Synthesis and structural properties of cyclophanes containing thiophene rings in the side-chain

Article abstract of DOI:10.3987/COM-06-10736

The synthesis of some cyclophanes bearing in the linear side-chain carbon-carbon triple bonds conjugated with thiophene rings has been reported. Structure analysis of the products based on extensive NMR investigation is presented. UV-Vis absorption spectra and fluorescence spectra have been measured. The analysis of the spectra points out a correlation between the maxima and the structure of the side-chain. The replacement of a benzene ring with a thiophene ring causes a bathochromic shift when the benzene ring close to the paracyclophane moiety is replaced.

Full text of DOI:10.3987/COM-06-10736

HETEROCYCLES, Vol. 68, No. 6, 2006
1249
HETEROCYCLES, Vol. 68, No. 6, 2006, pp. 1249 - 1257. © The Japan Institute of Heterocyclic Chemistry
Received, 16th March, 2006, Accepted, 21st April, 2006, Published online, 21st April, 2006. COM-06-10736
SYNTHESIS AND STRUCTURAL PROPERTIES OF CYCLOPHANES
CONTAINING THIOPHENE RINGS IN THE SIDE-CHAIN
Aldo Taticchi,a,* Assunta Marrocchi,a,* Lucio Minuti,a Selvaggia Landi,a and
Eszter Gacs-Baitzb
a Dipartimento di Chimica, Università degli Studi di Perugia, via Elce di Sotto 8,
06123 Perugia, Italy
bCentral Research Institute for Chemistry, Hungarian Academy of Sciences,
Budapest, Hungary
_
Abstract The synthesis of some cyclophanes bearing in the linear side-chain
carbon-carbon triple bonds conjugated with thiophene rings has been reported.
Structure analysis of the products based on extensive NMR investigation is
presented. UV-Vis absorption spectra and fluorescence spectra have been
measured. The analysis of the spectra points out a correlation between the
maxima and the structure of the side-chain. The replacement of a benzene ring
with a thiophene ring causes a bathochromic shift when the benzene ring close to
the paracyclophane moiety is replaced.
INTRODUCTION
In continuation of our study in the synthesis of [2.2]paracyclophanes, recently we described a synthetic
approach to novel cyclophanes containing conjugated acetylene triple bonds in the linear side-chain1. In
the last decade there has been much attention focused in the arylethynyl molecular systems with extended
π-conjugation due to their potential applications in the field of material science2. We have now extended
the study to the [2.2]paracyclophane-based molecules containing thiophene rings in the side-chain since
the insertion of such a heterocyclic ring gives higher electron delocalisation to the molecule3. Since the
aryl units are separated by acetylenic triple bonds rotational variations do not affect the π-overlap and,
hence, the conjugation.
This note reports the synthesis and physical properties of some novel [2.2]paracyclophanes bearing
thiophene rings conjugated with ethynyl units in the side-chain.
* Corresponding author. Tel. +39.075.5855537; fax: +39.075.5855560; e-mail: taticchi@unipg.it

1250
HETEROCYCLES, Vol. 68, No. 6, 2006
RESULTS AND DISCUSSION
The synthesis of the paracyclophanes was mainly based on the Pd/Cu catalysed Sonogashira cross
coupling reaction4 between 4-ethynyl[2.2]paracyclophane1,5 (1) and the pertinent aryliodides. This
methodology is known to be a powerful tool to synthesize arylethynyl systems.
I
S
S
I
S
S
PdCl2(PPh3)2/ CuI
THF, 75°C, 21h
PdCl2(PPh3)2/ CuI
THF, 75°C, 21h
2
1
3
99%
97%
PdCl2(PPh3)2/ CuI
THF, 25°C, 3-5h
4
5'
11'
12'
10'
4'
2
1
9'
6'
2'
R
1'
3
8'
3'
7'
14
8
4
S
14'
13'
13
12
15
7
5
16
6
11
10
5
9
48%, 63%
a, R=H;
b, R=OCH3;
i
ii
iii
R
I
R
R
I
S
4
i)Trimethylsilyl acetylene, PdCl2(PPh3)2/CuI, Et2NH; ii) tBu4NF, dry THF; iii) 2,5-diiodothiophene, PdCl2(PPh3)2/CuI, Et2NH
Scheme 1
The couplings were carried out under argon atmosphere in dry tetrahydrofuran with PdCl2(PPh3)2 as the
catalyst, CuI as the co-catalyst, in the presence of triethylamine. Schemes 1 and 2 summarize the
preparation of compounds (2-9).

