Lipase Microwave Assisted Reactions and Synthesis of Novel Heterocyclic Compounds

Abstract

No other aspect of organic synthesis has received as much attention as the preparation of enantiomerically pure compounds. Compounds that occur in nature are optically active because living organisms tend to produce only a single enantiomer of a given molecule. The asymmetry of these molecules arises from the inherent chirality of the enzymes that are responsible for their production. Receptor sites in biological systems, which are also optically active, have the ability to differentiate between the two enantiomers of a specified molecule and interact differently with opposite enantiomers. newlineThe synthesis of optically pure organic compounds, having one or more chiral centers, is one of the most challenging tasks in modem organic synthesis. The synthesis of such molecules can usually be achieved either by asymmetric induction on an achiral compound or by kinetic resolution of a racemic mixture. Biocatalysts have been increasingly employed nowadays for the preparation of chiral intermediates and target molecules. The most frequently used enzymes are lipases owing mainly to their low cost and wide tolerance towards a variety of organic molecules. newlinePolyphenolic compounds are widely distributed in nature and possess a variety of interesting biological properties, e.g. anticancer, antiviral and antimicrobial activity, etc. the synthesis and further elaboration of these compounds often require the selective protection and deprotection of specific phenolic hydroxyl group, which is quite cumbersome and inefficient to carry out by traditional chemical means. We have successfully employed porcine pancreatic lipase in tetrahydrofuran in the resolution of aryl alkyl ketones. These novel optically active aryl alkyl ketones can be utilized in the synthesis of chromanones, flavanoids and coumarins that are difficult to make in optically pure forms. newline