S. Chandrasekhar et al. / Tetrahedron Letters 45 (2004) 2421–2423
2423
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ventionally used solvents, and efficient retention of the
catalyst by the PEG during extraction of products with
ether due to solidification.
3. (a) Santaniello, E.; Manzocchi, A.; Sozzani, P. Tetra-
hedron Lett. 1979, 47, 4581–4582; (b) Badone, D.; Jommi,
G.; Pagliarin, R.; Tavecchia, P. Synthesis 1987, 920–921;
(
c) Babonneau, M.; Jacqier, R.; Lazaro, R.; Viallefont, P.
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Commun. 2002, 876–877.
Overall, the goal of the study has been to evaluate PEG
as an inexpensive, nonvolatile, nonpyrophoric, eco-
friendly, and Ôthe appropriateÕ solvent for catalyzed
reductions. Other catalyzed reduction reactions are
presently being explored.
4. (a) Greico, P. A. Organic Synthesis in Water; Blackie
Academic and Professional: London, 1998; (b) Li, C.-J.;
Chan, T.-H. Organic Reactions in Aqueous Media; John
Wiley & Sons: New York, 1997; (c) Breslow, R. Acc.
Chem. Res. 1991, 24, 159–164.
. Ionic liquids cost 60–400 USD/50 g, as against PEG (400)
which costs 23 USD/500 g.
. (a) Trost, B. M. Acc. Chem. Res. 2002, 35, 695–705; (b)
Trost, B. M. Science 1991, 254, 1471–1477; (c) Trost, B.
M.; Toste, F. D.; Greenman, K. J. Am. Chem. Soc. 2003,
Acknowledgements
5
Ch.N., G.C.S., and T.S.S. thank CSIR, New Delhi,
India for financial support.
6
125, 4518–4526; (d) Trost, B. M.; Jonasson, C. Angew.
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