The preparation of substituted bithiophenyl aldehydes via the ring opening of dithieno[2,3-b:3′,2′-d]thiophene in the presence of n-BuLi

Article abstract of DOI:10.1016/j.tet.2010.01.056

In the presence of n-BuLi in THF at low temperature, the phenomena of ring opening of symmetric substituted dithieno[2,3-b:3′,2′-d]thiophenes were observed. After quenching the organolithium intermediates with dry DMF, a series of substituted novel bithiophenyl aldehydes were prepared in good to excellent yields. The mechanism shows the key step for the ring opening of dithieno[2,3-b:3′,2′-d]thiophene is the nucleophilic attack of butyl anion onto the sulfur atom of the central ring. Total ten samples of symmetric substituted dithieno[2,3-b:3′,2′-d]thiophenes and their ring-opened products, the substituted bithiophenyl aldehydes were characterized by ¹H NMR, ¹³C NMR, and HRMS. Two ring-opened products were confirmed by X-ray single crystal analysis.

Full text of DOI:10.1016/j.tet.2010.01.056

Tetrahedron 66 (2010) 2168–2174
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Tetrahedron
journal homepage: www.elsevier.com/locate/tet
The preparation of substituted bithiophenyl aldehydes via the ring opening
of dithieno[2,3-b:30,20-d]thiophene in the presence of n-BuLi
*
Zhen Wang, Chunmei Zhao, Dongfeng Zhao, Chunli Li, Junli Zhang, Hua Wang
Key Lab for Special Functional Materials of Ministry of Education, Henan University, Kaifeng, Henan 475004, China
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 29 August 2009
Received in revised form 12 January 2010
Accepted 15 January 2010
Available online 21 January 2010
In the presence of n-BuLi in THF at low temperature, the phenomena of ring opening of symmetric
substituted dithieno[2,3-b:30,20-d]thiophenes were observed. After quenching the organolithium in-
termediates with dry DMF, a series of substituted novel bithiophenyl aldehydes were prepared in good to
excellent yields. The mechanism shows the key step for the ring opening of dithieno[2,3-b:30,20-d]thio-
phene is the nucleophilic attack of butyl anion onto the sulfur atom of the central ring. Total ten samples of
symmetric substituted dithieno[2,3-b:30,20-d]thiophenes and their ring-opened products, the substituted
bithiophenyl aldehydes were characterized by 1H NMR, 13C NMR, and HRMS. Two ring-opened products
were confirmed by X-ray single crystal analysis.
Ó 2010 Elsevier Ltd. All rights reserved.
1. Introduction
Iddon9 et al. reported the tandem ring-opening reactions of
substituted thienothiophenes (5) with one or two equivalents of
In recent years, isomeric dithienothiophenes have been applied
widely in the fields of organic semiconductors,1 photosensitive ma-
terials,2 and organic field effect transistors (OFETs).3 As one of six
isomeric dithienophenes, dithieno[2,3-b:30,20-d]thiophene (1a) has
received attention in its preparation4 and higher homologs synthe-
ses of carbon–sulfur (C2S) helicene with 1a as building blocks in
recent years.5,6
butyllithium in THF at ꢀ78 ꢁC to form the derivatives of ethynyl-
thiophene (6) or enediyne (7) (Eq. 2).
R
Br
R
LiS
S
S
R
R
R
S
SLi
SLi
R
Br
Br
6
5
7
S
S
The ring-opening of highly fused thiophenes, such as dithieno-
S
1a
thiophenes has not been reported up to now. However, the chemical
stability of dithienothiophenes is important in organic chemistry and
material science. In our previous work,10 we made the efficient for-
mylation and diformylation of dithieno[3,2-b:20,30-d]thiophene, an
isomer of 1a in the presence of n-BuLi in THF at ꢀ78 ꢁC and
quenching with dry DMF subsequently. At meanwhile, none of ring-
opening products were observed. However, we found the ring-
opening reaction happened to 1a at same conditions. In this paper,
we try to report the unexpected ring-opening reaction happened to
1a and its symmetric substituted compounds in the presence of
n-BuLi in THF at ꢀ78 ꢁC. After the organolithium intermediates were
quenched with dry DMF, a series of novel substituted bithiophenyl
aldehydes were obtained.
The chemical stability is one of most important properties for
fused oligothiophenes. It has been reported that ring-opening pro-
cess could be happened on both
gen substituted benzo[b]thiophene rings. The ring-opening process
could generate the derivatives of 1-butylsulfanyl-2-ethynylbenzene
(3) in the presence of n-BuLi in THF at ꢀ78 ꢁC (Eq. 1).
a b
position7 and position8 of halo-
Ar
Ar
Cl
1) BuLi,THF
-78
2) NH4Cl
1) BuLi,THF
-78
F
Ar
2) NH4Cl
S
S
SBu
2
4
3
2. Results and discussion
The preparation of substituted bithiophenyl aldehydes via ring-
opening reaction of 1a with 1.1 and 2.2 equiv of n-BuLi.
* Corresponding author. Tel.: þ86 378 3897112; fax: þ86 378 3881358.
E-mail address: hwang@henu.edu.cn (H. Wang).
0040-4020/$ – see front matter Ó 2010 Elsevier Ltd. All rights reserved.
doi:10.1016/j.tet.2010.01.056

Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
2169
OHC
b
OHC
+
a
8a
+
S
S
S
S
S
S
S
S
S
1a
S
S
CHO
S
CHO
8a
9
10
Scheme 1. The synthetic routes to 8a, 9, and 10. Reagents and conditions: (a) (i)1.1 equiv n-BuLi, THF, ꢀ78 ꢁC/2 h (ii) 2 equiv DMF. 8a, 90%; (b) (i) 2.1 equiv n-BuLi, THF, ꢀ78 ꢁC/2 h,
(ii) 3 equiv DMF, 8a, 23%; 9, 13%; 10, 55%.
2.1. Process of preparation
thiophene ring (Scheme 2). Carbanion 11 should be stable at
ꢀ78 ꢁC, which generates 8a when quenched with DMF. Carbanion
11 could also be changed into dicarbanion 12 when another
equivalent of n-BuLi is employed. When second deprotonation
As we known that n-BuLi could be used as S-butylation7 or
strong base11 agent in organic synthesis. One part of our previous
work was to make the efficient formylation and diformylation of 1a
by using LDA to treat with 1a, and then quenching with dry DMF.10
However, with 1.1 equiv or 2.2 equiv n-BuLi used as base to instead
of LDA, none of the products of formylation or diformylation of 1a
were obtained. Instead, we obtained the ring-opened products,
20-butylsulfanyl-[3,30]bithiophenyl-2-carbaldehyde (8a), 2-butyl-
sulfanyl-[3,30]bithiophenyl-5-carbaldehyde (9), and 20-butylsul-
fanyl-[3,30]bithiophenyl-2,50-dicarbaldehyde (10) in reasonable
yields (Scheme 1).
happened at
a position on left thiophene ring of 11 (Scheme 2),
dicarbanion 12 is generated, which gives 10 after quenching with
DMF. Higher temperature (such as 0 ꢁC) is helpful in the process of
making 12 from 11 (Entry 4, Table 1).
