Stille coupling of 2-diarylaminothiophenes with mono- and di-bromo(het)arylenes

Article abstract of DOI:10.1055/s-2005-861804

N,N-Diaryl-substituted 2-aminothiophenes 3 have been transformed by reaction with several bromobenzenes 5 and 2-bromothiophenes 6 in a palladium catalysed cross-coupling reaction, via 2-(N,N-diarylamino)-5-stannyl-thiophenes 4, into N,N-diaryl-substituted 2-amino-5-phenylthiophenes 7 and 5-amino-2,2′-bithiophenes 9 as well as into N,N′-peraryl-substituted 5,5′-diamino-2,2′-bithiophenes 8 and their phenylene and thienylene homologues 10-13.

Full text of DOI:10.1055/s-2005-861804

610
PAPER
Stille Coupling of 2-Diarylaminothiophenes with Mono- and Di-
bromo(het)arylenes
Stille
Coupling of
h
2-Diarylamin
c
othiophene
e
s
w
ith Mon
n
o- and
D
ibr
e
omo(het)arylenesTabet, Horst Hartmann*
Department of Chemistry, University of Applied Sciences, Geusaer Str., 06217 Merseburg, Germany
Fax +49(3461)462192; E-mail: Horst.Hartmann@cui.fh-merseburg.de
Received 10 August 2004; revised 11 November 2004
arylamino)substituted thiophenes 1b1 and 2,2¢-
bithiophenes 1b2 have been prepared by a palladium-ca-
talysed coupling reaction of diarylamines with 2,5-
dibromothiophene2 or 5,5¢-dibromo-2,2¢-bithiophene.3,4
Abstract: N,N-Diaryl-substituted 2-aminothiophenes 3 have been
transformed by reaction with several bromobenzenes 5 and 2-bro-
mothiophenes 6 in a palladium catalysed cross-coupling reaction,
via 2-(N,N-diarylamino)-5-stannyl-thiophenes 4, into N,N-diaryl-
substituted 2-amino-5-phenylthiophenes 7 and 5-amino-2,2¢-bi- The bis(N-diaryl)anilino-capped compounds 2bn have
thiophenes 9 as well as into N,N¢-peraryl-substituted 5,5¢-diamino-
2,2¢-bithiophenes 8 and their phenylene and thienylene homologues
10–13.
been prepared analogously by a nickel-catalysed coupling
reaction of N-(4-bromophenyl)diarylamines with 2,5-di-
bromothiophene or its thienyl homologues.12 The com-
pound 2b2 with NAr2 = N(4-BrC6H4)2 has been prepared
by an electrochemical mediated oxidative coupling reac-
tion of N,N-bis(4-bromophenyl)-N-[4-2-(thienyl) phe-
nyl]amine.5
Key words: cross-coupling, heterocycles, metalations, palladium,
Stille reaction
Although 2,5-disubstituted thiophenes and their homo-
logues of the general structure 1n have been known in a
large variety1 the bis-(diarylamino)substituted derivatives
1bn, which are end-capped by diarylamino moieties, have
been described only recently.2–4 Similar to their uncapped
The interesting material properties of the aforementioned
compounds stimulated us to synthesise several of their
structural analogues derived from N-(diaryl)substituited
2-aminothiophenes 3. These heteroaromatic tertiary
amines were unknown until recently, but are now easily
available, e.g. by a heavy-metal catalysed coupling reac-
tion between diarylamines and halothiophenes13 or, more
easily, by decarboxylation of N-(diaryl)substituted 2-ami-
nothiophene-5-carboxylates14 via a heterocyclisation
method starting from alkyl thioglycolates and 1-chloro-
vinamidinium salts.15 They are qualified for simple struc-
tural modifications which proceed via intermediate metal
organyls.