HETEROCYCLES, Vol. 68, No. 6, 2006
1251
13'
12'
11'
5'
14'
S
2
4'
3'
S
1
10'
2'
9'
6'
7'
1'
3
4
14
8
8'
6
8
13
12
15
16
7
5
1
6
9
PdCl2(PPh3)2/ CuI
THF, 25°C, 3h
PdCl2(PPh3)2/ CuI
THF, 25°C, 5h
11
10
7
9
79%
82%
S
S
I
I
I
I
S
S
i
i
6
8
i: 1,4-diiodobenzene, PdCl2(PPh3)2/CuI, Et2NH.
Scheme 2
1
The structures of all products were assigned by analysis of their spectroscopic data, in particular by H-
13
1
and C-NMR investigations, especially H-{1H}NOE experiments, HSQC and HMBC methods. In the
1
13
case of the [2.2]paracyclophane derivatives (2), (3), (5), (7), (9), the H- and C- chemical shifts of the
paracyclophane moiety are practically the same; furthermore, as shown by an inspection of the pertinent
data collected in the Experimental, a slight substituent effect of the methoxy-group can be observed in
compound (5b), even on the carbons of the remote triple bond.
Two photophysical properties, UV-Vis absorption and fluorescence emission in chloroform, were also
examined. In order to evaluate the effects of the thiophene rings on the optical properties, we have
measured also the spectra of the previously described1 compound (10) (Figure 1). The optical properties
of the compounds (2), (3), (5), (7), (9), (10) are summarized in Table 1.
OMe
10
Figure 1

1252
HETEROCYCLES, Vol. 68, No. 6, 2006
Table 1. The absorption λmax and fluorescence emission λmax measured in CHCl3 for compounds (2), (3),
(5), (7), (9), (10)
log ε
Φfa
Compound
UV-Vis
Fluorescence
λ
max, nm
λ
max, nm
2
3
319
299
356
362
340
330
336
4.32
4.11
4.46
3.81
4.25
4.56
4.65
377
334
0.04
0.008
0.27
0.16
0.16
0.43
0.65
5a
5b
7
397,419
403,422
376,395
367,381
372,389
9
10
aFluorescence quantum yield was determined relative to anthracene in ethanol.
All the UV-Vis spectra (Figure 2) were almost identical: there are two absorption bands, a weak one at
241-254 nm and a strong one at 299-362 nm. The bands are broad with little vibronic structure. The λmax
value of (2) is higher than that of (3) since 2-thienyl group allows a better conjugation. Moreover, the
comparison of the data for compounds (5b), (10) and (5a), (7) indicates a bathochromic or an
ipsochromic shift depending on the position of the thiophene ring in the side-chain.
1,0
(5a)
(5b)
(7)
(9)
0,8
0,6
0,4
0,2
0,0
150
200
250
300
350
400
450
500
550
600
Wavelength (nm)
Figure 2- UV-Vis Absorption spectra of compounds (5), (7), (9) in CHCl3
All of compounds show also fluorescence radiation emission; the wavelength and quantum yield are
summarized in Table 1. Some considerations can be remarked. First the fluorescence maxima show a

HETEROCYCLES, Vol. 68, No. 6, 2006
1253
dependence on the structure of the side-chain. A bathochromic effect is observed when a benzene ring
close to the [2.2]paracyclophane moiety is replaced with a thiophene ring as pointed out by comparing
maxima values of the methoxy-substituted compounds (5b), (10). This phenomenon, already evidenced in
the UV-Vis spectra, can be rationalized considering that replacing benzenoid rings with easily
delocalizable thiophene moieties favours a more extensive electron delocalization. Moreover both the
absorption and fluorescence maxima depend on the position, α or β, of the thiophene ring linked to the
triple bond as evidenced by the data reported in Table 1 for compounds (2), (3) and (7), (9). The quantum
yields seem to depend on the chain length and presence of the thiophene rings in the side-chain.
