F.-S. Han et al. / Tetrahedron 64 (2008) 9108–9116
9115
0.773 mmol), and PdCl2(PPh3)2 (9.0 mg, 0.013 mmol). The solution
was stirred at 80 ꢃC under argon atmosphere for 12 h. The reaction
vessel was recharged with K2CO3 (107 mg, 0.773 mmol), 8b (or 8c)
(0.258 mmol), and Pd catalyst (5 mol %) after being diluted with
additional 8 mL DMSO. The mixture was then heated at 80–120 ꢃC
until 8b (or 8c) had disappeared as monitored by TLC. The catalyst
was removed by filtration and washed with CHCl3 after the reaction
mixture was cooled to room temperature. The filtrate was then
washed with H2O (50 mL) for five times, and the organic layer was
dried over MgSO4, filtered, concentrated, and purified by column
chromatography on activated basic Al2O3 to give 14 and 15,
respectively.
4.4.2. Spacer tunable bis-terpyridine 18
White powder, 59% yield from 8b and 1,3-dibromobenzene; 1H
NMR (CDCl3)
d
¼8.72 (s, 4H), 8.29 (d, 4H, J¼7.5 Hz), 7.97 (d, 4H,
J¼8.1 Hz), 7.96 (s, 1H), 7.86 (d, 4H, J¼8.1 Hz), 7.77 (t, 4H, J¼8.1 Hz),
7.71 (dd, 2H, J1¼6.9 Hz, J2¼1.2 Hz), 7.62 (t, 1H, J¼6.9 Hz), 6.83 (d, 4H,
J¼7.5 Hz), 4.11 (s, 12H); 13C NMR (CDCl3)
¼163.7, 156.0, 153.8,
d
149.5, 141.7, 141.3, 139.4, 138.5, 129.5, 127.9, 127.8, 126.5, 126.1, 118.6,
114.2, 111.1, 53.3; MALDI-MS (%): m/z¼813 (100) [MþH]þ; HRMS
found m/z: 813.3207 [MþH]þ; C52H41N6O4 requires: 813.3207.
4.4.3. Spacer tunable bis-terpyridine 19
White powder, 32% yield from 8c and 1,3-dibromobenzene; 1H
NMR (CDCl3)
d
¼8.90 (s, 4H), 8.88 (dd, 4H, J1¼8.4 Hz, J2¼1.2 Hz),
4.3.1. Unsymmetric bis-terpyridine 14
8.07–8.03 (m, 8H), 8.00 (s, 1H), 7.91 (dd, 4H, J1¼6.9 Hz, J2¼2.1 Hz),
White powder, 58% yield from 8a and 8b; 1H NMR (CDCl3)
7.78 (dd, 4H, J1¼7.8 Hz, J2¼1.2 Hz), 7.73 (dd, 2H, J1¼6.9 Hz,
d
¼8.82 (s, 2H), 8.75 (ddd, 2H, J1¼5.7 Hz, J2¼1.8 Hz, J3¼0.9 Hz), 8.72
J2¼1.2 Hz), 7.65 (d, 1H, J¼6.9 Hz); 13C NMR (CDCl3)
¼157.6, 154.3,
d
(s, 2H), 8.70 (d, 2H, J¼7.8 Hz), 8.29 (dd, 2H, J1¼7.5 Hz, J2¼0.9 Hz),
8.05 (d, 2H, J¼7.5 Hz), 7.97 (d, 2H, J¼7.2 Hz), 7.90 (ddd, 2H,
J1¼J2¼7.8 Hz, J3¼1.8 Hz), 7.87 (d, 2H, J¼8.7 Hz), 7.81 (d, 2H,
J¼6.9 Hz), 7.76 (d, 2H, J¼7.8 Hz), 7.37 (dd, 2H, J1¼J2¼6.6 Hz), 6.83 (d,
150.8, 142.5, 141.2, 137.9, 136.8, 133.6, 130.8, 129.6, 128.3, 128.1,
127.9, 126.7, 124.3, 120.3, 117.3; MALDI-MS (%): m/z¼793 (100)
[MþH]þ; HRMS found m/z: 815.2391 [MþNa]þ; C52H28N10Na re-
quires: 815.2396.
