Synthesis of Ladder-Type π-Conjugated Heteroacenes
1
2H), 7.38 (td, J ) 7.6, 0.95 Hz, 2H). These H NMR data are
18b (289 mg, 0.75 mmol) and boron tribromide (4.5 mL, 4.5 mmol;
1.0 M in dichloromethane) in dichloromethane (7 mL) (0 °C, 8 h)
according to the procedure described for the synthesis of compound
4. Purification by column chromatography (silica gel; 50% AcOEt
in hexane as an eluent, Rf 0.30) provided 262 mg of the title product
identical to that in the previous literature.31 HRMS-FAB+ (m/z)
calcd for C18H10O2 258.0681, found 258.0681.
Synthesis of 2′-Chloro-2,5-dimethoxy-4-iodobiphenyl (17). The
crude material was obtained by using 1,4-diiodo-2,5-dimethoxy-
benzene36 (2.38 g, 6.1 mmol), 2-chlorophenylboronic acid (1.9 g,
12.2 mmol), Pd(PPh3)4 (352 mg, 0.30 mmol), Na2CO3 (424 mg,
24.4 mmol) in toluene (10 mL), EtOH (5 mL), and H2O (10 mL)
(80 °C, 2 days) according to the procedure described for the
synthesis of compound 14. Purification by column chromatography
(silica gel; 10% CHCl3 in hexane as an eluent, Rf 0.45) provided
371 mg of the title product as a colorless solid (99% yield): mp
1
as a colorless solid (98% yield): decompose at 229 °C; H NMR
(CDCl3) δ 7.82 (d, J ) 1.6 Hz, 1H), 7.66 (dd, J ) 7.8, 1.4 Hz,
1H), 7.57-7.54 (m, 2H), 7.41-7.39 (m, 3H), 6.82 (s, 1H), 6.80
(s, 1H), 4.644 (s, 1H), 4.636 (s, 1H); 13C NMR (acetone-d6) δ 148.3,
147.8, 143.9, 138.4, 135.6, 134.4, 134.1, 133.7, 133.0, 131.3, 130.4,
129.9, 129.1, 127.7, 126.4, 119.1, 118.28, 118.25, 113.4. Anal.
Calcd for C19H11Cl2NO2: C, 64.07; H, 3.11; N, 3.93. Found: C,
63.80; H, 3.38; N, 3.88.
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54.1-58.6 °C; H NMR (CDCl3) δ 7.49-7.45 (m, 1H), 7.38 (s,
1H), 7.32-7.28 (m, 3H), 6.70 (s, 1H), 3.84 (s, 3H), 3.74 (s, 3H);
13C NMR (CDCl3) δ 152.5, 151.6, 137.0, 133.8, 131.6, 129.6, 129.5,
129.0, 126.6, 122.7, 113.9, 85.4, 57.2, 56.7. HRMS-FAB+ (m/z)
calcd for C14H12ClIO2 373.9571, found 373.9572.
Synthesis of 2′,5′-Bis(1,1,2,2,3,3,4,4,4-nonafluorobutanesulfo-
nyloxy)-2,2′′-dichloro-4-hexyl[1,1′:4′,1′′-terphenyl] (20a). The
crude material was obtained by using 19a (369 mg, 0.90 mmol),
triethylamine (0.43 mL, 5.3 mmol), and nonafluorobutanesulfonic
anhydride (1.1 mL, 3.5 mmol) in dichloromethane (10 mL)
(-45 °C, 7 h) according to the procedure described for the synthesis
of compound 5. Purification by column chromatography (silica gel;
25% AcOEt in hexane as an eluent, Rf 0.50) provided 785 mg of
the title product as a colorless solid (90% yield): mp 61.1-64.2 °C;
1H NMR (CDCl3) δ 7.56 (d, J ) 7.8 Hz, 1H), 7.49 (d, J ) 6.0 Hz,
2H), 7.46-7.39 (m, 3H), 7.38 (s, 1H), 7.31 (br s, 1H), 7.22 (dd, J
) 7.8, 1.1 Hz, 1H), 2.67 (t, J ) 7.6 Hz, 2H), 1.66 (quint, J ) 7.6
Hz, 2H), 1.40-1.27 (m, 6H), 0.91 (t, J ) 6.9 Hz, 3H); 13C NMR
(CDCl3) δ 146.6, 145.8, 145.6, 135.1, 134.7, 133.7, 133.3, 132.7,
132.0, 131.7, 130.9, 130.1, 129.9, 129.7, 127.3, 127.1, 125.8, 125.7,
120.8-105.8 (m, CF2CF2CF2CF3), 35.6, 31.8, 31.2, 29.0, 22.7, 14.2.
