PAPER
New Parts for a Construction Set of Bifunctional Oligo(het)arylene Building Blocks
445
g of crude boronic acid, which was used for the esterification with-
out further purification.
mmol), reflux for 48 h, flash silica gel with hexane/EtOAc (20:1) as
eluent. Yield: 12 (500 mg, 76 %), colourless oil.
Rf = 0.82 (Hexane/EtOAc, 9:1).
1H NMR (CDCl3): d = 0.39 (s, 9H, TMS), 0.92 (t, 3H, J = 6.6 Hz,
CH3), 1.32-1.49 (m, 6H, g-, d-, e-CH2), 1.74 (quintet, 2H, J = 6.6
Hz, b-CH2), 3.63 (t, 2H, J = 6.6 Hz, a-CH2), 4.74 (s, 2H, benzyl-
CH2), 7.62-7.78 (m, 4H, phenyl-H), 7.89 (s, 1H, phenyl-H), 8.22 (s,
1H, phenyl-H), 8.45 (s, 1H, phenyl-H).
1H NMR (CDCl3): d = 0.32 (s, 9H, TMS), 0.89 (t, 3H, J = 6.7 Hz,
CH3), 1.32-1.53 (m, 6H, g-, d-, e-CH2), 1.56-1.72 (m, 2H, b-CH2),
3.52 (t, 2H, J = 6.6 Hz, a-CH2), 4.62 (s, 2H, benzyl-CH2), 7.49-
7.73 (m, 11H, phenyl-H).
13C NMR (CDCl3): d = -1.08, 14.01, 22.59, 25.90, 29.77, 31.68,
70.73, 72.81, 120.09, 126.71, 131.69, 133.61, 133.85, 138.89,
139.39, 141.04, 141.46.
13C NMR (CDCl3): d = -1.11, 14.04, 22.62, 25.92, 29.74, 31.69,
70.80, 72.73, 121.67, 125.05, 125.14, 125.72, 126.57, 127.25,
128.82, 131.85, 139.61, 131.99, 133.83, 140.64, 141.22, 142.02.
MS: m/z (%) for trimer C66H93B3O6Si3 = 1099 (M+, 16), 999 (11),
MS: m/z (%) = 496 (M+, 43), 481 (42), 396 (100), 380 (17), 315
813 (16), 739 (31), 451 (33), 351 (63), 325 (100).
(23), 73 (14).
Anal. Calcd for C66H93B3O6Si3 (1099.14): C, 72.12; H, 8.53. Found:
C, 71.57; H, 8.34.
HRMS: m/z calcd for (C28H35BrOSi) 494.164056. Found:
494.16287.
The crude boronic acid (1.39 g, 3.62 mmol) and 2,3-dimethylbu-
tane-2,3-diol (0.64 g, 5.41 mmol) were dissolved in 1,4-dioxane (20
mL) and the mixture warmed to 60 °C for 2 h. The solvent was then
removed under reduced pressure and the residue chromatographed
through flash silica gel using hexane/EtOAc (9:1) as eluent to give
10 (0.56-1.1 g, 10-20% with reference to 9) as a colourless oil.
4’’-Bromo-5’-hexyloxymethyl-4-iodo-[1,1’;3’,1’’]-terphenyl (13)
Synthesis and workup was similar to that of compound 6. Com-
pound 12 (500 mg, 1.01 mmol), CH2Cl2 (25 mL), and iodochloride
(200 mg, 1.23 mmol) in CH2Cl2 (10 mL) were used. Compound 13
(520 mg, 94%) was obtained as a colourless oil, which slowly crys-
tallized, mp 55-57 °C.
Rf = 0.77 (Hexane/EtOAc, 9:1).
Rf = 0.75 (Hexane/EtOAc, 9:1).
1H NMR (CDCl3): d = 0.30 (s, 9H, TMS), 0.89 (t, 3H, J = 6.6 Hz,
CH3), 1.29-1.39 (m, 6H, g-, d-, e-CH2), 1.35 (s, 12H, (CH3)2C-
C(CH3)2), 1.72 (quintet, 2H, J = 6.6 Hz, b-CH2), 3.48 (t, 2H, J = 6.6
Hz, a-CH2), 4.56 (s, 2H, benzyl-H), 7.51-7.64 (m, 4H, phenyl-H),
7.70 (s, 1H, phenyl-H), 7.73 (s, 1H, phenyl-H), 7.96 (s, 1H, phenyl-
H).
13C NMR (CDCl3): d = -1.10, 14.02, 22.61, 24.86, 25.89, 29.74,
31.69, 70.61, 72.80, 83.84, 126.59, 129.37, 132.81, 133.09, 133.65,
138.51, 139.07, 140.66, 141.41.
1H NMR (CDCl3): d = 0.88 (t, 3H, J = 6.6 Hz, CH3), 1.26-1.44 (m,
6H, g-, d-, e-CH2), 1.65 (quintet, 2H, J = 6.6 Hz, b-CH2), 3.53 (t,
2H, J = 6.6 Hz, a-CH2), 4.60 (s, 2H, benzyl-CH2), 7.33-7.38 (m,
2H, phenyl-H), 7.46 (s, 1H, phenyl-H), 7.49-7.51 (m, 3H, phenyl-
H), 7.56 (s, 1H, phenyl-H), 7.58-7.60 (m, 2H, phenyl-H), 7.76 (d,
2H, J = 7.8 Hz, phenyl-H).
