S.-W. Choi et al. / Organic Electronics 15 (2014) 1413–1421
1415
d 140.7, 136.9, 133.2, 128.8, 126.2, 123.6, 121.0, 120.5,
120.3, 109.7.
The solvent was removed in vacuo and the residue was
purified by SiO2 column chromatography. The final pure
materials were obtained by sublimation.
2.2.2. General Miyaura borylation procedure
A solution of haloarene (1.0 mmol ratio), bis(pinaco-
late)diboron (1.2 mmol ratio), KOAc (1.5 mmol ratio), and
PdCl2(dppf) (0.02 mmol ratio) in dry 1,4-dioxane (20 ml)
was refluxed for overnight under N2. After being cooled
to room temperature, the mixture was poured into H2O
and then extracted with dichloromethane. The combined
organic layer was washed with brine and dried over mag-
nesium sulfate. The solvent was removed in vacuo and
crude product was purified by chromatography (SiO2) elut-
ing with a mixture of DCM and n-hexane to afford the pure
products.
2.2.7. 3-(4-Bromo-2,5-dimethylthiophene-3-yl)-9-phenyl-
9H-carbazole (5)
3 (1.62 g, 4.40 mmol), 4 (1 g, 3.70 mmol), 2 M K2CO3
solution (10 ml), and Pd(PPh3)4 (0.05 g, 0.04 mmol) were
used for general Suzuki–Miyaura cross-coupling reaction.
The crude product was purified by chromatography
(SiO2) eluting with a mixture of DCM: n-hexane (1:2; v/
v) to give a white solid (0.96 g, 60%): m.p. = 155 °C; 1H
NMR d 8.13 (d, 1H), 8.04 (s, 1H), 7.62 (m, 3H), 7.44 (m,
3H), 7.29 (m, 2H), 2.42 (d, 6H); 13C NMR d 141.9, 141.5,
141.3, 137.5, 130.5, 128.2, 127.2, 126.9, 126.7, 124.0,
123.7, 123.1, 121.5, 120.7, 118.3, 110.6, 110.2, 109.6,
15.4, 11.9.
2.2.3. 9-(4-(4,4,5,5,-Tetramethyl-1,3,2-dioxaborolan-2-
yl)phenyl)-9H-carbazole (2)
9-(4-Bromophenyl)-9H-carbazole (5.5 g, 17.19 mmol),
bis(pinacolate)diboron (5.24 g, 20.63 mmol), KOAc (2.63 g,
25.76 mmol), and PdCl2(dppf) (0.15 g, 0.02 mmol) were
used to yield compound 2 (5.36 g, 85.1%) as a white solid:
m.p. = 170 °C; 1H NMR d 8.08 (d, 1H), 8.02 (d, 1H), 7.63 (d,
1H), 7.41 (m 5H), 7.29 (m, 4H), 1.23 (s, 12H); 13C NMR d
140.7, 140.5, 136.5, 126.2, 123.6, 120.4, 120.2, 110.0,
84.2, 25.1.
2.2.8. 9-(4-(2,5-Dimethyl-4-(9-phenyl-9H-carbazol-6-
yl)thiophen-3-yl)phenyl)-9H-carbazole (6)
A
solution of 5 (0.96 g, 2.22 mmol), 2 (0.98 g,
2.66 mmol) 2 M K2CO3 solution (10 ml), and Pd(PPh3)4
(0.1 g, 0.09 mmol) were used for general Suzuki–Miyaura
cross-coupling reaction. The crude product was purified
by chromatography (SiO2) eluting with
a mixture of
DCM: n-hexane (2:3; v/v) to give a white solid (0.73 g,
55%): m.p. = 242 °C; 1H NMR d 8.13 (s, 1H), 8.11 (d, 1H),
8.09 (d, 1H), 7.89 (s, 1H), 7.62 (m, 3H), 7.54 (m, 4H), 7.45
(m, 4H), 7.33 (m, 4H), 7.29 (m, 4H), 7.13 (d, 1H), 2.56 (d,
6H); 13C NMR d 141.4, 141.0, 139.8, 138.6, 137.9, 136.8,
135.7, 131.8, 131.5, 131.3, 129.8, 128.5, 128.2, 127.4,
127.1, 126.9, 126.7, 126.1, 126.0, 125.9, 123.4, 123.3,
122.2, 120.0, 119.5, 110.0, 109.8, 109.2, 14.1; ESI-MS: m/z
594.2 [M]+ (calcd. m/z 594.2).