HRMS-FAB+ (m/z) calcd for C32H22Cl2F18O6S2 977.9947, found
977.9947.
Synthesis of 2′,5′-Bis(1,1,2,2,3,3,4,4,4-nonafluorobutanesulfo-
nyloxy)-2,2′′-dichloro[1,1′4′,1′′-terphenyl]-4-yl Cyanide (20b).
The crude material was obtained by using 19b (160 mg, 0.45 mmol),
triethylamine (0.38 mL, 2.7 mmol), and nonafluorobutanesulfonic
anhydride (0.55 mL, 1.8 mmol) in dichloromethane (4.5 mL)
(-45 °C, 7 h) according to the procedure described for the synthesis
of compound 5. Purification by column chromatography (silica gel;
14% AcOEt in hexane as an eluent, Rf 0.30) provided 360 mg of
the title product as a colorless solid (87% yield): mp 66.2-68.4 °C;
1H NMR (CDCl3) δ 7.87 (d, J ) 1.6 Hz, 1H), 7.72 (dd, J ) 8.0,
1.6 Hz, 1H), 7.60-7.53 (m, 3H), 7.48-7.40 (m, 4H); 13C NMR
(CDCl3) δ 145.7, 145.0, 137.4, 136.1, 135.0, 133.6, 133.5, 133.0,
132.8, 132.2, 131.8, 131.2, 130.6, 130.2, 127.2, 126.1, 125.2,
118.4-107.8 (m, CF2CF2CF2CF3), 116.9, 115.1. HRMS-FAB+ (m/
z) calcd for C27H9Cl2F18NO6S2 918.8961, found 919.8962.
Synthesis of 5,11-Diphenyl-3-hexylindolo[3,2-b]carbazole (15a).
The crude material was obtained using 20a (98 mg, 0.10 mmol),
Pd(dba)2 (23 mg, 0.040 mmol), K3PO4 (85 mg, 0.40 mmol),
2-dicyclohexylphosphino-2′,6′-diisopropoxybiphenyl (21) (37 mg,
0.08 mmol), 2,6-di-tert-butyl-4-methylphenol (BHT) (66 mg, 0.30
mmol), and aniline (23 µL, 0.25 mmol) in toluene (0.30 mL)
(100 °C, 4 days) according to the procedure described for the
synthesis of compound 2c. Purification by column chromatography
(silica gel; 20% CHCl3 in hexane as an eluent, Rf 0.45) provided
28 mg of the title product as a pale yellow solid (58% yield): mp
88.6-90.1 °C; 1H NMR (CDCl3) δ 8.11 (d, J ) 7.8 Hz, 1H), 8.03
(d, J ) 6.0 Hz, 2H), 8.01 (d, J ) 8.0 Hz, 1H), 7.70-7.66 (m, 8H),
7.54-7.50 (m, 2H), 7.43-7.37 (m, 2H), 7.24-7.21 (m, 2H), 7.08
(d, J ) 8.0 Hz, 1H), 2.73 (t, J ) 7.8 Hz, 2H), 1.66 (quint, J ) 7.8
Hz, 2H), 1.37-1.27 (m, 6H), 0.87 (t, J ) 6.6 Hz, 3H); 13C NMR
(CDCl3) δ 142.6, 142.1, 141.8, 138.6, 138.5, 137.4, 137.2, 130.1,
127.5, 127.44, 127.36, 127.3, 125.9, 123.7, 123.0, 121.5, 120.4,
120.3, 120.1, 119.4, 109.6, 109.1, 99.9, 99.7, 36.9, 32.2, 31.9, 29.3,
22.8, 14.3. HRMS-FAB+ (m/z) calcd for C36H32N2 492.2565, found
492.2550.
Synthesis of 2,2′′-Dichloro-2′,5′-dimethoxy-4-hexyl[1,1′4′,1′′-
terphenyl] (18a). The crude material was obtained by using 17
(38 mg, 0.10 mmol), the crude 23 (75 mg, 0.20 mmol of 23, see
Supporting Information), Pd(PPh3)4 (6.0 mg, 0.0050 mmol), Na2-
CO3 (42 mg, 0.40 mmol) in toluene (0.60 mL), EtOH (0.20 mL),
and H2O (0.20 mL) (90 °C, 2 days) according to the procedure
described for the synthesis of compound 14. Purification by column
chromatography (silica gel; 10% CHCl3 in hexane as an eluent, Rf
0.40) provided 41 mg of the title product as a colorless solid (92%
1
yield): mp 102.8-103.4 °C; H NMR (CDCl3) δ 7.50 (dd, J )
7.6, 1.1 Hz, 1H), 7.41 (dd, J ) 6.9, 2.0 Hz, 1H), 7.36-7.30 (m,
4H), 7.15 (d, J ) 7.8, 0.7 Hz, 1H), 6.86 (s, 1H), 6.85 (s, 1H),
3.751 (s, 3H), 3.747 (s, 3H), 2.65 (t, J ) 7.8 Hz, 2H), 1.68 (quint,
J ) 7.8 Hz, 2H), 1.43-1. 30 (m, 6H), 0.92 (t, J ) 6.6 Hz, 3H);
13C NMR (CDCl3) δ 150.7, 150.5, 144.0, 137.7, 134.7, 134.0, 133.6,
132.0, 131.6, 129.6, 129.4, 128.9, 128.8, 128.6, 126.8, 126.6, 114.9,
114.6, 56.54, 56.52, 35.6, 31.9, 31.3, 29.2, 22.8, 14.3. Anal. Calcd
for C26H28Cl2O2: C, 70.28; H, 6.36. Found: C, 70.43; H, 6.36.
