C. Monnereau et al. / Tetrahedron 61 (2005) 10113–10121
10119
dissolved in THF and chromatographied on LH 20
4.2. General procedure for iodination of amino nitro-
benzoic acid (compound 13 or 19)
Sephadex stationary phase and the major green band was
collected. Finally, the green powder was dissolved in a
minimum volume of dichloromethane and precipitated with
methanol. After filtration, a green powder was obtained
(320 mg, 85%).
A solution of the amino nitrobenzoic acid 12 or 18 (4.5 g,
24.7 mmol) in 45 mL of 0.5 M aq NaOH was heated at
70 8C until complete dissolution. Then, 10 mL of 12 N HCl
were added dropwise, giving rise to a fine precipitate. The
mixture was then cooled at 0 8C with an ice bath and NaNO2
(1.7 g, 21.7 mmol) in 5 mL of water was added. The
precipitate partly dissolved and the mixture was stirred for
1 h at 0 8C. The mixture was filtered while the filtrate was
carefully kept at 0 8C. Then, a saturated solution of KI
(8.4 g, 50 mmol) was added dropwise on the precipitate
causing a strong release of N2. The mixture turned to red and
a precipitate appeared. The ice bath was removed and the
mixture was stirred for two additional hours. After filtration
and washing with water, the iodo nitrobenzoic acid was
obtained as an orange solid (4.7 g, 65%).
3
1H NMR (300 MHz, CDCl3), d (ppm): 9.77 (d, 2H, JZ
4.8 Hz); 9.72 (d, 2H, 3JZ4.5 Hz); 8.94 (m, 4H); 8.05 (d, 4H,
3
4
4JZ1.8 Hz); 7.87 (d, 2H, JZ9.0 Hz); 7.81 (t, 2H, JZ
1.8 Hz); 6.88 (d, 2H, 3JZ9.0 Hz); 6.14 (s, 1H); 5.62 (s, 1H);
3
3
4.38 (t, 2H, JZ6.3 Hz); 3.72 (t, 2H, JZ6.3 Hz); 3.55 (q,
2H, 3JZ7.2 Hz); 1.97 (s, 3H); 1.4–1.6 (m, 57H); 1.25 (t, 3H,
3JZ7.2 Hz). FT-IR (cmK1): 2960 (s, t-Bu); 2930 (s, i-Pr);
2863 (m, –CH2–); 2183 (m, C^C); 2136 (m, C^C);
1718 (m, C]O); 1212 (s). HR-ESMS, m/z: calcd for
C75H89N5O2SiZn: 1183.608 (MC%), found: 1183.609
(MC%).
4.2.1. 2-Iodo-5-nitrobenzoic acid 13.39,40 1H NMR 13
(300 MHz, CDCl3), d (ppm): 8.83 (d, 1H, 4JZ2.7 Hz); 8.30
(d, 1H, 3JZ8.7 Hz); 8.02 (dd, 1H, 3JZ8.7 Hz, 4JZ2.7 Hz);
6.3 (s broad, 1H). FT-IR (cmK1): 1710 (s, C]O); 1526 (s,
nasym NO2); 1347 (s, nsym NO2). EI-MS: MC% (%): 293
(100); 263 (36); 92 (35). MpZ197 8C.
When Plater’s conditions were used (mixture of tetrahydro-
furane (6 mL) and pyrrolidine (20mL) as solvents) and the
above catalyst (Pd2(dba)3$CHCl3 and triphenylarsine) was
replaced by Pd(PPh3)4 (6 mg) and CuI (3 mg)) the two
major products were formed. These two products were the
porphyrins 100 and 1000 that were isolated in variable yields
from one run to the other 100 (70–50%) and 1000 (10–30%).
4.2.2. 4-Iodo-3-nitrobenzoic acid 19.41,42 1H NMR 18
(300 MHz, CDCl3), d (ppm): 8.52 (d, 1H, 4JZ1.5 Hz); 8.21
(d, 1H, 3JZ6.0 Hz); 7.94 (dd, 1H, 3JZ6.0 Hz, 4JZ1.5 Hz);
4.8 (s broad, 1H). FT-IR (cmK1): 1700 (s, C]O); 1535
(s, nasym NO2); 1351 (s, nsym NO2). EI-MS: MC% (%): 293
(100); 263 (25); 136 (32); 92 (40). MpZ201 8C.
Porphyrin dimer 100. 1H NMR (300 MHz, CDCl3), d (ppm):
4
9.73 (m, 8H); 8.91 (m, 8H); 8.02 (d, 8H, JZ1.8 Hz); 7.80
4
(t, 4H, JZ1.8 Hz); 1.4–1.6 (m, 114H).
