Abstract
The use of nitrile hydratases (RCN + H2O → RCONH2) and nitrilases (RCN + 2 H2O → RCOO- + NH4 +) in biocatalysis attracts profound attention from the beginning of 1980s since it provides a useful alternative to the conventional nitrile hydrolysis using strong acid or base catalysts. In the past 5 years the potential of this branch of biotransformations has been broadened significantly by both the isolation of new mesophilic and thermophilic nitrile-metabolizing microorganisms and the purification of new nitrile-converting enzymes, including thermostable ones. Currently, the scope of products afforded by nitrile-converting biocatalysts encompass hundreds of compounds such as aliphatic, alicyclic, aromatic and heterocyclic carboxylic acids and their amides. New nitrile hydratases show high enantioselectivity towards racemic substituted 2-arylpropionitriles, 2-arylbutyronitriles and prochiral 3-arylglutaronitriles. Synthesis of optically active α-hydroxy and α-fluoro amides and acids employs whole-cell biocatalysts or purified nitrilases. (E)-Selectivity for a,ß-unsaturated nitriles and cis- or trans-selectivity for alicyclic nitriles is also demonstrated with some nitrile-converting enzymes. Regioselectivity and chemoselectivity of the biocatalysts enable preparation of diverse functional group-containing products such as cyanocarboxylic acids, cyanoamides, hemiesters and their amides and carboxylic acids and amides with ether groups. Stabilization of the nitrile-converting biocatalysts is achieved by entrapment in hydrogels or by lyophilization. Organic-aqueous mixtures are suitable as reaction media for numerous nitrile-converting enzymes.
Keywords: Nitrile-Converting Enzymes, hemiesters, carboxylic, cyanocarboxylic acids
Call for Papers in Thematic Issues
Advances of Heterocyclic Chemistry with Pesticide Activity
Global food safety and security will continue to be a global concern for the next 50 years and beyond. Plant diseases have had a significant impact on food safety and security throughout the entire food chain, from primary production to consumption. While conventional chemical pesticides have been traditionally used for ...read more
Calculation design of covalent/metal organic framework based catalysts
This research area combines theoretical computation and screening with machine learning for the design of covalent/metal organic framework-based catalysts, bridging the disciplines of organic chemistry, physical chemistry, computational chemistry, materials science, and machine learning. It covers several critical aspects: designing and synthesizing organic catalysts for improved performance, applying computational methods ...read more
Carbohydrates conversion in biofuels and bioproducts
Biomass pretreatment, hydrolysis, and saccharification of carbohydrates, and sugars bioconversion in biofuels and bioproducts within a biorefinery framework. Carbohydrates derived from woody biomass, agricultural wastes, algae, sewage sludge, or any other lignocellulosic feedstock are included in this issue. Simulation, techno-economic analysis, and life cycle analysis of a biorefinery process are ...read more
Catalytic C-H bond activation as a tool for functionalization of heterocycles
The major topic is the functionalization of heterocycles through catalyzed C-H bond activation. The strategies based on C-H activation not only provide straightforward formation of C-C or C-X bonds but, more importantly, allow for the avoidance of pre-functionalization of one or two of the cross-coupling partners. The beneficial impact of ...read more
Related Books
Advances in Organic Synthesis
The Synthetic Methods, Structures, and Properties of the Ca-C σ Bond Organocalcium Containing Compounds
Advances in Organic Synthesis
Chemistry of Bipyrazoles: Synthesis and Applications
Advances in Organic Synthesis
Advanced Nanocatalysis for Organic Synthesis and Electroanalysis
Advances in Organic Synthesis
Advances in Organic Synthesis
15