2H, J¼7.8 Hz), 4.12 (s, 6H); 13C NMR (CDCl3)
¼163.6, 156.3, 156.0,
d
155.9, 153.7, 149.7, 149.4, 149.2 (2C), 141.0, 139.4, 138.4, 137.7, 136.9,
127.9, 127.7 (2C), 127.6, 123.9, 121.4, 118.7, 118.6, 114.1, 111.1, 53.3;
MALDI-MS (%): m/z¼677 (100) [MþH]þ; HRMS found m/z:
677.2652 [MþH]þ; C44H33N6O2 requires: 677.2665.
4.4.4. Spacer tunable bis-terpyridine 20
White powder, 47% yield from 8a and 2,6-dibromopyridine; 1H
NMR (CDCl3)
d
¼8.83 (s, 4H), 8.76 (ddd, 4H, J1¼0.9 Hz, J2¼1.8 Hz,
J3¼4.8 Hz), 8.69 (dt, 4H, J1¼0.9 Hz, J2¼8.1 Hz), 8.34 (d, 4H, J¼8.4 Hz),
8.08 (d, 4H, J¼8.4 Hz), 8.04 (d, 1H, J¼8.7 Hz), 7.92–7.81 (m, 6H), 7.36
(ddd, 4H, J1¼0.9 Hz, J1¼4.8 Hz, J3¼7.5 Hz); 13C NMR (CDCl3)
4.3.2. Unsymmetric bis-terpyridine 15
White powder, 65% yield from 8a and 8c; 1H NMR (CDCl3)
d
¼156.5, 156.2, 149.9, 149.2, 140.1, 139.2, 137.6, 136.8, 127.9, 127.7,
d
¼8.90 (s, 2H), 8.88 (dd, 2H, J1¼8.1 Hz, J2¼1.2 Hz), 8.83 (s, 2H), 8.76
127.6, 123.8, 121.4, 119.0, 118.9; MALDI-TOF MS: m/z 693.9 (100)
[MþH]þ.
(dd, 2H, J1¼3.6 Hz, J2¼0.9 Hz), 8.70 (d, 2H, J¼8.1 Hz), 8.08–8.01 (m,
6H), 7.92–7.87 (m, 4H), 7.85 (d, 2H, J¼8.1 Hz), 7.78 (dd, 2H,
J1¼7.8 Hz, J2¼1.2 Hz), 7.37 (ddd, 2H, J1¼J2¼7.5 Hz, J3¼1.8 Hz); 13C
4.4.5. Spacer tunable bis-terpyridine 21
NMR (CDCl3)
d
¼157.6, 156.5, 156.2, 154.3, 149.2, 141.9, 140.9, 137.9,
Pale yellow powder, 59% yield from 8a and 2,5-dibromothio-
136.8 (2C), 133.6, 132.7, 130.8, 128.8, 128.4, 128.0 (2C), 127.9, 127.7,
124.4, 123.8, 121.4, 120.3, 118.9, 117.3; MALDI-MS (%): m/z¼667
(100) [MþH]þ; HRMS found m/z: 667.2383 [MþH]þ; C44H27N8 re-
quires: 667.2359.
phene; 1H NMR (CDCl3)
d
¼8.79 (s, 4H), 8.75 (br d, 4H, J¼4.8 Hz),
8.68 (d, 4H, J¼7.8 Hz), 7.97 (d, 4H, J¼8.4 Hz), 7.88 (ddd, 4H,
J1¼0.9 Hz, J2¼1.8 Hz, J3¼7.8 Hz), 7.79 (d, 4H, J¼8.4 Hz), 7.43 (s, 2H),
7.36 (ddd, 4H, J1¼0.9 Hz, J2¼4.8 Hz, J3¼7.5 Hz); 13C NMR (CDCl3)
d
¼156.3, 156.1, 149.5, 149.2, 143.5, 137.6, 136.9, 135.0, 127.9, 126.1,
4.4. General procedure for the two-step in situ synthesis of
spacer tunable bis-terpyridines (17–24)
124.7, 123.8, 121.4, 118.6; MALDI-TOF MS: m/z 698.1 (100) [M]þ.
4.4.6. Spacer tunable bis-terpyridine 22
To a 40 mL DMSO solution of terpyridine 8a (or 8b,c, 200 mg)
was added bis(pinacolato)diboron 9 (1.1 equiv), KOAc (3.0 equiv),
and PdCl2(PPh3)2 (5 mol %). The solution was degassed and stirred
at 80 ꢃC under argon atmosphere for 6 h. The reaction vessel was
recharged in situ with K2CO3 (3.0 equiv), dibromo coupling partner
16 (0.5 equiv), and PdCl2(PPh3)2 (5 mol %). The mixture was then
heated at 80–100 ꢃC until the dibromo compound had disappeared
as monitored by TLC. The catalyst was removed by filtration and
washed thoroughly with CHCl3 after the reaction mixture was
cooled to room temperature. The filtrate was washed with H2O (ca.
