Baker's Yeast Catalyzed Multicomponent Reactions: A New Hope?

Baker’s yeast (Saccharomyces cerevisiae) catalyzed synthesis of bioactive heterocycles and some stereoselective reactions

Saccharomyces cerevisiae, commonly known as baker’s yeast, has gained significant importance as a mild, low-cost, environmentally benign biocatalyst. Initially it was mostly employed as an efficient catalyst for the enantioselective reduction of carbonyl compounds. Over the last decade, baker’s yeast has found versatile catalytic applications in various organic transformations. Many multicomponent reactions were also catalyzed by baker’s yeast. Various heterocyclic scaffolds with immense biological activities were synthesized by employing baker’s yeast as catalyst at room temperature. In this communication, we have summarized baker’s yeast catalyzed various organic transformations focusing primarily on heterocyclic synthesis.

Catalytic Approaches to Multicomponent Reactions: A Critical Review and Perspectives on the Roles of Catalysis

In this review, we comprehensively describe catalyzed multicomponent reactions (MCRs) and the multiple roles of catalysis combined with key parameters to perform these transformations. Besides improving yields and shortening reaction times, catalysis is vital to achieving greener protocols and to furthering the MCR field of research. Considering that MCRs typically have two or more possible reaction pathways to explain the transformation, catalysis is essential for selecting a reaction route and avoiding byproduct formation. Key parameters, such as temperature, catalyst amounts and reagent quantities, were analyzed. Solvent effects, which are likely the most neglected topic in MCRs, as well as their combined roles with catalysis, are critically discussed. Stereocontrolled MCRs, rarely observed without the presence of a catalytic system, are also presented and discussed in this review. Perspectives on the use of catalytic systems for improved and greener MCRs are finally presented.

A comprehensive survey upon diverse and prolific applications of chitosan-based catalytic systems in one-pot multi-component synthesis of heterocyclic rings

Heterocyclic compounds are among the most prestigious and valuable chemical molecules with diverse and magnificent applications in various sciences. Due to the remarkable and numerous properties of the heterocyclic frameworks, the development of efficient and convenient synthetic methods for the preparation of such outstanding compounds is of great importance. Undoubtedly, catalysis has a conspicuous role in modern chemical synthesis and green chemistry. Therefore, when designing a chemical reaction, choosing and or preparing powerful and environmentally benign simple catalysts or complicated catalytic systems for an acceleration of the chemical reaction is a pivotal part of work for synthetic chemists. Chitosan, as a biocompatible and biodegradable pseudo-natural polysaccharide is one of the excellent choices for the preparation of suitable catalytic systems due to its unique properties. In this review paper, every effort has been made to cover all research articles in the field of one-pot synthesis of heterocyclic frameworks in the presence of chitosan-based catalytic systems, which were published roughly by the first quarter of 2020. It is hoped that this review paper can be a little help to synthetic scientists, methodologists, and catalyst designers, both on the laboratory and industrial scales.

Bio-Catalysis in Multicomponent Reactions

Enzyme catalysis is a very active research area in organic chemistry, because biocatalysts are compatible with and can be adjusted to many reaction conditions, as well as substrates. Their integration in multicomponent reactions (MCRs) allows for simple protocols to be implemented in the diversity-oriented synthesis of complex molecules in chemo-, regio-, stereoselective or even specific modes without the need for the protection/deprotection of functional groups. The application of bio-catalysis in MCRs is therefore a welcome and logical development and is emerging as a unique tool in drug development and discovery, as well as in combinatorial chemistry and related areas of research.

Sustainable chemo-enzymatic preparation of enantiopure (R)-β-hydroxy-1,2,3-triazoles via lactic acid bacteria-mediated bioreduction of aromatic ketones and a heterogeneous “click” cycloaddition reaction in deep eutectic solvents

A chemo-enzymatic strategy for the preparation of enantiopure (R)-β-hydroxy-1,2,3-triazoles using a lactic acid bacterium as a whole-cell biocatalyst and a heterogeneous “click” cycloaddition reaction in deep eutectic solvents is disclosed.