π-Stacking of Shape-Persistent Cyclophanes
9 (R ) CO2C12H25). In a screw-cap tube, 6 (1.00 g, 3.52
mmol) and 7 (4.50 g, 9.1 mmol) were dissolved in triethylamine
(50 mL). PPh3 (600 mg, 2.3 mmol), Pd(dba)2 300 mg, 0.54
mmol) and CuI (80 mg, 0.42 mmol) were added in that order.
The yellow suspension was stirred at room temperature for
40 min before being heated at 50 °C for 2 h. The reaction was
cooled back to room temperature after being checked by TLC.
Another portion of Pd/Cu catalyst (PPh3 (600 mg, 2.3 mmol),
Pd(dba)2 (300 mg, 0.54 mmol), and CuI (80 mg, 0.42 mmol))
and TMSA (3 mL. 2.2 g, 2.3 mmol) were added to the reaction
vessel. The reaction was then stirred at room temperature for
40 min before being heated to 70 °C for 16 h. After being cooled
back to room temperature, the reaction was diluted with
petroleum ether and washed with water (3×). The organic
phase was dried over Na2SO4 and concentrated in vacuo. The
residue was purified by flash chromatography (30-50% CH2-
Cl2 in petroleum ether) to give the desired product as yellow
viscous oil (3.15 g, 84%) that solidified to become a wax solid
after several days at room temperature: 1H NMR (400 MHz,
CDCl3) δ 8.13 (t, J ) 2 Hz, 2 H), 8.10 (t, J ) 2 Hz, 2 H), 7.81
(t, J ) 2 Hz, 2 H), 7.57 (t, J ) 2 Hz, 1 H), 7.41 (d, J ) 2 Hz,
2 H), 4.36 (t, J ) 7 Hz, 4 H), 3.86 (t, J ) 7 Hz, 2 H), 2.85 (t,
J ) 7 Hz, 2 H), 1.79 (m, 4 H), 1.29 (m, 36 H), 0.90 (s, 9 H),
0.89 (t, J ) 7 Hz, 6 H), 0.29 (s 18 H), 0.02 (s, 6 H); 13C NMR
(100 MHz, CDCl3) δ 165.67, 140.56, 139.03, 133.20, 132.92,
132.89, 132.70, 131.56, 124.42, 124.18, 123.30, 103.47, 96.61,
90.36, 88.39, 66.06, 64.17, 39.36, 32.30, 30.03, 30.01, 29.97,
29.89, 29.73, 29.67, 29.09, 26.37, 26.03, 23,07, 18.70, 14.47,
0.23, -5.3; IR (KBr) 2924, 2853, 2160, 1728, 1592, 1466, 1281,
1110, 895 cm-1; MS (MALDI) found m/z 1076.42 ([M + Na]+,
1), required 1076.72.
Dia lk yn e 10 (R ) OC12H25). Compound 8 (1.00 g, 1 mmol)
was dissolved in a CH2Cl2/MeOH mix solvent (20 mL/20 mL).
K2CO3 (1.00 g, 0.07 mol) was added to the solution, and the
reaction was stirred at room temperature for 1.5 h. The
reaction was poured into a water/petroleum ether mixture. The
organic phase was washed with water (2×), dried (Na2SO4),
and concentrated in vacuo. Pure product was obtained after
flash chromatography (CH2Cl2/hexane ) 1/2) as a thick yellow
liquid (0.85 g, 99%): 1H NMR (400 MHz, CDCl3) δ 7.56 (t, J )
2 Hz, 1 H), 7.38 (d, J ) 2 Hz, 2 H), 7.27 (t, J ) 2 Hz, 2 H),
7.06 (m, 2 H), 7.02 (m, 2 H), 3.98 (t, J ) 7 Hz, 4H), 3.85 (t, J
) 7 Hz, 2 H), 3.09 (s, 2H), 2.84 (t, J ) 7 Hz, 2 H), 1.81 (m, 4
H), 1.37-1.28 (m, 36 H), 0.93 (s, 9 H), 0.91 (t, J ) 7 Hz, 6 H),
0.03 (s, 6 H); 13C NMR (100 MHz, CDCl3) δ 159.18, 140.36,
132.97, 132.88, 128.02, 124.70, 123.72, 123.50, 118.94, 118.65,
89.37, 89.18, 83.22, 77.85, 68.71, 64.26, 39.39, 32.34, 30.09,
30.06, 30.02, 29.99, 29.77, 29.54, 26.40, 26.32, 23.11, 18.72,
14.54, -5.04; IR (KBr) 3305, 2925, 2853, 1580, 1465, 1419,
1149, 839 cm-1; MS (CI) found m/z 853.60 [(M + H)+, 20],
required 853.59.