2.2.4. 9-Phenyl-3-(4,4,5,5,-tetramethyl-1,3,2-dioxaborolan-2-
yl)-9H-carbazole (3)
3-Bromo-9-phenyl-9H-carbazole (4 g, 12.4 mmol),
bis(pinacolate)diboron (3.79 g, 14.9 mmol), KOAc (1.9 g,
18.6 mmol), and PdCl2(dppf) (0.14 g, 0.02 mmol) were
used to yield compound 3 (4.1 g, 88.4%) as a white solid:
m.p. = 160 °C; 1H NMR d 8.63 (s, 1H), 8.10 (d, 1H), 7.95
(d, 1H), 7.58 (m, 5H), 7.41 (m, 4H), 1.23 (s, 12H); 13C
NMR d 143.1, 141.1, 137.6, 132.5, 130.0, 127.8, 127.7,
126.1, 123.6, 123.2, 120.6, 120.4, 109.9, 109.2, 83.8, 25.1.
2.2.9. 3-(2,5-Dimethyl-4-(9-phenyl-9H-carbazol-6-
yl)thiophen-3-yl)-9-phenyl-9H-carbazole (7)
A solution of 3 (3.28 g, 8.89 mmol), 4 (1 g, 3.70 mmol),
2 M K2CO3 solution (20 ml), and Pd(PPh3)4 (0.1 g,
0.09 mmol) were used for general Suzuki–Miyaura
cross-coupling reaction. The crude product was purified
2.2.5. 3,4-Dibromo-2,5-dimethylthiophene (4)
A solution of 2,5-dimethylthiophene (5 g, 44.7 mmol) in
glacial acetic acid (50 ml) was added dropwise to a bro-
mine (10.7 g, 133.7 mmol) at 0 °C. The mixture was stirred
for overnight at room temperature. The reaction mixture
was poured into H2O and then extracted with diethyl
ether. The combined organic layer was washed with brine
and dried over magnesium sulfate. The solvent was
removed in vacuo and crude product was purified by chro-
matography (SiO2) eluting with an n-hexane to give a
white solid (8 g, 67%): m.p. = 46 °C; 1H NMR d 2.54 (s,
6H); 13C NMR d 132.7, 109.5, 14.1.
by chromatography (SiO2) eluting with
a mixture of
DCM: n-hexane (1:1; v/v) to give a white solid (1.19 g,
54%): m.p. = 237.0 °C; 1H NMR d 8.03 (d, 2H), 7.96 (s, 2H),
7.55 (q, 6H), 7.39 (m, 6H), 7.22 (m, 6H), 7.07 (d, 2H), 2.49
(s, 6H); 13C NMR d 141.2, 140.6, 139.8, 137.7, 131.0,
130.0, 129.7, 128.5, 127.7, 127.2, 125.6, 123.9, 123.2,
122.2, 120.4, 120.0, 110.2, 109.6, 14.2; ESI-MS: m/z 594.2
[M]+ (calcd. m/z 594.2).
2.2.6. General Suzuki–Miyaura cross-coupling procedure
A mixture of 4 (1 equiv.), boronic acid pinacol ester
(1.2–2.4 equiv.) and 2 M K2CO3 (10 ml) in toluene was
bubbled with argon with stirring for 30 min. Pd(PPh3)4
(0.02–0.04 equiv.) was added to the mixture, and the
resulting mixture was refluxed for overnight under argon
atmosphere. The reaction mixture was cooled down to
room temperature, poured into H2O and then extracted
with dichloromethane. The combined organic layer was
washed with brine and dried over magnesium sulfate.
2.2.10. 9-(4-(4-(4-(9H-carbazol-9-yl)phenyl)-2,5-
dimethylthiophen-3-yl)phenyl)-9H-carbazole (8)
A solution of 2 (3.28 g, 8.89 mmol), 4 (1 g, 3.70 mmol),
2 M K2CO3 solution (20 ml), and Pd(PPh3)4 (0.1 g,
0.09 mmol) were used for general Suzuki–Miyaura cross-
coupling reaction. The crude product was purified by
chromatography (SiO2) eluting with a mixture of DCM:
n-hexane (1:1; v/v) to give white solid (1.23 g, 56%):
m.p. = 303 °C; 1H NMR d 8.16 (d, 2H), 7.51 (d, 2H), 7.40
(m, 20H), 2.49 (s, 6H); 13C NMR d 141.1, 138.5, 136.2,