From arylthallium compounds

This phenol synthesis complements the analogous reaction (see below) from arylthallium ditrifluoroacetates (147). Although yields are only moderate, the procedure represents a viable conversion of aryl Grignard reagents to phenols. It is a practical method, however, only when the diarylthallium trifluoroacetate precursor is formed via the Grignard route the alternative synthesis via symmetrization of arylthallium ditrifluoroacetates is obviously circuitous, since the latter compounds may be converted directly to phenols. 

When the reaction of the arylthallium compound ArTlX2 with the nucleophile Nu" leads to a too stable intermediate AtT1Nu2, competing protonolysis may become predominant. This is circumvented by using copper salts, which favours the removal of a ligand from the thallium metal. According to Uemura et al, this reaction leads to substitution in a concerted process by reductive displacement of... 

Other monovinylthallium(ni) compounds such as (132), the product of oxythallation of acetylenes, react analogously to the arylthallium compounds. Halogenodethallation and pseudohalogeno-dethallation reactions result from the interaction of the oxyalkenylthallium compound with either potassium iodide or with the appropriate copper derivatives. 6... 

The thallium is initially introduced into the position that is most reactive toward electrophiles, but the reaction is reversible, so that heating gives a mixture having a composition governed by the relative thermodynamic stability of the various possible isomers. In some cases, then, thallation followed by isomerization can lead to a product with an orientation different from that obtained by direct electrophilic substitution." The arylthallium compounds can also be converted to phenols via a procedure that involves oxidation and hydrolysis" ... 

Syntheses of dialkylthallium halides with bulky alkyl groups such as trimethyl-silylmethyl and neopentyl have been described, these compounds are dimeric. (Acyloxy)arylthallium compoimds have been prepared from organotin compounds, reactions (40), (41). ... 

Arylthallium bis(trifluoroacetate)s are converted by successive treatment with KF and BF3 into aryl fluorides.Thallium(iii) nitrate (TTN) readily oxidizes dialkyl sulphides and selenides to the corresponding sulphoxides or selenoxides, and 2-(alkylthio)-l-arylethanones (37) into compounds (38) in methanolic solution.In a modification of the TTN oxidative conversion of aryl alkyl ketones into arylacetic acids, enol ethers derived from the ketones are used instead of the ketones themselves. This reduces the formation of side products. Cyclic aralkyl ketones (39) may be ring-expanded and alkylated to give compounds (40) via treatment of their Wittig-derived alkenes with TTN/ an extrapolation of the basic reaction discovered previously. 

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