J.L. Ormsby et al. / Tetrahedron 64 (2008) 11370–11378
11377
NMR (CDCl3, 500 MHz):
(s, 2H), 3.90 (s, 6H), 3.84 (s, 6H), 3.50 (s, 6H), 3.38 (s, 6H), 0.00 (18H).
13C NMR (CDCl3, 126 MHz):
149.1, 147.3 (two peaks, coincidentally
degenerate), 147.28, 146.6, 142.0, 135.0, 131.0, 130.6, 117.6, 115.2,
114.1, 56.3, 56.0, 55.6, 55.5, 31.1, 1.2. UV–vis (CH2Cl2, nm): lmax 231
d
7.11 (s, 2H), 6.80 (s, 2H), 6.43 (s, 2H), 6.35
reaction was immediately quenched with trimethylsilyl chloride
(4.10 mL, 0.032 mol) and allowed to warm to room temperature.
The solution was diluted with water (60 mL). The organic layer was
separated, and the aqueous layer was extracted with diethyl ether
(3ꢂ50 mL). The organic layers were combined and dried under
vacuum. The product was recrystallized from methanol, filtered,
and dried under vacuum to yield white crystals (8.728 g, 86%). Mp
d
(ꢀlog
3 4.63), 297. MALDI-TOF-MS: m/z 690.22. Anal. Calcd for
C38H50O8Si2: C, 66.05; H, 7.29. Found: C, 65.79; H, 7.19.
104–105 ꢁC. 1H NMR (CDCl3, 500 MHz):
7.00 (s, 1H), 6.94 (s, 1H), 2.33 (s, 3H), 2.30 (s, 3H), 2.29 (s, 3H), 2.23
(s, 3H), 0.00 (s, 9H). 13C NMR (CDCl3, 126 MHz):
145.5, 141.8, 137.6,
137.0, 136.2, 135.6, 135.0, 135.0, 133.4, 133.1, 131.5, 121.1, 19.9, 19.8,
4.86), 282, 287.
d 7.40 (s, 1H), 7.37 (s, 1H),
4.7. 3,3%,4,40,400,4%,50,500-Octamethoxy-1,10,20,100,200,1%-
quaterphenyl (9)
d
A
solution of the bistrimethylsilyl ortho-quaterphenyl (8)
19.5, 19.3, 0.4. UV–vis (EtOH, nm): lmax 208 (ꢀlog
3
(82 mg, 0.012 mmol) in CH2Cl2 (5 mL) at 0 ꢁC was treated with
tetrafluoroboric acid (HBF4) (0.10 mL of a 54 wt % solution in diethyl
ether, 0.6 mmol) and the reaction mixture was stirred for 2 h at this
temperature, then quenched with saturated aqueous NaHCO3. The
mixture was extracted with ethyl acetate (3ꢂ10 mL). The combined
organic layers were dried with anhydrous Na2SO4, filtered, and
dried under vacuum. The residue was purified by silica gel column
chromatography using ethyl acetate/hexanes (50:50). The solvent
was removed to yield white crystals (62 mg, 96%). Mp 154–156 ꢁC
(lit.22 219 ꢁC). 1H and 13C NMR match the literature.22 1H NMR
GC–MS: m/z 347. Anal. Calcd for C19H25BrSi: C, 63.15; H, 6.97. Found:
C, 63.21; H, 6.90.
4.12. 4,40,4,00,4%,5,50,500,5%-Octamethyl-2,2%-bistrimethylsilyl-
1,10,20,100,200,1000-quaterphenyl (18)
A solution of 17 (7.73 g, 21.4 mmol), 2,20-bipyridyl (4.81 g,
32.1 mmol), 1,5-cyclooctadiene (3.9 mL, 31.8 mmol), dry DMF
(85 mL), and dry toluene (315 mL) was heated to 80 ꢁC. Bis(1,5-
cyclooctadiene)nickel(0) (7.66 g, 32.1 mmol) was added and the
reaction mixture was stirred overnight. The reaction mixture was
diluted with water and the organic layer was separated. The
aqueous layer was extracted with toluene (3ꢂ100 mL). The organic
layers were combined and the solvent was removed under vacuum.
The solid was recrystallized from EtOH twice to yield 3.11 g (51%) of
(CDCl3, 500 MHz):
6.22 (dd, J¼8/2 Hz, 2H), 6.18 (d, J¼2 Hz, 2H), 3.90 (s, 6H), 3.89 (s,
6H), 3.84 (s, 6H), 3.53 (s, 6H). 13C NMR (CDCl3, 126 MHz):
148.3,
148.1, 148.0, 147.4, 133.9, 133.7, 132.3, 121.5, 114.8, 112.9, 112.6, 110.6,
56.4, 56.2, 56.0, 55.6. UV–vis (CH2Cl2, nm): lmax 230 (ꢀlog 4.62),
292 (ꢀlog 4.30). MADLI-TOF-MS: m/z 546.15.
