Engineered Asymmetric Catalysis

The asymmetric catalysts thus prepared can be further evolved into a highly activated catalyst by engineering with chiral activators (Fig. 7-1). The term asymmetric activation can be proposed for this process in an analogy to the activation 

While non-racemic catalysts thns developed can generate non-racemic products with or without the non-linear relationship in enantiomeric excesses between catalysts and products [8], racemic catalysts inherently give only a racemic mixture of chiral products. Recently, a strategy whereby a racemic catalyst is selectively deactivated by a chiral molecule has been reported to yield non-racemic products (Fig. 7-3). However, we have reported a conceptually opposite strategy to asymmetric catalysts in which a chiral activator selectively activates one enantiomer of a racemic chiral catalyst (Fig. 7-2). The advantage of this activation strategy over the deactivation counterpart is that the activated catalyst can produce a greater enantiomeric excess (Xact% ee) in the products, even with the catalytic amount of the chiral activator to the chiral catalyst, than can the enantiomerically pure catalyst on its own (x% ee). 

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R. Noyori and T. Ohkuma, Asymmetric Catalysis by Architectural and Functional Molecular Engineering Practical Chemo- and Stereoselective Hydrogenation of Ketones , Angew. Chem. Int. Ed. Engl, 2001, 40, 40. 

Noyori, R. and Okhuma, T. (2001) Asymmetric catalysis by architectural and functional molecular engineering practical chemo- and stereoselective hydrogenation of ketones. Angewandte Chemie-International Edition, 40 (1), 40-73. 

The field of biocatalysis differs substantially from that of traditional chemical asymmetric catalysis. Whereas the range of optimal operational conditions may be broader for the latter case, the issue of substrate specificity of the former is more complex. The practical integration of biological catalysts into synthetic schemes has two main requirements (1) a suitable biocatalyst able to perform the required transformation must be identified and (2) the ability of the identified biocatalyst to perform the required transformation efficiently on the target substrate on a preparative scale must be assessed and if necessary engineered. Both of these requirements have been recognized and efforts to facilitate the implementation of biocataysts have been studied.2... 

In the present edition some space is dedicated to special topics such as electrocatalysis, photocatalysis, asymmetric catalysis, phase-transfer catalysis, environmental catalysis, and fine chemicals manufacture. On the basis of fundamental reaction engineering equations, examples for calculation and modeling of catalysis reactors are given with the easy-to-learn PC program POLYMATH. Well over 170 exercises help die reader to test and consolidate the gained knowledge. 

Catalysis in organic synthesis chemistry and engineering of catalysis by solids homogeneous catalysis and asymmetric synthesis, with emphasis on asymmetric catalysis ... 

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