DMF
S
S
S
S
S
S
S
S
S
CHO
1a
11
Bu Li
8a
Bu Li
2.2. Reaction conditions
The reaction conditions and the relative distribution of products
are shown in Table 1. It is clear that temperature is one of the factors
affecting the selection of the reaction. If 1.1 equiv of n-BuLi is used
at ꢀ78 ꢁC for 2 h, only 8a is obtained in 90% yield after quenching
with DMF (Entry 1). If the reaction temperature is kept up to 0 ꢁC
for 0.5 h after addition of n-BuLi, and then changed back to ꢀ78 ꢁC,
both 8a and 9 are afforded in 78% and 12% yield, respectively after
quenching with DMF (Entry 3), and 8a is the main product. It is
concluded that the precursor of 9 might be formed easier from the
precursor of 8a at 0 ꢁC than ꢀ78 ꢁC.
OHC
DMF
S
S
S
S
S
S
CHO
10
12
Scheme 2. The possible mechanism for generating 8a and 10.
When 2.2 equiv of n-BuLi used in the reaction at ꢀ78 ꢁC,
a mixture of 8a, 9 and 10 is obtained at same time in the yields of
23%, 13%, and 55%, respectively (Entry 2, Table 1), and 10 is the main
product. Similar to entry 3, high temperature (0 ꢁC) makes different
distribution of products (Entry 4). Only 9 and 10 are given in yields
of 13% and 77%, respectively. However, none of 8a is observed at
same time. Therefore, it is also concluded that higher temperature
is helpful to generate 10. All three ring-opening products are
regarded as alkyl and formyl thiophene derivatives, but the syn-
thetic method is different from what reported.12
The possible mechanism for making 9 could be regarded as an
intermolecular anion exchange process. After the charge equilib-
rium between carbanion 11 and 13 formed,13 the side product, 9 is
obtained when the reaction mixture was quenched with dry DMF.
2.4. Crystal structure of 2-butylsulfanyl-[3,30]bithiophenyl-
5-carbaldehyde (9)
The structure of 9 was confirmed by X-ray crystal analysis14
(Fig. 1). The two linked thiophene rings are coplanar with the tor-
Table 1
The conditions of the ring-opening reaction and the distribution of products
Entry
1a (g)
n-BuLi (equiv)
Temperature (ꢁC)
DMF (equiv)
8aa (g/%)
9a (g/%)
10a (g/%)
1
2
3
4
0.26
0.30
0.30
0.30
1.1
2.2
1.1
2.2
ꢀ78
2.0
3.0
2.0
3.0
0.33/90%
0.10/23%
0.34/78%
d
d
d
ꢀ78
0.056/13%
0.052/12%
0.057/13%
0.26/55%
d
ꢀ78 to 0
ꢀ78 to 0
0.37/77%
a
isolated yields.
2.3. Possible mechanisms
sion angle (C5–C4–C7–C8) of 8.11ꢁ. The dihedral angle between the
two thiophenes is 7.964ꢁ. The butylsulfanyl groups is also coplanar
with the linked thiophene ring, the dihedral angle between them is
1.656ꢁ. The torsion angle (S1–C5–S3–C10) is 1.88ꢁ. The crystal
packing is in the order of layer by layer with a distance of 2.703 Å
(O–H10A). In each layer, there are short contacts including hydro-
gen bonding among the molecules. The distances of O1/H3, O1/
H9, and H1/H8 are 2.569, 2.710 and 2.243 Å, respectively.
Based on the results in Table 1, the possible mechanisms for
generation of 8a and 10 are proposed in Scheme 2. Different from
the case of deprotonation at
anion from n-BuLi attacks on the sulfur atom of central ring directly
for nucleophilic substitution. After the central ring opened, carb-
anion 11 is generated, and the charge is transferred to the right
a
position of 1a with LDA,10 the butyl

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Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
Br
a
b
S
S
S
S
S
S
1j 65%
17 62%
Scheme 4. The synthetic route to 1j. Reagents and conditions: (a) (i) n-BuLi
(1.05 equiv), Et2O, ꢀ78 ꢁC; (ii) dry CuCl2; (b) (i) n-BuLi (3.2 equiv), Et2O, ꢀ78 ꢁC, then
reflux 2 h; (ii) (PhSO2)2S (1.0 equiv), ꢀ78 ꢁC to rt overnight.
in 62%yield. With n-BuLiasbasetodeproton17 and (PhSO2)2Susedfor
annelation, 1j was obtained in 65% yield (Scheme 4).
2.6. The preparation of substituted thiophene aldehyes
via the ring opening of symmetric 2,5-disubstitued
dithieno[2,3-b:30,20-d]thiophenes
Figure 1. Crystallographic structure of 9 (top) and its crystal packing (bottom).
Using same conditions for making 8a, a series of substituted
bithiophenyl aldehyes (8b–j) were obtained via the ring opening of
symmetric 2,5-disubstitued dithieno[2,3-b:30,20-d]thiophenes (1b–j)
The preparation of substituted thiophene aldehyes via the ring
opening of symmetric 2,5-disubstituted dithieno[2,3-b:30,20-
d]thiophene in the presence of 1.1 equiv n-BuLi.
X
X
1) 1 eq n-BuLi
2) DMF
X
X
S
S
2.5. The preparation of symmetric 2,5-disubstitued
dithieno[2,3-b:30,20-d]thiophenes
S
S
S
S
CHO
1a, X = -H
8a 90%
In order to have a further study on the ring-opening phenom-
enon of 1a, a series of symmetric 2,5-disubstitued dithieno[2,3-
b:30,20-d]thiophene were synthesized (Scheme 4). 1c9 and 1d4c
were obtained according to the methods from the literatures.
With 1a as starting material, 2,5-dimethyldithieno[2,3-b:30,20-
d]thiophene (1b) was obtained in 85% yield by dilithiation of 1a with
LDA (2.2 equiv) first and then quenching with iodomethane.
2,5-Dibromodithieno[2,3-b:30,20-d]thiophene (14) and dithieno[2,3-
b:30,20-d]thiophene-2,5-dicarbaldehyde (15) were obtained accord-
ingtoourpreviouswork.10 Oxidationof15 withKMnO4 in1,4-dioxane
to obtained dithieno[2,3-b:30,20-d]thiophene-2,5-dicarboxylic acid
(16) in 86% yield. Esterification of 16 in dry ethanol with concentrated
H2SO4 as catalyst could obtain dithieno[2,3-b:30,20-d] thiophene-2,5-
dicarboxylic acid diethyl ester (1e) in 83% yield. Suzuki coupling
reactions were employed to generate 2,5-diaryldithieno[2,3-b:30,20-
d]thiophene (1f–i) by using 14 with relative boric acids in yield range
of 62–66% (Scheme 3).