1
parent compounds 1an or to other end-capped deriva-
tives, such as the bis-N-(diaryl)anilino-capped com-
pounds 2bn (Figure 1),5 they should exhibit a high
oxidation ability and a large tendency to form amorphous
glasses in which the charged species generated by their
oxidation have a high mobility.6 Therefore, such com-
pounds are of interest as new charge-generation and
charge-transport materials for manufacturing a variety of
electronic, microelectronic, or optoelectronic devices,
such as photocopiers,7 OFETs,8 solar cells,9 or OLEDs.10
As exemplified with 2-diphenylaminothiophene 3A and
its 2-(N-phenothiazinyl)thiophene analogue 3B,14 these 2-
aminothiophene derivatives can be transformed analo-
gously to reported procedures,16 via their corresponding
5-lithiated species, into the 5-tributylstannylated com-
pounds 4A and 4B and used as starting materials for sev-
eral CC-coupling reactions. These coupling reactions
were performed by using some monobromo- and dibro-
mobenzenes 5 as well as mono- and dibromothiophenes 6
and were catalysed, analogously to reported procedures,16
with Pd(PPh3)2Cl2 or Pd(PPh3)4.
X
X
S
S
n
n
X
X
2n
1n
X
1,2
a H
b NAr2
In the course of these reactions it was found that the pal-
ladium-catalysed coupling reactions between 4A or 4B
and the bromobenzenes 5a–5d run, in general, without
difficulties. They give rise to the formation of the cou-
pling products 7 in relatively high or moderate yields (50–
80%). In all cases a chromatographic purification of the
crude products has been performed to separate completely
palladium traces incorporating the products and some by-
products formed in course of the coupling reaction. There-
fore, the yields given in Table 1 for the purified products
are significantly lower.
Figure 1
The above-mentioned compounds 1bn and 2bn (Figure 1)
have been prepared by simple heavy-metal catalysed CC-
or CN-coupling reactions, which were introduced by sev-
eral working groups in the last years.11 Thus, the bis-(di-
SYNTHESIS 2005, No. 4, pp 0610–0616
Advanced online publication: 09.02.2005
DOI: 10.1055/s-2005-861804; Art ID: T09404SS
© Georg Thieme Verlag Stuttgart · New York
x
x
.
x
x
.2
0
0
5

PAPER
Stille Coupling of 2-Diarylaminothiophenes with Mono- and Dibromo(het)arylenes
611
In some cases, such as by starting from the unsubstituted tion, the self-coupling products 8 of the starting stannylat-
or methyl-substituted bromobenzenes 5a or 5d, the homo- ed thiophenes 4 have been obtained in moderate yield
coupling products 8 of the starting compounds 4 were again (Scheme 1).
formed to a considerable extent as by-products. Obvious-
ly, they were formed via a transmetallation step or an ox-
idative coupling mediated by the palladium catalyst used.
This assumption is supported by the findings, that the
An interesting result has been obtained by starting from
the dibromo compounds 5e and 6c. Beside the possible
mono-substitution products 7e and 9c and the expected
bis-coupling products 10 and 12 products of the structure
yields of the corresponding hetero-coupling products 7
11 and 13 have also been obtained in low amounts. Obvi-
can be significantly raised by using Pd(PPh3)4 as catalyst.
ously, these compounds result from the reaction of the
This Pd0 species was prepared in situ from PdCl2 and PPh3
mono-coupling products 7e and 9c primarily formed by it-
self via a transmetalation reaction in the course of a homo-
coupling. In higher yields, the compounds 11 and 13 have
been obtained by allowing to react 4,4-dibromobiphenyl
by reaction with hydrazine hydrate in DMSO according to
the literature.17 Obviously, by starting with the Pd(II)-cat-
alyst and less-reactive bromo compounds an oxidative
dimerisation of the stannylated starting material 4, ob-
(14) or 5,5¢-dibromo-2,2¢-bithiophene (15), respectively,
served in several other cases,18 is more favoured than its
with an excess of a stannylated 2-diarylaminothiophene 4.
coupling with the appropriate co-reagent.
It is worth mentioning that the mono-coupling products 7e
and 9c resulting in the course of a 1:1 reaction of the cor-
responding starting materials could be detected only in
traces. This finding indicates that the substitution of the
first bromine by the appropriate 2-aminothiophene start-
ing compound 4 is slower than the substitution of the sec-
ond bromine.
