The Journal of Organic Chemistry
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solvent was removed in vacuo. Degassed MeOH (10 mL) was added
to the resulting residue. The mixture was stirred for 10 min to produce
a blue precipitate of the title compound (50 mg, 82% isolated yield),
which was collected by filtration.
125.9, 128.5, 128.8, 129.31, 129.34, 131.8, 132.2, 132.4, 135.1, 135.2;
HRMS (ESI) calcd for C108H154 1451.2051, found 1451.2029. Anal.
Calcd for C108H154: C, 89.31; H, 10.69. Found: C, 89.23; H, 10.57.
Preparation of TCNE Adduct 6b from 5b. The title compound
(120 mg) was prepared in the same way as described for 6a in 70%
yield from 5b (145 mg, 0.1 mmol). 6b: yellow solid; 1H NMR
(CDCl3, Me4Si) δ −0.27 to −0.17 (m, 2 H), −0.03 to −0.10 (m, 2 H),
0.01 (t, J = 7.2 Hz, 6 H), 0.28−0.46 (m, 8 H), 0.42 (t, J = 7.2 Hz, 6 H),
0.59−0.69 (m, 2 H), 0.65 (t, J = 7.2 Hz, 6 H), 0.74−1.17 (m, 14 H),
0.90 (t, J = 7.2 Hz, 6 H), 0.95 (t, J = 7.2 Hz, 6 H), 0.99 (t, J = 7.2 Hz,
6 H), 1.04 (t, J = 7.2 Hz, 6 H), 1.16 (t, J = 7.2 Hz, 6 H), 1.26−1.50
(m, 24 H), 1.54−1.61 (m, 8 H), 1.62−1.75 (m, 10 H), 1.93−2.01 (m,
2 H), 2.07−2.19 (m, 4 H), 2.34−2.43 (m, 4 H), 2.51−2.62 (m, 6 H),
2.64−2.70 (m, 2 H), 2.84−2.94 (m, 4 H), 3.05−3.15 (m, 4 H), 5.52
(s, 2 H), 5.90 (s, 2 H), 6.71 (s, 2 H), 8.42 (s, 2 H), 8.60 (s, 2 H); 13C
NMR (CDCl3, Me4Si) δ 12.8, 13.3, 13.6, 13.7, 13.8, 13.9, 14.1, 14.2,
22.9, 23.0, 23.3, 23.4 (2 C), 23.5 (2 C), 23.6, 28.1, 28.2, 28.6, 28.8,
29.1, 29.3, 30.02, 30.05, 31.4, 32.3, 32.6, 33.39 (2 C), 33.44, 33.5, 34.6,
45.7, 47.1, 47.2, 49.8, 110.3, 110.9, 112.1, 114.0, 122.6, 124.0, 127.8,
128.1, 129.1, 129.2, 129.6, 130.87, 130.91 (2C), 131.8, 132.1, 133.3,
133.5, 135.8, 137.2, 137.5, 137.9, 140.4, 141.4; HRMS (FAB; m/z)
calcd for C120H154N8 1707.2296, found 1707.2302.
Preparation of TCNE Adduct 6a from 5a. In a 20 mL Schlenk
tube, tetracyanoethylene (26 mg, 0.20 mmol) was added to a degassed
toluene solution (3 mL) of compound 5a (62 mg, 0.10 mmol) under a
nitrogen atmosphere. The mixture was stirred at room temperature.
