A. Mouradzadegun, M. R. Ganjali, E. Sabbagh, and F. Abadast
Vol 000
provides a more sustainable ionic liquid than [bmim]BH4
due to the concept of hard and soft acids and bases.
The stereochemistry of the ring opening product was
found to be in the trans-configuration as determined from
reaction, as monitored by thin-layer chromatography,
products were extracted from a quenched reaction
mixture with n-hexane, solvent was evaporated under
vacuum, and residual recrystalized in EtOH.
1
the coupling constants associated with the H NMR
spectral data (see Supporting Information).
Acknowledgment. This work was partially supported by the
Research Council at the University of Shahid Chamran.
In summary, this paper describes a new and general
protocol for the synthesis of aromatic dienones as only
product from the regiospecific reduction of triarylpyrylium
perchlorates
with
1-butyl-3-methylimidazolium
REFERENCES AND NOTES
borohydride, which play the triple role of nucleophile,
solvent, and promoter. This environmentally friendly
methodology also offers marked improvements with
regard to operational simplicity, short reaction times,
easy workup, high isolated yields of products, greenness
of the procedure also avoiding hazardous organic
solvent and toxic catalyst.
[
1] (a) Barton, D. H. R.; Magnws, P. D.; Pearson, M. J J Chem Soc
(
C) 1971 2231; (b) Jackson, L. B.; Waring, A. J J Chem Soc Perkin Trans
I 1988 1791; (c) Pilkington, J. W.; Waring, A. J. J Chem Soc Perkin Trans
I 1976 1349; (d) Inoue, Y.; Dmaizumi, S. J Mol Catal 1988, 49, 19; (e)
Fomina, Y. A.; Golikov, A. G.; Kriven’ko, A. P. Russ J Org Chem
2
008, 44, 706; (f) Mandell, L.; Caine, D.; Kilpatrick, G. E. J Am Chem
Soc 1961, 83, 4457; (g) Liotta, D.; Saindane, M.; Barnum, C. J Am Chem
Soc 1981, 103, 3224; (h) Hutson, G. E.; Türkmen, Y. E.; Rawal, V. H. J
Am Chem Soc 2013, 135, 4988; (i) Krasnaya, Z. A. Chem Heterocycl
Compd 1999, 35, 1255; (j) Drygina, O. V.; Garnovskii, A. D.; Kazantsev,
A. V. Chem Heterocycl Compd 1985, 21, 239.
EXPERIMENTAL
[2] Liu, C.; Shi, C.; Mao, F.; Xu, Y.; Liu, J.; Wei, B.; Zhu, J.;
Xiang, M.; Li, J. Molecules 2014, 19, 15653.
[
[
3] Ahn, B.-Z.; Sok, D.-E. Curr Pharm Des 1996, 2, 274.
4] (a) Balaban, A. T.; Mihai, G.; Nenitzescu, C. D. Tetrahedron
Chemicals were purchased from Fluka, Merck, and
Aldrich chemical companies (Tehran, Iran). Monitoring
of the reactions was accomplished by thin-layer
chromatography. IR spectra were obtained on a Bomen
MB:102 Fourier transform infrared spectrophotometer. H
NMR spectra were recorded on 400 MHz Brucker using
1
962, 18, 257; (b) Balaban, A. T.; Bratu, C.; Rentea, C. N. Tetrahedron
1964, 20, 265; (c) Berberova, N. T.; Dorofeenko, G. N.; Okhlobystin,
O. Y. Chem Heterocycl Compd 1977, 13, 250.
1
[5] Mouradzadegun, A.; Kiasat, A. R.; Elahi, S. J Chem 2013 5.
[
6] (a) Welton, T. Chem Rev 1999, 99, 2071; (b) Wassercheid, P.;
Keim, W. Angew Chem Int Ed 2000, 39, 3772; (c) Sheldon, R. Chem
Commun 2001 2399; (d) Wilkes, J. S. Green Chem 2002, 4, 73; (e)
Hardacre, C.; Holbrey, J. D.; Nieuwenhuyzen, M.; Youngs, T. G. A.
