Dithiocarboxylate salts, alkali metals

Convenient syntheses for ammonium311 320 and alkali metal salts (from trimethylsilyl dithiocarboxylates and alkali metal fluorides),321,322 useful for preparative purposes of their metal complex and organometallic derivatives, are now available. The reactions of bis(thioacyl)disul-fanes, [RC(S)S]2 (R = Pr , Ph, p-MeOC6H4, p-Tol, p-ClC6H4, CK-C10H7) with secondary amines yield substituted ammonium dithiocarboxylates, [R NHJP CSJ.323... 

The dithiocarboxylic acids can be isolated as such, but in most cases their salts, in particular alkali metal salts, are preferred for further use. The synthetic methods used for the preparation of dithiocarboxylic acids or their salts include 300... 

A number of main group and transition metal dithiocarboxylates have been described. They are commonly prepared by metathesis between alkali metal dithiocarboxylates and metal halides. Heavy metal derivatives usually precipitate from aqueous solutions, but are soluble in organic solvents and can be solvent extracted. The alkali metal, ammonium, phosphonium, and arsonium salts are water soluble.300 The composition of metal complexes is sensitive to preparation conditions and is frequently pH dependent. 

Similarly, the alkali metal salts of dialkyl cyanomethylphosphonates react with thionocarbox-ylie. dithiocarboxylic, and xanthogenic esters to give alkali metal salts of 2-substituted 2-mercapto-1-cyanovinylphosphonates. These salts are protonated or alkylated to the thioenol ethers, isolated as mixtures of ( )- and (Z)-isomers. ... 

Method (a) is the most atom-economical method. It is mostly used for synthesizing the salts of transition metals, alkali metals and alkaline earth metals. Some alkyllithiums and Grignard reagents are useful for synthesizing the corresponding lithium and magnesium dithiocarboxylate salts [4]. Method... 

The dithiocarboxylate salts of alkali metals readily react with alkyl halides. The lithium, sodium, and potassium salts 1-3 readily react with methyl iodide to give the corresponding methyl ester 11 at room temperature in good yields, while similar reactions of rubidium and cesium salts 4 and 5 result in low yields (Scheme 3) [38]. 

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