CONCLUSIONS
In summary some new [2.2]paracyclophanes containing conjugated ethynylthienyl units in the linear side-
chain have been prepared by Pd/Cu catalysed Sonogashira reaction and characterized. Their structure has
13
been assigned by an extensive NMR (1H and C) analysis. Photophysical properties, i.e. UV-Vis and
fluorescence, have been examined and discussed. The dependence of the UV-Vis and fluorescence
maxima on the position of the thiophene ring in the side-chain has been observed. A bathochromic shift
was observed when the thiophene unit in the side-chain was close to the [2.2]paracyclophane framework.
ACKNOWLEDGEMENT
A.T., A.M., L.M., S.L. gratefully acknowledge financial support from the M.I.U.R., Rome, Italy. E.G.-B.
thanks the Hungarian Academy of Sciences. The Authors appreciate assistance of Dr. Loredana Latterini
in measurements of fluorescence.
EXPERIMENTAL
General Methods. Melting points were determined on a Büchi melting point apparatus and are
uncorrected. MS were recorded on a Hewlett Packard 6980 Series GC System /5973 Mass Selective
Detector equipped with an EI ionizer at 70 eV. Adsorption chromatography was carried out on Riedel de
Haën silica gel (32-63 µm; 230-400 mesh ASTM). UV-Vis spectra were recorded on a Kontron Uvikon
923 spectrophotometer. NMR spectra were recorded on a Varian Associates VXR-400 multinuclear
instrument (internal Me4Si). Fluorescence spectra were recorded on a Spex Fluorolog-2 F112A1
spectrofluorimeter. Petroleum ether refers to 40°-60°C boiling fraction.
General procedure for the synthesis of compounds (4), (6), (8). The procedure described for preparing
(4a) is that used for preparing compounds (4), (6), (8).

1254
HETEROCYCLES, Vol. 68, No. 6, 2006
2-Iodo-5-(phenylethynyl)thiophene (4a). Dry diethylamine (3 mL), 2,5-diiodothiophene (0.70 g, 2.1
mmol), CuI (0.0013 g, 0.007 mmol), PdCl2(PPh3)2 (0.010 g, 0.014 mmol) and phenylacetylene (0.068 g,
0.67 mmol) were placed in a flask and degassed with Ar. The mixture was held at –20°C for 5 h and at
25°C for further 20 h. The solvent was then removed under reduced pressure and the residue was
chromatographed on silica gel. Elution with pentane afforded pure 4a as pale yellow crystals (67% yield).
mp 83-84°C (MeOH). 1H-NMR (CDCl3): δ 6.93 (d, 1H, J = 3.8 Hz, H-4), 7.14 (d, 1H, J = 3.8 Hz, H-3),
13
7.35 (m, 3H, H-9, H-11, H-13), 7.49 (m, 2H, H-10, H-12). C-NMR (CDCl3): δ 74.8 (C-2), 81.6 (C-6),
95.1 (C-7), 122.8 (C-8), 128.8 (C-10, C-12), 128.9 (C-11), 129.8 (C-5), 131.7 (C-9, C-13), 133.3 (C-4),
137.3 (C-3). MS, m/e (rel. int.) 91 (6), 139 (45), 183 (8), 310 (M+, 100). UV-Vis (CHCl3): [λmax nm
(logε)] 243 (3.92), 311 (4.23). Anal. Calcd for C12H7IS: C, 46.47; H, 2.27. Found: C, 46.40; H, 2.28%.