Acc Chem Res 2007, 40, 1146; (f) Martins, M. A. P.; Frizzo, C. P.;
Moreira, D. N.; Zanatta, N.; Bonacorso, H. G. Chem Rev 2008, 108,
2015; (g) Gua, Y.; Li, G. Adv Synth Catal 2009, 351, 817.
CDCl as the solvent and TMS as the internal standard.
3
General procedure for the synthesis of triarylpyrylium
perchlorates.
All triarylpyrylium perchlorates were
synthesized from the corresponding aldehydes and
ketones by the method previously described [10]. Briefly,
corresponding benzaldehyde (0.1 mol) and acetophenone
[
7] (a) Buijsman, R. C.; Vuuren, E. V.; Serrenburg, J. G. Org
Lett 2001, 3, 3785; (b) Fraile, J. M.; Garcia, J. I.; Herrerias, C. I.;
Mayoral, J. A.; Carrie, M. Tetrahedron Asymmetry 2002, 12, 1891; (c)
Anna, M. M.; Gallo, V.; Mastrorilli, P.; Nobile, C. F.; Romanazzi, G.;
Suranna, G. P. Chem Commun 2002 434; (d) Kubisa, P. Prog Polym Sci
(
(
0.2 mol) were stirred at room temperature; sulfuric acid
6 mL) was added dropwise during 30 min. The mixture
2
004, 29, 3; (e) Kubisa, P. J Polym Sci Part A: Polym Chem 2005, 43, 4675.
8] (a) Hoogerstraete, T. V.; Onghena, B.; Binnemans, K. J Phys
Chem Lett 2013, 4, 1659; (b) Davis, J. H. Chem Lett 2004, 33, 1072.
9] (a) Mouradzadegun, A.; Abadast, F. Monatsh Chem 2013, 144,
75; (b) Mouradzadegun, A.; Abadast, F. Synth Commun 2014, 44, 640;
c) Mouradzadegun, A.; Dianat, S. J Heterocycl Chem 2009, 46, 778; (d)
Mouradzadegun, A.; Abadast, F. Tetrahedron Lett 2013, 54, 2641; (e)
Mouradzadegun, A.; Abadast, F. Synlett 2014, 25, 448; (f)
Mouradzadegun, A.; Abadast, F. Chem Commun 2014, 50, 15983.
10] (a) Balaban, A. T.; Dinculescu, A.; Dorofeenko, G. N.;
was stirred at 100°C for 60 min. Then, ethanol (200 mL)
and perchloric acid 70% (10 mL) were added. The
mixture was excluded in order to form a precipitate for
[
[
3
(
2
4 h. The precipitates recrystalized from acetic acid.
mixture
-methylimidazole (4.1 g, 0.05 mol) and 1-bromobutane
Synthesis
of
[bmim]BH4.
A
of
1
(6.85 g, 0.05 mol) in the absence of solvent was heated
[
with stirring at 80°C for 3 h. Then, the product was washed
with dimethyl ether and dried in vacuum to afford [bmim]
Br. On completion, according to Wang et al. [11], 50 mL
of CH CN and 2.28 g NaBH (0.06 mol) were added in
sequence. The mixture was stirred for 24 h at room
temperature under nitrogen. After filtrating, the filtrate was
evaporated in vacuo to obtain [bmim]BH4 (7.39 g,
Fischer, G. W.; Koblik, A. V.; Mezheritskii, V. V.; Schroth, W. Advances
in Heterocyclic Chemistry; Katritzky, A. R. (ed); Academic: New York,
1982, 2, Suppl 1; (b) Balaban, A. T.; Schroth, W.; Fischer, G. W.
Pyrylium Salts, In Advances in Heterocyclic Chemistry; In Katritzky,
A. R. Ed.; Academic: New York, 1969; Vol 10, p. 241 and references
therein.
3
4
[11] Wang, J.; Song, G.; Peng, Y.; Zhu, Y. Tetrahedron Lett 2008,
49, 6518.
0
.048 mol, yield 96%) as a viscous liquid.
General procedure for the reaction of pyrylium salts with
SUPPORTING INFORMATION
[
bmim]BH4.
Reactions were typically carried out by
addition of 0.1 mol pyrylium salts to the 0.12 mol
bmim]BH4 and heated to 50°C. After completion of
Additional Supporting Information may be found online
in the supporting information tab for this article.
[
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet