Synthesis of Conjugated Dendrons
G1-Ester . A mixture consisting of compounds 5 (0.387 g,
0.59 mmol), 7b (0.238 g, 1.18 mmol), Pd(PPh3)2Cl2 (0.017 g,
0.023 mmol), and CuI (0.009 g, 0.047 mmol) in 5 mL of
anhydrous triethylamine was stirred at room temperature
under N2. After 12 h, the solvent was removed under reduced
pressure and the residue was dissolved in CH2Cl2. The
resulting solution was washed with an aqueous HCl solution
and then with water. The organic layer was separated and
dried over Na2SO4. After removal of solvent, the brown resi-
due was flash chromatographed on a column of silica gel
eluting with 5:5:1 hexane/ethyl acetate/MeOH to give the
compound G1-E st er as a colorless oil (0.412 g, 87%). 1H
NMR (CDCl3, ppm): δ 7.97 (d, J ) 8.5 Hz, 4H), 7.57 (d, J )
8.5 Hz, 4H), 7.10 (s, 2H), 4.17 (t, J ) 5.0 Hz, 4H), 3.89 (t, J )
5.0 Hz, 4H), 3.79-3.64 (m, 12H), 3.56 (t, J ) 5.0 Hz, 4H), 3.38
(s, 6H), 1.61 (s, 18H). 13C NMR (CDCl3, ppm): δ 165.3, 149.4,
131.6, 131.3, 129.6, 129.5, 127.7, 124.9, 123.9, 119.0, 117.8,
116.7, 92.1, 91.0, 81.5, 72.1, 71.1, 70.9, 70.7, 69.7, 69.0, 59.2,
28.4. Anal. Calcd for C46H58O12: C, 68.81; H, 7.28. Found: C,
68.63; H, 7.14. Calcd MALDI-TOF for C46H58O12 802.95, found
802.86.
Com p ou n d 10b. The synthetic procedure is similar to that
of G2-Ester . Yield: 81%. Mp: 113-115 °C. H NMR (CDCl3,
1
ppm): δ 7.99 (d, J ) 8.5 Hz, 4H), 7.92 (d, J ) 8.5 Hz, 4H),
7.79 (s, 2H), 7.56 (d, J ) 8.5 Hz, 4H), 7.50 (d, J ) 8.5 Hz, 4H),
7.15 (s, 2H), 7.08 (s, 2H), 6.22 (s, 1H), 3.95-3.91 (m, 9H), 1.61
(s, 18H), 1.56 (s, 18H). 13C NMR (CDCl3, ppm): δ 165.3, 162.7,
159.5, 159.4, 147.1, 146.4, 137.4, 132.0, 131.6, 131.3, 129.7,
129.6, 127.5, 127.0, 126.5, 119.8, 118.4, 117.9, 114.3, 113.8,
95.2, 94.8, 94.7, 92.3, 90.8, 90.2, 87.9, 87.6, 81.6, 81.4, 56.3,
28.3. Anal. Calcd for C77H68O12: C, 78.02; H, 5.78. Found: C,
77.93; H, 5.91.
Com p ou n d 11b. The synthetic procedure is similar to that
of compound 9b. Yield: 75%. Mp 137-139 °C. 1H NMR (CDCl3,
ppm): δ 7.98 (d, J ) 8.5 Hz, 4H), 7.90 (d, J ) 8.5 Hz, 4H),
7.78 (s, 2H), 7.56 (d, J ) 8.5 Hz, 4H), 7.49 (d, J ) 8.5 Hz,
4H), 7.23 (s, 2H), 7.11 (s, 2H), 3.99 (s, 3H), 3.92 (s, 6H), 1.62
(s, 18H), 1.55 (s, 18H). 13C NMR (CDCl3, ppm): δ 165.3,
159.6, 151.5, 138.3, 137.6, 137.4, 132.2, 131.7, 131.4, 129.7,
129.6, 127.5, 127.4, 127.0, 125.8, 119.3, 118.5, 116.0, 113.9,
113.6, 95.2, 95.0, 93.2, 92.9, 92.6, 92.5, 90.9, 90.7, 90.6, 90.0,
89.9, 89.5, 81.7, 81.5, 56.8, 56.3, 28.4. Anal. Calcd for
C
78H67F3O14S: C, 71.11; H, 5.13. Found: C, 70.97; H, 5.21.
