Spitler et al.
M) and TBAF (1.0 M soln in THF, 10 equiv) was added. The
solution was stirred at room temperature until it was determined to
be complete by TLC (typically <1 h). The reaction mixture was
then concentrated, dissolved in Et2O, and washed with H2O (3 ×
50 mL). The organic phase was collected, dried with MgSO4, and
filtered through a pad of silica gel eluting with hexanes. The solvent
was removed in vacuo and deprotected precycle was dissolved in
pyridine (0.005 M). Cu(OAc)2 (12.5 equiv per transformation) and
CuCl (10 equiv per transformation) were dissolved in pyridine:
MeOH (1.5:1, ∼2.5 L per mmol precycle). To this mixture was
injected the deprotected precycle solution via syringe pump over
40 h at 60 °C. The reaction mixture was stirred until complete by
TLC, then concentrated, rediluted in hexanes:CH2Cl2 (4:1), and
filtered through a pad of silica gel. The solvent was removed in
vacuo and the product was triturated with hexanes.
The organic phase was dried over MgSO4 and filtered through a
pad of silica gel eluting with hexanes:CH2Cl2 (7:3). The solvent
was removed in vacuo to yield 29 (7.4 g, 83%) as an orange oil.
1H NMR (CDCl3) δ 8.08 (s, 1H), 7.52 (d, 1H, J ) 5.1 Hz), 7.45
(d, 1H, J ) 5.1 Hz), 3.97 (s, 2H), 3.84 (s, 2H), 1.75 (m, 6H). 13C
NMR (CDCl3) δ 153.0, 136.4, 136.3, 126.0, 125.9, 117.4, 96.0,
53.4, 44.6, 26.7, 24.4. IR (NaCl) ν 2938, 2853, 1600, 1423, 1388,
1320, 1253, 1164, 1118, 1075 cm-1. HRMS (EI) for C12H13F3IN3
[M]+ calcd 383.0106, found 383.0100. MS (APCI) m/z ([isotope],
%) 383.0 (M+, 100), 384.0 (M+ [13C], 9).
Acceptor Iodide 30. Triazene 29 (7.3 g, 19 mmol), PdCl2(PPh3)2
(134 mg, 0.19 mmol), and CuI (0.073 g, 0.38 mmol) were dissolved
in THF (75 mL) and i-Pr2NH (75 mL), and the solution was purged
with bubbling Ar for 30 min. TIPSA (6.4 mL, 29 mmol) was
injected via syringe, and the reaction mixture was left stirring 24
h at room temperature under an atmosphere of Ar. The reaction
mixture was then concentrated, rediluted in hexanes:CH2Cl2 (2:1),
and filtered through a pad of silica gel. The solvent was removed
in vacuo, and the crude material was redissolved in MeI (30 mL).
The solution was stirred for 72 h at 155 °C in a high-pressure
reaction vessel. The reaction mixture was then cooled, concentrated,
rediluted in hexanes:CH2Cl2 (4:1), and filtered through a pad of
silica gel. The solvent was removed in vacuo to yield 30 (6.4 g,
1,4-Bis[(4′-N,N-dibutylaminophenyl)ethynyl]-2,5-bis[(4′-trif-
luoromethylphenyl)ethynyl]benzene (3). TMSA (130 mg, 1.3
mmol) was coupled to diyne 161c (304 mg, 0.44 mmol) by using
general procedure A. The resulting red oil was coupled to
4-bromobenzotrifluoride (990 mg, 4.4 mmol) by using general
procedure B. The crude material was chromatographed on silica
gel (4:1 hexanes:CH2Cl2) to yield 3 (255 mg, 67%) as a bright
1
yellow solid. Mp 125-127 °C dec. H NMR (CDCl3) δ 7.71 (s,
1
74%) as a red oil. H NMR (CDCl3) δ 7.96 (d, 1H, J ) 9.0 Hz),
2H), 7.60-7.70 (m, 8H), 7.40 (d, J ) 8.4 Hz, 4H), 6.60 (d, J )
8.4 Hz, 4H), 3.32 (t, J ) 7.5 Hz, 8H), 1.61 (quin, J ) 6.6 Hz, 8H),
1.39 (sext, J ) 7.2 Hz, 8H), 1.00 (t, J ) 7.2 Hz, 12H). 13C NMR
(CDCl3) δ 148.6, 134.8, 133.4, 132.2, 127.4, 125.9, 125.6, 125.5,
124.6, 111.5, 108.4, 98.0, 93.6, 90.8, 86.0, 51.0, 29.7, 20.6, 14.3.
