Carbodithioic Acid Esters

Abstract

Recent works (published over the last decade) on the syntheses and reactions of dithioic acid esters (dithioates) are reviewed. Dithioates have been synthesized by various means, including: (i) reaction of dithioic acids and their salts with electrophiles; (ii) thionation of S-substituted thioates; (iii) [3,3]-sigmatropic (thio-Claisen) rearrangements of ketene alkyl allyl dithioacetals and [2,3]-sigmatropic rearrangement; (iv) elimination of one of the S-substituents of ketene dithioacetal; (v) sulfuration of iminium salts. Dithioates are useful substrates for aldol reactions, conjugate additions and cycloadditions. Dithioates undergo thiophilic and carbophilic additions with nucleophiles, the nature of which depends on the character of the nucleophile. Reactivites of α-carbenium dithioates derived from inner salts of dithioic acids are discussed. Five-, six-, and seven-membered heterocyclic compounds with -C(S)S- groups in their ring systems, cyclic anhydrides of dithioic acids, S-M dithioates (M=Group 14, 15, and 16 elements), and transition metal complexes of dithioic acids are also briefly described.DithioatesDithioic acidThionationThiophilic additionCarbophilic addition