2-Iodo-5-[(p-methoxyphenyl)ethynyl]thiophene (4b). Purified by column chromatography on silica gel
1
eluting with petroleum ether/chloroform 8:1; pale yellow plates (57% yield). mp 72-73°C (MeOH). H-
NMR (CDCl3): δ 3.83 (s, 3H, OMe), 6.87 (m, 2H, H-10, H-12), 6.89 (d, 1H, J = 3.8 Hz, H-4), 7.13 (d, 1H,
J = 3.8 Hz, H-3), 7.43 (m, 2H, H-9, H-13). 13C-NMR (CDCl3): δ 55.5 (OMe), 74.1 (C-2), 80.3 (C-6), 95.2
(C-7), 114.3 (C-9, C-10, C-12), 130.3 (C-5), 132.8 (C-4), 133.2 (C-13), 133.3 (C-8), 137.2 (C-3), 160.3
(C-11). MS, m/e (rel. int.) 126 (7), 169 (26), 213 (9), 325 (35), 340 (M+, 100). UV-Vis (CHCl3): [λmax nm
(logε)] 250 (4.07), 320 (4.39). Anal. Calcd for C13H9IOS: C, 45.90; H, 2.67. Found: C, 45.85; H, 2.68%.
2-[(p-Iodophenyl)ethynyl]thiophene (6). Purified by column chromatography on silica gel eluting with
pentane; white plates (60% yield). mp 105-106°C (MeOH) [lit.6, 89-91°C, hexane]. 1H-NMR (CDCl3): δ
7.01 (dd, 1H, J =5.1, 3.6 Hz, H-4), 7.24 (m, 2H, H-9, H-13), 7.27 (dd, 1H, J =3.6, 1.2 Hz, H-3), 7.29 (dd,
13
1H, J =5.1, 1.2 Hz, H-5), 7.69 (m, 2H, H-10, H-12). C-NMR (CDCl3): δ 84.3 (C-6), 92.3 (C-11), 94.5
(C-7), 122.7 (C-8), 123.2 (C-2), 127.4 (C-5), 127.8 (C-4), 132.4 (C-3), 133.1 (C-9, C-13), 137.8 (C-10, C-
12). MS, m/e (rel. int.) 91 (3), 139 (25), 183 (6), 310 (M+, 100). UV-Vis (CHCl3): [λmax nm (logε)] 261
(4.09), 309 (4.40). Anal. Calcd for C12H7IS: C, 46.47; H, 2.27. Found: C, 46.65; H, 2.26%.
3-[(p-Iodophenyl)ethynyl]thiophene (8). Purified by column chromatography on silica gel eluting with
1
petroleum ether/dichloromethane 24:1; white plates (62% yield). mp 139-140°C (MeOH). H-NMR
(CDCl3): δ 7.18 (dd, 1H, J = 5.0, 1.2 Hz, H-4), 7.23 (m, 2H, H-9, H-13), 7.30 (dd, 1H, J = 5.0, 3.0 Hz, H-
5), 7.53 (dd, 1H, J = 3.0, 1.2 Hz, H-2), 7.67 (m, 2H, H-10, H-12). 13C-NMR (CDCl3): δ 86.2 (C-6), 88.2
(C-11), 94.2 (C-7), 122.2 (C-3), 123.0 (C-8), 125.7 (C-5), 129.1 (C-2), 130.1 (C-4), 133.2 (C-9, C-13),
137.8 (C-10, C-12). MS, m/e (rel. int) 91 (4), 139 (30), 183 (6), 310 (M+, 100). UV-Vis (CHCl3): [λmax
nm (logε)] 292 (4.36), 309 (4.30). Anal. Calcd for C12H7IS: C, 46.47; H, 2.27. Found: C, 46.40; H, 2.27%.
General procedure for the Sonogashira coupling reaction of 4-ethynyl[2.2]paracyclophane (1). The
following discussion of the reaction of 4a with 4-ethynyl[2.2]paracyclophane (1) is a typical procedure
used for all coupling reactions.

