1,3-BicycloACHTREUNG[1.1.1]pentanediyl
FULL PAPER
3
¯
dide 25 (942 mg, 2.0 mmol), Pd
G
1.29736(2) nm , Z=2, space group P1, MoKa radiation at 71.073 pm, T=
100(2) K, 1=1.394 Mgmꢁ3, absorption coefficient: 0.308 mmꢁ1, Fo =564,
q range for data collection: 2.05 to 24.48, reflections collected: 5303, inde-
pendent reflections: 5303 [Rint =0.0000], completeness to q=26.408:
99.6%, max. and min. transmission: 0.9410 and 0.9133, refinement
method: full-matrix least squares on F2, data/restraints/parameters: 5303/
0/323, goodness of fit on F2: 1.396; final R indices [I > 2s(I)]: R1 =
105 mmol) and Ph3P (50 mg, 190 mmol) were placed in a flame-dried
round-bottomed flask (25 mL) with a side-arm. The flask was closed with
a septum, evacuated, filled with nitrogen, and this cycle was repeated two
more times. Then anhydrous THF (12 mL) was introduced through the
septum, the mixture was stirred at room temperature for 10 min, and
Et3N (0.5 mL) was added. The mixture was stirred at 388C for 36 h, dilut-
ed with CHCl3 (50 mL), washed with sat. aq. NH4Cl containing 2% (v/v)
of 25% aq. NH3 (20 mL), water (20 mL), 1m aq. HCl (20 mL) and brine
(20 mL). The organic layer was dried, evaporated in vacuo, the residue
was taken up in hot CHCl3 and applied on top of a column with flash
silica gel (200 g). Elution with a CHCl3/hexane mixture (1:3 ! 3:1) af-
forded first the unreacted diiodide 25 (ca. 0.5 g), then the orange band
with the title compound (230 mg) followed by a red band, which con-
tained the by-product. Recrystallization from CHCl3 gave 24 (171 mg,
35%). M.p. 2708C (decomp); 1H NMR (250 MHz, CDCl3): d=2.33 (s,
6H), 4.09 (s), 4.10 (s) (ꢀ 6H), 6.90 (d, J=7.8, 2H), 7.04 (d, J=7.8, 2H),
7.32 (d, J=7.8, 2H), 7.35–7.42 (m, 3H), 7.46 (t, J=7.8, 2H), 7.63–7.73
(m, 6H), 8.52 ppm (dd, J=7.8 and 3, 2H); 13C NMR (75 MHz, CDCl3):
0.0731, wR2 =0.1420; R indices (all data): R1 =0.0758, wR2 =0.1431; larg-
est diff. peak and hole: 0.493 and ꢁ0.424 e
ꢁ3
.
4-[2-(2,4-Dimethyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluorocyclo-
penten-1-yl]-3,5-dimethylthiophene (38-H): To a solution of 38-SiMe3
(350 mg, 0.64 mmol) in anhydrous THF (8.0 mL), was added slowly at
room temperature Bu4NF (1.0m in THF, 1.2 mmol, 1.2 mL), and stirring
was continued for 10 min. The mixture was diluted with Et2O (100 mL),
washed with water (50 mL), dried and filtered. The solvents were re-
moved in vacuo, and the title compound (280 mg, 93%) was isolated by
chromatography (50 g silica gel, column 220 cm, pentane) as a colorless
oil. Rf =0.48 (pentane); 1H NMR (250 MHz, CDCl3): d=2.06 (s, 6H),
2.32 (s, 6H), 6.73 (s, 1H), 7.42–7.28 ppm (m, 5H); 13C NMR (75.5 MHz,
CDCl3):[37] d=14.58, 14.63, 14.8, 15.19, 116.2, 119.4, 127.4, 128.5, 129.19,
132.0, 134.0, 136.2, 136.9 ppm; 19F NMR (282 MHz, CDCl3): d=ꢁ133.4
to ꢁ133.3 (m, 2F), ꢁ110.7 to ꢁ110.15 ppm (m, 4F); IR (film): n˜ =2959,
2929, 2867, 1473, 1442, 1342, 1274, 1191, 1144, 1114, 1057, 989, 874, 758,
697 cmꢁ1; MS (EI): m/z (%): 472 (100) [M +]; elemental analysis calcd
(%) for C23H18F6S2 (472.51): C 58.46, H 3.84; found: C 58.63, H 3.95.
d=40.7 (C), 41.0 (C), 54.1 (CH2), 56.1 (MeO), 90.7 (C ), 91.8 (C-I),
ꢂ
ꢂ
102.2 (C ), 102.3 (C ), 105.6 (CH), 115.4, 115.6, 120.2 (CH), 122.9, 124.7,
125.5, 126.3 (CH), 126.5ACHTREUNG(CH2), 128.2 (CH), 128.3 (CH2), 128.5 (CH
2), 131.3 (CH2), 131.4 (CH2), 134.9, 137.3 (CH2), 140.5, 140.8,
156.9 ppm; IR (KBr): n˜ = 2925, 2360, 2340, 1264„ 1185, 1034, 756, 694,
517 cmꢁ1; MS (EI): m/z (%): 708 (3)/707 (33)/706 (92) [M +], 582 (8), 581
(42), 580 (100) [M +ꢁI+H], 142 (58); elemental analysis calcd (%) for
C43H31IO2 (706.61): C 73.09, H 4.42; found: C 73.32, H 4.79.