1b, X = -CH3
1c, X = -C8H17
1d, X = -TMS
8b 99%
8c 59%
8d 76%
8e 41%
1e, X = -COOC2H5
1f, X = -Ph
8f 90%
8g 80%
8h 58%
1g, X =
1h, X =
1i, X =
1j, X =
N
8i 61%
8j 87%
The synthesisof bis(benzo[4,5]thieno)[2,3-b:30,20-d]thiophene (1j)
was different from others. Bromination of benzo[b]thiophene to
generate 3-bromobenzo[b]thiophene was made according to the
method of literature.15 After Br/Liexchange and treatmentof CuCl2, the
coupling product, [3,30]bi[benzo[b]thiophenyl] (17) 15b was obtained
Scheme 5. The substituted thiophene aldehyes (8a–j) were obtained via the ring
opening of symmetric 2,5-disustituted dithieno[2,3-b:30,20-d]thiophenes (1a–j).
OHC
CHO
HO2C
CO2H
EtO2C
CO2Et
S
S
S
S
S
S
c
S
S
S
d
1e 83%
16 86.5%
15
b
H3C
CH3
Br
Br
Ar
Ar
S
a
e
f
S
S
S
S
S
S
S
S
S
S
S
1a
14
1b 85.3%
1f Ar = C6H4N(CH3)2 64.1%
1g Ar = 1-Np 63.1%
1h Ar = 2-Np 66.1%
1i Ar = Ph 62.1%
Scheme 3. The synthetic route to substituted dithieno[2,3-b:30,20-d]thiophenes. Reagents and conditions: (a) (i) LDA (2.2 equiv), Et2O, 0 ꢁC; (ii) CH3I (3.0 equiv), ꢀ78 ꢁC; (b) see Ref.11;
(c) KMnO4 (15 equiv),1,4-dioxane; (d) Anhyd EtOH (excess), concentrated H2SO4, reflux;(e) see Ref.11; (f) ArB(OH)2 (2.2 equiv), Pd(PPh3)4 (6% mol), K2CO3 aq (10 equiv, 2 M), THF, reflux.

Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
2171
in the presence of n-BuLi at ꢀ78 ꢁC and then quenching with excess
dry DMF (Scheme 5). The ring-opened products are type of novel
bithiophenyl aldehydes with butylsulfanyl group.
As shown in Scheme 5, with different substituted groups, in-
cluding alkyl groups, aryl groups, and electron-withdrawing group,
all of the reactions proceeded smoothly to give the corresponding
substituted thiophene aldehyes (8a–j) with yields ranging from 41–
99%. Obvious low yield (41%) of making 8e may due to the side
reaction happened by the two ester groups in 1e with n-BuLi.
vacuum stop-cock, were employed. All starting materials and re-
agents were commercially available.
NMR spectra were obtained using chloroform-d (CDCl3) as sol-
vent. The chemical shift references were as follows: (1H) CDCl3,
7.26 ppm (CHCl3); (13C) CDCl3, 77.00 ppm (CDCl3); (1H) DMSO-d6,
2.50 ppm; (13C) DMSO-d6, 39.50 ppm; IR spectra were obtained
using an FTIR instrument, equipped with an ATR sampling acces-
sory. MS analysis was carried out at 70 eV, using a direct insertion
technique or a GC insertion. HRMS spectra were recorded on a mass
spectrometer equipped with TOF (EIþ). Melting point determination
was taken on a Melt-Temp apparatus and was uncorrected.
The X-raycrystallographic analyses were performed using crystals
of compounds 9 and 8j with the size 0.24ꢂ0.14ꢂ0.05 mm and
0.18ꢂ0.12ꢂ0.09 mm, respectively. The intensity data were collected
2.7. The crystal structure of 20-butylsulfanyl-
[3,30]bi[benzo[b]thiophenyl]-2-carbaldehyde (8j)
The structure of 8j was confirmed by X-ray crystal analysis
(Fig. 2).16 The two moieties of benzo[b] thiophenyl rings are linked
together in the molecule with the torsion angle (C6–C7–C10–C11)
of 70.97ꢁ and a dihedral angle of 73.14ꢁ. There are short contacts of
hydrogen bonding are found in the crystal packing. The distances of
S/H and O/H are 2.869 Å (S2–H9A) and 2.511 Å (O1–H12), re-
spectively. In the crystal packing, the neighbored benzo[b]thio-
phenyls with aldehyde groups are parallel with distances of 3.635 Å
(C8–C8) and 3.895 Å (C8–S1). At the meanwhile, the neighbored
benzo[b]thiophenyls with butylsulfanyl groups are also parallel
with 3.889 Å (S2–S2) and 3.868 Å (S2–C17).
with the
using Mo K
u
scan mode (207 K) on a diffractometer with CCD detector
radiation (
¼0.71073 Å). The data were corrected for
a
l
Lorentz and polarization effects and absorption corrections were
performed using SADABS program.20 The crystal structures were
solved using the SHELXTL program and refined using full matrix least
squares.21 The positions of hydrogen atoms were calculated theoret-
ically and included in the final cycles of refinement in a riding model
along with attached carbons. Further details are in the deposited CIFs.
Slowevaporationofsolutionsof8jand9inCHCl3/CH3OH(1:1,1:5 v/v)
were employed, respectively for growing single crystals.
4.2. Synthesis of 2,5-dimethyldithieno[2,3-b:30,20-d]-
thiophene (1b)
n-BuLi (2.5 M in hexane, 0.9 mL, 2.25 mmol, 2.2 equiv) was added
dropwise to diisopropyl amine (0.33 mL, 2.34 mmol, 2.3 equiv) in dry
ethyl ether (10 mL) at 0 ꢁC. After keeping at 0 ꢁC for 0.5 h, the pre-
pared LDA solution was transferred into a solution of 1a (0.20 g,
1.03 mmol) in dry Et2O (40 mL) at ꢀ78 ꢁC, then warmed slowly to
0 ꢁC. After keeping at 0 ꢁC for 2 h, the reaction mixture was cooled to
ꢀ78 ꢁC, CH3I (0.2 mL, 3.09 mmol, 3.0 equiv) was added dropwise. The
reaction mixture was kept at ꢀ78 ꢁC for 1 h and then warmed slowly
to ambient temperature overnight. After quenched with H2O (30 mL),
extracted with Et2O (2ꢂ30 mL) and then washed with H2O (30 mL).
After drying over MgSO4, the solvent was removed in vacuo. The
residue was purified by column chromatography on silica gel with
petrol ether (60–90 ꢁC) as eluent to yield 1b (0.197 g, 85.3%) as
Figure 2. Crystallographic structure of 8j (left) and its crystal packing (right).