G1-OH (8b): The synthetic procedure for 8b is similar to
that of G1-Ester . Yield: 87%. Mp: 180-182 °C. 1H NMR
(CDCl3, ppm): δ 7.97 (d, J ) 8.5 Hz, 4H), 7.57 (d, J ) 8.5 Hz,
4H), 7.13 (s, 1H), 7.05 (s, 1H), 5.87 (s, 1H), 3.95 (s, 3H), 1.61
(s, 18H). 13C NMR (CDCl3, ppm): δ 147.1, 146.4, 131.5, 131.4,
131.3, 129.6, 127.7, 119.5, 118.1, 117.9, 113.8, 92.0, 91.7, 91.2,
90.9, 81.5, 56.3, 28.4. Anal. Calcd for C33H32O6: C, 75.55; H,
6.15. Found: C, 75.38; H, 6.27.
G1-OTf (9b). A 0.42-g sample of trifluoromethanesulfonic
anhydride (1.5 mmol, 1.5 equiv) was added slowly to the
solution of compound 8b (0.52 g, 1.0 mmol) in 10 mL of
anhydrous pyridine at 0 °C. The resulting mixture was
warmed to room temperature and stirred for 4 h, then poured
into 50 mL of water. The aqueous solution was extracted with
CH2Cl2. The organic layer was washed with an aqueous HCl
solution and then dried over Na2SO4. After the solvent was
stripped off, the residue was purified by flash column chro-
matography eluting with 6:1 hexane/ethyl acetate to yield the
title compound as a white solid (0.54 g, 83%). Mp: 175-177
oC. 1H NMR (CDCl3, ppm): δ 7.99 (d, J ) 8.5 Hz, 4H), 7.57 (d,
J ) 8.5 Hz, 4H), 7.43 (s, 1H), 7.21 (s, 1H), 3.99 (s, 3H), 1.61 (s,
18H). 13C NMR (CDCl3, ppm): δ 165.3, 165.2, 151.6, 138.4,
132.3, 132.0, 131.6, 131.5, 129.7, 127.1, 127.0, 126.6, 125.9,
121.4, 118.9, 116.3, 116.1, 94.7, 93.4, 89.3, 89.0, 81.7, 81.6, 56.7,
28.4. Anal. Calcd for C34H31F3O8S: C, 62.19; H, 4.76. Found:
C, 62.13; H, 4.91.
G3-Ester . The synthetic procedure is similar to that of G2-
1
Ester . Yield: 62%. Mp: 135-137 °C. H NMR (CDCl3, ppm):
δ 7.99-7.84 (m, 16H), 7.78 (s, 1H), 7.72 (s, 1H), 7.55-7.43 (m,
16H), 7.29-7.26 (m, 4H), 7.13-7.03 (m, 8H), 4.24 (t, J ) 5.0
Hz, 4H), 3.95-3.91 (m, 22H), 3.78 (t, J ) 5.0 Hz, 4H), 3.72-
3.69 (m, 8H), 3.57 (t, J ) 5.0 Hz, 4H), 3.39 (s, 6H), 1.68-1.55
(m, 72H). 13C NMR (CDCl3, ppm): δ 165.2, 159.6, 159.4, 149.2,
137.6, 137.3, 132.1, 131.9, 131.6, 131.3, 129.7, 129.6, 129.5,
127.6, 127.4, 127.0, 126.9, 126.8, 126.6, 119.5, 118.7, 118.5,
116.7, 114.1, 113.9, 113.8, 113.6, 95.0, 94.9, 94.6, 94.0, 92.5,
92.3, 90.9, 90.8, 90.7, 90.4, 90.1, 88.4, 88.3, 81.6, 81.5, 81.3,
72.1, 71.1, 70.9, 70.8, 69.7, 68.9, 59.2, 56.3, 28.3. Anal. Calcd
for C178H166O30: C, 76.76; H, 6.01. Found: C, 76.66; H, 5.97.
Calcd MALDI-TOF for C178H166O30 2785.20, found 2784.81.
The synthetic procedures for G1-CN, G2-CN, and G3-CN
are similar to those of G1-Ester , G2-Ester , and G3-Ester ,
respectively. The procedures for the synthesis of 8a , 9a , 10a ,
and 11a are similar to those of 8b, 9b, 10b, and 11b,
respectively.
G1-CN. Yield: 42%. Mp: 70-71 °C. 1H NMR (CDCl3, ppm):
δ 7.69-7.43 (m, 8H), 7.08 (s, 2H), 4.24 (t, J ) 5.0 Hz, 4H),
3.90 (t, J ) 5.0 Hz, 4H), 3.76 (t, J ) 5.0 Hz, 4H), 3.66 (m, 8H),
3.54 (t, J ) 5.0 Hz, 4H), 3.37 (s, 6H). 13C NMR (CDCl3, ppm):
δ 149.8, 132.4, 132.0, 128.4, 118.6, 118.5, 116.8, 111.7, 92.6,
91.0, 72.1, 71.1, 70.9, 70.8, 69.7, 69.0, 59.2. Anal. Calcd for
C
38H40N2O8: C, 69.92; H, 6.18. Found: C, 70.10; H, 6.22.
