1 H, CH2), 3.92 (d,
J = 14.4 Hz, 1 H, CH2), 4.97 (dd, J = 10.4, 1.1 Hz, 1 H, H-
2¢), 6.47 (dd, J = 8.0, 1.1 Hz, 1 H, H-3¢¢), 6.75 (dt, J = 7.5,
1.1 Hz, 1 H, H-5¢¢), 6.84 (t, J = 7.4 Hz, 1 H, H-6¢), 6.87 (s, 1
H, OH), 6.93–6.97 (m, 2 H, H-5¢ and H-4¢¢), 7.12 (dd,
J = 7.4, 1.4 Hz, 1 H, H-7¢), 7.20 (dd, J = 7.5, 1.6 Hz, 1 H, H-
6¢¢), 7.52–7.55 (m, 1 H, Hp-Ph), 7.66–7.76 (m, 11 H, Hm,p-
Ph), 8.17–8.33 (m, 8 H, Ho-Ph), 8.77 (d, J = 4.7 Hz, 1 H, H-
b), 8.89 (d, J = 4.7 Hz, 1 H, H-b), 8.93 (s, 2 H, H-b), 8.95 (s,
2 H, H-b), 9.26 (s, 1 H, H-3). 13C NMR (75 MHz, CDCl3):
d = 26.3 (C-4¢), 30.5 (CH2), 31.2 (C-3¢), 75.3 (C-2¢), 116.4
(C-3¢¢), 120.3 (C-5¢¢), 120.6, 120.8 (C-6¢), 121.07, 121.13,
121.4, 122.2 (C-4¢a), 126.2, 126.4, 126.5 (Cm,p-Ph), 127.0
(Cm,p-Ph, C-1¢¢), 127.5, 127.6, 127.8 (C-8¢), 128.1 (C-4¢¢,
C-7¢, C-5¢, Cm,p-Ph), 128.2, 130.4 (C-6¢¢), 130.5; 131.5,
132.06, 132.1, 132.2, 132.4 (C-b), 132.8 (C-3), 133.4, 133.6,
134.4, 134.5, 134.9 (Co-Ph), 142.8, 142.9, 144.9, 145.8,
148.1, 150.2, 150.2, 150.4, 150.4, 150.5, 150.8, 151.6 (C-
8¢a), 154.0 (C-2¢¢). UV/vis (CHCl3): lmax (log e): 420 (5.72),
547 (4.59) nm. HRMS (ESI+): m/z [M]+ calcd for
(13) Data for {2-(5-Oxo-2,3,4,5-tetrahydro-2H-pyrano[3,2-
c]chromen-2-yl)-5,10,15,20-
tetraphenylporphyrinato}zinc(II) (10a)
1H NMR (500 MHz, CDCl3): d = 2.25–2.29 (m, 2 H, H-3¢
and H-4¢), 2.61–2.67 (m, 2 H, H-3¢ and H-4¢), 5.04 (d, J = 8.5
Hz, 1 H, H-2¢), 7.19 (ddd, J = 8.1, 7.2, 1.0 Hz, 1 H, H-9¢),
7.34 (dd, J = 8.5, 1.0 Hz, 1 H, H-7¢), 7.40–7.45 (m, 1 H, Hp-
Ph), 7.49 (ddd, J = 8.5, 7.2, 1.4 Hz, 1 H, H-8¢), 7.71–7.81 (m,
12 H, Hm,p-Ph, H-10¢), 8.16–8.23 (m, 8 H, Ho-Ph), 8.75 (d,
J = 4.6 Hz, 1 H, H-b), 8.90 (d, J = 4.6 Hz, 1 H, H-b), 8.94 (s,
2 H, H-12 and H-13), 8.95 (d, J = 4.6 Hz, 1 H, H-b), 8.97 (d,
J = 4.6 Hz, 1 H, H-b), 9.15 (d, J = 0.5 Hz, 1 H, H-3). 13
C
NMR (125 MHz, CDCl3): d = 20.9 (C-3¢), 30.0 (C-4¢), 75.9
(C-2¢), 101.2 (C-4¢a), 115.9 (C-10¢a), 116.5 (C-7¢), 120.5,
121.1, 121.3, 121.6, 122.5 (C-10¢), 123.7 (C-9¢), 126.4,
126.5, 126.6, 126.7, 127.6, 127.7, 128.5 (Cm,p-Ph), 131.2
(C-8¢), 131.7, 132.3, 132.35, 132.6 (C-b), 133.4, 133.5,
134.37, 134.4, 134.42, 134.47, 134.5 (Co-Ph), 142.3, 142.4,
142.5, 142.7, 143.5 (C-1), 145.6, 147.8, 150.2, 150.4, 150.5,
150.6, 150.9, 152.4 (C-6¢a), 160.7 (C-10¢b), 163.4 (C-5¢).
UV/vis (CHCl3): lmax (log e): 425 (4.94), 555 (4.54), 596
C60H42N4O2Zn: 914.2594; found: 914.2583.
(18) Dorrestijn, E.; Kranenburg, M.; Ciriano, M. V.; Mulder, P.
J. Org. Chem. 1999, 64, 3012.
Synlett 2011, No. 13, 1841–1844 © Thieme Stuttgart · New York