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The blue color disappeared gradually after around /2 h. Then the
reaction mixture was purified by flash chromatography (silica gel,
CHCl3 as eluent) to afford the title compound as a yellow solid
1
(56 mg, 64% isolated yield, 86% NMR yield). 6a: H NMR (CDCl3,
Me4Si) δ −0.27 to −0.18 (m, 2 H), −0.11 (t, J = 7.2 Hz, 6 H), 0.33 (t,
J = 7.2 Hz, 6 H), 3.31−0.36 (m, 4 H), 0.48−0.56 (m, 2 H), 0.65 (t, J =
7.2 Hz, 6 H), 0.81−0.90 (m, 4 H), 0.96 (t, J = 7.2 Hz, 6 H), 1.05 (t, J =
7.2 Hz, 6 H), 1.06 (t, J = 7.2 Hz, 6 H), 1.16 (t, J = 7.2 Hz, 6 H), 1.19−
1.37 (m, 10 H), 1.27 (t, J = 7.2 Hz, 6 H), 1.44−1.54 (m, 8 H), 1.65−
1.78 (m, 8 H), 1.87−1.92 (m, 2 H), 2.05−2.10 (m, 2 H), 2.14−2.19
(m, 2 H), 2.33−2.38 (m, 4 H), 2.50−2.56 (m, 4 H), 2.57−2.62 (m,
2 H), 2.65−2.70 (m, 2 H), 2.82−2.87 (m, 2 H), 2.90−2.95 (m, 2 H),
3.06−3.11 (m, 2 H), 3.14−3.19 (m, 2 H), 5.54 (s, 2 H), 5.91 (s, 2 H),
6.71 (s, 2 H), 8.43 (s, 2 H), 8.62 (s, 2 H); 13C NMR (CDCl3, Me4Si) δ
13.9, 14.2, 14.67, 14.74, 14.87, 14.91, 14.94, 15.0, 23.1, 23.3, 24.2, 24.3,
24.4, 24.7, 24.9, 25.6, 30.4, 30.7, 31.0, 31.4, 31.8, 31.9, 32.65, 32.68,
45.8, 47.1, 47.2, 49.8, 110.3, 110.9, 112.1, 114.0, 122.6, 123.8, 127.9,
128.0, 129.1, 129.2, 129.7, 130.78, 130.82, 130.9, 131.8, 131.9, 133.3,
133.5, 135.9, 137.2, 137.3, 137.9, 140.5, 141.4; HRMS (FAB; m/z)
calcd for C104H122N8 1482.9792, found 1482.9807.
Reaction of Pentacene Derivative 4a with (±)-10-Camphor-
sulfonic Acid. In a 20 mL Schlenk tube, pentacene derivative 4a
(62 mg, 0.10 mmol) and (±)-10-camphorsulfonic acid (CSA; 2.3 mg,
0.01 mmol) was dissolved in degassed mesitylene (3 mL). Under a
nitrogen atmosphere, the mixture was stirred for 6 h at 120 °C in the
dark. The color of the reaction mixture changed from purple to blue.
After it was cooled to room temperature, the reaction mixture was
purified by silica gel chromatography under nitrogen (hexane:toluene
50:1 as eluent). The blue solution was collected and evaporated to
produce a blue solid, which was purified by GPC under nitrogen again
to afford the trimeric species 7 (32 mg, 53% isolated yield) as a blue
Preparation of 1,2,3,4,8,9,10,11-Octabutyl-5,7,12,14-tetra-
hydropentacene (2b) from 1b. The title compound (336 mg)
was prepared in the same way as described for 2a in 46% yield from 1b
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(592 mg, 1.0 mmol). 2b: H NMR (CDCl3, Me4Si) δ 0.98 (t, J =
7.2 Hz, 12 H), 1.02 (t, J = 7.2 Hz, 12 H), 1.46−1.58 (m, 32 H), 2.53−
2.57 (m, 8 H), 2.68−2.71 (m, 8 H), 3.86 (s, 8 H), 7.22 (s, 2 H); 13C
NMR (CDCl3, Me4Si) δ 13.9, 14.0, 23.4, 23.5, 29.3, 29.4, 32.9, 33.1,
33.9, 125.3, 133.3, 135.3, 135.5, 136.4; HRMS (FAB; m/z) calcd for
C54H82Na (M + Na+) 753.6314, found 753.6313.