Similar results have been obtained by performing the cou-
pling reaction with the 2-bromothiophenes 6a–6c. Where-
as by starting from the educts 4 and 5-acetyl-2-
bromothiophene (6b) relatively high yields of the corre-
sponding coupling products 9b were obtained; a low yield
of the corresponding coupling products 9a was obtained
by starting from the parent bromothiophene 6a. In addi-
Ar1
N
Ar2
H
S
S
3
Ar1
N
Ar2
Sn(Bu)3
5
a
b
c
d
e
R
R
6
H
4
a
b
c
H
COCH3
COOEt
CH3
COCH3
Br
Br
R
Br
6
Pd(PPh3)3X2
R
5
S
Br
Ar1
Ar1
Ar1
S
R
S
N
R
Ar1
N
N
Ar2
S
S
S
N
Ar2
Ar2
Ar2
7
8
9
(R = Br)
(R = Br)
Ar1
Ar1
S
N
N
S
S
Ar1
Ar1
S
S
n
Ar2
Ar2
N
Ar2
N
Ar2
n
12
13
10
11
n = 1
n = 2
Ar1Ar2N
3 - 13
+ 4
Pd(PPh3)3X2
Pd(PPh3)3X2
+ 4
N
A
S
Br
Br
2
Br
Br
2
N
S
B
15
14
Scheme 1
Synthesis 2005, No. 4, 610–616 © Thieme Stuttgart · New York

612
A. Tabet, H. Hartmann
PAPER
It is also worth mentioning that by starting from acceptor- Pd(PPh3)2Cl2 (variation A) or Pd(PPh3)4 (variation B). By
group free bromobenzenes 5 and 2-bromothiophenes 6, using the dibromo compounds 14 and 15 as coupling re-
e.g. 5a or 6a, the yields of the corresponding coupling agent a 2–3 fold excess of the corresponding tributylstan-
products can be significantly raised by using Pd(PPh3)4 as nyl compounds 4 had to be used to avoid the noticeable
catalyst. This Pd0 species was prepared in situ from PdCl2 formation of mono-coupling products. The reactions were
and PPh3 by reaction with hydrazine hydrate in DMSO ac- quenched by addition of aqueous MeOH to the reaction
cordingly to ref. 17 Obviously, by starting with the Pd(II)- mixture and the products were isolated by filtration. The
catalyst and less-reactive bromo compounds an oxidative primary products were obtained mostly in moderate yield.
dimerisation of the stannylated starting material 4, ob- Their purification was performed by repeated chromatog-
served in several other cases,18 is more favoured than its raphy on silica using cyclohexane or toluene as eluent un-
coupling with the appropriate co-reagent.
til no side products could be detected by TLC and sharp
melting peaks were recorded by different scanning calo-
rimetry.
As standard procedure for the synthesis of all the CC-cou-
pling products described here a mixture of the necessary
reactants were allowed to react in anhydrous toluene or
THF under argon in the presence of 5 mol% of
Table 1 Characteristic Data of the Compounds Prepared
Entry
R
Yield [%]
Mp [°C]
Formula (mw)
Anal. Calcd (above), Found (below)
C
H
N
S
3A
–
103
C16H13NS
(251.3)
76.46
76.31
68.29
68.29
80.70
80.31
73.91
74.15
78.02
78.12
72.15
72.10
75.16
74.92
69.90
69.91
80.90
80.90
74.37
74.37
76.76
76.42
68.51
68.42
5.21
5.37
3.94
3.95
5.23
5.21
4.23
4.53
5.18
5.22
4.29
4.28
5.30
5.50
4.46
4.74
5.61
5.64
4.61
4.81
4.83
4.89
3.59
3.53
5.57
5.54
4.98
4.97
4.28
3.98
3.92
3.93
3.79
3.75
3.51
3.80
3.51
3.52
3.26
3.26
4.10
3.92
3.77
3.51
5.60
5.34
5.00
4.76
12.76
12.84
22.79
22.77
9.79
3B
–
104
90
C16H11NS2
(281.4)
7Aa
7Ba
7Ab
7Bb
7Ac
7Bc
7Ad
7Bd
8A
H
43
50
47
40
45
40
21
41
13
14
C22H17NS
(327.4)
9.60
H
190
130
191
106
156
116
175
185
296
C22H15NS2
(357.4)
17.94
17.88
8.68
COCH3
COCH3
COOEt
COOEt
CH3
CH3
–
C24H19NOS
(369.3)
8.70
C24H17NOS2
(399.3)
16.05
16.18
8.03
C25H21NO2S
(399.5)
8.03
C25H19NO2S2
(429.4)
14.93
14.90
9.39
C23H19NS
(341.3)
9.13
C23H17NS2
(371.3)
17.26
17.03
12.81
12.64
22.87
22.53
C32H24N2S2
(500.7)
8B
–
C32H20N2S4
(560.8)
