Catalysis of Organic..

Robitaille, Clément, Chapuzet and Lessard 287O 2 NH 2 NXX26 27pH = 6 pH = 13.5H 2 NClX28X = NH 73-83%X = NCH 3 46-64%X = O 53-67%X = S 72-76%85-88%100%72-76%79-85%Zn/HCl75%78%73%70%Scheme 9ConclusionsThe reduction of polyfunctional nitro compounds, nitroaryl as well as nitroalkylcompounds, to the corresponding amines in basic aqueous alcoholic solutions onRaney copper (RCu) is more selective if carried out by generating chemisorbedhydrogen by electroreduction of water (ECH method) than by generating it byleaching of the alloy in situ (CCH method) except in the case of o-iodonitrobenzene(2) for which the CCH method is more selective. However, the most selectivemethod in all cases studied is ECH in neutral medium (pH 3-7).AcknowledgementsFinancial support from NSERC of Canada, the Fonds FCAR of Quebec, the Ministryof Energy and Natural Resources of Québec, and the Université de Sherbrooke isgratefully acknowledged.References1. J.M. Chapuzet, R. Labrecque, M. Lavoie, E. Martel, and J. Lessard. J. Chim.Phys., 93, 601 (1996).2. J.M. Chapuzet, A. Lasia and J. Lessard, Electrocatalysis, Frontiers ofElectrochemistry Series, J. Lipkowski and P.R. Ross, Eds, Wiley-VCH, Inc.,New York, 1998, p. 155-196.3. J. Lessard, Chemical Industries (CRC Press), 104, (Catal. Org. React.) 3-12(2005).4. E. S. Chan-Shing, D. Boucher and J. Lessard, Can. J. Chem., 77, 687 (1999).5. H. Lund, Organic Electrochemistry, H. Lund and O. Hammerich, Eds, MarcelDekker, Inc., New York-Basel, 2001, p. 379.6. A. Cyr, E. Laviron, and J. Lessard, J. Electroanal. Chem., 263, 69 (1989).7. A. Cyr. P. Huot, G. Belot, and J. Lessard, Electrochim. Acta, 35, 147 (1990).8. G. Belot, S. Desjardins, and J. Lessard, Tetrahedron Lett. 25, 5347 (1984).9. B. Côté. M.Sc. Dissertation, Université de Sherbrooke, 1993.10. J.M. Chapuzet, B. Côté, M. Lavoie, E. Martel, C. Raffin, and J. Lessard. "TheSelective Reduction of Aliphatic and Aromatic Nitro Compounds" in NovelTrends in Electroorganic Synthesis, S. Torii, Ed., Kodansha, Tokyo, 1995, p.321.