70 mL) for five times, and the organic layer was separated, dried
over MgSO4, then filtered, concentrated, and purified by column
chromatography on activated basic Al2O3 (CH2Cl2/hexane¼4:1–9:1,
then pure CH2Cl2) to give the target compounds 17–24.
Pale yellow powder, 48% yield from 8a and 2,5-dibromo-3-
octylthiophene; 1H NMR (CDCl3)
d
¼8.82–8.75 (m, 8H), 8.69 (d, 4H,
J¼7.8 Hz), 8.06–7.76 (m, 11H), 7.65 (d, 2H, J¼8.1 Hz), 7.36 (br t, 4H,
J¼6.3 Hz), 2.75 (t, 2H, J¼7.5 Hz), 1.72 (m, 2H), 1.28 (m, 10H), 0.88 (t,
3H, J¼6.6 Hz); 13C NMR (CDCl3)
¼156.3 (2C), 156.0, 149.7 (2C),
d
149.2, 141.8, 141.0, 140.5, 137.7, 137.3 (2C), 136.9, 135.4, 135.1, 129.6,
127.8, 127.6, 127.5, 126.4, 125.9, 123.8, 121.4, 118.7 (2C), 118.5, 31.9,
31.1, 29.7, 29.4, 29.3, 29.1, 22.6, 14.1; MALDI-TOF MS: m/z 833.5
(100) [MþNa]þ.
Acknowledgements
We thank the Ministry of Education, Culture, Sports, Sciences,
and Technology, Japan for financial support.
4.4.1. Spacer tunable bis-terpyridine 17
References and notes
White powder, 61% yield from 8a and 1,3-dibromobenzene; 1H
NMR (CDCl3)
d
¼8.82 (s, 4H), 8.75 (ddd, 4H, J1¼4.8 Hz, J2¼1.8 Hz,
1. For recent reviews, see: (a) Cooke, M. W.; Hanan, G. S. Chem. Soc. Rev. 2007, 36,
1466; (b) Constable, E. C. Chem. Soc. Rev. 2007, 36, 246; (c) Kurth, D. G.; Higuchi,
M. Soft Matter 2006, 2, 915; (d) Medlycott, E. A.; Hanan, G. S. Chem. Soc. Rev.
2005, 34, 133; (e) Andres, P. R.; Schubert, U. S. Adv. Mater. 2004, 16, 1043.
2. Mortimer, R. J.; Dyer, A. L.; Reynolds, J. R. Displays 2006, 27, 2 and references
therein.
3. For recent research articles, see: (a) Cooke, M. W.; Hanan, G. S.; Loiseau, F.;
Campagna, S.; Watanabe, M.; Tanaka, Y. J. Am. Chem. Soc. 2007, 129, 10479; (b)
Camerel, F.; Ziessel, R.; Donnio, B.; Bourgogne, C.; Guillon, D.; Schmutz, M.;
Iacovita, C.; Bucher, J. P. Angew. Chem., Int. Ed. 2007, 46, 2659; (c) Song, B.;
J3¼0.9 Hz), 8.69 (d, 4H, J¼7.5 Hz), 8.05 (d, 4H, J¼8.7 Hz), 7.98 (s, 1H),
7.89 (dt, 4H, J1¼7.5 Hz, J2¼1.8 Hz), 7.83 (d, 4H, J¼8.7 Hz), 7.71 (dd,
2H, J1¼7.5 Hz, J2¼1.2 Hz), 7.60 (t, 1H, J¼7.2 Hz), 7.37 (ddd, 4H,
J1¼7.5 Hz, J2¼6.3 Hz, J3¼0.9 Hz); 13C NMR (CDCl3)
¼156.3, 156.0,
d
149.7, 149.1, 141.7, 141.1, 137.5, 136.8, 129.4, 127.8, 127.7, 126.5, 126.0,
123.8, 121.4, 118.7; MALDI-MS (%): m/z¼693 (100) [MþH]þ; HRMS
found m/z: 715.2563 [MþNa]þ; C48H32N6Na requires: 715.2563.