HETEROCYCLES, Vol. 68, No. 6, 2006
1255
3’-{[2.2]Paracyclophan-4-ylethynyl}-6’-[phenylethynyl]thiophene (5a). Dry THF (3 mL), 4-
ethynyl[2.2]paracyclophane (1) (0.094 g, 0.57 mmol), triphenylphosphine (0.010 g, 0.04 mmol), CuI
(0.004 g, 0.02 mmol), aryliodide (4a) (0.084g, 0.27 mmol), PdCl2(PPh3)2 (0.014 g, 0.02 mmol) and dry
triethylamine (1.3 mL) were placed in a flask and degassed with Ar. The mixture was kept at 25°C for 3h.
The solvent was then removed under reduced pressure and the residue was chromatographed on silica gel
(elution: petroleum ether/chloroform 24:1) to obtain 5a as pale yellow crystals (48% yield). mp 145-
146°C (MeOH). 1H-NMR (CDCl3): δ 2.90 (ddd, 1H, J = 13.1, 10.2, 5.3 Hz, H-2), 2.96-3.16 (m, 5H, H-1,
Hs-9, Hs-10), 3.23 (m, 1H, H-1), 3.59 (ddd, 1H, J = 13.1, 10.2, 2.8 Hz, H-2), 6.47-6.53 (m, 5H, H-7, H-8,
H-12, H-13, H-16), 6.57 (d, 1H, J = 1.8 Hz, H-5), 6.97 (dd, 1H, J = 7.8, 1.9 Hz, H-15), 7.17 (d, 1H, J =
3.8 Hz, H-4’ or H-5’), 7.19 (d, 1H, J = 3.8 Hz, H-4’ or H-5’), 7.36 (m, 2H, H-11’, H-13’), 7.37 (m, 1H,
H-12’), 7.53 (m, 2H, H-10’, H-14’). 13C-NMR (CDCl3): δ 34.6 (C-1), 34.8 (C-2), 35.4, 35.7 (C-9, C-10),
82.6, 85.8 (C-2’, C-7’), 94.3, 94.9 (C-1’, C-8’), 122.9 (C-9’), 124.5, 124.7 (C-3’, C-6’), 125.5 (C-4),
128.6 (C-11’, C-13’), 128.8 (C-12’), 130.4 (C-15), 131.4, 132.1 (C-4’, C-5’), 131.7 (C-10’, C-14’), 132.7,
132.9, 133.5 (C-12, C-13, C-16), 133.4 (C-7), 134.2 (C-8), 137.0 (C-5), 139.5 (C-11), 139.6 (C-14), 140.1
(C-6), 142.8 (C-3). UV-Vis (CHCl3): [λmax nm (logε)] 242 (4.14), 356 (4.46). Anal. Calcd for C30H22S: C,
86.92; H, 5.35. Found: C, 86.98; H, 5.34%.
3’-{[2.2]Paracyclophan-4-ylethynyl}-thiophene (2). Reaction temperature: 75°C; reaction time: 21 h.
Purified by column chromatography on silica gel eluting with petroleum ether/chloroform 4:1; white
1
plates (99%). mp 122-123°C (MeOH). H-NMR (CDCl3): δ 2.88 (ddd, 1H, J = 13.1, 10.3, 5.5 Hz, H-2),
2.90-3.15 (m, 5H, H-1, Hs-9, Hs-10), 3.24 (ddd, 1H, J = 13.2, 10.2, 5.3 Hz, H-1), 3.61 (ddd, 1H, J = 13.1,
10.3, 2.6 Hz, H-2), 6.48 (d, 1H, J = 7.9 Hz, H-8), 6.50-6.54 (m, 4H, H-7, H-12, H-13, H-16), 6.56 (d, 1H,
J = 1.7 Hz, H-5), 7.00 (dd, 1H, J = 7.8, 1.8 Hz, H-15), 7.05 (dd, 1H, J = 4.9, 3.9 Hz, H-5’), 7.31 (dd, 1H,
J = 4.9, 1.1 Hz, H-6’), 7.32 (dd, 1H, J = 3.9, 1.1 Hz, H-4’). 13C-NMR (CDCl3): δ 34.6 (C-1), 34.8 (C-2),
35.4, 35.7 (C-9, C-10), 86.2 (C-2’), 93.7 (C-1’), 124.2 (C-3’), 124.8 (C-4), 127.2 (C-6’), 127.4 (C-5’),
130.4 (C-15), 131.6 (C-4’), 132.7 (C-12), 132.9 (C-16), 133.2 (C-7), 133.5 (C-13), 134.2 (C-8), 137.0 (C-
5), 139.6 (C-11), 139.7 (C-14), 140.0 (C-6), 142.7 (C-3). UV-Vis (CHCl3) [λmax nm (logε)] 244 (4.19),
319 (4.32). Anal. Calcd for C22H18S: C, 84.03; H, 5.77. Found: C, 84.10; H, 5.78%.