d
6.94 (s, 2H), 6.71 (s, 2H), 6.57 (d, J¼8 Hz, 2H),
d
3
3
18. Mp 180–181 ꢁC. 1H NMR (CDCl3, 500 MHz):
2H), 6.74 (s, 2H), 6.62 (s, 2H), 2.21 (s, 6H), 2.16 (s, 6H), 2.03 (s, 6H),
2.00 (s, 6H), 0.00 (18H). 13C NMR (DMSO, 126 MHz):
144.9, 139.3,
135.3, 135.3, 135.2, 134.7, 132.6, 132.3, 132.3, 132.2, 131.9, 130.5, 18.4,
4.27), 265
d 7.30 (s, 2H), 6.83 (s,
4.8. 1,2,5,6,9,10,12,13-Octamethoxydibenzo-
[fg,op]naphthacene (11)
d
18.1, 17.8, 17.6, 0.2. UV–vis (EtOH, nm): lmax 212 (ꢀlog
3
The octamethoxy-ortho-quaterphenyl (9) (181 mg, 0.332 mmol)
was dissolved in CH2Cl2 (10 mL). A solution of PIFA (285 mg,
0.66 mmol) and BF3$Et2O (0.166 mL, 1.33 mmol) was added at
25 ꢁC. After 24 h of stirring, the reaction mixture was diluted with
degassed MeOH. Aqueous NaOH (2.5 M, 5 mL) was added, and the
mixture was extracted with methylene chloride (3ꢂ5 mL). The
combined organic layers were combined and purified by flash
chromatography on alumina (ethyl acetate/methylene chloride
10:90), and the solvent was removed under vacuum (85 mg, 47%
yield). NOE and crystallography established connectivity. 1H NMR
(shoulder), 287 (shoulder). GC–MS: m/z 563. Anal. Calcd for
C38H50Si2: C, 81.07; H, 8.95. Found: C, 80.86; H, 9.03.
4.13. 3,3%,4,40,400,4%,50,500-Octamethyl-1,10,20,100,200,1000
-
quaterphenyl (19)
A solution of the bistrimethylsilyl ortho-quaterphenyl (18)
(2.414 g, 4.296 mmol) in CH2Cl2 (40 mL) at 0 ꢁC was treated with
tetrafluoroboric acid (HBF4) (7.4 mL of a 54 wt % solution in diethyl
ether, 44 mmol) and the reaction mixture was stirred and allowed
to slowly rise to room temperature overnight, then quenched with
saturated aqueous NaHCO3. The mixture was diluted with CH2Cl2
and washed with saturated NaHCO3 (3ꢂ20 mL) and water
(3ꢂ20 mL). The solvent was removed under vacuum, and the
remaining solid was recrystallized from EtOH. The recrystallized
solid was collected and washed with hexane on a vacuum filter and
dried under vacuum to yield white crystals (1.410 g, 78.5%). Mp
(CD2Cl2, 500 MHz):
d 9.31 (s, 2H), 8.17 (s, 2H), 7.98 (s, 2H), 4.21 (s,
6H), 4.13 (s, 6H), 4.07 (s, 6H), 3.94 (s, 6H). 13C NMR (CD2Cl2,
126 MHz):
d 152.2, 150.4, 149.0, 145.9, 125.3, 125.1, 124.2, 123.1,
119.9, 110.2, 105.6, 105.1, 60.9, 56.9, 56.6, 56.1. Mp 219–220 ꢁC.
4.9. 4,5-Dibromo-ortho-xylene (15)
Prepared according to the literature.36 The material was
211 ꢁC. 1H NMR (CDCl3, 500 MHz):
d 7.21 (s, 2H), 6.88 (s, 2H), 6.70
recrystallized to give 106 g of 15 (0.402 mol, 53% yield). 1H NMR
(d, J¼7 Hz, 2H), 6.32 (dd, J¼7/2 Hz, 2H), 6.21 (d, J¼2 Hz, 2H), 2.33 (s,
(CDCl3, 400 MHz):
d
7.38 (s, 2H), 2.20 (s, 6H).
6H), 2.28 (s, 6H), 2.18 (s, 6H), 2.02 (s, 6H). 13C NMR (CDCl3,
126 MHz):
130.5, 128.4, 126.7, 19.7, 19.6, 19.6, 19.5. UV–vis (EtOH, nm): lmax
4.46), 260 (shoulder). GC–MS: m/z 419. Anal. Calcd
d 139.0, 138.7, 137.8, 135.5, 135.3, 135.1, 133.5, 133.1, 131.2,
4.10. 2,20-Dibromo-4,40,5,50-tetramethylbiphenyl (16)
209, 238 (ꢀlog
3
Prepared according to the literature.20 The product was recrys-
tallized from absolute ethanol, filtered, and dried under vacuum to
yield white crystals (15.33 g, 71% yield). 1H NMR (CDCl3, 500 MHz):
for C32H34: C, 91.81; H, 8.19. Found: C, 91.71; H, 8.38.
4.14. 1,2,5,6,9,10,12,13-Octamethyldibenzo[fg,op]-
d
7.43 (s, 2H), 6.99 (s, 2H), 2.29 (s, 6H), 2.42 (s, 6H). GC–MS: m/z 368.
naphthacene (20)
4.11. 2-Bromo-20-trimethylsilyl-4,40,5,50-
tetramethylbiphenyl (17)
The octamethyl-ortho-quaterphenyl (19) (43.5 mg, 0.104 mmol)
was dissolved in CH2Cl2 (35 mL). MoCl5 (80.0 mg, 0.208 mmol) was
added to the stirring solution at 0 ꢁC under nitrogen, and the re-
action mixture was allowed to warm slowly to room temperature
overnight. The reaction was quenched by filtration through silica
gel in CH2Cl2. The solvent was removed under vacuum, and the
To a stirring solution of 2,20-dibromo-4,40,5,50-tetramethylbi-
phenyl (10.338 g, 0.028 mol) in THF (100 mL), n-BuLi (22.9 mL,
0.031 mol, 2.50 M in hexane) was added dropwise at ꢀ78 ꢁC. The