Stereoselectivity of heterogeneous catalysts, modified by optically active polyelectrolytes
The hydrogenation of the methyl ester ofα-acetamidocinnamic acid over Pd-black and sketetal Ni, modified by optically active copolymers of styrene with alanine maleimide, gives an optically active phenylalanine with an optical purity of 1–2%.
The modification of Pd-black by aqueous solutions of optically active copolymers revealed that the modification pH affects not only the value, but also the sign of rotation of the formed phenylalanine.
The value and character of the catalyst stereoselectivity as a function of the modification pH is explained by the formation of various types of complexes on the catalyst surface, due to the configurational and conformational changes in the optically active polyelectrolyte as a function of its degree of dissociation.
KeywordsHydrogenation Methyl Ester Aqueous Solution Methyl Ester
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- 1.S. L. Davydova, N. A. Plate, and V. A. Kargin, Usp. Khim.,39, 2256 (1970).Google Scholar
- 2.E. I. Klabunovskii, Stereospecific Catalysis [in Russian], Nauka (1968).Google Scholar
- 3.H. Hirai and T. Furuta, J. Polymer Sci., B, Polymer Letters,9, 459 (1971).Google Scholar
- 4.V. K. Latov and K. K. Babievskii, Izv. Akad. Nauk SSSR, Ser. Khim.,1972, 2036.Google Scholar
- 5.J. Greenstein and M. Winitz, Chemistry of Amino Acids and Peptides [Russian translation], Mir (1965).Google Scholar
- 6.M. Legrand and R. Viennet, Bull. Soc. Chim. France, 2798 (1966); A. Moscowitz, A. Rosenberg, and A. E. Hansen, J. Am. Chem. Soc.,87, 1813 (1965).Google Scholar
- 7.Problems in Kinetics and Catalysis, No. 13, Complex Formation in. Catalysis [in Russian], Nauka (1968).Google Scholar
- 8.R. L. Augustine and J. F. Van Peppen, Ann. New York Acad. Sci.,172, 244 (1970).Google Scholar
- 9.B. Bosnich, J. Chem. Soc.,A1966, 1394.Google Scholar
- 10.G. Morawetz, Macromolecules in Solution [Russian translation], Mir (1967).Google Scholar
- 11.M. Mandel and J. C. Leyte, J. Polymer Sci.,A2, 2883 (1969).Google Scholar
- 12.B. B. Wayland and R. F. Schramm, Inorg. Chem.,8, 971 (1969).Google Scholar
- 13.G. S. Libinson, Physicochemical Properties of Carboxylate Cationites [in Russian], Nauka (1969).Google Scholar
- 14.K. Weigand, Experimental Methods in Organic Chemistry [Russian translation], Part 2, IL (1950), P. 22.Google Scholar
- 15.E. Erlenmeyer, Ann. Chem.,337, 271 (1904).Google Scholar
- 16.Manual on Inorganic Chemistry [in Russian], GNTIKhL (1957), p. 393.Google Scholar