scholarly journals REAÇÕES EM CASCATA ENZIMÁTICA, QUIMIOENZIMÁTICA E FOTOENZIMÁTICA: PERSPECTIVAS PARA UMA SÍNTESE ORGÂNICA MAIS SUSTENTÁVEL

Química Nova ◽  
2021 ◽  
Author(s):  
Shirley Castilho ◽  
Humberto Milagre ◽  
Cintia Milagre
Keyword(s):  
Organic Synthesis ◽  
Continuous Flow ◽  
Cascade Reactions ◽  
Industrial Research ◽  
Reaction Vessel ◽  
Isolation And Purification ◽  
Intermediate Products ◽  
Individual Reaction ◽  
Subsequent Step

ENZYMATIC, CHEMOENZYMATIC AND PHOTOENZYMATIC CASCADE REACTIONS: PERSPECTIVES FOR A MORE SUSTAINABLE ORGANIC SYNTHESIS. Chemicals are rarely the result of a single transformation but rather the consequence of several individual reaction steps. Classically, these individual steps are carried out in sequence, including isolation and purification of the intermediate products. However, the reasons for choosing to carry out cascade reactions can be multiple, such as (i) the chance to prepare unstable and/or toxic intermediates, which are consumed directly in a subsequent step, (ii) the option to shift the equilibrium of a reaction by removing the co (product), or (iii) simply bypass the tedious work of isolating and purifying intermediates, saving reagents, solvents, time and money, and still generating less waste. Therefore, it is not surprising that so-called cascade reactions are gaining considerable interest in academic and industrial research. The purpose of this review is to show recent, promising research and new trends, the potential and current limitations of cascade reactions in organic synthesis that involves at least one enzymatic step in the cascade. This review will address cascades involving multi enzymatic, chemoenzymatic, and photoenzymatic cascades, where all steps are performed in one reaction vessel simultaneously or sequentially and the cascades in the regime of continuous flow.

Automation of organic synthesis in industrial research laboratories

1992 ◽  
Vol 17 (1) ◽  
pp. 137-143 ◽  
Author(s):  
Pascal Métivier ◽  
Patrick Josses ◽  
Henry Bulliot ◽  
Jean-Pierre Corbet ◽  
Bernard Joux
Keyword(s):  
Organic Synthesis ◽  
Industrial Research

scholarly journals Non-Aqueous Continuous-Flow Electrophoresis (NACFE): Separation Complement for Continuous-Flow Organic Synthesis

2019 ◽  
Author(s):  
Nikita A. Ivanov ◽  
Yimo Liu ◽  
Sven Kochmann ◽  
Sergey N. Krylov
Keyword(s):  
Steady State ◽  
Organic Synthesis ◽  
Flow Separation ◽  
Continuous Flow ◽  
Organic Molecules ◽  
Water Electrolysis ◽  
Organic Salt ◽  
Aqueous Electrolytes ◽  
Differential Distribution ◽  
Steady State Operation

<div>Continuous-flow organic synthesis naturally requires continuous-flow separation of reaction components. The most common continuous-flow separation approach is liquid-liquid extraction based on differential distribution of molecules between organic and aqueous phases. This approach has limited selectivity; it can hardly separate different hydrophobic organic molecules from each other. Continuous-flow electrophoresis can facilitate much more selective separation in a single phase, but it is currently limited to aqueous electrolytes which are incompatible with many hydrophobic organic molecules. Further, water electrolysis in aqueous electrolytes results in generation of large volumes of gas making steady-state operation a major technical challenge. Here, we introduce non-aqueous continuous-flow electrophoresis (NACFE) in which the electrolyte is a solution of an organic salt in an aprotic organic solvent. We demonstrate that NACFE can maintain stable separation of multiple species during 10 hours. The non-aqueous nature of NACFE and its ability to support steady-state operation make it suitable for its incorporation into continuous-flow organic synthesis.</div>

scholarly journals One Pot Use of Combilipases for Full Modification of Oils and Fats: Multifunctional and Heterogeneous Substrates

Catalysts ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 605 ◽  
Author(s):  
Sara Arana-Peña ◽  
Diego Carballares ◽  
Ángel Berenguer-Murcia ◽  
Andrés R. Alcántara ◽  
Rafael C. Rodrigues ◽  
...  
Keyword(s):  
High Specificity ◽  
Reaction Rates ◽  
Cascade Reactions ◽  
Enzyme Specificity ◽  
Case Scenario ◽  
One Pot ◽  
Worst Case ◽  
Intermediate Products ◽  
Global Reaction ◽  
Hydrolysis Of

Lipases are among the most utilized enzymes in biocatalysis. In many instances, the main reason for their use is their high specificity or selectivity. However, when full modification of a multifunctional and heterogeneous substrate is pursued, enzyme selectivity and specificity become a problem. This is the case of hydrolysis of oils and fats to produce free fatty acids or their alcoholysis to produce biodiesel, which can be considered cascade reactions. In these cases, to the original heterogeneity of the substrate, the presence of intermediate products, such as diglycerides or monoglycerides, can be an additional drawback. Using these heterogeneous substrates, enzyme specificity can promote that some substrates (initial substrates or intermediate products) may not be recognized as such (in the worst case scenario they may be acting as inhibitors) by the enzyme, causing yields and reaction rates to drop. To solve this situation, a mixture of lipases with different specificity, selectivity and differently affected by the reaction conditions can offer much better results than the use of a single lipase exhibiting a very high initial activity or even the best global reaction course. This mixture of lipases from different sources has been called “combilipases” and is becoming increasingly popular. They include the use of liquid lipase formulations or immobilized lipases. In some instances, the lipases have been coimmobilized. Some discussion is offered regarding the problems that this coimmobilization may give rise to, and some strategies to solve some of these problems are proposed. The use of combilipases in the future may be extended to other processes and enzymes.

scholarly journals Continuous flow multi-step organic synthesis

2010 ◽  
Vol 1 (6) ◽  
pp. 675 ◽  
Author(s):  
Damien Webb ◽  
Timothy F. Jamison
Keyword(s):  
Organic Synthesis ◽  
Continuous Flow
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