3. Conclusions
In summary, we have synthesized
a series of symmetric
substituted dithieno[2,3-b:30,20-d]thiophene (1a–j) and prepared the
corresponding novel substituted bithiophenyl aldehydes (8a–j) in
good to excellent yields via the ring-opening reactions of 1a–j in the
presence of n-BuLi at ꢀ78 ꢁC in THF. The crystal structures of two
ring-opened products showed interesting crystal packing with some
short contacts including hydrogen bonding interactions, S/S in-
a white solid. Mp: 150–151 ꢁC. 1H NMR (400 MHz, CDCl3)
d
¼6.98 (s,
2H), 2.59 (s, 6H),13C NMR (100 MHz, CDCl3):
d
¼142.29,138.13,135.29,
116.93, 16.37. IR (KBr): 2910, 2848 (C–H) cmꢀ1. HRMS (EI): m/z calcd
for C10H8S3 [M]þ: 223.9788, found: 223.9790.
teractions and p/p interactions. The ring-opening reactions of 1a–j
4.3. Synthesis of dithieno[2,3-b:30,20-d]thiophene-2,5-
dicarboxylic acid diethyl ester (1e)
are important in theoretical understanding for the stability of
dithienothiophenes. The symmetric substituted dithieno[2,3-b:30,20-
d]thiophenes (1a–j) could be used in organic functional materials.3,17
The substituted bithiophenyl aldehydes (8a–j) could be derived from
their aldehyde groups and used as pharmaceutical and pesticide
intermediates.
4.3.1. Synthesis of dithieno[2,3-b:30,20-d]thiophene-2,5-dicarboxylic
acid (16). A solution of KMnO4 (1.40 g, 15 equiv) in water (30 mL)
was added into a solution of dithieno[2,3-b:30,20-d]thiophene-2,5-
dicarbaldehyde (15)10 (150 mg, 0.59 mmol) in dioxane (70 mL). The
reaction mixture was stirred at ambient temperature overnight. After
the brownprecipitate was filtered, the filtrate was treated with NaOH
(5%) until pH¼12, then extracted with ethyl ether (3ꢂ40 mL) and the
water phase was acidified with HCl (2 M) until pH¼1. The acidified
water phase was extracted with ethyl ether (4ꢂ50 mL), washed with
water (3ꢂ50 mL) and dried over MgSO4. After removing the solvent
in vacuo, a white powder of 16 (125 mg, 74.5%) was obtained. Mp
4. Experimental
4.1. General
Ether and tetrahydrofuran (THF) for use were freshly distilled
from sodium/benzophenone prior to use. Bis(phenylsulfo-
nyl)sulfide was obtained according to the literature method.18
Concentration of n-BuLi (hexane) was determined by titration with
N-pivaloyl-o-toluidine.19 Column chromatography was carried out
on silica gel (300–400 mesh). Analytical thin-layer chromatography
was performed on glass plates of Silica Gel GF-254 with detection
by UV. Standard techniques for synthesis under inert atmosphere,
using gasbag and Schlenk glassware equipped with an 8 mm PTFE
>300 ꢁC, 1H NMR (400 MHz, DMSO-d6):
13C NMR (100 MHz, DMSO-d6):
¼163.06, 145.97, 137.48, 136.91,
124.97. IR (KBr): 2963, 2853, 2809 (C–H), 1673 (C]O) cmꢀ1
d¼13.30 (s, 2H), 8.25 (s, 2H).
d
.
4.3.2. Synthesis of dithieno[2,3-b:30,20-d]thiophene-2,5-dicarboxylic
acid diethyl ester (1e). Compound 16 (167 mg, 0.59 mmol) and

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Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
H2SO4 (0.1 mL, 98%) was added to absolute EtOH (10 mL), the re-
action mixture was refluxed for four days at 110 ꢁC. After cooling to
ambient temperature, H2O (30 mL) was added, the reaction mix-
ture was extracted with CHCl3 (2ꢂ30 mL) and then washed with
H2O (2ꢂ30 mL). After drying over MgSO4, the solvent was removed
in vacuo. The residue was purified by column chromatography
twice on silica gel with chloroform as eluent to yield 1e (166 mg,
for 1 h, ꢀ50 ꢁC for 3 h, and then warmed slowly to ambient tem-
perature overnight. The reaction was quenched with water. After
HCl (2 M, 40 mL) was added, the reaction mixture was extracted
with ethyl ether (4ꢂ40 mL), and the organic phase was washed
with saturated NaHCO3 (50 mL), saturated NaCl (50 mL) and then
dried over MgSO4. The solvent was removed in vacuo, and the
residue was purified by column chromatography on silica gel with
petroleum ether (60–90 ꢁC) as eluent and then recrystallization
from hexane to yield 17 (343.2 mg, 62.0%). Mp: 80–82 ꢁC (lit.15b
83%). Mp: 192–194 ꢁC. 1H NMR (400 MHz, CDCl3):
d
¼8.05 (s, 2H),
4.40 (q, J¼7.2 Hz, 4H), 1.41 (t, J¼7.2 Hz, 6H). 13C NMR (100 MHz,
CDCl3):
d
¼161.96, 145.51, 137.89, 136.56, 124.36, 61.57, 14.33. IR
72 ꢁC). 1H NMR (400 MHz, CDCl3):
(m, 2H), 7.57 (s, 2H), 7.45–7.33 (m, 4H). 13C NMR (100 MHz, CDCl3):
d¼7.98–7.94 (m, 2H), 7.77–7.73
(KBr): 3096, 2980, 2928 (C–H), 1718 (C]O) cmꢀ1. HRMS (EI): m/z
calcd for C14H12O4S3 [M]þ: 339.9898, found: 339.9901.
d
¼140.17, 138.55, 131.39, 124.72, 124.60, 124.29, 123.21, 122.82. IR
(KBr): 3091, 3060, (C–H) cmꢀ1. MS (CI, 70 eV): m/z¼265.94 [Mþ].
4.4. General procedure for the preparation of compounds 1f–i
4.4.5.2. Synthesis of bis(benzo[4,5]thieno)[2,3-b:30,20-d]thiophene
(1j). To a solution of 17 (100.9 mg, 0.38 mmol) in dry Et2O (35 mL),
n-BuLi (2.34 M, 0.52 mL, 1.21 mmol, 3.2 equiv) was added dropwise
at ꢀ78 ꢁC, and then warmed to ambient temperature and refluxed
for 2 h. After cooling to ꢀ78 ꢁC again, (PhSO2)2S (120 mg,
0.38 mmol, 1.0 equiv) was added, the reaction mixture was kept at
ꢀ78 ꢁC for 1 h, and then slowly warmed to ꢀ55 ꢁC. After keeping at
ꢀ55 ꢁC for 2 h, slowly warmed to ambient temperature overnight.
The reaction mixture was quenched with H2O (50 mL), extracted
with Et2O (3ꢂ40 mL), washed with H2O (50 mL), and finally dried
over MgSO4. After removing the solvent in vacuo, the residue was
purified by column chromatography on silica gel with petroleum
ether (60–90 ꢁC) as eluent to yield 1j as white solid (73 mg, 65%).
