Reactions at a sulfur centre

Treatment of a thiol or thiophenol with carbonyl chloride fluoride in the presence of a tertiary amine (in an inert solvent such as heptane) results in the formation of the corresponding thiol fluoroformate in 75-85% yield [1555a]  

In particular, in benzene solution at 50 C and 1.3 MPa, COCIF combines with thiophenol in the presence of tributylamine, over 12 h, to give a 100% yield of phenyl thiofluoroformate, with a conversion of phenol of 100% [380]  

Dimethylsulfoxide reacts with COCIF at room temperature, in a sealed tube, to form CHjSCHjCl (c/. corresponding reaction with COClj, Section 10.6.5.1) and ClCHjOC(0)F, the relative proportions depending upon the stoicheiometric ratio of dmso-COClF. At a molar ratio of dmso/COClF = 2 1, the formation of sulfide is favoured, whilst at 1 2 the ester is favoured [1204b]. 

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A very similar reaction at a sulfur centre is seen in a thermal reaction of the complex obtained from the reaction of cobalt(n) chloride with methyl thiocyanate (Fig. 4-47). The initial adduct is probably [Co(MeSCN)2Cl2], but the mechanism of the thermal rearrangement to give a salt of [Co(NCS)4]2-is not known. 

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