IR (NaCl) ν 2197, 1602, 1519, cm-1. HRMS (ESI) for C56H54F6N2
[M + H]+ calcd 869.4264, found 869.4268. MS (APCI) m/z
([isotope], %) 871.3 (M+[213C], 18), 870.5 (M+[13C], 62), 869.2
(M+, 100). UV (CH2Cl2) λmax (log ꢀ) 383 (4.64), 440 (4.48). Em
λmax 546.
7.68 (d, 1H, J ) 2.7 Hz), 7.20 (dd, 1H, J ) 9.0, 2.7 Hz), 1.17 (s,
21H). 13C NMR (CDCl3) δ 139.6, 131.3, 129.7, 125.7, 106.9, 105.4,
98.0, 90.5, 81.8, 18.9, 11.5. IR (NaCl) ν 2952, 2889, 2160, 1597,
1565, 1462, 1395, 1328, 1280, 1252, 1209, 1177, 1126, 1082 cm-1
.
HRMS (EI) for C18H24F3ISi [M]+ calcd 452.0644, found 452.0641.
MS (APCI) m/z ([isotope], %) 452.4 (M+, 100), 453.3 (M+ [13C],
31).
Acceptor Segment 31. Iodoarene 30 (6.4 g, 14 mmol), PdCl2-
(PPh3)2 (390 mg, 0.56 mmol), and CuI (0.11 g, 1.1 mmol) were
dissolved in THF (100 mL) and iPr2NH (100 mL), and the solution
was purged with bubbling Ar for 30 min. TMSA (4 mL, 28 mmol)
was injected via syringe, and the reaction mixture was stirred 24 h
at room temperature under an atmosphere of Ar. The reaction
mixture was then concentrated, rediluted in hexanes:CH2Cl2 (2:1),
and filtered through a pad of silica gel. The solvent was removed
in vacuo to yield 31 (5.6 g, 95%) as a yellow solid. Mp 65-69 °C.
1H NMR (CDCl3) δ 7.69 (s, 1H), 7.57 (d, 1 H, J ) 8.1 Hz), 7.46
(d, 1 H, J ) 8.1 Hz), 1.16 (s, 21 H), 0.26 (s, 9H). 13C NMR (CDCl3)
δ 133.5, 129.9, 129.3, 126.7, 124.5, 122.0, 104.0, 102.3, 101.5,
97.4, 81.8, 18.9, 11.6, 0.03. IR (NaCl) ν 2955, 2944, 2890, 2865,
1,4-Bis[(4′-N,N-dibutylaminophenyl)ethynyl]-2,5-bis(2′,3′,4′,5′,6′-
pentafluorophenylethynyl)benzene (9). TMSA (94 mg, 0.96
mmol) was coupled to diyne 161c (221 mg, 0.32 mmol) by using
general procedure A. The resulting red oil was desilylated by
dissolving in THF:MeOH (5:1, 40 mL) with KOH (90 mg, 1.6
mmol) and stirring for 2 h. The red solution was concentrated in
vacuo and filtered through a pad of silica with CH2Cl2. After
reconcentration, the red oil was immediately coupled to pentaflu-
oroiodobenzene (470 mg, 1.60 mmol) by using general procedure
B with omission of KOH in the reaction mixture and injection of
the deprotected alkyne over 18 h at 45 °C. The crude material was
chromatographed on silica gel (5:1 hexanes:CH2Cl2) to yield 9 (100
mg, 35%) as a bright yellow solid. Mp 130-170 °C dec. 1H NMR
(CDCl3) δ 7.72 (s, 2H), 7.38 (d, J ) 9.0 Hz, 4H), 6.58 (d, J ) 9.0
Hz, 4H), 3.30 (t, J ) 7.5 Hz, 8H), 1.59 (quin, J ) 8.1 Hz, 8H),
1.38 (sext, J ) 7.5 Hz, 8H), 0.97 (t, J ) 7.5 Hz, 12H). 13C NMR
(CDCl3) δ 149.5, 148.5, 146.9, 139.5, 135.5, 133.5, 125.5, 123.8,
111.2, 111.2, 108.3, 100.2, 98.6, 85.4, 78.4, 50.9, 29.6, 20.6, 14.2.