4.4.1. 2,5-Diphenyldithieno[2,3-b:30,20-d]thiophene (1f). A mixture
of 2,5-dibromodithieno[2,3-b:30,20-d]thiophene (14) (500 mg,
1.4 mmol), phenyl boronic acid (379.4 mg, 3.1 mmol, 2.2 equiv),
tetrakis(triphenyl-phosphine)palladium
(99 mg,
0.043 mmol,
6% equiv), and K2CO3 aq (7 mL, 2 M) in THF (60 mL) was refluxed
and stirred under argon for 20 h. After cooling, the mixture was
quenched with H2O (50 mL), extracted with CHCl3 (2ꢂ50 mL) and
then washed with H2O (50 mL). After drying over MgSO4, the sol-
vent was removed in vacuo. The residue was purified by column
chromatography on silica gel with petrol ether (60–90 ꢁC) and
chloroform (1:1, v/v) to yield 1f as white solid (0.306 g, 62.1%). Mp:
207–208 ꢁC. 1H NMR (400 MHz, CDCl3):
d
¼7.65 (d, J¼7.6 Hz, 4H),
7.60 (s, 2H), 7.43 (t, J¼7.6 Hz, 4H), 7.33 (t, J¼7.2 Hz, 2H). 13C NMR
Mp: 200–202 ꢁC. 1H NMR (400 MHz, CDCl3):
d
¼8.63 (d, J¼8.0 Hz,
(100 MHz, CDCl3):
d
¼147.01, 139.18, 137.68, 134.65, 129.03, 127.80,
2H), 7.91 (d, J¼8.4 Hz, 2H), 7.57 (td, J¼7.6 Hz, 0.8 Hz, 2H), 7.42 (td,
125.79, 114.69. IR (KBr): 2953, 2923, 2847 (C–H) cmꢀ1. HRMS (EI):
J¼7.6 Hz, 0.8 Hz, 2H). 13C NMR (100 MHz, CDCl3):
¼143.11, 139.53,
d
m/z calcd for C20H12S3 [M]þ: 348.0101, found: 348.0104.
134.52, 132.48, 124.68, 123.92, 123.44, 123.14. IR(KBr): 3110, 3051,
3030 (C–H) cmꢀ1. HRMS (EI): m/z calcd for C16H8S3 [M]þ: 295.9788,
found: 295.9790.
4.4.2. 2,5-Dinaphthalen-1-yl-dithieno[2,3-b:30,20-d]thiophene
(1g). From the reaction on the 100 mg scale of 14, 80.0 mg (63.1%) of
1g was obtained as white solid. Mp: 162–163 ꢁC. 1H NMR (400 MHz,
4.5. General procedure for the preparation of
compounds 8a–j
CDCl3):
1.2 Hz, 2H), 7.51–7.58 (m, 8H).13C NMR (100 MHz, CDCl3):
138.66, 138.33, 133.83, 132.31, 131.91, 128.86; 128.56, 128.37, 126.68,
d
¼8.38–8.31 (m, 2H), 7.96–7.89 (m, 4H), 7.67 (dd, J¼7.2 Hz,
d
¼144.26,
4.5.1. 20-Butylsulfanyl-[3,30]bithiophenyl-2-carbaldehyde
(8a). Compound 1a (0.255 g, 1.30 mmol) was dissolved in dry THF
(40 mL) and cooled to ꢀ78 ꢁC under argon. n-BuLi (2.62 M in hex-
ane, 0.55 mL, 1.44 mmol, 1.1 equiv) was added dropwise at ꢀ78 ꢁC.
After keeping at ꢀ78 ꢁC for 2 h, DMF (0.20 mL, 2.60 mmol, 2.0 equiv)
was added dropwise, then kept at ꢀ78 ꢁC for 1 h, the reaction
mixture was warmed up slowly to ambient temperature overnight.
The reaction mixture was quenched with H2O (30 mL), extracted
with CHCl3 (2ꢂ30 mL) and then washed with H2O (30 mL). After
drying over MgSO4, the solvent was removed in vacuo. The residue
was purified by column chromatography on silica gel with petrol
ether (60–90 ꢁC) and chloroform (1:1, v/v) as eluents to yield 8a
(0.33 g, yield: 90.0%) as a yellow liquid. 1H NMR (400 MHz, CDCl3):
126.16,125.66,125.21,119.22. IR (KBr): 2958, 2926, 2854 (C–H) cmꢀ1
.
HRMS (EI): m/z calcd for C28H16S3 [M]þ: 448.0414, found: 448.0417.
4.4.3. 2,5-Dinaphthalen-2-yl-dithieno[2,3-b:30,20-d]thiophene
(1h). From the reaction on the 150 mg scale of 14, 125.6 mg (66.1%)
of 1h was obtained as pale yellow solid. Mp: 243–245 ꢁC. 1H NMR
(400 MHz, CDCl3):
J¼8.0 Hz, 2H), 7.80 (d, J¼8.0 Hz, 2H), 7.75 (s, 2H), 7.50 (qn, J¼8.0 Hz,
4H). 13C NMR (100 MHz, CDCl3):
d¼8.08 (s, 2H), 7.92–7.87 (m, 4H), 7.85 (d,
d
¼147.13, 139.31, 137.92, 133.61,
132.86, 132.02, 128.75; 128.04, 127.76, 126.73, 126.17, 124.18, 124.04,
115.10. IR (KBr): 2955, 2922, 2851 (C–H) cmꢀ1. HRMS (EI): m/z calcd
for C28H16S3 [M]þ: 448.0414, found: 448.0418.
d
¼9.78 (d, J¼1.2 Hz, 1H), 7.74 (dd, J¼5.2 Hz, 1.2 Hz, 1H), 7.41 (d,
4.4.4. 2,5-bis[4-(dimethylamino)phenyl]dithieno[2,3-b:30,20-d]thio-
phene (1i). From the reaction on the 250 mg scale of 14, 198.0 mg
(64.1%)of1iwasobtainedaswhitepalegraysolid.Mp:270–272 ꢁC.1H
J¼5.6 Hz, 1H), 7.23 (d, J¼5.2 Hz, 1H), 7.10 (d, J¼5.2 Hz, 1H), 2.67 (t,
J¼7.2 Hz, 2H), 1.42 (qn, J¼7.2 Hz, 2H), 1.25 (sx, J¼7.2 Hz, 2H), 0.80 (t,
J¼7.2 Hz, 3H). 13C NMR (100 MHz, CDCl3):
¼183.82, 144.31, 139.05,
d
NMR (400 MHz, CDCl3):
d
¼7.52 (d, J¼8.4 Hz, 4H), 7.41 (s, 2H), 6.77 (d,
137.06, 133.98, 133.50, 130.93, 130.05, 127.66, 38.16, 31.02, 21.36,
13.47. IR (KBr): 2957, 2923, 2870 (C–H), 1661 (C]O) cmꢀ1. HRMS
(ESI): m/z calcd for C13H15OS3 [MþH]þ: 283.0285, found: 283.0282;
C13H14NaOS3 [MþNa]þ: 305.0104, found: 305.0096.
J¼8.4 Hz, 4H), 3.00 (s, 12H) . IR (KBr): 2883, 2853, 2798 (C–H) cmꢀ1
.
HRMS (EI): m/z calcd for C24H22N2S3 [M]þ: 434.0945, found:
434.0949.
