Thalliums reactions with

A mild and effective method for obtaining N- acyl- and N- alkyl-pyrroles and -indoles is to carry out these reactions under phase-transfer conditions (80JOC3172). For example, A-benzenesulfonylpyrrole is best prepared from pyrrole under phase-transfer conditions rather than by intermediate generation of the potassium salt (81TL4901). In this case the softer nature of the tetraalkylammonium cation facilitates reaction on nitrogen. The thallium salts of indoles prepared by reaction with thallium(I) ethoxide, a benzene-soluble liquid. 

Isobutylene oxide is produced in a way similar to propylene oxide and butylene oxide by a chlorohydrination route followed by reaction with Ca(OH)2. Direct catalytic liquid-phase oxidation using stoichiometric amounts of thallium acetate catalyst in aqueous acetic acid solution has been reported. An isobutylene oxide yield of 82% could be obtained. 

Vicinal iodo carboxylates may also be prepared from the reaction of olefins either with iodine and potassium iodate in acetic acid/ or with N-iodosuccinimide and a carboxylic acid in chloroform. " A number of new procedures for effecting the hydroxylation or acyloxylation of olefins in a manner similar to the Prevost or Woodward-Prevost reactions include the following iodo acetoxylation with iodine and potassium chlorate in acetic acid followed by acetolysis with potassium acetate reaction with iV-bromoacetamide and silver acetate in acetic acid reaction with thallium(III) acetate in acetic acid and reaction with iodine tris(trifluoroacetate) in pentane. ... 

The salt is a colorless crystalline solid which is virtually insoluble in all common organic solvents. It reacts slowly with chloroform and carbon tetrachloride to give thallium(I) chloride 25), gives a characteristic red coloration with carbon disulfide, and undergoes the Diels-Alder reaction with maleic anhydride 110). It is rapidly decomposed by acids, but is stable to water this latter fact has been interpreted (55) in terms of the small free energy change for the reaction... 

Uson, R., Laguna, A. and Cuenca, T. (1980) Chlorobis (polyfluorophenyl) thallium(III) complexes and their reactions with gold(l) and tin(ll) compounds. Journal of OrganometaUic Chemistry, 194(3), 271-275. 

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... 

Somei and co-workers made extensive use of the Heck reaction with haloindoles in their synthetic approaches to ergot and other alkaloids [26, 40, 41, 240-249]. Thus, 4-bromo-l-carbomethoxyindole (69%) [26], 7-iodoindole (91%) (but not 7-iodoindoline or l-acetyl-7-iodoindoline) [40, 41], and l-acetyl-5-iodoindoline (96%) [41] underwent coupling with methyl acrylate under standard conditions (PdlOAc /PhsP/EtjN/DMF/100 °C) to give the corresponding (E)-indolylacrylates in the yields indicated. The Heck coupling of methyl acrylate with thallated indoles and indolines is productive in some cases [41, 241, 246]. For example, reaction of (3-formylindol-4-yl)thallium bis-trifluoroacetate (186) affords acrylate 219 in excellent yield [241], Similarly, this one-pot thallation-palladation operation from 3-formylindole and methyl vinyl ketone was used to synthesize 4-(3-formylindol-4-yl)-3-buten-2-one (86% yield). 

Thallium(i) salts have long been used in reactions with organic and organometallic halide complexes as a means of activating the halide by removal as insoluble T1X. However, the thallium ions proved not to be innocent bystanders, and numerous examples were reported in COMC (1995) where the metal-bound thallium complexes were formed. Deliberate reactions of thallium(i) and thallium(m) salts with metal carbonyl anions have yielded a variety of complexes of the form T1 MLJ3. In the past decade, new examples of metal carbonyl derivatives of thallium have been prepared (see Table 2). In addition, the propensity for Tl+ to form adducts with 16-electron noble metal complexes has been exploited. 

The thallium benzoate and thallium 2-oxocarboxylates are available via the reaction of thallium acetate with benzoic acid or the 2-oxocarboxylic acids, due to the lower values of these acids (benzoic acid 4.22, benzoylformic acid 1.2, 2-oxoglutaric acid 31/5.14, pyruvic acid 2.49) compared to acetic acid (4.76) (167). The free acetic acid is distilled off with water as an azeotrope and the thallium carboxylates are obtained in high purity. 

The required chirally substituted indoloazepine 219 was prepared by reaction of (5)-l-(l-naphthyl)ethylamine with the methiodide of 4-piper-idone (223), followed by a Fischer indole reaction leading to the V-carboline 224 (Scheme 56). Chlorination and reaction with thallium dimethylmalonate, followed by decarbomethoxylation of the resulting in-... 

The preparation of U(CsH5)2Cl2 91) and U(C5Hs)Cl3 -DME 92) were reported shortly after thallium(I) cyclopentadienide was found to be useful in controlhng the stoichiometries of reactions with uranium and thorium tetrachloride 93, 94). 

Aromatic radical-cations are generated by pulse-radiolysis of benzene derivatives in aqueous solution. Radiolysis generates solvated electrons, protons and hydroxyl radicals. The electrons are converted by reaction with peroxydisulpbate ion to form sulphate radical-anion, which is an oxidising species, and sulphate. In another proceedure, electrons and protons react with dissolved nitrous oxide to form hydroxyl radicals and water, Hydroxyl radicals are then made to react with either thallium(i) or silver(i) to generate thallium(ii) or silver(ll) which are powerfully... 

Thallium burns in fluorine with incandescence. Reactions with other halogens form halides. Thallium combines with several elements forming binary compounds. 

---