Synthesis 2005, No. 4, 610–616 © Thieme Stuttgart · New York

PAPER
Stille Coupling of 2-Diarylaminothiophenes with Mono- and Dibromo(het)arylenes
613
Table 1 Characteristic Data of the Compounds Prepared (continued)
Entry
R
H
Yield [%]
40
Mp [°C]
72
Formula (mw)
Anal. Calcd (above), Found (below)
C
H
N
S
9Aa
C20H15NS2
(333.5)
72.03
72.08
66.08
66.26
70.37
70.30
65.15
65.37
79.13
78.95
71.66
71.42
80.95
81.13
74.12
74.27
74.19
73.98
67.26
67.55
72.25
72.36
66.26
66.66
4.53
4.50
3.60
3.90
4.56
4.66
3.73
3.93
4.89
5.01
3.80
4.10
4.94
4.98
3.96
3.98
4.50
4.70
3.45
3.67
4.24
4.55
3.34
3.50
4.20
3.95
3.85
3.82
3.73
3.74
3.45
3.34
4.86
4.80
4.40
4.23
4.29
4.22
3.93
3.65
4.81
4.68
4.36
4.23
4.21
4.29
3.86
3.77
19.23
19.23
26.46
25.91
17.08
17.07
23.72
23.56
11.12
11.34
20.14
19.95
9.82
9Ba
9Ab
9Bb
10A
10B
11A
11B
12A
12B
13A
13B
H
62
57
68
11
21
10
24
33
33
32
34
167
115
194
270
311
304
284
179
220
207
252
C20H13NS3
(363.5)
COCH3
C22H17NOS2
(375.5)
COCH3
C22H15NOS3
(405.6)
–
–
–
–
–
–
–
–
C32H28N2S2
(576.5)
C38H24N2S2
(636.6)
C44H32N2S2
(652.9)
9.11
C44H28N2S4
(712.7)
17.99
17.44
16.51
16.35
24.94
24.09
19.29
19.25
26.54
26.76
C36H26N2S3
(582.8)
C36H22N2S5
(642.9)
C40H28N2S4
(664.9)
C40H24N2S6
(725.0)
The structures of the products prepared have been con- idised into stabilised radical monocations and non-radi-
firmed, in all cases, by means of elemental analyses, mass calic dications. Their UV–Vis and ESR-spectroscopic
spectra, and NMR measurements. The relevant data are characteristics will be reported more in detail in a forth-
collected in the Tables 1 and 2. Thus, all the coupling coming paper in advance. Some preliminary results have
1
products 7–13 prepared exhibit in their H NMR spectra been published very recently.19
at about 6.50–7.00 ppm characteristic doublets with cou-
pling constants of about J = 3.9 Hz. The doublets can be
All melting points were determined by means of a differential scan-
attributed to the thiophene protons at C3 and C4 of the 2-
diarylaminothiophene moieties. However, the doublets of
the protons at C4 are usually hidden under the multiplets
originating from the protons of the arylamino moieties.
ning calorimeter (Mettler, Toledo). NMR spectra were recorded
with a Varian 300 MHz spectrometer (Gemini 300). Elemental
analysis data were obtained with a LECO CHNS 932 analyser and
the mass spectra with an AMO spectrometer 402 (70 eV, EI).
As characteristic properties of the prepared compounds
their ability to fluoresce and their ability to be oxidised
5-Aryl-substituted 2-Diarylaminothiophenes 7; General Proce-
dure
very easily have to be mentioned. As far as the com- Step a: To a solution of a 2-diarylaminothiophene 3A (8 mmol) in
anhyd THF (10 mL) a solution (1.6 M) of BuLi in n-hexane (7 mL)
was added dropwise under Ar at – 70 °C. After warming to r.t. tribu-
tylstannyl chloride (3 mL, 0.1 M) was added to the reaction mixture,
pounds are end-capped by two diarylamino moieties, such
as the compounds 8 and 10–13, they can be reversibly ox-
Synthesis 2005, No. 4, 610–616 © Thieme Stuttgart · New York

614
A. Tabet, H. Hartmann
PAPER
which was then allowed to stand overnight. The resulting mixture
was poured into water (30 mL) and the product formed was extract-
ed with CH2Cl2 (25 mL). The organic layer was dried with Na2SO4,
filtrated, and evaporated in vacuo. The remaining product was used
without further manipulation in the next step.
