Catalytic dehydrogenative cross-coupling: forming carbon-carbon bonds by oxidizing two carbon-hydrogen bonds

Based on the principles and metrics of green chemistry and sustainable development, biocatalysis is both a green and sustainable technology. This is largely a result of the spectacular advances in molecular biology and biotechnology achieved in the past two decades. Protein engineering has enabled the optimization of existing enzymes and the invention of entirely new biocatalytic reactions that were previously unknown in Nature. It is now eminently feasible to develop enzymatic transformations to fit predefined parameters, resulting in processes that are truly sustainable by design. This approach has successfully been applied, for example, in the industrial synthesis of active pharmaceutical ingredients. In addition to the use of protein engineering, other aspects of biocatalysis engineering, such as substrate, medium, and reactor engineering, can be utilized to improve the efficiency and cost-effectiveness and, hence, the sustainability of biocatalytic reactions. Furthermore, immobilization of an enzyme ...

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Role of Biocatalysis in Sustainable Chemistry

The current demands of the world’s biotechnological industries are enhancement in enzyme productivity and development of novel techniques for increasing their shelf life. These requirements are inevitable to facilitate large-scale and economic formulation. Enzyme immobilization provides an excellent base for increasing availability of enzyme to the substrate with greater turnover over a considerable period of time. Several natural and synthetic supports have been assessed for their efficiency for enzyme immobilization. Nowadays, immobilized enzymes are preferred over their free counterpart due to their prolonged availability that curtails redundant downstream and purification processes. Future investigations should endeavor at adopting logistic and sensible entrapment techniques along with innovatively modified supports to improve the state of enzyme immobilization and provide new perspectives to the industrial sector.

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Enzyme immobilization: an overview on techniques and support materials.

Industrial applications of enzyme biocatalysis: Current status and future aspects.

https://rua.ua.es/dspace/bitstream/10045/57890/5/2015_Barbosa_etal_BiotechAdv_preprint.pdf

Strategies for the one-step immobilization–purification of enzymes as industrial biocatalysts

The review compiles artificial cascades involving enzymes with a focus on the last 10 years. A cascade is defined as the combination of at least two reaction steps in a single reaction vessel without isolation of the intermediates, whereby at least one step is catalyzed by an enzyme. Additionally, cascades performed in vivo and in vitro are discussed separately, whereby in vivo cascades are defined here as cascades relying on cofactor recycling by the metabolism or on a metabolite from the living organism. The review introduces a systematic classification of the cascades according to the number of enzymes in the linear sequence and differentiates between cascades involving exclusively enzymes and combinations of enzymes with non-natural catalysts or chemical steps. Since the number of examples involving two enzymes is predominant, the two enzyme cascades are further subdivided according to the number, order, and type of redox steps. Furthermore, this classification differentiates between cascades where al...

Artificial Biocatalytic Linear Cascades for Preparation of Organic Molecules

Multi-enzymatic cascade reactions, i.e., the combination of several enzymatic transformations in concurrent one-pot processes, offer considerable advantages: the demand of time, costs and chemicals for product recovery may be reduced, reversible reactions can be driven to completion and the concentration of harmful or unstable compounds can be kept to a minimum. This review summarizes the developments in multi-enzymatic cascades employed for the asymmetric synthesis of chiral alcohols, amines and amino acids, as well as for CC bond formation. In addition, a general classification of biocatalytic cascade systems is provided and bioprocess engineering aspects associated with the topic are discussed.

Multi-Enzymatic Cascade Reactions: Overview and Perspectives

Chiral amines represent a prominent functional group in pharmaceuticals and agrochemicals and are hence attractive targets for asymmetric synthesis. Since the pharmaceutical industry has identified biocatalysis as a valuable tool for synthesising chiral molecules with high enantiomeric excess and under mild reaction conditions, enzymatic methods for chiral amine synthesis are increasing in importance. Among the strategies available in this context, the asymmetric reduction of imines by NAD(P)H-dependent enzymes and the related reductive amination of ketones have long remained underrepresented. However, recent years have witnessed an impressive progress in the application of natural or engineered imine-reducing enzymes, such as imine reductases, opine dehydrogenases, amine dehydrogenases, and artificial metalloenzymes. This review provides a comprehensive overview of biocatalytic imine reduction and reductive amination of ketones, highlighting the natural roles, substrate scopes, structural features, and potential application fields of the involved enzymes.

Biocatalytic Imine Reduction and Reductive Amination of Ketones

Recent biocatalytic oxidation-reduction cascades.

Biocatalysis, using defined enzymes for organic transformations, has become a common tool in organic synthesis, which is also frequently applied in industry. The generally high activity and outstanding stereo-, regio-, and chemoselectivity observed in many biotransformations are the result of a precise control of the reaction in the active site of the biocatalyst. This control is achieved by exact positioning of the reagents relative to each other in a fine-tuned 3D environment, by specific activating interactions between reagents and the protein, and by subtle movements of the catalyst. Enzyme engineering enables one to adapt the catalyst to the desired reaction and process. A well-filled biocatalytic toolbox is ready to be used for various reactions. Providing nonnatural reagents and conditions and evolving biocatalysts enables one to play with the myriad of options for creating novel transformations and thereby opening new, short pathways to desired target molecules. Combining several biocatalysts in one pot to perform several reactions concurrently increases the efficiency of biocatalysis even further.

Joerg H. Schrittwieser

Papers

Artificial Biocatalytic Linear Cascades for Preparation of Organic Molecules

Multi-Enzymatic Cascade Reactions: Overview and Perspectives

Biocatalytic Imine Reduction and Reductive Amination of Ketones

Recent biocatalytic oxidation-reduction cascades.

Power of Biocatalysis for Organic Synthesis.