Electrochemically Promoted Synthesis Of Polysubstituted Oxazoles And Sulfonamides

Oxazoles are a variety of natural products which have lots of biological activities. Naturallyoccurring oxazoles were considered rare until the late1980s when a number of unprecedentednatural products were isolated, which are mainly from marine organisms. These oxazoles arederived from enzymatic post-translational modifications of peptide based precursors. Due totheir fascinating structures and interest in their biological activities, oxazole-containingnatural products have attracted the attention of many researchers who pursue their totalsyntheses.Sulfonamides are a structural component of a vast number of biologically active naturaland unnatural compounds. Their synthesis has been the objective of organic syntheticresearch for over a century, and a variety of well-established classical methods are nowavailable in the literature.Our objectives are to develop new catalytic system and electrochemical synthetic methodfor the preparation of oxazoles and sulfonamides compounds.In Chapter1, the current situation of synthesis of oxazoles and sulfonamides and thesignificance of this research subject have been introduced.In Chapter2, we have investigated an electrochemical synthesis of polysubstituted oxazolesfrom readily available benzylamine and β-diketone derivatives in one-pot procedure. Thiselectrochemical procedure does not need the use of hazardous oxidants and transition metalcatalysts as well as molecular I2additive. Compared with traditional thermo-chemical method,the present electrochemical method is greener and more efficient.In Chapter3, a convenient and practical route of synthetic sulfonamides usingelectrochemical catalyst from sodium sulfinate and amines in a one-pot procedure has beenreported. With H2O as solvent, the electrochemical synthesis of sulphonamides appears to begreener. In the present case, the target product could be separated easily from the electrolyticsystem because sodium sulfinate and some amines have high solubility in the aqueous phase,while the product sulfonamide is insoluble. In addition, the electrolyte solution could bereused up to10times without obvious reduction in yield.