1,4-Bis(2-diarylamino-5-thienyl)benzenes 10; General Proce-
dure
In analogy to the previous procedure a tributylstannyl compound 4
(8 mmol) was allowed to react with 1,4-dibromobenzene (5e, 3
mmol, 0.7 g) in anhyd toluene (25 mL) in the presence of Pd(PPh3)4
(0.12 mmol, 0.14 g). After evaporation of the solvent the products
formed (see Table 1) were purified by column chromatography us-
ing silica as adsorbent and cyclohexane–toluene as eluent.
Step b: The tributylstannyl compound (8 mmol) so obtained was
dissolved in anhyd toluene (25 mL) and mixed, under Ar and under
stirring, with an appropriate aryl bromide 5 (12 mmol) and
Pd(PPh3)4 (0.12 mmol, 0.14 g). After heating the resulting mixture
at 80 °C for 8 h the solvent was removed at reduced pressure and the
residue was purified by column chromatography using silica as ad-
sorbent and cyclohexane–toluene as eluent. For the products 7 so
obtained see Table 1.
4,4¢-Bis(2-diarylamino-5-thienyl)biphenyls 11; General Proce-
dure
In analogy to the previous procedure a tributylstannyl compound 4
(8 mmol) was allowed to react with 4,4¢-dibromobiphenyl (14, 3
mmol, 1.0 g) in anhyd toluene (25 mL) in the presence of Pd(PPh3)4
(0.12 mmol, 0.14 g). After evaporation of the solvent the products
formed (see Table 1) were purified by column chromatography us-
ing silica as adsorbent and cyclohexane–toluene as eluent.
5-Diarylamino-2,2¢-bithiophenes 9; General Procedure
In analogy to the previous procedure the corresponding tributylstan-
nyl compound 4 (8 mmol) prepared according to the step a was al-
lowed to react with an appropriate 2-bromothiophene derivative 6
(12 mmol). The products obtained (see Table 1) were purified by
column chromatography using silica as adsorbent and cyclohexane–
toluene as eluent.
Table 2 Spectroscopic Data of the Compounds Prepared
Comp.
1H NMR (CDCl3) d (ppm)
13C NMR (CDCl3) d (ppm)
m/z
3A
6.75 (d, J = 3.3 Hz, 1 H), 6.91 (t, J = 3.6 Hz, 1 H), 7.01 (d, 120.7, 121.4, 122.2, 122.7, 125.8, 129.0, 147.9,
J = 4.5 Hz, 1 H), 7.05 (d, J = 7.2 Hz, 2 H), 7.16 (d, J = 8.1 151.4
Hz, 4 H), 7.24–7.31 (m, 4 H)
251
3B
6.65 (d, J = 8.1 Hz, 2 H), 6.89 (t, J = 7.5 Hz, 2 H), 6.96 (t, 116.6, 121.1, 123.1, 125.5, 126.2, 126.6, 126.9,
J = 8.2 Hz, 2 H), 7.06 (t, J = 8.1 Hz, 2 H), 7.13 (dd, J = 4.5 128.0, 143.4, 143.9
Hz, 2 H), 7.37 (d, J = 5.1 Hz, 1 H)
281
327
357
369
399
399
429
7Aa
7Ba
7Ab
7Bb
7Ac
7Bc