G1-OH (8a ). Yield: 82%. Mp: 190-192 °C. 1H NMR (CDCl3,
G2-Ester . A solution of 6 (0.38 g, 0.75 mmol) in 2 mL of
DMF was added slowly by portion within 1 h to the mixture
of compound 9b (0.656 g, 1.0 mmol), Pd(PPh3)2Cl2 (0.021 g,
0.03 mmol), CuI (0.012 g, 0.06 mmol), anhydrous triethylamine
(0.21 g, 2.0 mmol), and 5 mL of DMF at 75-80 °C under N2.
The resulting mixture was stirred under this temperature for
an additional 4 h. After cooling to room temperature, the
mixture was poured into water and extracted with CH2Cl2.
The organic layer was washed with an aqueous HCl solution
and then dried over Na2SO4. After removal of the solvent, the
brown residue was flash chromatographed on a column of silica
gel eluting with 5:5:1 hexane/ethyl acetate/MeOH to give the
compound G2-Ester as a bright yellow solid (0.67 g, 92%).
ppm): δ 7.66-7.57 (m, 8H), 7.14 (s, 1H), 7.05 (s, 1H), 6.10 (s,
1H), 3.97 (s, 3H). 13C NMR (CDCl3, ppm): δ 147.6, 146.9, 135.5,
134.1, 133.2, 132.1, 132.0, 130.5, 128.4, 127.9, 119.0, 118.7,
118.3, 118.1, 117.6, 114.0, 111.7, 92.8, 92.5, 90.9, 90.6, 56.4.
Anal. Calcd for C25H14N2O2: C, 80.20; H, 3.77. Found: C,
80.11; H, 3.63.
G1-OTf (9a ). Yield: 60%. Mp: 200-201 °C. 1H NMR
(CDCl3, ppm): δ 7.70-7.62 (m, 8H), 7.46 (s, 1H), 7.23 (s, 1H),
4.01 (s, 1H). 13C NMR (CDCl3, ppm): δ 152.1, 138.7, 133.2,
132.7, 132.5, 132.3, 132.2, 127.7, 127.3, 126.6, 126.3, 121.4,
118.5, 118.4, 116.4, 112.7, 112.4, 93.4, 92.3, 90.7, 90.5, 56.9.
Anal. Calcd for C26H13 F3N2O4S: C, 61.66; H, 2.59. Found: C,
61.58; H, 2.64.
G2-CN. Yield: 44%. Mp: 165-166 °C. 1H NMR (CDCl3,
ppm): δ 7.79 (s, 2H), 7.70 (d, J ) 8.5 Hz, 4H), 7.61-7.55 (m,
8H), 7.47 (d, J ) 8.5 Hz, 4H), 7.10 (s, 2H), 7.08 (s, 2H), 4.23 (t,
J ) 5.0 Hz, 4H), 3.93 (m, 10H), 3.77 (t, J ) 5.0 Hz, 4H), 3.71-
3.66 (m, 8H), 3.56 (t, J ) 5.0 Hz, 4H), 3.38 (s, 6H). 13C NMR
(CDCl3, ppm): δ 159.8, 149.4, 137.7, 132.5, 132.3, 132.1, 132.0,
128.1, 127.5, 125.8, 119.2, 118.5, 118.4, 117.8, 116.6, 114.9,
114.0, 112.6, 111.8, 95.5, 93.5, 92.1, 91.8, 91.2, 87.7, 72.1, 71.1,
1
Mp: 121-123 °C. H NMR (CDCl3, ppm): δ 7.98 (d, J ) 8.5
Hz, 4H), 7.92 (d, J ) 8.5 Hz, 4H), 7.80 (s, 2H), 7.57 (d, J ) 8.5
Hz, 4H), 7.51 (d, J ) 8.5 Hz, 4H), 7.11 (s, 2H), 7.01 (s, 2H),
4.22 (t, J ) 5.0 Hz, 4H), 3.93 (m, 10H), 3.78 (t, J ) 5.0 Hz,
4H), 3.72-3.66 (m, 8H), 3.56 (t, J ) 5.0 Hz, 4H), 3.39 (s, 6H),
1.61 (s, 18H), 1.56 (s, 18H). 13C NMR (CDCl3, ppm): δ 165.3,
159.5, 149.2, 137.4, 132.0, 131.6, 131.3, 129.7, 129.6, 127.5,
127.0, 126.5, 119.4, 118.4, 116.5, 114.2, 113.8, 94.9, 94.7, 92.4,
90.8, 90.2, 88.0, 81.6, 81.4, 72.1, 71.1, 70.9, 70.7, 69.7, 68.8,
59.2, 56.3, 28.3. Anal. Calcd for C90H94O18: C, 73.85; H, 6.47.
Found: C, 73.69; H, 6.53. Calcd MALDI-TOF for C90H94O18
1463.70, found 1462.18.
70.9, 70.8, 69.7, 68.9, 59.2, 56.4. Anal. Calcd for C74H58N4O10
C, 76.40; H, 5.03. Found: C, 76.31; H, 5.14.
:
J . Org. Chem, Vol. 67, No. 22, 2002 7785