4’-{[2.2]Paracyclophan-4-ylethynyl}-thiophene (3). Reaction temperature: 75°C; reaction time: 21 h.
Purified by column chromatography on silica gel eluting with petroleum ether/chloroform 4:1; white
1
plates (97%). mp 143-144°C (MeOH). H-NMR (CDCl3): δ 2.88 (ddd, 1H, J = 13.1, 10.4, 5.3 Hz, H-2),
2.92-3.15 (m, 5H, H-1, Hs-9, Hs-10), 3.25 (ddd, 1H, J = 13.1, 10.2, 5.4 Hz, H-1), 3.63 (ddd, 1H, J = 13.1,
10.3, 2.7 Hz, H-2), 6.49-6.53 (m, 5H, H-7, H-8, H-12, H-13, H-16), 6.58 (d, 1H, J = 1.8 Hz, H-5), 7.02
(dd, 1H, J = 7.8, 1.8 Hz, H-15), 7.27 (dd, 1H, J = 5.0, 3.0 Hz, H-5’), 7.35 (dd, 1H, J = 5.0, 1.2 Hz, H-6’),
7.55 (dd, 1H, J = 3.0, 1.2 Hz, H-3’). 13C-NMR (CDCl3): δ 34.6 (C-1), 34.8 (C-2), 35.4, 35.7 (C-9, C-10),

1256
HETEROCYCLES, Vol. 68, No. 6, 2006
88.1 (C-2’), 89.4 (C-1’), 123.1 (C-4’), 125.1 (C-4), 125.7 (C-6’), 128.2 (C-3’), 130.2 (C-5’), 130.3 (C-15),
132.7 (C-12), 133.0 (C-7, C-16), 133.5 (C-13), 134.1 (C-8), 137.2 (C-5), 139.6 (C-11), 139.8 (C-14),
140.0 (C-6), 142.6 (C-3). UV-Vis (CHCl3): [λmax nm (logε)] 241 (4.05), 299 (4.11). Anal. Calcd for
C22H18S: C, 84.03; H, 5.77. Found: C, 84.15; H, 5.74%.
3’-{[2.2]Paracyclophan-4-ylethynyl}-6’-[(p-methoxyphenyl)ethynyl]thiophene
(5b).