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solid. 7: H NMR (C6D6, Me4Si) δ 0.17 (t, J = 7.2 Hz, 6 H), 0.35−
0.40 (m, 8 H), 0.36 (t, J = 7.2 Hz, 6 H), 0.55−0.73 (m, 12 H), 0.62 (t,
J = 7.2 Hz, 3 H), 0.80−1.18 (m, 24 H), 0.81 (t, J = 7.2 Hz, 6 H), 0.87
(t, J = 7.2 Hz, 12 H), 0.88 (t, J = 7.2 Hz, 6 H), 0.94 (t, J = 7.2 Hz,
3 H), 0.96 (t, J = 7.2 Hz, 3 H), 0.98 (t, J = 7.2 Hz, 3 H), 1.04 (t, J = 7.2
Hz, 6 H), 1.07 (t, J = 7.2 Hz, 3 H), 1.17 (t, J = 7.2 Hz, 6 H), 1.23 (t,
J = 7.2 Hz, 3 H), 1.28−1.45 (m, 18 H), 1.34 (t, J = 7.2 Hz, 6 H),
1.48−1.53 (m, 2 H), 1.57−1.72 (m, 8 H), 1.83−1.96 (m, 8 H), 2.10−
2.13 (m, 4 H), 2.19−2.26 (m, 8 H), 2.31−2.39 (m, 8 H), 2.40−2.59
(m, 20 H), 2.65−2.68 (m, 2 H), 2.73−2.85 (m, 12 H), 3.12−3.19 (m,
2 H), 3.24−3.39 (m, 6 H), 3.48−3.54 (m, 2 H), 4.57 (d, J = 17.4 Hz,
1 H), 5.10 (d, J = 17.4 Hz, 1 H), 5.14 (d, J = 11.4 Hz, 1 H), 5.50 (d, J =
11.4 Hz, 1 H), 7.45 (s, 2 H), 7.50 (s, 2 H), 7.75 (s, 2 H), 8.31 (s, 2 H),
8.57 (s, 1 H), 8.79 (s, 1 H, sp3 CH, determined by C−H COSY), 9.13
(s, 1 H), 9.14 (s, 1 H), 9.25 (s, 1 H), 10.28 (s, 1 H); 13C NMR (C6D6,
Me4Si) δ 14.2, 14.87, 14.89, 14.98, 15.00, 15.03, 15.1, 15.2, 15.27,
15.32, 15.34, 15.6, 23.5, 23.7, 23.8, 24.4, 24.5, 24.7, 24.9, 25.0, 25.1,
25.2, 25.3, 25.4, 31.2, 31.28, 31.31, 31.8, 31.9, 32.0, 32.1, 32.5, 32.7,
32.8, 32.9, 33.2, 37.6, 44.5, 54.3, 55.1, 118.0, 122.5, 123.8, 124.4, 125.3,
126.2, 126.3, 126.6, 129.9, 130.3, 130.4, 130.6,130.66, 130.73, 131.0,
131.3, 132.1, 132.2, 132.3, 133.4, 133.6, 133.96, 134.04, 134.4, 134.7,
134.9, 135.6, 135.77, 135.84, 136.3, 136.9, 137.8.
