Organocatalysis biocatalysis

Mahrwald R (2004) Modem aldol reactions, vol. 1. Enolates, organocatalysis, biocatalysis and natural product synthesis. Wiley-VCH, Weinheim, 335 pp... 

Modem Aldol Reactions. Vol. 1 Enolates, Organocatalysis, Biocatalysis and Natural Product Synthesis. Edited by Rainer Mahrwald... 

W.-D. Fessner, Enzyme-catalyzed aldol additions, in M. Rainer (Ed.), Modern Aldol Reactions. Enolates, Organocatalysis, Biocatalysis and Natural Product Synthesis, Wiley-VCH Verlag GmbH Co. KgaA, Weinheim, 2004, pp. 201 -272. 

In recent decades, chemists have demonstrated the proficiency of organo-catalysis as a useful synthetic tool for obtaining enantioenriched compounds. Thus, asymmetric organocatalysis has become a field of central importance along with biocatalysis and metal-mediated catalysis. In this chapter, we discuss the tremendous progress that has been achieved in the design and synthesis of various chiral 2-substituted pyrrolidine... 

Many attempts have been made during the last two decades to demonstrate the utility and limitations of aldolases, as illustrated by the plethora of reports surveyed in the literature. Protein engineering techniques and screening of novel aldol activities in nature are important tools for future aldolase development, which is expected to produce unprecedented innovative structures and access to new reactions. These advances offer promising perspectives for the application of aldolases, particularly after the thrihing emergence of organocatalysis as an alternative to biocatalysis. 

In addition to transition-metal catalysis, biocatalysis and organocatalysis are very important aspects of stereoselective catalysis. Recently, dual catalysis, involving combinations of several types of catalysis, for example, transition-metal catalysis and biocatalysis, has become of interest. Multicomponent and domino reactions are desirable because of the often high atom economy and efficiency. All these aspects have been pursued within the Heidelberg Collaborative Research Network (Sonderforschungsbereich, SFB 623), though most of the effort has been devoted to transition-metal catalysis. 

Like combinations of metal- and organocatalysis, combining biocatalysis and organocatalysis is a powerful strategy by which to improve the synthetic efficiency. A sequential two-step synthesis based on the organocatalytic aldol reaction and biocatalytic reduction leads to all four possible stereoisomers of 1,3-diols 72 in enan-tiomerically pure form (Scheme 28.5). The stereochemistry depends on the combination of the organocatalyst 70 and alcohol dehydrogenase (ADH). 

Zandvoort, E., Geertsema, E. M., Baas, B. J., Quax, W. J., and Poelarends, G. J., Bridging between organocatalysis and biocatalysis Asymmetric addition of acetaldehyde to ss-nitrostyrenes catalyzed by a promiscuous proline-based tautomerase. Angew. Chem. Int. Ed. 2012, 51 (5), 1240-1243. 

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