IR (NaCl): ν 3014, 2281, 2187, 1728, 1689, 1575, 1571, 1524
cm-1. HRMS (ESI) for C54H46F10N2 [M + H]+ calcd 913.3574,
found 913.3576. MS (APCI) m/z ([isotope], %) 915.5 (M+[213C],
16), 914.5 (M+[13C], 50), 913.2 (M+, 100). UV (CH2Cl2) λmax (log
ꢀ) 385 (4.74), 462 (4.56). Em λmax 563.
Acceptor Triazene 29. Aniline 28 (6.71 g, 23 mmol) and CH3-
CN (5 mL) were cooled in an ice salt bath to -5 °C and concd
HCl (21 mL) was added dropwise. A solution of NaNO2 (3.85 g,
56 mmol) in H2O (3 mL) was added dropwise maintaining the
temperature below 0 °C. Upon completion, the reaction mixture
was stirred at -5 °C for 15 min. In a separate flask, K2CO3 (18.3
g, 130 mmol) and piperidine (21.5 g, 302 mmol) were dissolved in
CH3CN (110 mL) and H2O (300 mL) and cooled to 0 °C in an ice
salt bath. The reaction mixture was transferred into the basic
solution via canula while maintaining temperature below 5 °C, and
then left stirring open to air for 12 h while warming to rt. The
mixture was then concentrated and taken up in Et2O, then washed
successively with H2O, brine solution, and H2O (100 mL each).
2156, 2058, 1608, 1464, 1406, 1331, 1262, 1248, 1136, 1172 cm-1
.
HRMS (EI) for C23H33F3Si2 [M]+ calcd 422.2073, found 422.2076.
MS (APCI) m/z ([isotope], %) 422.2 (M+, 100), 423.3 (M+ [13C],
56).
Acceptor-Functionalized Aryl Bromide 32. Diyne 31 (200 mg,
0.54 mmol) was coupled to 1,5-dibromo-2,4-diiodobenzene (100
mg, 0.24 mmol) by using general procedure C to yield 32 (205
1
mg, 93%) as a yellow solid. Mp 52-53 °C. H NMR (CDCl3) δ
7.92 (s, 1H), 7.77 (s, 2H), 7.74 (s, 1H), 7.67 (d, 2H, J ) 8.1 Hz),
7.56 (d, 2H, J ) 8.1 Hz), 1.10 (s, 42H). 13C NMR (CDCl3) δ 137.7,
136.1, 133.2, 132.9, 130.7, 129.9, 128.6, 127.0, 126.1, 124.8, 124.5,
103.7, 98.2, 92.8, 92.0, 18.9, 11.5. IR (NaCl) ν 2944, 2890, 2867,
2157, 1614, 1490, 1452, 1382, 1324, 1258, 1200, 1130, 1068 cm-1
.
MS (APCI) m/z ([isotope], %) 931.1 (M+,[279Br], 90), 932.2 (M+
[79Br81Br], 100), 933.2 (M+ [281Br], 57).
BisDBA Precursor 34. Diyne 331b (478 mg, 1.15 mmol) was
coupled to tetrayne 32 (446 mg, 0.48 mmol) by using general
procedure D to yield 34 (555 mg, 73%) as an amorphous yellow
1
solid. H NMR (CDCl3, 500 MHz) δ 7.72, (s, 1H), 7.68 (s, 1H),
7.63 (d, 2H, J ) 8.0 Hz), 7.44 (d, 2H, J ) 8.0 Hz), 7.27 (d, 2H,
J ) 7.0 Hz), 6.72 (d, 2H, J ) 2.5 Hz), 6.48 (dd, 2H, J ) 7.0, 2.5
Hz), 3.27 (t, 8H, J ) 7.0 Hz), 1.56 (m, 8H, J ) 7.5 Hz), 1.35 (m,
8H, J ) 7.5 Hz), 0.96 (t, 12H, J ) 7.5 Hz). 13C NMR (CDCl3) δ
148.0, 135.4, 135.2, 133.8, 133.5, 133.3, 129.7, 129.5, 127.4, 127.1,
126.6, 124.5, 123.6, 115.4, 111.9, 111.6, 111.3, 106.5, 103.9, 97.8,
2222 J. Org. Chem., Vol. 73, No. 6, 2008