4-[2-(2,4-Dimethyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluorocyclo-
penten-1-yl]-5-methoxy-3-methylthiophene (41-H) was obtained from
heptafluorcyclopentyl derivative 19[36] (0.60 g, 1.6 mmol) and the 3-thienyl
bromide 40[9c] (1.8 mmol) in two steps and isolated as an oil (327 mg,
42%) as described above for compound 38-H. 1H NMR (300 MHz,
CDCl3): d=2.08 (s, 3H), 2.11 (d, J=1, 3H), 2.29 (s, 3H), 6.25 (q, J=1,
1H), 7.29–7.41 ppm (m, 5H); 13C NMR (75.5 MHz, CDCl3):[37] d=14.1
(Me), 14.2 (Me), 16.3 (Me), 60.9 (MeO), 107.4 (CH), 107.8, 126.9, 127.3
(CH), 128.5 (CH), 128.5 (CH), 129.0 (CH2), 132.3, 134.2, 134.5, 135.6,
138.6, 165.5 ppm; IR (film): n˜ = 3023, 2968, 2928, 2864, 1600, 1557, 1494,
1448, 1395, 1341, 1278, 1192, 1142, 1112, 1060, 1022, 982, 906, 871, 758,
698, 539, 505 cmꢁ1; MS (ESI, positive mode): m/z (%): 491 (10)/490 (24)/
489 (100) [M+H]+; HRMS (ESI): m/z: calcd for C23H19F6OS2: 489.07815,
found: 489.07728 [M+H]+.
3-Bromo-2,4-dimethyl-5-trimethylsilylthiophene (37):[38] To a solution of
the thiophene 11 (2.15 g, 7.96 mmol) in anhydrous THF (20 mL), was
added t at ꢁ788C nBuLi (2.5m in hexanes, 3.3 mL, 8.25 mmol). During
the addition, the solution turned yellow, then green and then brown.
After 10 min, freshly distilled Me3SiCl (1.26 mL, 1.09 g, 10 mmol) in THF
(5 mL) was added dropwise to the reaction mixture, and the mixture was
left to warm up to room temperature. It was diluted with hexane
(50 mL), the mixture washed with brine (50 mL), the organic phase was
dried and concentrated. The title compound was isolated from the oily
residue (2.09 g) by chromatography on silica gel (125 g) eluting with
hexane (Rf ꢀ0.75), yield 37 as a colorless liquid (1.54 g, 74%), which was
used in the next step without further purification. 1H NMR (250 MHz,
CDCl3): d=0.34 (s, 9H), 2.28 (s, 3H), 2.41 ppm (s, 3H); 13C NMR
(62.9 MHz, CDCl3): d=ꢁ0.5 (Me3Si), 15.3 (Me), 17.1 (Me), 115.1, 129.7,
4-[2-(2-Methoxy-4-methyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluoro-
cyclopenten-1-yl]-3,5-dimethylthiophene (42-H):[38] 4-[2-(2-Methoxy-4-
methyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluorocyclopenten-1-yl]-
3,5-dimethyl-2-trimethylsilylthiophene (42-SiMe3)[9c] was synthesized
from the thiophenes 37 (438 mg, 1.66 mmol) and 39 (555 mg, 1.40 mmol)
as described above for the compound 38-SiMe3, to yield 42-SiMe3 a pale
blue solid (600 mg, 76%). Rf =0.65 (pentane); m.p. 85–878C; 13C NMR
(75.4 MHz, CDCl3):[37] d=ꢁ0.18, 14.29, 14.55, 15.87, 60.98, 124.39, 127.16,
128.53, 129.15, 129.79, 133.95 ppm; 19F NMR (282 MHz, CDCl3): d=
ꢁ114.9 to ꢁ106.1 (brm, 2F), ꢁ113.0 (s, 2F), ꢁ133.4 ppm (s, 2F); IR
(KBr): n˜ = 3007, 2957, 2928, 1602, 1560, 1486, 1450, 1394, 1345, 1273,
1253, 1191, 1147, 1104, 1061, 1021, 942, 922, 839, 762, 702 cmꢁ1; MS (EI):
m/z (%): 560 (100) [M +]; elemental analysis calcd (%) for
C26H26F6OS2Si (560.69), C 55.70, H 4.67; found: C 55.94, H 4.59.
