Arylthallium trifluoroacetates nitriles

Arylthallium bis(trifluoroacetates) (see 12-21) can be converted to aryl nitriles by treatment with copper(I) cyanide in acetonitrile. Another procedure uses excess aqueous KCN followed by photolysis of the resulting complex ion ArTl(CN)3 in the presence of excess KCN. Alternatively, arylthallium acetates react with Cu(CN)2 or CuCN to give aryl nitriles. Yields from this procedure are variable, ranging from almost nothing to 90 or 100%. 

Thallium(III), particularly as the trifluoroacetate salt, is also a reactive electrophilic metallating species, and a variety of synthetic schemes based on arylthallium intermediates have been devised.75 Arylthallium compounds are converted to chlorides or bromides by reaction with the appropriate cupric halide.76 Reaction with potassium iodide gives aryl iodides.77 Fluorides are prepared by successive treatment with potassium fluoride and boron trifluoride.78 Procedures for converting arylthallium compounds to nitriles and phenols have also been described.79... 

The enhancement of the electrophilic properties of thallium(III) trifluoroacetate makes it a very important thallation reagent. The products of thallation, eg, arylthallium bis(trifluoracetate), undeigo a variety of substitution reactions, yielding iodides, fluorides, nitriles, thiophenols, phenols, and biaryls. 

Mercuration- Thallation. Mercuric acetate and thallium trifluoroacetate react with benzene to yield phenylmercuric acetate [62-38-4] or phenylthallic trifluoroacetate. The arylthallium compounds can be converted into phenols, nitriles, or aryl iodides (31). 

Aryl nitriles.5 Arylthallium bis(trifluoroacetates) react with CuCN in refluxing CH3CN to give aryl nitriles in 60-85% yield. A one-pot synthesis is possible by thallation of the arene in CH3CN. 

Synthesis of phenols and aromatic nitriles.3 In a new phenol synthesis, an aromatic hydrocarbon is first thallated with the reagent in trifluoroacetic acid to give an arylthallium ditrifluoroacetate (which can be isolated) and then oxidized with lead tetraacetate in the presence of 1 equivalent of triphenylphosphine. The resulting aryl trifluoroacetate is then hydrolyzed with dilute base. The triphenyl-... 

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