Thallium acetate, and

THALLIUM, SOLUBLE OCMPOUNDS (as Tl) (Soluble thallium compounds have variable molecular formulas. The molecular formula for thallium is Tl. The molecular formula for thallium acetate is C2H3O2TI. The molecular formula for thallium iodide is ITl. Soluble thallium compounds have variable formula weights. The formula weight for thallium 204.37. The formula weights for thallium acetate and thallium iodide are 263.42 and 331.27 respectively.)... 

Stereoselective cis-dihydroxylation of the more hindered side of cycloalkenes is achieved with silver(I) or copper(II) acetates and iodine in wet acetic acid (Woodward gly-colization J.B. Siddall, 1966 L. Mangoni, 1973 R. Criegee, 1979) or with thallium(III) acetate via organothallium intermediates (E. Glotter, 1976). In these reactions the intermediate dioxolenium cation is supposed to be opened hydrolytically, not by Sn2 reaction. 

Selectivity of propylene oxide from propylene has been reported as high as 97% (222). Use of a gas cathode where oxygen is the gas, reduces required voltage and eliminates the formation of hydrogen (223). Addition of carbonate and bicarbonate salts to the electrolyte enhances ceU performance and product selectivity (224). Reference 225 shows that use of alternating current results in reduced current efficiencies, especiaHy as the frequency is increased. Electrochemical epoxidation of propylene is also accompHshed by using anolyte-containing silver—pyridine complexes (226) or thallium acetate complexes (227,228). 

Thallium (ITT) salts of formic, acetic, and trifluoroacetic acids are prepared from the corresponding acid and thaUium(III) oxide (11). Other thaUium(III) carboxylates can be obtained from the metathesis of thaUium(III) acetate and the carboxyUc acid (12). They are colorless, hygroscopic soUds. 

The relative toxicities of thallium compounds depend on their solubHities and valence states. Soluble univalent thallium compounds, eg, thaHous sulfate, acetate, and carbonate, are especiaHy toxic. They are rapidly and completely absorbed from the gastrointestinal tract, skin peritoneal cavity, and sites of subcutaneous and intramuscular injection. Tb allium is also rapidly absorbed from the mucous membranes of the respiratory tract, mouth, and lungs foHowing inhalation of soluble thallium salts. Insoluble compounds, eg, thaHous sulfide and iodide, are poorly absorbed by any route and are less toxic. 

Mercuration-Thallation. Mercuric acetate and thallium ttifluoroacetate react with benzene to yield phenyHnercuric acetate [62-38-4] or phenylthaHic ttifluoroacetate. The arylthalHum compounds can be converted iato phenols, nitriles, or aryl iodides (31). 

N-Alkylations, especially of oxo-di- and tetra-hydro derivatives, e.g. (28)->(29), have been carried out readily using a variety of reagents such as (usual) alkyl halide/alkali, alkyl sulfate/alkali, alkyl halide, tosylate or sulfate/NaH, trialkyloxonium fluoroborate and other Meerwein-type reagents, alcohols/DCCI, diazoalkanes, alkyl carbonates, oxalates or malon-ates, oxosulfonium ylides, DMF dimethyl acetal, and triethyl orthoformate/AcjO. Also used have been alkyl halide/lithium diisopropylamide and in one case benzyl chloride on the thallium derivative. In neutral conditions 8-alkylation is observed and preparation of some 8-nucleosides has also been reported (78JOC828, 77JOC997, 72JOC3975, 72JOC3980). 

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. 

In room temperature phosphorescence, a treatment of the paper substrate with sodium dodecyl sulfate in conjunction with thallium acetate enhances the results and the technique can be used in routine environmental analysis of organic pollutants [156]. 

STEREOSELECTIVE HYDROXYLATION WITH THALLIUM(I) ACETATE AND IODINE trans- AND cis-l,2-CYCLOHEXANEDIOLS... 

Oxidation of the steroidal olefin (XXVII) with thallium(III) acetate gives mainly the allylic acetates (XXXI)-(XXXIII) (Scheme 15), again indicating that trans oxythallation is the preferred reaction course (19). Addition of the electrophile takes place from the less-hindered a-side of the molecule to give the thallinium ion (XXVIII), which by loss of a proton from C-4 would give the alkylthallium diacetate (XXIX). Decomposition of this intermediate by a Type 5 process is probably favorable, as it leads to the resonance-stabilized allylic carbonium ion (XXX), from which the observed products can be derived. Evidence in support of the decomposition process shown in Scheme 15 has been obtained from a study of the exchange reaction between frawr-crotylmercuric acetate and thallium(III) acetate in acetic acid (Scheme 16) (142). 