Porphyrin 1000. 1H NMR (300 MHz, CDCl3), d (ppm): 10.44
3
3
(s, 1H, CHO); 9.78 (d, 2H, JZ4.5 Hz); 9.42 (d, 2H, JZ
4.5 Hz); 9.05 (d, 2H, 3JZ4.5 Hz); 9.01 (d, 2H, 3JZ4.5 Hz);
4.2.3. tert-Butyl 2-iodo-5-nitrobenzoate: 14. Compound
13 (1.75 g, 6 mmol) was dissolved in THF (36 mL).
Dicyclohexylcarbodiimide (DCC, 1.85 g, 6.9 mmol) and
tert-BuOH (2.83 mL, 30 mmol) were added. DMAP
(20 mg) were added and the mixture was heated for 20 h
at 70 8C. The solvents were removed and the residue was
purified by a column chromatography on silica gel eluted
with the mixture dichloromethane/petroleum ether: 30:70.
The pure product 14 was isolated as white crystals (1.35 g,
65%).
8.04 (d, 4H, JZ1.8 Hz); 7.80 (t, 2H, 4JZ1.8 Hz); 5.98 (s,
4
2H); 1.4–1.6 (m, 57H). FT-IR (cmK1): 2956–2900 (vs, t-Bu,
i-Pr); 2864 (m, –CH2–); 2810 and 2710 (w, CO–H); 2138
(m, C^C); 1724 (m, C]O). MS(MALDI-TOF), m/z: calcd
for C61H72N4OSiZn: 970.492 (MC%), found: 970 (77%),
971 (48%), 972 (100%), 973 (72%), 974 (74%), 975 (35%).
4.1.8. {5,15-Bis-(3,5-di-tert-butylphenyl)-10-ethynyl-20-
[ethyl(methacryloyloxyethyl) aminophenylethynyl]-por-
phyrinato} zinc (II): 11. One hundred and fifty microlitres
of 1 M Bu4NF in THF (0.15 mmol) was added to a solution
of porphyrin 10 (150 mg, 0.126 mmol in 150 mL of THF).
The mixture was stirred for 30 min at room temperature.
The solvent was partly removed, water was added and the
mixture was extracted with dichloromethane. After evapo-
ration of the solvents, the residue was redissolved in a
minimum amount of dichloromethane, petroleum ether was
added to precipitate the porphyrin (130 mg, 100%).
4
1H NMR (300 MHz, CDCl3), d (ppm): 8.47 (d, 1H, JZ
3.1 Hz); 8.16 (d, 1H, 3JZ8.7 Hz); 7.93 (dd, 1H, 3JZ8.7 Hz,
4JZ3.1 Hz); 1.65 (s, 9H). 13C NMR (300 MHz, CDCl3), d
(ppm): 164.22; 147.69; 142.30; 138.71; 125.69; 124.89;
101.83; 84.20; 28.07. FT-IR (cmK1): 2980 (m, tert-Bu);
1713 (s, C]O); 1526 (s, nasym NO2); 1341 (s, nsym NO2).
EI-MS: MC% (%): 349 (16); 293 (97); 276 (38); 75 (36); 57
(89); 56 (100). MpZ107 8C.
3
1H NMR (300 MHz, CDCl3), d (ppm): 9.74 (d, 2H, JZ
4.2.4. {5,15-Bis-(3,5-di-tert-butylphenyl)-10-(4-nitro-2-
carboxyphenyl)ethynyl-20-[ethyl (methacryloyloxy-
ethyl)aminophenylethynyl]-porphyrinato} zinc (II): 15.
Porphyrin 11 (75 mg, 0.073 mmol) and compound 13
(25 mg, 0.085 mmol) were dissolved in THF (2 mL),
Et3N (2 mL) and toluene (6 mL). The mixture was
intensively degassed with three freeze–pump–thaw cycles.
Pd2(dba)3$CHCl3 (7 mg) and AsPh3 (7 mg) were added and
the mixture was heated for 2 h at 50 8C. The crude reaction
mixture was filtered through a short plug of celite and the
4.8 Hz); 9.64 (d, 2H, 3JZ4.5 Hz); 8.96 (m, 4H); 8.06 (d, 4H,
3
4
4JZ1.8 Hz); 7.82 (d, 2H, JZ9.0 Hz); 7.80 (t, 2H, JZ
1.8 Hz); 6.85 (d, 2H, 3JZ9.0 Hz); 6.13 (s, 1H); 5.61 (s, 1H);
3
3
4.38 (t, 2H, JZ6.3 Hz); 4.06 (s, 1H); 3.71 (t, 2H, JZ
6.3 Hz); 3.54 (q, 2H, 3JZ7.2 Hz); 1.97 (s, 3H); 1.4–1.6 (m,
57H); 1.28 (t, 3H, 3JZ7.2 Hz). FT-IR (cmK1): 2960 (s, tert-
Bu); 2863 (m, –CH2–); 2138 (m, C^C); 1718 (m, C]O);
1212 (s). UV–vis (CH2Cl2): lmax, nm (3, molK1 L cmK1):
432 (205,000); 568 (11,000); 616 (10,000).