Heterogeneous asymmetric catalysis organic catalysts

Polymerised preformed [(N,N -dimethyl-l,2-diphenylethane diamine)2Rh] complex allows us to obtain enantioselective material. We have then shown that it is possible to imprint an optically pure template into the rhodium-organic matrix and to use the heterogeneous catalyst in asymmetric catalysis with an obvious template effect. The study of yield versus conversion graphs has shown that the mechanism occurs via two parallel reactions on the same site without any inter-conversion of the final products. Adjusting the cross-linker ratio at 50/50 allows us to find a compromise between activity and selectivity. Phenyl ethyl ketone (propiophenone) was reduced quantitatively in 2 days to (R)-l-phenyl propanol with 7tf% enantiomeric excess We have then shown that the imprinting effect is obvious for molecules related in structure to the template (propiophenone, 4 -trifluoromethyl acetophenone). It is not efficient if the structure of the substrate is too different to that of the template. 

Tai, A. (2002) Asymmetrically modified nickel catalyst (MNi) a heterogeneous catalyst for the enantio-differentiating hydrogenation, Murray Raney plenary lecture in Chemical Industries Series Catalysis of organic reactions) (Dekker), Morrell D.G. (ed.). 

This book contains many publications which represent analyses of the steps of elaboration of effective heterogeneous enantioselective hydrogenation catalysts, of their significant role in the theory of catalysis, and of their role in the practice of asymmetric catalysis. In addition to reviewing the first works on catal Tic hydrogenation of C=C double bond in prochiral compounds on metal catalysts supported on chiral carriers, which admittedly have only historical interest, the Chapters 1-3 review data on asymmetric adsorption of enantiomers and separation of racemic mixtures on organic and inorganic adsorbents. 

Asymmetric catalysis can be homogeneous or heterogeneous and can take place either in the organic phase or (as recently found) in the aqueous phase. Table 9.5 presents a broad classification of the major categories of asymmetric catalysis. The most common is homogeneous catalysis in the aqueous phase, and the most recent and novel is the use of aqueous phase catalysts immobilized on solid supports. The various categories are considered in the following sections. 

Falkowski JM, Liu S, Lin W. Asymmetric catalysis with chiral metal organic frameworks. In Llabres i Xamena FX, Gascon J, editors. Metal organic frameworks as heterogeneous catalysts. Cambridge The Royal Society of Chemistry 2013. p. 344-64. 

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