4.4.5. Synthesis of bis(benzo[4,5]thieno)[2,3-b:30,20-d]thiophene (1j).
4.5.2. 20-Butylsulfanyl-5,50-dimethyl-[3,30]bithiophenyl-2-carbalde-
hyde (8b). From the reaction on the 103 mg scale of 1b, 140.2 mg
(99.0%) of 8b was obtained yellow liquid. 1H NMR (400 MHz, CDCl3)
4.4.5.1. Synthesis of 3,30-bibenzo[b]thiophene (17). To a solution
of 3-bromobenzo[b]thiophene (0.8853 g, 4.15 mmol) in dry ethyl
ether (50 mL), n-BuLi (1.74 mL, 1.05 equiv) was added dropwise at
ꢀ78 ꢁC. After keeping at same time for 3 h, dry CuCl2 (1.008 g,
1.8 equiv) was added. The reaction temperature was kept at ꢀ78 ꢁC
d
¼9.68 (s,1H), 6.88 (s,1H), 6.73 (s,1H), 2.62 (t, J¼7.2 Hz, 2H), 2.57 (s,
3H), 2.47 (s, 3H), 1.42 (qn, J¼7.2 Hz, 2H), 1.25 (sx, J¼7.2 Hz, 2H), 0.80
(t, J¼7.2 Hz, 3H). 13C NMR (100 MHz, CDCl3)
d¼183.41, 149.29,
145.26, 142.15, 137.83, 137.10, 130.54, 129.63, 128.35, 38.38, 31.11,

Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
2173
21.38, 16.21, 15.48, 13.47. IR (KBr): 2956, 2925, 2870 (C–H), 1659
(C]O) cmꢀ1. HRMS (EI): m/z calcd for C15H18OS3 [M]þ: 310.0520,
found:310.0522.
66.2 mg (57.7%) of 8h was obtained as yellow liquid. 1H NMR
(400 MHz, CDCl3):
d¼9.91 (s, 1H), 8.21 (d, J¼1.2 Hz, 1H), 8.06 (d,
J¼1.2 Hz, 1H), 7.94–7.83 (m, 6H), 7.81 (dd, J¼8.6 Hz, 1.8 Hz, 1H), 7.73
(dd, J¼8.6 Hz, 1.8 Hz, 1H), 7.64 (s, 1H), 7.58–7.46 (m, 5H), 2.82 (t,
J¼7.2 Hz, 2H), 1.56 (qn, J¼7.2 Hz, 2H), 1.34 (sx, J¼7.2 Hz, 2H), 0.84 (t,
4.5.3. 20-Butylsulfanyl-5,50-dioctyl-[3,30]bithiophenyl-2-carbalde-
hyde (8c). From the reaction on the 160 mg scale of 1c, 110.3 mg
(59.3%) of 8c was obtained as yellow liquid. 1H NMR (400 MHz,
J¼7.2 Hz, 3H). 13C NMR (100 MHz, CDCl3):
¼183.51, 152.30, 145.88,
d
145.21, 138.11, 137.96, 133.68, 133.58, 133.52, 133.35, 133.01, 130.55,
130.30, 129.01, 128.87, 128.41, 128.09, 127.80, 127.77, 127.01, 126.99,
126.93, 126.82, 126.41, 125.90, 125.57, 124.31, 123.90, 123.66, 38.39,
31.25, 21.52, 13.55. IR (KBr): 3055, 3016, 2957, 2928, 2858 (C–H),
1655 (C]O) cmꢀ1. HRMS (EI): m/z calcd for C33H26OS3 [M]þ:
534.1146, found: 534.1151.
CDCl3):
d
¼9.70 (s, 1H), 6.91 (s, 1H), 6.75 (s, 1H), 2.86 (t, J¼7.6 Hz,
2H), 2.77 (t, J¼7.6 Hz, 2H), 2.63 (t, J¼7.2 Hz, 2H), 1.76–1.64 (m, 4H),
1.44–1.21 (m, 24H), 0.88 (t, J¼6.8 Hz, 6H), 0.80 (t, J¼7.2 Hz, 2H). 13C
NMR (100 MHz, CDCl3):
d¼183.58, 155.39, 148.25, 145.24, 137.64,
136.63, 130.22, 128.55, 127.21, 38.35, 31.80, 31.26, 31.12, 30.77,
30.29, 29.24, 29.23, 29.15, 29.07, 28.99, 22.62, 21.38, 14.06, 13.50. IR
(KBr): 2955, 2927, 2854 (C–H), 1662 (C]O) cmꢀ1. HRMS (EI): m/z
calcd for C29H46OS3 [M]þ: 506.2711, found: 506.2714.
4.5.9. 20-Butylsulfanyl-5,50-bis(4-dimethylamino-phenyl)-[3,30]bithio-
phenyl-2-carbaldehyde (8i). From the reaction on the 120 mg scale
of 1i, 87.6 mg (61.4%) of 8i was obtained as yellow solid. Mp: 197–
4.5.4. 20-Butylsulfanyl-5,50-bis-trimethylsilanyl-[3,30]bithiophenyl-2-
carbaldehyde (8d). From the reaction on the 200 mg scale of 1d,
190.2 mg (75.6%) of 8d was obtained as yellow liquid. 1H NMR
200 ꢁC. 1H NMR (400 MHz, CDCl3):
d
¼9.78 (s, 1H), 7.59 (d,
J¼8.8 Hz, 2H), 7.46 (d, J¼8.8 Hz, 2H), 7.32 (s, 1H), 7.17 (s, 1H), 6.72
(d, J¼8.8 Hz, 4H), 3.03 (s, 6H), 3.00 (s, 6H), 2.71 (t, J¼7.2 Hz, 2H),
1.48 (qn, J¼7.2 Hz, 2H), 1.29 (sx, J¼7.2 Hz, 2H), 0.80 (t, J¼7.2 Hz,
(400 MHz, CDCl3)
d
¼9.75 (s, 1H), 7.31 (s, 1H), 7.17 (s, 1H), 2.72 (t,
J¼7.2 Hz, 2H), 1.45 (qn, J¼7.2 Hz, 2H), 1.27 (sx, J¼7.2 Hz, 2H), 0.80 (t,
3H). 13C NMR (100 MHz, CDCl3):
d
¼183.39, 153.64, 151.08, 150.33,
J¼7.2 Hz, 3H), 0.37 (s, 9H), 0.33 (s, 9H). 13C NMR (100 MHz, CDCl3):
146.95, 146.15, 138.89, 135.48, 129.97, 127.40, 126.61, 124.23,
123.38, 121.52, 120.86, 112.38, 112.10, 40.36, 40.21, 38.47, 31.20,
d
¼183.70, 150.64, 145.20, 143.17, 142.93, 139.03, 137.60, 137.09,
136.53, 37.98, 31.13, 21.45, 13.52, ꢀ0.24, ꢀ0.46. IR (KBr): 2957, 2930,
21.46, 13.55. IR (KBr): 2957, 2924, 2857 (C–H), 1643 (C]O) cmꢀ1
.
2872 (C–H), 1667 (C]O) cmꢀ1
.
HRMS (EI): m/z calcd for
HRMS (EI): m/z calcd for C29H32N2OS3, [M]þ: 520.1677, found:
C19H30OSi2S3 [M]þ: 426.0997, found:426.1001.
520.1680.