1 a n d 2 (1, R ) OC12H25, 2, R ) COOC12H25). CuCl (8.00 g,
80 mmol) and CuCl2 (1.60 g, 12 mol) (both grounded powder)
were added to pyridine (250 mL). The dark green suspension
was gently heated and sonicated to break up the lumps of Cu
salt before it was heated to 65 °C in an oil bath. The terminal
dialkyne 7 (0.84 g, 0.98 mmol) was dissolved in pyridine (50
mL) and was slowly added to the CuCl/CuCl2 suspension in
96 h with a syringe pump. The reaction was cooled to room
temperature and stirred overnight after the addition was
completed. The reaction was diluted with CH2Cl2 (1000 mL),
and the dark solution was washed with 4 M NH4OH (4×), 1
M HCl (2×), saturated NaHCO3 (1×), and water (1×). The
remaining organic phase was dried over Na2SO4 and concen-
trated in vacuo. The residual dark solid was purified by flash
chromatography (20% CH2Cl2 in hexane). Cyclophane 1 was
obtained as a white solid (0.42 g, 50%): 1H NMR (400 MHz,
CDCl3) δ 7.63 (t, J ) 2 Hz, 2 H), 7.37 (m, 8 H), 7.07 (m, 4 H),
7.02 (m, 4 H), 3.99 (t, J ) 7 Hz, 8 H), 3.85 (t, J ) 7 Hz, 4 H),
2.84 (t, J ) 7 Hz, 4 H), 1.82 (m, 8 H), 1.30-1.35 (m, 72 H),
0.92 (s, 18 H), 0.91 (t, J ) 7 Hz, 12 H), 0.03 (s, 12 H); 13C
NMR (100 MHz, CDCl3) δ 159.23, 140.31, 132.68, 129.02,
124.93, 123.48, 123.31, 118.98, 118.58, 89.71, 89.16, 81.24,
74.45, 68.78, 64.29, 39.43, 32.34, 30.09, 30.06, 30.03, 30.00,
29.78, 29.53, 26.40, 26.33, 26.30, 23.11, 18.73, 14.55, -5.01;
IR (KBr) 2924, 2853, 2219, 1578, 1467, 1416, 1370, 1198, 1097,
1056, 868, 838 cm-1; MS (MALDI) found, m/z ) 1724, ([M +
Na]+, <1), 1702 ([M + H]+, <1), required 1724.13 and 1701.14.
Cyclophane2 was synthesized from dialkyne 11 by a pro-
cedure similar to that for 1 from 10. The only difference was
the solvent polarity for the flash chromatography (70% CH2-
Cl2 in hexane). Cyclophane 2 was obtained as a yellow waxy
solid (35% yield): 1H NMR (400 MHz, CDCl3, diluted solution)
δ 8.30 (t, J ) 2 Hz, 4 H), 7.94 (t, J ) 2 Hz, 4 H), 7.86 (t, J )
2 Hz, 4 H), 7.50 (t, J ) 2 Hz, 2 H), 7.30 (d, J ) 2 Hz, 4 H),
4.35 (t, J ) 7 Hz, 8 H), 3.83 (t, J ) 7 Hz, 4 H), 2.78 (t, J ) 7
Hz, 4 H), 1.81 (m, 8 H), 1.46-1.49 (m, 72 H), 0.94 (s, 18 H),
0.91 (t, J ) 7 Hz, 12 H), 0.05 (s, 12 H); 13C NMR (100 MHz,
CDCl3, concentrated solution) δ 165.29, 140.57, 139.69, 133.49,
133.25, 133.06, 131.78, 124.61, 123.17, 122.83, 90.67, 88.23,
80.67, 75.41, 66.19, 64.13, 39.34, 32.32, 30.06, 30.04, 30.03,
29.94, 29.75, 29.72, 29.09, 26.41, 26.31, 23.08, 18.69, 14.49,
-5.02; IR (KBr) 2924, 2853, 2217, 1752, 1593, 1456, 1254,
1110, 837, 770 cm-1; MS (MALDI) found m/z 1922.65 ([M +
Ag]+, 1), required 1922.03.