6.67 (d, J = 3.9 Hz, 1 H), 7.06 (t, J = 7.2 Hz, 2 H), 7.12 (d, 122.2, 122.5, 123.3, 123.7, 125.8, 127.7, 129.4,
J = 3.9 Hz, 1 H), 7.18–7.36 (m, 12 H), 7.53 (d, J = 9.6 Hz, 129.8, 135.2, 138.9, 148.4, 151.6
1 H)
6.80 (d, J = 8.1 Hz, 2 H), 6.90 (t, J = 7.2 Hz, 2 H), 7.00 (t, 117.5, 122.1, 122.4, 124.0, 126.4, 127.4, 127.7,
J = 7.2 Hz, 2 H), 7.05–7.08 (m, 3 H), 7.34 (d, J = 7.2 Hz, 2 128.6, 129.6. 129.7, 134.7, 143.2, 144.5, 144.6
H), 7.39–7.44 (m, 2 H), 7.64 (d, J = 8.1 Hz, 2 H)
2.58 (s, 3 H, CH3), 6.64 (d, J = 3.9 Hz, 1 H), 7.91 (d, J = 5.1 120.4, 123.1, 123.6, 124.5, 129.0, 129.2, 129.7,
Hz, 2 H), 7.56 (d, J = 4.8 Hz, 2 H), 7.26–7.32 (m, 4 H),
7.18–7.22 (m, 5 H), 7.08 (t, J = 7.2 Hz, 2 H)
131.8, 135.1, 135.2, 139.0, 147.4, 153.2, 197.0
2.62 (s, 3 H, CH3), 6.82 (d, J = 8.1 Hz, 2 H), 6.93 (m, 2 H), 27.2, 118.0, 122.9, 124.2, 124.3, 126.1, 127.6,
7.00 (m, 2 H), 7.04–7.10 (m, 3 H), 7.44 (d, J = 3.9 Hz, 1 H), 127.8, 129.0, 129.8, 136.7, 139.0, 142.1, 144.3,
7.68–7.71 (m, 2 H), 7.98–8.00 (m, 2 H)
145.6, 197.8
1.39 (t, J = 7.2 Hz, 3 H), 4.37 (q, J = 7.2 Hz, 2 H), 6.64 (d, 15.0, 61.5, 121.4, 123.7, 124.0, 124.2, 125.1,
J = 3.9 Hz, 1 H), 7.07 (m, 2 H), 7.19 (m, 5 H), 7.29 (m, 4
H), 7.54 (d, J = 6.6 Hz, 2 H), 7.98 (d, J = 6.6 Hz, 2 H)
129.1, 129.9, 130.8, 136.3, 139.4, 148.2, 153.5,
166.9
1.42 (t, J = 7.2 Hz, 3 H), 4.40 (q, J = 7.2 Hz, 2 H), 6.81 (d, 15.0, 61.7, 117.9, 122.7, 124.0, 124.1, 124.2,
J = 9.6 Hz, 2 H), 6.91 (t, J = 7.2 Hz, 2 H), 7.00 (t, J = 7.5 125.9, 127.5, 127.8, 129.2, 130.2, 131.0, 142.5,
Hz, 2 H), 7.06–7.09 (m, 3 H), 7.42 (d, J = 3.9 Hz, 1 H), 7.66 144.4, 145.2, 166.8
(d, J = 8.4 Hz, 2 H), 8.06 (d, J = 8.4 Hz, 2 H)
7Ad
7Bd
2.30 (s, 3 H), 6.71 (d, J = 4.5 Hz, 1 H), 7.04–7.12 (m, 5 H), 20.3, 121.4, 121.9, 121.4, 122.9, 124.4, 129.1,
341
371
7.18 (d, J = 8.4 Hz, 2 H), 7.24 (d, J = 3.9 Hz, 1 H), 7.30–
7.35 (m, 5 H), 7.44 (d, J = 8.1 Hz, 2 H)
129.2, 130.9, 136.4, 137.6, 147.0, 149.3
2.38 (s, 3 H), 6.79 (d, J = 8.1 Hz, 2 H), 6.88 (t, J = 7.2 Hz, 21.8, 117.5, 121.9, 122.0, 123.9, 126.3, 127.4,
2 H), 6.98 (t, J = 7.8 Hz, 2 H), 7.04–7.07 (m, 3 H), 7.21 (d, 127.8, 129.8, 130.3, 132.0, 138.6, 142.6, 144.7,
J = 7.8 Hz, 2 H), 7.28 (d, J = 3.6 Hz, 1 H), 7.53 (d, J = 8.1 144.8
Hz, 2 H)
Synthesis 2005, No. 4, 610–616 © Thieme Stuttgart · New York

PAPER
Stille Coupling of 2-Diarylaminothiophenes with Mono- and Dibromo(het)arylenes
615
Table 2 Spectroscopic Data of the Compounds Prepared (continued)
Comp.