4.5.5. 20-Butylsulfanyl-2-formyl-[3,30]bithiophenyl-5,50-dicarboxylic
acid diethyl ester (8e). From the reaction on the 100 mg scale of 1e,
51.2 mg (40.7%) of 8e was obtained as yellow liquid. 1H NMR (CDCl3,
4.5.10. 20-Butylsulfanyl-[3,30]bi[benzo[b]thiophenyl]-2-carbaldehyde
(8j). From the reaction on the 116 mg scale of 1j, 130.6 mg (87.0%)
of 8j was obtained as yellow solid. Mp: 108–109 ꢁC. 1H NMR
400 MHz):
d
¼9.81 (s,1H), 7.82, (s,1H), 7.71 (s,1H), 4.38 (sx, J¼7.2 Hz,
(400 MHz, CDCl3):
d
¼9.81 (s, 1H), 7.98 (d, J¼8.4 Hz, 1H), 7.86 (d,
4H), 2.87 (t, J¼7.2 Hz, 2H), 1.57 (qn, J¼7.2 Hz, 2H), 1.40–1.32 (m, 8H),
J¼8.0 Hz, 1H), 7.57–7.47 (m, 2H), 7.41–7.24 (m, 4H), 2.88–2.75 (m,
0.87 (t, J¼7.2 Hz, 3H). 13C NMR (CDCl3, 100 MHz):
¼183.61, 161.33,
d
2H), 1.56–1.42 (m, 2H), 1.30–1.13 (m, 2H), 0.75 (t, J¼7.2 Hz, 3H). 13C
161.07, 144.14, 143.13, 142.10, 140.18, 135.14, 134.86, 133.69, 133.34,
62.11, 61.61, 37.21, 30.96, 21.62, 14.31, 14.21, 13.46. IR (KBr): 2957,
2926, 2854 (C–H), 1716, 1673 (C]O) cmꢀ1. HRMS (EI): m/z calcd for
C19H22O5S3 [M]þ: 426.0629, found:426.0633.
NMR (100 MHz, CDCl3):
d
¼185.35, 141.92, 140.43, 139.85, 139.81,
139.79, 138.92, 138.88, 128.80, 128.36, 125.50, 125.08, 124.93,
123.39, 122.63, 121.94, 36.60, 31.34, 21.49, 13.37. IR (KBr): 3053,
2956, 2927, 2912, 2843 (C–H), 1668 (C]O) cmꢀ1. HRMS (ESI): m/z
calcd for C21H18OS3 [MþH]þ: 383.0598, found: 383.0596.
4.5.6. 20-Butylsulfanyl-5,50-diphenyl-[3,30]bithiophenyl-2-carbalde-
hyde (8f). From the reaction on the 111 mg scale of 1f, 124.6 mg
(89.8%) of 8f was obtained as yellow liquid. 1H NMR (CDCl3,
4.5.11. The synthesis of 2-butylsulfanyl-[3,30]bi- thiophenyl-5-car-
baldehyde (9) and 20-butylsulfanyl-[3,30]bithiophenyl-2,50-di-
carbaldehyde (10) (Entry 4, Table 1). To a solution of 1a (0.30 g,
1.54 mmol) in THF (20 mL), n-BuLi (2.62 M in hexane, 1.29 mL,
3.38 mmol, 2.2 equiv) was added dropwise at ꢀ78 ꢁC. After keeping
at ꢀ78 ꢁC for 1 h, the reaction mixture was warmed up slowly to
0 ꢁC, and then cooled back to ꢀ78 ꢁC. DMF (0.36 mL, 4.61 mmol,
3.0 equiv) was added dropwise at ꢀ78 ꢁC, then kept at ꢀ78 ꢁC for
1 h, the reaction mixture was warmed up slowly to ambient tem-
perature over night. Workup is same to making 8a. Light yellow
solid 9 (0.057 g, 13%) and yellow liquid 10 (0.366 g, 77.2%) were
obtained by column chromatography on silica gel with petrol ether
(60–90 ꢁC) and chloroform (1:1, v/v) as eluents.
400 MHz):
d¼9.85 (s,1H), 7.74–7.69 (m, 2H), 7.62–7.57 (m, 2H), 7.49–
7.31 (m, 8H), 2.76 (t, J¼7.2 Hz, 2H), 1.51 (qn, J¼7.2 Hz, 2H), 1.31 (sx,
J¼7.6 Hz, 2H), 0.817 (t, J¼7.4 Hz, 3H). 13C NMR (CDCl3, 100 MHz):
d
¼183.55, 152.22, 145.86, 145.13, 138.04, 137.82, 133.31, 133.17,
132.95, 129.44, 129.19, 129.09, 128.27, 126.63, 126.34, 125.63, 125.53,
38.33, 31.19, 21.47,13.53. IR (KBr): 3059, 2955, 2928, 2870 (C–H),1651
(C]O) cmꢀ1. HRMS(ESI): m/z calcd for C25H22OS3 [MþH]þ: 435.0911,
found: 435.0901.
4.5.7. 20-Butylsulfanyl-5,50-di-naphthalen-1-yl-[3,30]bithiophenyl-2-
carbaldehyde (8g). From the reaction on the 158 mg scale of 1g,
150.4 mg (79.9%) of 8g was obtained as yellow liquid. 1H NMR
Compound 9, Mp: 55–57 ꢁC. 1H NMR (400 MHz, CDCl3)
1H), 7.78 (s, 1H), 7.61–7.58 (m, 1H), 7.42–7.37 (m, 2H), 3.04 (t,
d
¼9.78 (s,
(400 MHz, CDCl3):
d
¼10.04 (s, 1H), 8.37–8.27 (m, 2H), 7.98–7.88 (m,
4H), 7.69 (d, J¼7.2 Hz, 1H), 7.63 (d, J¼6.8 Hz, 1H), 7.60–7.50 (m, 7H),
7.36 (s, 1H), 2.89 (t, J¼7.2 Hz, 2H), 1.61 (qn, J¼7.2 Hz, 2H), 1.39 (sx,
J¼7.2 Hz, 2H), 0.88 (t, J¼7.2 Hz, 3H). 13C NMR (100 MHz, CDCl3):
J¼7.2 Hz, 2H), 1.72 (qn, J¼7.2 Hz, 2H), 1.45 (sx, J¼7.2 Hz, 2H), 0.92 (t,
J¼7.2 Hz, 3H). 13C NMR (100 MHz, CDCl3):
¼181.39, 145.99, 140.43,
d
137.76, 135.45, 134.76, 127.34, 125.79, 123.25, 36.41, 30.85, 20.87,
13.51. IR (KBr): 2956, 2925, 2867 (C–H), 1651 (C]O) cmꢀ1. HRMS
(ESI): m/z calcd for C13H15OS3 [MþH]þ: 283.0285, found: 283.0282;
C13H14NaOS3 [MþNa]þ: 305.0104, found: 305.0098.
d
¼183.61, 150.39, 144.39, 143.79, 138.74, 137.18, 134.23, 133.86,
131.33, 131.29, 131.13, 131.05, 129.97, 129.78, 129.06, 128.59, 128.52,
128.27, 128.17, 127.06, 126.86, 126.39, 126.25, 125.25, 125.20, 125.15,
38.47, 31.30, 21.54, 13.60. IR (KBr): 3051, 2954, 2924, 2854 (C–H),
1658 (C]O) cmꢀ1. HRMS(ESI): m/z calcd for C33H26OS3 [M]þ:
534.1146, found: 534.1148.