13C NMR (CDCl3): d = 14.02, 22.62, 25.90, 29.72, 31.67, 70.88,
72.61, 93.34, 118.71, 121.79, 124.70, 124.98, 127.23, 128.80,
129.03, 131.88, 139.73, 140.22, 140.31, 140.81, 140.87.
MS: m/z (%) = 466 (M+, 87), 451 (62), 366 (100), 351 (98), 266 (9),
73 (7).
MS: m/z (%) = 548 (M+, 34), 448 (100), 370 (23), 242 (59), 165 (7).
Anal. Calcd for C25H26BrIO (549.29): C, 54.67; H, 4.77. Found: C,
54.96; H 4.94.
Anal. Calcd for C28H43BO3Si (466.54): C, 72.09; H, 9.29. Found: C,
71.53; H, 9.20.
2-Bromo-5-(4’’-bromo-5’-hexyloxymethyl-[1,1’;3’,1’’]-terphe-
nyl-4-yl)pyridine (15)
Method A:
2-(5-Hexyloxymethyl-4’-iodobiphenyl-3-yl)-4,4,5,5-tetrameth-
yl-[1,3,2]-dioxaborolane (11)
Synthesis and workup similar to compound 6: compound 10 (1.12
g, 2.40 mmol), CH2Cl2 (25 mL), iodochloride (0.47 g, 2.89 mmol),
CH2Cl2 (10 mL), flash silica gel with hexane/EtOAc (19:1) as elu-
ent. Compound 11 (1.20g, 96 %) was obtained as a colourless oil,
which slowly crystallized, mp 54-56 °C.
Iodo compound 13 (510 mg, 0.93 mmol) and 2-bromo-5-(trimeth-
ylstannyl)pyridine (14) (357 mg, 1.11 mmol) were dissolved in tol-
uene (15 mL). The mixture was degassed, then (PPh3)4Pd (21 mg,
0.018 mmol) added and the system degassed again. This mixture
was refluxed for 48 h then cooled to r.t. and extracted with sat. KF
(10 mL). The crude product was chromatographed through flash sil-
ica gel with hexane/EtOAc (4:1) as eluent to give 15 (90 mg, 16 %)
as a colourless viscous oil.
Rf = 0.68 (Hexane/EtOAC, 9:1).
1H NMR (CDCl3): d = 0.87 (t, 3H, J = 6.7 Hz, CH3), 1.26-1.45 (m,
6H, g-, d-, e-CH2), 1.34 (s, 12H, (CH3)2C-C(CH3)2), 1.56-1.63 (m,
2H, b-CH2), 3.47 (t, 2H, J = 6.7 Hz, a-CH2), 4.54 (s, 2H, benzyl-
CH2), 7.36 (d, 2H, J = 7.3 Hz,), 7.63 (s, 1H, phenyl-H), 7.71-7.75
(m, 3H, phenyl-H), 7.92 (s, 1H, phenyl-H).
13C NMR (CDCl3): d = 13.99, 22.58, 24.83, 25.85, 29.68, 31.64,
70.67, 72.64, 83.89, 94.55, 128.97, 129.07, 132.36, 133.39, 134.06,
137.65, 138.72, 139.49, 140.50.
Method B:
Synthesis and workup similar to compound 5: Boronic ester 17
(4.12 g, 11.44 mmol), iodo compound 6 (5.41 g, 11.44 mmol), tol-
uene (115 mL), aq Na2CO3 (1 M, 115 mL), (PPh3)4Pd (198 mg, 0.17
mmol), reflux for 48 h, flash silica gel, hexane/EtOAc (4:1). Com-
pound 15 (4.18 g, 63 %) was obtained as a colourless viscous oil.
HRMS: m/z calcd for C25H34BIO3 (M+) 520.16457. Found:
520.16296.
Rf = 0.44 (Hexane/EtOAc, 9:1).
1H NMR (CDCl3): d = 0.88 (t, 3H, J = 6.6 Hz, CH3), 1.24-1.43 (m,
6H, g-, d-, e-CH2), 1.66 (quintet, 2H, J = 6.6 Hz, b-CH2), 3.55 (t,
2H, J = 6.6 Hz, a-CH2), 4.61 (s, 2H, benzyl-CH2), 7.47-7.62 (m,
8H, phenyl-H), 7.68-7.76 (m, 5H, phenyl- and pyrid-H), 8.61 (d,
1H, J = 2.2 Hz, pyrid-H).
13C NMR (CDCl3): d = 13.98, 22.56, 25.86, 29.68, 31.62, 70.85,
72.59, 121.75, 124.76, 125.42, 127.27, 127.93, 128.73, 131.83,
135.30, 135.44, 136.62, 140.22, 139.71, 140.73, 140.93, 148.22.
Anal. Calcd for C25H34BrIO3 (520.25): C, 57.72; H, 6.59. Found: C,
57.83; H, 6.40.
4’’-Bromo-5’-hexyloxymethyl-4-trimethylsilyl-[1,1’;3’,1’’]-ter-
phenyl (12)
Synthesis and workup similar to compound 5: Boronic ester 10 (620
mg, 1.33 mmol), 1-bromo-4-iodobenzene (4) (410 mg, 1.45 mmol),
toluene (15 mL), aq Na2CO3 (1 M, 15 mL), (PPh3)4Pd (30 mg, 0.026
Synthesis 2000, No. 3, 442–446 ISSN 0039-7881 © Thieme Stuttgart · New York