1H NMR (CDCl3) d (ppm)
13C NMR (CDCl3) d (ppm)
m/z
500
8A
6.35 (d, J = 3.9 Hz, 2 H), 6.65 (d, J = 3.9 Hz, 2 H), 6.84 (t, 121.6, 121.8, 123.1, 123.4, 129.5, 132.6, 148.2,
4 H), 7.04 (t, 8 H), 7.13 (d, 8 H)
150.5
8B
6.46 (d, J = 3.9 Hz, 2 H), 6.60–6.67 (m, 4 H), 6.73 (d, J =
3.9 Hz, 2 H), 6.76–6.78 (m, 8 H), 6.90–6.94 (m, 4 H)
117.3, 122.3, 122.5, 123.6, 126.9, 127.0, 128.4,
136.5, 143.2, 144.0
560
333
9Aa
6.65 (d, J = 4.1 Hz, 1 H), 7.01–7.04 (m, 2 H), 7.06–7.09 (m, 122.0, 122.9, 123.4, 123.6, 123.9, 124.4, 128.4,
6 H), 7.17 (d, J = 3.6 Hz, 1 H), 7.30–7.35 (m, 4 H), 7.41 (d, 129.9, 132.2
J = 5.3 Hz, 1 H)
9Ba
9Ab
9Bb
10A
6.80 (d, J = 8.1 Hz, 2 H), 6.91 (dd, J = 7.5 Hz, 2 H), 6.98– 117.6, 122.2, 122.9, 124.1, 124.7, 125.5, 127.4,
363
375
405
576
7.08 (m, 5 H), 7.20 (d, J = 3.9 Hz, 1.5 H), 7.22 (d, J = 3.6
Hz, 1 H), 7.27 (d, J = 4.5 Hz, 1.5 H)
127.8, 128.6, 129.5, 137.7, 137.8, 142.8, 144.5
2.51 (s, 3 H), 6.55 (d, J = 4.2 Hz, 1 H), 6.98 (d, J = 3.9 Hz, 27.1, 120.2, 123.5, 124.0, 124.6, 125.4, 129.3,
1 H), 7.06–7.11 (m, 3 H), 7.17–7.20 (m, 4 H), 7.27–7.32
130.1, 134.1, 147.3, 148.0, 154.2, 167.6, 190.8
(m, 4 H), 7.53 (d, J = 3.9 Hz, 1 H)
2.56 (s, 3 H), 6.83 (m, 2 H), 6.91–7.01 (m, 3 H), 7.00–7.06 27.2, 118.5, 123.6, 124.6, 124.9, 125.1, 127.7,
(m, 2 H), 7.08–7.11 (m, 2 H), 7.16 (d, J = 3.9 Hz, 1 H), 7.30 127.9, 128.0, 133.8, 135.2, 143.5, 144.2, 146.0,
(d, J = 3.9 Hz, 1 H), 7.59 (d, J = 3.9 Hz, 1 H)
146.2, 190.8
6.66 (d, J = 3.9 Hz, 2 H), 7.05 (t, J = 7.2 Hz, 4 H), 7.11 (d, 122.2, 122.4, 123.4, 123.8, 126.1, 129.9, 133.9,
J = 3.9 Hz, 2 H), 7.18 (d, J = 7.2 Hz, 8 H), 7.25–7.31 (m, 8 137.9, 138.3, 148.4
H), 7.47 (s, 4 H)
10B
11B
6.82 (d, J = 8.1 Hz, 4 H), 6.90 (t, J = 7.5 Hz, 4 H), 7.00 (m, 117.8, 122.7, 124.2, 126.9, 127.5, 127.8, 129.6,
4 H), 7.07 (m, 6 H), 7.37 (d, J = 3.9 Hz, 2 H), 7.66 (s, 4 H) 134.3, 136.2, 143.6, 144.0, 144.6
636
712
6.82 (d, J = 8.1 Hz, 4 H), 6.90 (m, 4 H), 7.01 (m, 4 H), 7.07 117.8, 122.5, 122.7, 124.1, 126.9, 127.5, 127.8,
(m, 4 H), 7.17 (d, J = 7.5 Hz, 2 H), 7.39 (d, J = 3.9 Hz, 2
128.1, 129.7, 134.1, 140.5, 143.8, 143.9, 144.7
H), 7.70 (m, 8 H)
12A
12B
13A
13B
6.57 (d, J = 3.9 Hz, 2 H), 6.89 (s, 2 H), 6.91 (d, J = 3.9 Hz, 121.1, 122.0, 122.7, 123.2, 123.3, 129.1, 131.0,
2 H), 7.05 (t, 4 H), 7.17 (m, 8 H), 7.27 (m, 8 H) 135.9, 147.5, 150.4
582
642
664
724