Scheme 20), these acetals could readily be converted into isofiavones. Unfortunately, very low yields of rearrangement products were obtained using thallium(III) acetate, and separation and purification of acetals such as (XXXIV) was extremely tedious. Reaction of chalcones with TTN, on the other hand, is generally complete within a few hours at room temperature 95), and Farkas et al. (J75) have developed the Ollis procedure into a simple method for the preparation of isofiavones (Scheme 21). 

The potassium derivatives obtained from the reaction mixture are typically not isolated in pure form, and the crude products are often converted directly to the thallium complexes by metathesis with either thallium nitrate or thallium acetate [Eqs. (1) and (2)]. 

Polarography has also been applied to the determination of potassium in seawater [535]. The sample (1 ml) is heated to 70 °C and treated with 0.1 M sodium tetraphenylborate (1 ml). The precipitated potassium tetraphenylborate is filtered off, washed with 1% acetic acid, and dissolved in 5 ml acetone. This solution is treated with 3 ml 0.1 M thallium nitrate and 1.25 ml 2M sodium hydroxide, and the precipitate of thallium tetraphenylborate is filtered off. The filtrate is made up to 25 ml, and after de-aeration with nitrogen, unconsumed thallium is determined polarographically. There is no interference from 60 mg sodium, 0.2 mg calcium or magnesium, 20 pg barium, or 2.5 pg strontium. Standard eviations at concentrations of 375, 750, and 1125 pg potassium per ml were 26.4, 26.9, and 30.5, respectively. Results agreed with those obtained by flame photometry. 

Grigg expanded his Pd-catalyzed cascade cyclization reactions to include carbonylation as the termination step [427]. Thus, indoline 329 is obtained in excellent yield and the spiroindoline 330 is secured as a single diastereomer. Thallium acetate results in significant improvement in these reactions by allowing for low-pressure carbonylation. 

Mercuric acetate and thallic acetate have also been used for the oxidative cydiza-tion of vinylallenes (Eq. 13.24) [29]. Exposure of vinylallene 75 to stoichiometric mercuric acetate in acetic acid led to cydopentenone 76 in 75% yield. With thallium acetate as the oxidant, the yield of 76 was 60%. The presumed mechanism of the oxidative cyclization involves a Nazarov cyclization of acetoxymercury intermediate 77. 

Significant amounts of the bicyclo[3.3.1]nonane adduct and of the octahydropental-enes were isolated also from the reaction of 3 with preformed iodine acetate and iodine acetate thallium (equation 75)94 whereas only the monocyclic 1,2-adducts were obtained from treatment of 3 with iodine azide, iodine isocyanate or iodine nitrate95. The different propensity to give transannular products with these latter reagents has been related to the different positive charge density on carbons in the corresponding iodonium ion intermediates. 

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 chemical oxidation of cis- or iranx-stilbene was also investigated (Vinogradov et al. 1976). The oxidant was cobalt or manganese acetate and, in separate experiments, thallium trifluoroac-etate. Acetic or triflnoroacetic acid was used as a solvent. The results of such chemical oxidation were considered from the geometrical standpoint of the recovered (nonreacted) part of the initial substrate and stereoisomeric composition of the products obtained. This allowed the desirable comparison of electrochemical and chemical reactions to be made. 

Method B A solution of 0.5 mmol of (2/ /.S,3/t/5 )-2,3-dialkyl-l,4-diarylbutane and 0.125 mL (1.0 mmol) of boron trifluoridc-dicthyl ether complex in 2 mL of CH2C12 is added to a stirred suspension of 0.12 g (0.26 mmol) of thallium(III) oxide in 10 mL of CH2C12 containing 0.4 mL of trifluoroacetic acid and 0.2 mL of trifluoroacetic anhydride at the stated temperature under argon. The mixture is stirred until the end of the reaction and then diluted with ethyl acetate and worked up as in method A. 

A clean twofold Heck coupling of unsubstituted butadiene 46 (R = H) in the 1- and 4-positions has not been reported. However, the initial carbopalladation product from 46 (R = H) and an in situ formed arylpalladium halide, the cr-allylpalladium halide 47 equilibrating with the corresponding 7r-allylpalladium halide, can efficiently be trapped with the anion formed by arylation of malononitrile or cyanoacetate to give 48, a product of reductive 1,4-arylation-alkylation of 1,3-butadiene 46 (R = H)." /3-Hydride elimination from the intermediate 47 (R H) can be accomplished when the reaction is carried out in the presence of silver acetate or thallium acetate, leading to the... 

All these protocols allow us to form a new carbocycle in a bimolecular process. The cyclization involving two different molecules besides CO has been realized, involving carbapalladation of norbornene, migratory insertion of CO, and subsequent intramolecular Heck-like attack at thiophene residue. Thallium acetate is required as electrophilic co-catalyst (Scheme 18). ... 

TlSe was first deposited from a solution of thallium(l) acetate and selenosulphate with added NaOH and hydrazine at room temperature [97]. The initial films were... 

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