Application of Transaminases in a Disperse System for the Bioamination of Hydrophobic Substrates

Abstract

The challenging bioamination of hydrophobic substrates has been attained through the employment of a disperse system consisting of a combination of a low polarity solvent (e. g. isooctane or methyl‐tert‐butylether), a non‐ionic surfactant and a minimal amount of water. In these conditions, amine transaminases (ATA) were shown to efficiently carry out the reductive amination of variously substituted cyclohexanones, providing good conversions often coupled with a superior stereoselectivity if compared with the corresponding chemical reductive amination. An array of synthetically useful 4‐substituted aminocyclohexanes was consequentially synthesized through biocatalysis, analyzed and stereochemically characterized.

Amine Transaminase Mediated Synthesis of Optically Pure Piperazinones and 1,4‐Diazepanones

“…The effect of the cosolvent was evaluated using acetonitrile and ethanol, commonly used in ATA‐catalysed processes, and also the less frequently used t ‐butyl methyl ether (TBME) or n ‐heptane [18] . We theorize that the use of a two‐phase system would minimise the undesired side reaction.…”

“…The effect of the cosolvent was evaluated using acetonitrile and ethanol, commonly used in ATAcatalysed processes, and also the less frequently used tbutyl methyl ether (TBME) or n-heptane. [18] We theorize that the use of a two-phase system would minimise the undesired side reaction. In order to better evaluate the effect of cosolvent in the process, the concentration of isopropylamine was reduced to 0.1 M. Effectively, the best results were obtained using the water-immiscible cosolvents.…”

Lipase-Catalyzed Kinetic Resolution of Alcohols as Intermediates for the Synthesis of Heart Rate Reducing Agent Ivabradine

“…Enzymes often constitute an environmentally friendly alternative to conventional chemical catalysts; they can operate under mild conditions and at low temperature and are nontoxic and biodegradable. The high chemo-, regio-, and stereoselectivity often exhibited enable purer and more selective reactions, and may even diminish the need for functional group protections, which will increase the atom economy and afford shorter synthetic routes [26][27][28]. This is attractive from both an economical and an environmental point of view, so that in recent years, there has been an increase in the use of biocatalysis in industry [29,30], with hydrolases being the most common enzymes employed [31][32][33][34], the class to which esterases and lipases belong to.…”

Biocatalytic Site-Selective Hydrogen Isotope Exchange of Unsaturated Fragments with D2O

“…Due to the sustainable process and outstanding selectivity, biocatalysis has become a powerful protocol in preparing chemicals, offering an attractive option for organic synthesis. − In comparison to chemical catalysts, enzymes can only catalyze their natural reactions in most cases, which limits their further applications. , The development of new reactivity catalyzed by natural enzymes is highly desirable in the field of biocatalysis; however, it remains a big challenge. , Recently, significant advances have been achieved in the design of novel enzymatic functions enabling the construction of versatile chemical bonds (such as C–N, C–C, C–Si, and C–B bonds). − Among them, enzymatic deuteration has been used as a powerful tool for mechanistic study. , It is recognized that these impressive studies suffer from the difficulty in controlling the chemoselectivity of deuterium incorporation and the unsatisfactory deuteration level. To date, there have been mainly two kinds of enzymatic deuteration methodologies reported for the practical synthesis of deuterated compounds.…”