Reaction
temperature: 25°C; reaction time: 5 h. Purified by column chromatography on silica gel eluting with
petroleum ether/chloroform 4:1; pale yellow plates (63%). mp 142-143°C (MeOH). 1H-NMR (CDCl3): δ
2.90 (ddd, 1H, J = 13.1, 10.3, 5.2 Hz, H-2), 2.95-3.16 (m, 5H, H-1, Hs-9, Hs-10), 3.23 (m, 1H, H-1), 3.59
(ddd, 1H, J = 13.1, 10.2, 2.7 Hz, H-2), 3.84 (s, 3H, OMe), 6.47 (d, 1H, J = 7.9 Hz, H-8), 6.49-6.54 (m, 4H,
H-7, H-12, H-13, H-16), 6.57 (d, 1H, J = 1.9 Hz, H-5), 6.87 (m, 2H, H-11’, H-13’), 6.97 (dd, 1H, J = 7.8,
1.8 Hz, H-15), 7.14 (d, 1H, J = 3.8 Hz, H-4’ or H-5’), 7.16 (d, 1H, J = 3.8 Hz, H-4’ or H-5’), 7.47 (m, 2H,
13
H-10’, H-14’). C-NMR (CDCl3): δ 34.6 (C-1), 34.8 (C-2), 35.4, 35.7 (C-9, C-10), 55.5 (OMe), 81.3,
85.9 (C-2’, C-7’), 94.4, 94.6 (C-1’, C-8’), 114.4 (C-11’, C-13’), 115.0 (C-9’), 124.5 (C-3’), 125.0 (C-6’),
125.2 (C-4), 130.4 (C-15), 131.4, 131.6 (C-4’, C-5’), 132.7, 132.9, 133.5 (C-12, C-13, C-16), 133.3 (C-
10’, C-14’), 133.4 (C-7), 134.2 (C-8), 137.0 (C-5), 139.5 (C-11), 139.6 (C-14), 140.0 (C-6), 142.8 (C-3),
160.2 (C-12’). UV-Vis (CHCl3): [λmax nm (logε)] 254 (2.99), 362 (3.81). Anal. Calcd for C31H24OS: C,
83.75; H, 5.44. Found: C, 83.68; H, 5.43%.
11’-{[p-([2.2]Paracyclophan-4-ylethynyl)phenyl]ethynyl}thiophene (7). Reaction temperature: 25°C;
reaction time: 3h. Purified by column chromatography on silica gel eluting with petroleum
ether/chloroform 8:1; pale yellow plates (79%). mp 170-171°C (MeOH). 1H-NMR (CDCl3): δ 2.91 (ddd,
1H, J = 13.1, 10.5, 5.4 Hz, H-2), 2.87-3.16 (m, 5H, H-1, Hs-9, Hs-10), 3.26 (m, 1H, H-1), 3.65 (ddd, 1H, J
= 13.1, 10.3, 2.8 Hz, H-2), 6.49 (dd, 1H, J = 7.8, 1.8 Hz, H-16), 6.49-6.53 (m, 2H, H-12, H-13), 6.50-6.54
(m, 2H, H-7, H-8), 6.59 (d, 1H, J = 1.8 Hz, H-5), 6.99 (dd, 1H, J = 7.8, 1.8 Hz, H-15), 7.02 (dd, 1H, J =
5.0, 3.8 Hz, H-13’), 7.29 (dd, 1H, J = 5.0, 1.2 Hz, H-14’), 7.31 (dd, 1H, J = 3.8, 1.2 Hz, H-12’), 7.51-7.56
(m, 4H, H-4’, H-5’, H-7’, H-8’). 13C-NMR (CDCl3): δ 34.6, 34.7 (C-1, C-2), 35.4, 35.7 (C-9, C-10), 84.7
(C-10’), 92.1 (C-1’), 92.8 (C-2’), 93.1 (C-9’), 122.8, 123.4 (C-3’, C-6’), 124.1 (C-11’), 124.8 (C-4), 127.3
(C-14’), 127.7 (C-13’), 130.4 (C-15), 131.6 (C-4’, C-5’, C-7’, C-8’), 132.3 (C-12’), 132.7, 132.9 (C-12,
C-16), 133.2 (C-7), 133.5 (C-13), 134.1 (C-8), 137.2 (C-5), 139.6, 139.7, 140.0 (C-6 , C-11, C-14), 142.8
(C-3). UV-Vis (CHCl3): [λmax nm (logε)] 241 (4.17), 340 (4.25). Anal. Calcd for C30H22S: C, 86.92; H,