Compound 10, 1H NMR (400 MHz, CDCl3)
d 9.80 (s, 1H), 9.79 (s,
1H), 7.80 (d, J¼4.8 Hz,1H), 7.68 (s, 1H), 7.24 (d, J¼4.8 Hz,1H), 2.99 (t,
J¼7.4 Hz, 2H), 1.67 (qn, J¼7.5 Hz, 2H), 1.40 (sx, J¼7.4 Hz, 2H), 0.90 (t,
J¼7.4 Hz, 3H). 13C NMR (100 MHz, CDCl3):
¼182.85, 181.14, 149.86,
d
4.5.8. 20-Butylsulfanyl-5,50-di-naphthalen-2-yl-[3,30]bithiophenyl-2-
carbaldehyde (8h). From the reaction on the 96 mg scale of 1h,
142.35, 141.20, 139.55, 138.41, 134.40, 132.75, 130.34, 36.32, 30.75,
21.74, 13.43. IR (KBr): 2957, 2928, 2857 (C–H), 1663 (C]O) cmꢀ1
.

2174
Z. Wang et al. / Tetrahedron 66 (2010) 2168–2174
HRMS (ESI): m/z calcd for C14H15O2S3 [MþH]þ: 311.0234, found:
311.0230; C13H14NaO2S3 [MþNa]þ: 333.0054, found: 305.0038.
11. (a) Nicolas, Y.; Blanchard, P.; Roncali, J.; Allain, M.; Mercier, N.; Deman, A.-L.;
Tardy, J. Org. Lett. 2005, 7, 3513–3516; (b) Kabir, S. M. H.; Miura, M.; Sasaki, S.;
Harada, G.; Kuwatani, Y.; Yoshida, M.; Iyoda, M. Heterocycles 2000, 52, 761–774.
12. (a) Pu, S.; Li, M.; Fan, C.; Liu, G.; Shen, L. J. Mol. Struct. 2009, 919, 100–111; (b)
Zheng, C.; Pu, S.; Xu, J.; Luo, M.; Huang, D.; Shen, L. Tetrahedron 2007, 63, 5437–
5439; (c) Lee, S. B.; Hong, J.-I. Tetrahedron Lett. 1995, 46, 8439–8442.
13. The possible mechanism for generating 9.
Acknowledgements
The authors thank Mr. Pengtao Ma for discussion and crystal
measurement. This research was supported by the NSFC (20972041,
20672028 and 20572015), Program for Innovation Scientists and
Technicians Troop Construction Projects of Henan Province, Pro-
gram for NCET-05-0610, SRF for ROCS-SEM.
OHC
DMF
S
S
S
S
S
S
S
S
S
11
9
13
Supplementary data
Electronic supplementary data available: 1H NMR, 13C NMR,
HRMS, and X-ray crystallographic. Supplementary data associated
with this article can be found, in the online version, at doi:10.1016/
j.tet.2010.01.056.
14. Crystal data for 9: M¼282.42, C13H14OS3, monoclinic, space group P2(1)/c,
a¼10.7974(15) Å, b¼9.9673(14) Å, c¼13.4751(18) Å,
a
¼90ꢁ,
b
¼111.692(2)ꢁ,
g
¼90ꢁ, V¼1347.5(3) Å3, Z¼4, Dcalcd¼1.392 g/cm3.
A colorless crystal of di-
mensions 0.24ꢂ0.14ꢂ0.05 mm was used for measurement at 293(2) K with the
u
scan mode on a Bruker Smart APEX diffractometer with CCD detector using
Mo K radiation (
a
l
¼0.71073 Å). The data were corrected for Lorentz and po-
larization effects and absorption corrections were performed using SADABS
program. The crystal structures were solved using the SHELXTL program and
refined using full matrix least squares. The positions of hydrogen atoms were
calculated theoretically and included in the final cycles of refinement in a riding
model along with attached carbons. The final cycle of full-matrix least-squares
References and notes
1. Li, X. C.; Sirringhaus, H.; Garnier, F.; Holmes, A. B.; Morratti, S. C.; Feeder, N.;
Clegg, W.; Teat, S. J.; Friend, R. H. J. Am. Chem. Soc. 1998, 120, 2206–2207.
2. Halls, J. J. M.; Walsh, C. A.; Greenham, N. C.; Marseglia, E. A.; Friend, R. H.;
Moratti, S. C.; Holmes, A. B. Nature (London) 1995, 376, 498–500.
refinement was based on 7224 independent reflections [I>2
iable parameters with R1¼0.0498, wR2¼0.0781.
s(I)] and 154 var-
3. (a) Xiao, K.; Liu, Y.; Qi, T.; Zhang, W.; Wang, F.; Gao, J.; Qiu, W.; Ma, Y.; Cui, G.;
Chen, S.; Zhan, X.; Yu, G.; Qin, J.; Hu, W.; Zhu, D. J. Am. Chem. Soc. 2005, 127,
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Demartin, F.; Pilati, T. J. Org. Chem. 1996, 61, 6244–6251.
16. Crystal data for 8j: M¼382.53, C21H18OS3, triclinic, space group P-1, a¼9.
903(2) Å, b¼10.102(2) Å, c¼10.120(2) Å,
a
¼90.205(4)ꢁ,
b
¼103.568(4)ꢁ,
g
¼107.
486(4)ꢁ, V¼935.7(4) Å3, Z¼2, Dcalcd¼1.358 g/cm3.
A colorless crystal of di-
mensions 0.18ꢂ0.12ꢂ0.09 mm was used for measurement at 293(2) K. The
structure was solved by the same methods of 9. The final cycle of full-matrix
least-squares refinement was based on 4833 observed reflections [I>2
226 variable parameters with R1¼0.0441, wR2¼0.1238.
s(I)] and
17. (a) Barbarella, G.; Melucci, M.; Sotgiu, G. Adv. Mater. 2005, 17, 1581–1593; (b)
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L.; Meng, Q.; Jiang, H.; Li, H.; Hu, W. Adv. Mater. 2007, 19, 3008–3011; (d) Fong,
H. H.; Pozdin, V. A.; Amassian, A.; Malliaras, G. G.; Smilgies, D.-M.; He, M.;
Gasper, S.; Zhang, F.; Sorensen, M. J. Am. Chem. Soc. 2008, 130, 13202–13203.
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Belley, M.; Douida, Z.; Mancuso, J.; De Vleeschauwer, M. Synlett 2005, 247–250.
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20. Sheldrick, G. M. SADABS; University of Go¨ttingen: Germany, 1996.
21. Sheldrick, G. M. SHELXTL, version 5.1; Bruker Analytical X-ray Systems: Madison,
WI, 1997.