Construction of Heterocycles and related systems utilizing Dithioesters and Acetals

Abstract

Organic chemistry and the chemical industry have played a vital role in creation a flourishing and healthy human society. The heart of chemistry beats for humanity, and is like the engine for the society which contributes in our day-to-day life from every angle. Organic synthesis being one of the major streams of chemistry has super constructive influence in the modern civilization. Several millions of organic compounds made over the last century have useful applications in everyday life. Organic synthesis is directly involved in the production of drugs, dyes/pigments, insecticides, polymers, detergents and numerous other important materials. newlineHeterocyclic chemistry plays an important role in our diurnal life as well as works as one of the decisive factor for the future of mankind too. The most important heterocyclic compounds are those with nitrogen, oxygen and/or sulfur in five or six-membered systems as they are widely distributed in nature, and are essential to life playing a vital role in the metabolism of all living cells. Among them sulfur containing compounds are extensively used in various fields such as drugs, agricultural chemicals, research chemicals etc. For biomolecular systems, sulfur is considered as an essential element. newlineThiols, thioic acids, thioamides are some renowned thio-precursors which have been introduced and exhaustively employed in different synthetic methodologies. But in spite of these pre-existing synthons, precursors with tuneable functionality are still of prior demand to achieve a wide range of thioskeletons having higher degree of molecular complexity and functional diversity. newlineApart from these general thio-ancestors there are many precursors, which are less investigated. So there is a need of up gradation of this library. In this regard, and#61537;-enolic dithioester, and#61537;-oxoketene-S,S-acetal andand#61472;and#61537;-oxoketene-N,S-acetal have given less importance compared to the aforementioned precursors. Regarding the one of the most fabulous thio-precursor and#61537;-enolic dithioester the keto-enol tautomeric equilibrium mostly lies towards and#61537;-enolic structure unlike and#61538;-keto esters. Due to the dominance of the and#61537;-enolic tautomer, almost all the chemical properties of dithioester are directed by its and#61537;-enolic form. In addition to that, the reactivity of its pre-existing in and#61537;-enolic form can be tuned from S-centre to C-centre by means of changes in the reaction medium and conditions. Thus a broad range of heterocyles can be synthesized by the virtue of the tuneable reactivity of and#61538;-keto/and#61537;-enolic dithioesters. newline