Formation of 1,3-oxathiole-2-thione and 1,2,4-trithiolane derivatives by the catalytic reaction of α-diazocarbonyl compounds with carbon disulfide

Abstract

The rhodium(II) acetate-catalyzed decomposition of α-diazocarbonyl compounds such as substituted α-diazoacetophenones, cyclic diazoketones, cyclic diazodiketones, and α-diazo-β-ketoesters in carbon disulfide gave 1,3-oxathiole-2-thione derivatives in good yields. Diazomalonates also gave alkyl 5-alkoxy-2-thioxo-1,3-oxathiole-4-carboxylates together with 3,5-bis[bis(alkoxycarbonyl)methylene]-1,2,4-trithiolanes. The formation of 1,3-oxathiole-2-thiones can be explained by the intermediacy of zwitterionic intermediate containing rhodium(II) acetate formed by the reaction of carbon disulfide with ketocarbenoids generated in the catalytic decomposition of the diazocarbonyl compounds.