Synthesis of 2,2′′-Dichloro-2′,5′-dimethoxy[1,1′:4′,1′′-terphe-
nyl]-4-yl Cyanide (18b). The crude material was obtained by using
17 (712 g, 1.9 mmol), 24 (1.0 mg, 3.8 mmol, see Supporting
Information), Pd(PPh3)4 (216 mg, 0.19 mmol), Na2CO3 (600 mg,
5.7 mmol) in toluene (5.0 mL), EtOH (2.5 mL), and H2O (5.0 mL)
(90 °C, 2 days) according to the procedure described for the
synthesis of compound 14. Purification by column chromatography
(silica gel; 20% AcOEt in hexane as an eluent, Rf 0.40) provided
639 mg of the title product as a colorless solid (88% yield): mp
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213.1-215.7 °C; H NMR (CDCl3) δ 7.78 (d, J ) 1.4 Hz, 1H),
7.62 (dd, J ) 7.8, 1.6 Hz, 1H), 7.52-7.48 (m, 2H), 7.39-7.31 (m,
3H), 6.86 (s, 1H), 6.80 (s, 1H), 3.74 (s, 6H); 13C NMR (CDCl3) δ
150.7, 150.2, 142.9, 137.3, 135.2, 133.9, 133.0, 132.8, 131.8, 130.1,
130.0, 129.7, 129.0, 126.8, 126.7, 117.8, 114.6, 114.0, 112.6, 56.6,
56.4. HRMS-FAB+ (m/z) calcd for C21H15Cl2NO2 383.0480, found
383.0497.
Synthesis of 2,2′′-Dichloro-4-hexyl[1,1′:4′,1′′-terphenyl]-2′,5′-
diol (19a). The crude material was obtained by using 18a (275
mg, 0.62 mmol) and boron tribromide (1.9 mL, 1.9 mmol; 1.0 M
in dichloromethane) in dichloromethane (6.0 mL) (0 °C, 8 h)
according to the procedure described for the synthesis of compound
4. Purification by column chromatography (silica gel; 20% AcOEt
in hexane as an eluent, Rf 0.30) provided 245 mg of the title product
as a colorless solid (95% yield): mp 85.6-86.8 °C; 1H NMR
(CDCl3) δ 7.53-7.51 (m, 1H), 7.41-7.34 (m, 4H), 7.29 (d, J )
7.8 Hz, 1H), 7.18 (dd, J ) 7.8, 1.1 Hz, 1H), 6.815 (s, 1H), 6.810
(s, 1H), 4.71 (br s, 1H), 2.64 (t, J ) 7.8 Hz, 2H), 1.66 (quint, J )
7.8 Hz, 2H), 1.41-1.31 (m, 6H), 0.91 (t, J ) 6.8 Hz, 3H); 13C
NMR (CDCl3) δ 146.4, 146.2, 145.3, 135.6, 133.9, 133.5, 132.4,
132.2, 131.9, 130.2, 130.0, 129.8, 127.7, 127.4, 127.2, 127.1, 118.1,
117.8, 35.6, 31.8, 31.2, 29.1, 22.7, 14.2. HRMS-FAB+ (m/z) calcd
for C24H24Cl2O2 414.1153, found 414.1160.
Synthesis of 5,11-Diphenylindolo[3,2-b]carbazol-3-yl Cyanide
(15b). The crude material was obtained using 20b (92 mg, 0.10
mmol), Pd(dba)2 (23 mg, 0.040 mmol), K3PO4 (85 mg, 0.40 mmol),
Synthesis of 2,2′′-Dichloro-2′,5′-dihydroxy[1,1′4′,1′′-terphen-
yl]-4-yl Cyanide (19b). The crude material was obtained by using
J. Org. Chem, Vol. 72, No. 14, 2007 5127