LETTER
451
Synthesis of 9,10-Diarylanthracene Derivatives via bis Suzuki-Miyaura Cross-
coupling Reaction
Synthesis of
9
a
,10-Diaryla
m
nthracene
D
erivativ
b
es via Suzuk
a
i–Miyaura
sR eaction ivarao Kotha,* Arun Kumar Ghosh
Department of Chemistry, Indian Institute of Technology-Bombay, Mumbai-400076, India
Fax +91(22)5723480; E-mail: srk@chem.iitb.ac.in
Received 20 November 2001
13C NMR spectral data. Various 9,10-diarylanthracenes
3–9) prepared by this procedure are included in Table.
Since polycyclic anthracene derivatives posses useful ap-
Abstract: A convenient and one-step synthesis of 9,10-diarylan-
thracenes is described via a bis Suzuki–Miyaura (SM) cross-cou-
pling reaction. In this regard, 9,10-dibromoanthracene was reacted
(
9
10
with various aryl boronic acids in presence of palladium(0) catalyst plications in fluorescence, electrochemiluminescence
11
to give 9,10-diarylanthracenes in good yield.
and nonlinear optical materials preparation, the method-
ology reported here may find useful applications in mate-
Key words: arenes, palladium, boron, cross-coupling, polycycles
1
2
13
rial science and polymer synthesis.
In summary, starting from the commercially available
In connection with the synthesis of unusual amino acids 9,10-dibromoanthracene (1), we have shown that highly
derivatives, we needed a simple and useful methodology functionalized 9,10-diarylanthracenes can be efficiently
for the preparation of various 9,10-diarylanthracene de- prepared in a one-step procedure using the SM cross-cou-
rivatives. In this respect, a perusal of literature disclosed pling reaction. The advantages of this approach are nu-
that 9,10-diarylanthracenes preparations involve Grignard merous, good yields, short synthetic sequence and simple
1
,2
type reagents in the key step. In spite of several applica- operating conditions. It may be pertinent to mention that
tions of 9,10-diarylanthracenes for polymer synthesis and the substrate 9 listed in Table has been prepared in a four-
material science, only a limited number of derivatives is step sequence involving Grignard addition reaction as a
3
–5
13
available in the literature. Furthermore, some commer- key step. Moreover, the aldehyde functionality present
6
cially available 9,10-diarylanthracenes derivatives are in 9 can be used for further synthetic manipulation.
very expensive. In recent years, the palladium-catalyzed
7
Suzuki-Miyaura (SM) cross-coupling reaction has be-
come one of the most efficient methods for the construc-
A Typical Experimental Procedure for Suzuki–Miyaura Coup-
tion of carbon-carbon bonds. Therefore, it would be ling Reaction:
advantageous to develop the cross-coupling strategy to A mixture of 9,10-dibromoanthracene (1) (105 mg, 0.31 mmol), 4-
methylphenylboronic acid (105 mg, 0.78 mmol), Na CO (83 mg,
prepare a range of functionalized 9,10-diarylanthracenes
from commercially available starting material(s) in a one-
step procedure. In this regard, the inexpensive 9,10-dibro-
moanthracene (1) was reacted with various aryl boronic
acid derivatives and found that 9,10-diarylanthracenes (3–
2
3
0
(
.78 mmol) in water (1 mL) and solvent [THF (3 mL) and toluene
3 mL)] was degassed for 15 minutes by bubbling nitrogen through
the reaction mixture. Tetrakis(triphenylphosphine)palladium
Pd(PPh ) ] (10.5 mg, 3 mol%) was added to the reaction mixture
8
[
3
4
and heated at 85 °C under nitrogen for 3 h. Then, the reaction mix-
ture was diluted with water (10 mL) and extracted with diethyl ether
9
) were obtained in good yield (Scheme).
(
3
25 mL). The combined organic layer was washed with water
(15 mL), brine (10 mL) and dried over magnesium sulfate. The sol-
vent was evaporated and the crude product was charged on a silica
gel column. Elution of the column with ethyl acetate–hexane mix-
ture gave the desired cross-coupling product 8 (109 mg, 99%).
Selected 13C NMR (75.4 MHz, CDCl ) spectral data
3
(
4): 110.9, 112.4, 125.9, 126.5, 127.7, 131.4, 142.9, 150.6. (6):
Scheme
125.1, 125.2, 125.4, 126.8, 130.5, 130.9, 132.2, 138.8. (8): 21.6,
1
1
23.6, 125.0, 127.2, 129.3,130.2, 131.4, 136.2, 137.2. (9): 125.6,
26.5, 129.3, 129.8, 132.0, 135.7, 136.1, 145.7, 191.9.
In a typical procedure the 9,10-dibromoanthracene (1)
was treated with ArB(OH) in presence of catalytic quan-
2
tities (2–3 mol%) of tetrakis(triphenylphosphine)palladi- Acknowledgement
um [Pd(PPh ) ] under standard coupling conditions. The
3
4
We gratefully acknowledge DST for the financial support and RSIC
Mumbai for recording the Mass and NMR spectral data. We would
like to thank Prof. A. Srikrishna and Department of Organic Chemi-
cross-coupling products were purified by silica gel col-
1
umn chromatography and characterized by H NMR and
1
3
stry (IISc) for providing the C NMR spectral data.
Synlett 2002, No. 3, 04 03 2002. Article Identifier:
1
©
437-2096,E;2002,0,03,0451,0452,ftx,en;D25701ST.pdf.
Georg Thieme Verlag Stuttgart · New York
ISSN 0936-5214
Kotha, Sambasivarao