138.2, 143.1 ppm; IR (KBr): n˜
839 cmꢁ1; MS (EI): m/z (%): 264/262 (24) [M +], 249/247 (100) [M +
ꢁMe], 138/136 (20).
4-[2-(2,4-Dimethyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluorocyclo-
penten-1-yl]-3,5-dimethyl-2-trimethylsilylthiophene (38-SiMe3): To a solu-
tion of the thiophene 37 (363 mg, 1.38 mmol) in anhydrous THF
(2.0 mL), was added slowly at ꢁ788C nBuLi (2.5m in hexanes, 0.56 mL,
1.40 mmol), and the mixture was stirred at this temperature for 30 min.
A solution of compound 19[36] (500 mg, 1.32 mmol) in anhydrous THF
(2.0 mL) was added slowly at ꢁ788C. The reaction mixture was allowed
to warm-up to room temperature, stirred for 30 min, diluted with Et2O
(100 mL), and washed with water (50 mL). After drying, the solvents
were removed in vacuo. The residue was subjected to chromatography on
silica gel (50 g, column 220 cm, pentane) to give the title compound as
a colorless solid (476 mg, 66%). Rf =0.75 (pentane); m.p. 120–1228C;
1H NMR (250 MHz, CDCl3, 2 rotamers): d=0.28 (s, 9H), 2.047 (s), 2.053
(s), 2.067 (s), 2.073 (s) (ꢀ 3H), 2.086 (s), 2.094 (s), 2.117 (s), 2.123 (s) (ꢀ
3H), 2.30 (s, 3H), 2.32 (s), 2.33 (s) (ꢀ 3H), 7.30–7.39 ppm (m, 5H);
13C NMR (62.9 MHz, CDCl3):[37] d=0.3, 14.6, 14.89, 14.95, 16.3, 127.2,
127.4, 128.5, 129.1, 131.1, 132.0, 134.1, 136.1, 138.7 (d, J=1.9), 143.2,
144.5 ppm (d, J=15.7); IR (KBr): n˜ =3022, 2956, 2928, 1653, 1443, 1269,
1251, 1192, 1141, 1109, 1066, 1026, 990, 945, 839, 757, 704 cmꢁ1; MS (EI):
m/z (%): 544 (100) [M +]; elemental analysis calcd (%) for C26H26F6S2Si
(544.69): C 57.33, H 4.81; found: C 57.59, H 5.05.
Compound 42-H was synthesized from 42-SiMe3 (500 mg, 0.89 mmol) as
described above for the compound 38-H, to obtain
a colorless oil
(397 mg, 91%) which gradually crystallized into a pale blue solid. M.p.
99–1018C; Rf =0.35 (pentane); 1H NMR (250 MHz, CDCl3): d=2.078 (s,
3H), 2.083 (s, 3H), 2.31 (s, 3H), 3.78 (s, 3H), 6.71 (brs, 1H), 7.27–
7.41 ppm (m, 5H); 13C NMR (75.4 MHz, CDCl3):[37] d=14.5, 14.6, 15.0,
61.1, 109.2, 118.7, 124.5, 125.5, 127.2, 128.52, 129.2, 129.7, 133.9, 137.1,
163.8 ppm; 19F NMR (282 MHz, CDCl3): d=ꢁ112.4 to ꢁ108.8 (brm, 4F),
ꢁ133.2 ppm (s, 2F); IR (film): n˜ = 2959, 2929, 2872, 1600, 1559, 1501,
1448, 1395, 1341, 1275, 1228, 1191, 1143, 1111, 1059, 1022, 985, 920, 758,
698 cmꢁ1; MS (EI): m/z (%): 488 (100) [M +]; HRMS: m/z: calcd for
C23H18F6OS2: 488.0748; found: 488.0748 [M+H]+.
Crystal structure analysis of compound 38-SiMe3:[28] Crystal size 0.30
4-[2-(2-Methoxy-4-methyl-5-phenylthiophen-3-yl)-3,3,4,4,5,5-hexafluoro-
cyclopenten-1-yl]-5-methoxy-3-methythiophene (43-H):[38] To a solution
of the thiophene 40 (558 mg, 2.00 mmol) in anhydrous THF (4.0 mL),
0.200.20 mm3,
triclinic,
a=1063.85(9),
b=1175.17(10),
c=
1238.74(11) pm, a=63.963(10), b=75.887(10), g=69.7010(8)8, V=
Chem. Eur. J. 2007, 13, 2503 – 2516
ꢀ 2007 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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