Preparation of 1,2,3,4,8,9,10,11-Octabutylpentacene (4b)
from 2b via the Pentacene−DDQ Adduct 3b. The title
compound (595 mg) was prepared in the same way as described for
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4a in 82% yield from 2b (730 mg, 1.0 mmol). 3b: yellow solid; H
NMR (CDCl3, Me4Si) δ 1.01 (t, J = 7.2 Hz, 6 H), 1.03 (t, J = 7.2 Hz,
6 H), 1.05 (t, J = 7.2 Hz, 6 H), 1.05 (t, J = 7.2 Hz, 6 H), 1.46−1.75
(m, 32 H), 2.68−2.78 (m, 8 H), 2.93−2.99 (m, 4 H), 3.04−3.14 (m, 4
H), 5.26 (s, 2 H), 7.88 (s, 2 H), 8.25 (s, 2 H); 13C NMR (CDCl3,
Me4Si) δ 13.9 (2 C), 14.07, 14.09, 23.4, 23.51 (2 C), 23.54, 28.7, 28.9,
29.97, 30.01, 33.49, 33.53 (2 C), 33.73, 56.70, 57.74, 114.5, 122.2,
122.6, 129.4, 130.7, 130.8, 131.2, 134.71, 137.73, 138.5, 139.1, 143.7,
179.8; HRMS (ESI; m/z) calcd for C62H78Cl2N2O2Na (M + Na+)
1
975.5338, found 975.5331. 4b: blue solid; mp 168−169 °C dec; H
NMR (CDCl3, Me4Si) δ 1.05 (t, J = 7.2 Hz, 12 H), 1.11 (t, J = 7.2 Hz,
12 H), 1.53−1.82 (m, 32 H), 2.76−2.79 (m, 8 H), 3.17−3.20 (m, 8
H), 8.77 (s, 4 H), 8.94 (s, 2 H); 13C NMR (CDCl3, Me4Si) δ 14.0,
14.2, 23.6, 23.7, 29.0, 30.1, 33.1, 33.6, 122.5, 125.7, 129.6, 130.3, 133.2,
136.1; HRMS (EI; m/z) calcd for C54H78 726.6104, found 726.6099.
Anal. Calcd for C54H78: C, 89.19; H, 10.81. Found: C, 89.24; H, 10.66.
Preparation of 1,2,3,4,8,9,10,11,1′,2′,3′,4′,8′,9′,10′,11′-
Hexadecabutyl[6,6′]bipentacenyl (5b) from 4b. The title
compound (158 mg) was prepared in the same way as described for
5a in 80% yield from 4b (200 mg, 0.27 mmol). The title product 5b
could also be synthesized from 2b in 76% yield in the same way as
ASSOCIATED CONTENT
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S
* Supporting Information
A CIF file and ORTEP diagram of compound 6a and figures
and tables giving 1H and 13C NMR spectra of compounds 2a−
6a, 2b−6b, and 7, UV absorption and fluorescence spectra of
compounds 4a, 5a, 4b, 5b, and 7, GPC separation chart, mass
spectra, and a C−H COSY NMR spectrum of 7. This material
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desired for 5a from 2a. 5b: mp 176−177 °C dec; H NMR (C6D6,
Me4Si, 352 K) δ 0.17 (t, J = 5.2 Hz, 12 H), 0.55−0.59 (m, 8 H), 0.80
(t, J = 5.2 Hz, 12 H), 0.92−0.99 (m, 8 H), 0.97 (t, J = 5.2 Hz, 12 H),
1.14 (t, J = 5.2 Hz, 12 H), 1.26−1.29 (m, 8 H), 1.35−1.41 (m, 8 H),
1.46−1.50 (m, 8 H), 1.56−1.64 (m, 8 H), 1.72−1.78 (m, 8 H), 2.02−
2.04 (m, 8 H), 2.34−2.37 (m, 8 H), 2.58−2.60 (m, 8 H), 2.83−2.85 (m,
8 H), 3.39−3.42 (m, 8 H), 8.52 (s, 4 H), 9.20 (s, 4 H), 9.38 (s, 2 H);
13C NMR (DMSO-d6, Me4Si, 423 K) δ 11.7, 12.4, 12.5, 12.8, 21.1, 21.6,
21.7, 21.9, 27.3, 27.6, 28.5, 28.6, 31.3, 32, 1, 32.2, 32.4, 120.7, 122.0,
AUTHOR INFORMATION
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Corresponding Author
9986
dx.doi.org/10.1021/jo201659q|J. Org. Chem. 2011, 76, 9983−9987