5.35. Found: C, 86.70; H, 5.35%.
12’-{[p-([2.2]Paracyclophan-4-ylethynyl)phenyl]ethynyl}thiophene (9). Reaction temperature: 25°C;
reaction time: 5h. Purified by column chromatography on silica gel eluting with petroleum
ether/chloroform 6:1; white plates (82%). mp 176-177°C (MeOH). 1H-NMR (CDCl3): δ 2.91 (ddd, 1H, J
= 13.2, 10.5, 5.5 Hz, H-2), 2.96-3.16 (m, 5H, H-1, Hs-9, Hs-10), 3.25 (m, 1H, H-1), 3.66 (ddd, 1H, J =

HETEROCYCLES, Vol. 68, No. 6, 2006
1257
13.2, 10.2, 2.7 Hz, H-2), 6.49 (dd, 1H, J = 7.8, 1.8 Hz, H-16), 6.49-6.53 (m, 4H, H-7, H-8, H-12, H-13),
6.59 (d, 1H, J = 1.8 Hz, H-5), 7.00 (dd, 1H, J = 7.8, 1.8 Hz, H-15), 7.22 (dd, 1H, J = 5.0, 1.2 Hz, H-13’),
13
7.33 (dd, 1H, J = 5.0, 3.0 Hz, H-14’), 7.51-7.57 (m, 5H, H-4’, H-5’, H-7’, H-8’, H-11’). C-NMR
(CDCl3): δ 34.6, 34.8 (C-1, C-2), 35.4, 35.7 (C-9, C-10), 86.6 (C-10’), 89.0, 91.9 (C-1’, C-9’), 92.8 (C-2’),
122.4 (C-12’), 123.1, 123.8 (C-3’, C-6’), 124.8 (C-4), 125.7 (C-14’), 129.1 (C-11’), 130.1 (C-13’), 130.4
(C-15), 131.6, 131.7 (C-4’, C-5’, C-7’, C-8’), 132.7, 133.0 (C-12, C-16), 133.2 (C-7), 133.5 (C-13), 134.2
(C-8), 137.3 (C-5), 139.6, 139.7, 140.0 (C-6 , C-11, C-14), 142.8 (C-3). UV-Vis (CHCl3): [λmax nm
(logε)] 241 (4.17), 330 (4.56). Anal. Calcd for C30H22S: C, 86.92; H, 5.35. Found: C, 86.50; H, 5.36%.
REFERENCES
1.
L. Minuti, A. Taticchi, A. Marrocchi, S. Landi, and E. Gacs-Baitz, Tetrahedron Lett., 2005, 46,
5735.
2.
(a) S. Miyata and H. S. Nalwa, “Organic Electroluminescence Materials and Devices,” Gordon-
Breach, Amsterdam, 1997. (b) F. Garnier, Acc. Chem. Res., 1999, 32, 209. (c) L. M. Tolbert,
Acc. Chem. Res., 1992, 25, 561. (d) M. C. Petty, M. R. Bryce, and D. Bloor, “Introduction to
Molecular Electronics,” Edward Arnold, London, 1995. (e) R. Gimenez, M. Pinol, and J. L.
Serrano, Chem. Mater., 2004, 16, 1377. (f) L. Liu, Z. Liu, W. Xu, H. Xu, D. Zhang, and D. Zhu,
Tetrahedron, 2005, 61, 3813.
3.
4.
(a) A. Abbotto, S. Bradamante, A. Facchetti, and G. A. Pagani, J. Org. Chem., 1997, 62, 5755.
(b) I.-Y. Wu, I. T. Lin, C.-S. Li, W. C. Wang, T. H. Huang, Y. S. Wen, T. Chow, and C. Tsai,
Tetrahedron, 1999, 55, 13973.
(a) K. Sonogashira, Y. Tohda, and N. Hagihara, Tetrahedron Lett., 1975, 16, 4467. (b) K.
Sonogashira, in “Metal Catalyzed Cross-Coupling Reactions,” ed. by F. Diederich and P. J.
Stang, Wiley-VCH, Weinheim, 1998.
5.
6.
L. Bondarenko, I. Dix, H. Hinrichs, and H. Hopf, Synthesis, 2004, 2751.
J. G. Rodriguez, A. Lafuente, and L. Rubio, Tetrahedron Lett., 2004, 45, 5685.