A influência de diferentes solventes na reação de Henry catalisada por enzimas baseados em alguns relatos da literatura

Abstract

In recent years, the demand for optically active compounds has made the search for new synthetic routes, as well as selective catalysts, take a prominent position in the scientific landscape. Among the reactions that can generate a stereogenic center, we can mention the Henry reaction that leads to the formation of β-nitro alcohol, a versatile compound within the organic synthesis, which has wide applicability in the pharmaceutical industry. Obtaining these optically active compounds is still restricted, as it is necessary to use catalysts that confer a defined stereochemistry to the generated stereogenic centers. Thus, the use of chiral catalysts, such as enzymes, bring many advantages, as they act under mild reaction conditions, generate few or no secondary products, have high specificity, and can be region, enantio, diastereo or chemoselective. Enzymes are macromolecules generally of a protein nature and have a certain amount of water in their structure, which is of great importance for the maintenance of their conformation. Its selectivity and catalytic activity may be influenced by the solvent, as it interacts with the water present in its protein structure. Therefore, understanding how different types of solvents can interact with the enzyme is of paramount importance to obtain better reaction conditions, leading to higher yields and avoiding enzymatic deactivation. This work is a biobibliographic review that aims to evaluate the effect of different solvents on the selectivity and yields of the enzymecatalyzed Henry reaction. For this, we used the Mendeley database and the keywords to search in English “Henry reaction”, “enzymes” and “solvents”. The enzymatic activity is related to the amount of water bound to the protein structure, because this increases the mobility and flexibility of the active sites of the protein structure.Organic solvents provide a lower flexibility of enzyme molecules, which leads to better selectivity, but a high content of organic solvent in the reaction medium can lead to enzyme inactivation. Polar solvents have a greater interaction with the water present in the protein structure, causing a displacement of the hydration molecules from the enzyme surface, which can cause its denaturation, in addition, protic solvents can also cause enzymatic deactivation, due to their ease of forming bonds. Of hydrogen with the surface of the enzyme. There are still few reports about the nitroaldol reaction using enzymes as a catalyst, but the studies udos report that the presence of a certain amount of water in the reaction medium is essential to obtain better yield results, regardless of the enzyme used as catalyst.