6.80 (m, 4 H), 6.91 (m, 4 H), 7.01 (m, 6 H), 7.07 (m, 4 H), 117.7, 117.8, 122.5, 123.1, 123.3, 124.2, 125.3,
7.12 (s, 2 H), 7.20 (t, J = 4.2 Hz, 2 H) 127.5, 127.8, 129.3, 129.4, 144.4
6.58 (d, J = 3.9 Hz, 2 H), 6.93 (t, 4 H), 7.00 (d, J = 3.9 Hz, 121.6, 123.0, 123.5, 124.0, 124.7, 128.9, 129.9,
2 H), 7.06 (t, 4 H), 7.17 (m, 8 H), 7.72 (m, 8 H) 131.5, 136.0, 137.7
6.79 (d, J = 1.5 Hz, 2 H), 6.82 (d, J = 1.5 Hz, 2 H), 6.90 (d, 117.8, 122.5, 123.1, 124.2, 125.2, 125.4, 127.5,
J = 1.5 Hz, 2 H), 6.98–7.02 (m, 6 H), 7.06 (d, J = 1.8 Hz, 2 127.8, 129.3, 136.2, 144.5
H), 7.08 (d, J = 1.5 Hz, 4 H), 7.12 (s, 4 H), 7.18 (d, J = 3.9
Hz, 2 H)
5,5¢¢-Bis(2-diarylamino)-2,2¢:5¢,2¢¢-trithiophenes 12; General
Procedure
5,5¢-Bis(diarylamino)-2,2¢-bithiophenes 8
Method A: The 5,5¢-bis(diarylamino)-2,2¢-bithiophenes 8A and 8B
were obtained as by-products in course of the synthesis of the com-
pounds 7 or 9–13 and separated from those by column chromatog-
raphy.
In analogy to the previous procedure a tributylstannyl compound 4
(8 mmol) was allowed to react with 2,5-dibromothiophene (6c, 3
mmol, 0.7 g) in anhyd toluene (25 mL) in the presence of Pd(PPh3)4
(0.12 mmol, 0.14 g). After evaporation of the solvent the products
formed (see Table 1) were purified by column chromatography us-
ing silica as adsorbent and cyclohexane–toluene as eluent.
Method B: 2-Diarylaminothiophene 3 (8 mol) was transformed into
its 5-tributylstannyl derivative 4 according to the reported proce-
dure and treated, subsequently, in toluene (25 mL) with
Pd(PPh3)2Cl2 (0.1 mmol) as described for the synthesis of the com-
pounds 7.
5,5¢¢¢-Bis(2-diarylamino)-2,2¢:5¢,2¢¢:5¢¢,2¢¢¢-tetrathiophenes 13;
General Procedure
In analogy to the previous procedure a tributylstannyl compound 4
(8 mmol) was allowed to react with 5,5¢-dibromo-2,2¢-bithiophene
(15, 3 mmol, 1.0 g) in anhyd toluene (25 mL) in presence of
Pd(PPh3)4 (0.12 mmol, 0.14 g). After evaporation of the solvent the
products formed (see Table 1) were purified by column chromatog-
raphy using silica as adsorbent and cyclohexane–toluene as eluent.
Acknowledgment
The authors are grateful to the Deutsche Forschungsgemeinschaft
for generous financial support.
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616
A. Tabet, H. Hartmann
PAPER
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Synthesis 2005, No. 4, 610–616 © Thieme Stuttgart · New York