Diol 3 (R ) OC12H25). Compound 1 (0.40 g, 0.245 mmol)
was dissolved in THF (5 mL). Tetrabutylammonium fluoride
(1.0 mL, 1 M solution in THF, 1 mmol) was added, and the
reaction was stirred at room temperature for 2 h. The solution
was passed through a short silica gel column (eluent 1:1 ether/
chloroform), and the solvent was removed in vacuo. The crude
product was purified by flash chromatography (5% diethyl
ether in chloroform) to give the desired cyclophane diols as a
white solid (0.25 g, 72%): 1H NMR (400 MHz, CDCl3) δ 7.57
(t, J ) 2 Hz, 2 H), 7.32 (d, J ) 2 Hz, 4 H), 7.31 (t, J ) 2 Hz,
4 H), 6.99 (m, 4 H), 6.93 (m, 4 H), 3.87-3.94 (m, 12 H), 2.84
(t, J ) 7 Hz, 4 H), 1.76 (m, 8 H), 1.27 (m, 72 H), 0.89 (t, J )
7 Hz, 12 H); 13C NMR (100 MHz, CDCl3) δ 159.14, 139.60,
133.93, 132.29, 129.02, 124.78, 123.92, 123.33, 118.88, 118.63,
89.53, 89.49, 81.24, 74.52, 68.76, 63.59, 39.10, 32.35, 30.11,
30.08, 30.05, 30.03, 29.83, 29.79, 29.57, 26.42, 23.12, 14.55;
IR (KBr) 3354, 2921, 2851, 1579, 1416, 1368, 1198, 1050, 864,
844 cm-1; MS (MALDI) found m/z 1474 ([M + H]+, <1),
required 1473.97.
Diol 4 (R ) CO2C12H25). Cyclophane 2 (0.15 g, 0.083 mmol)
was dissolved in THF (5 mL). Tetrabutylammonium fluoride
(0.4 mL, 1 M solution in THF, 0.4 mmol) was added, and the
reaction was stirred at room temperature for 2 h. The solution
was passed through a short silica gel column (50% ether in
chloroform), and the solvent was removed in vacuo. The crude
product was purified by flash chromatography (10-20% di-
ethyl ether in chloroform) to give the desired cyclophane diol
as an off-white solid (125 mg, 94%): 1H NMR (400 MHz,
Dia lk yn e 11 (R ) CO2C12H25). Compound 9 (1.00 g, 0.95
mmol) was dissolved in CH2Cl2 (30 mL), and the solution was
cooled to 0 °C. Tetrabutylammonium fluoride (0.25 mL, 1 M
solution in THF 0.25 mmol) was added. The reaction was
stirred at 0 °C for 15 min. The reaction mixture was passed
through a short silica gel column (eluted with CH2Cl2). The
solvent was then removed in vacuo to give the terminal
dialkyne as colorless sticky oil (0.78 g, 90%): 1H NMR (400
MHz, CDCl3) δ 8.17 (t, J ) 2 Hz, 2 H), 8.12 (t, J ) 2 Hz, 2 H),
7.82 (t, J ) 2 Hz, 2 H), 7.59 (t, J ) 2 Hz, 1 H), 7.42 (d, J ) 2
Hz, 2 H), 4.36 (t, J ) 7 Hz, 4 H), 3.84 (t, J ) 7 Hz, 2 H), 3.18
(s, 2 H), 2.85 (t, J ) 7 Hz, 2 H), 1.80 (m, 4 H), 1.33 (m, 36 H),
0.92 (s, 9 H), 0.89 (t, J ) 7 Hz, 6 H), 0.03 (s, 6 H); 13C NMR
(100 MHz, CDCl3) δ 165.56, 140.59, 139.11, 133.31, 133.16,
133.14, 132.93, 131.66, 124.32, 123.39, 123.21, 90.52, 88.24,
82.24, 79.17, 66.14, 64.18, 39.35, 32.32, 30.58, 30.04, 30.00,
29.93, 29.76, 29.69, 29.07, 26.40, 26.30, 22.10, 18.71, 14.53,
-5.03; IR (KBr) 3306, 2924, 2853, 1725, 1592, 1463, 1237, 1105
cm-1; HRMS (CI) found m/z ) 909.6 [(M + H)+, 16], required
909.58.
Gen er a l P r oced u r e for th e Syn th esis of Cyclop h a n e
J . Org. Chem, Vol. 67, No. 22, 2002 7767