III Acetate

C-H Arylation. The combination of Mg(OiBu)2 in DMF was found ideal for the C-H functionalization of benzothiazoles 13 with base-sensitive iodoarenes 14. This was a milder alternative to the LiOfBu/dioxane conditions, which proved problematic for some sensitive functional groups (ester, cyano, nitro, triflu-oromethyl). In the presence of Ni(OAc)2 (10 mol%), bipy 

Daniela Sustac Roman Universite de Montreal, Montreal, Quebec, Canada 

Physical Data the commercially available dihydrate is cinnamon brown. The anhydrous form is dark brown. The crystal structure 

A list of General Abbreviations appears on the front Endpapers 

Solubility sol acetic acid, ethanol, and a variety of other organic solvents disproportionates in water. 

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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. 

Thallium(III) acetate reacts with alkenes to give 1,2-diol derivatives (see p. 128) while thallium(III) nitrate leads mostly to rearranged carbonyl compounds via organothallium compounds (E.C. Taylor, 1970, 1976 R.J. Ouelette, 1973 W. Rotermund, 1975 R. Criegee, 1979). Very useful reactions in complex syntheses have been those with olefins and ketones (see p. 136) containing conjugated aromatic substituents, e.g. porphyrins (G. W. Kenner, 1973 K.M. Smith, 1975). 

CIHORINE OXYGEN ACIDS AND SALTS - DICIHORDIE MONOXIDE, HYPOCIHOROUS ACID, AND HYPOCIHORITES] (Vol 5) Basic iron(III) acetate [10450-55-2]... 

Iron(III) acetate [1834-30-6], Ee(C2H202)3, is prepared industrially by treatment of scrap iron with acetic acid followed by air oxidation. Iron(III) acetate is used as a catalyst in organic oxidation reactions, as a mordant, and as a starting material for the preparation of other iron-containing compounds. 

The brown crystalline manganese(III) acetate dihydrate is of considerable commercial importance because it is often used as the source material for other trivalent manganese compounds. It can be made by oxidation of manganese(II) acetate using chlorine or potassium permanganate, or by reaction of manganese(II) nitrate and acetic anhydride. 

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. 

Miscellaneous Compounds. Among simple ionic salts cerium(III) acetate [17829-82-2] as commercially prepared, has lV2 H2O, has a moderate (- 100 g/L) aqueous solubiUty that decreases with increased temperature, and is an attractive precursor to the oxide. Cerous sulfate [13454-94-9] can be made in a wide range of hydrated forms and has solubiUty behavior comparable to that of the acetate. Many double sulfates having alkaU metal and/or ammonium cations, and varying degrees of aqueous solubiUty are known. Cerium(III) phosphate [13454-71 -2] being equivalent to mona2ite, is very stable. 

Europium (III) acetate (2H2O) [62667-64-5] M 383.1, pKj 8.31 (for aquo Eu " ). Recrystd several times from water [Ganapathy et al. J Am Chem Soc 108 3159 1986]. For europium shift reagents see lanthanide shift reagents in Chapter 4. 

Bismuth(III) acetate catalyzes the synthesis of azlactones (17) from aromatic aldehydes in moderate to good yields via the Erlenmeyer synthesis. While the standard procedure for azlactone synthesis consists of using a stoichiometric amount of fused anhydrous sodium acetate, 10 mol% of Bi(OAc)3 is sufficient to catalyze the reaction and the crude product is found to be > 98% pure. 

Chromium(II) phthalocyanine (PcCr) is prepared from phthalonitrile and hexacarbonylchro-mium(O) in 1-chlornaphthalene.234 PcCr(OAc) is prepared from phthalonitrile and chro-mium(III) acetate without solvent235 or in nitrobenzene starting from chromium(II) acetate236 under reflux. Chromium(lll) phthalocyanine also forms /t-oxo dimeric complexes,237 which are more common with iron phthalocyanines. 

In the case of lanthanide elements, other sandwich-like compounds such as the triple-decker phthalocyanincs have been reported. Yttrium(III) acetate hexahydratc when treated with phthalonitrile at 230 C for 8 hours forms a triple-decker phthalocyanine.202... 

Another example of the formation of a tris(phthalocyanine) starting from dysprosium(III) acetate trihydrate and 2,3,9,10,16,17,23,24-octabutoxyphthalocyanine is the formation of didysprosium(III) tris(octabutoxy)phthalocyanine.203... 

In the preparation of lutetium(III) 2,9,16,23-tetra-ter -butylbis(phthalocyanine) from lutetium(III) acetate, dilithium phthalocyanine and dilithium 2,9,16,23-tetra-terr-butyl-phthalocyaninc in refluxing 1 -chloronaphthalene for one hour, only one of the phthalocyanine moieties carries all of the substituents (yield 20%).185... 

Alkenes can also be oxidized with metallic acetates such as lead tetraacetate or thallium(III) acetate " to give bis-acetates of glycols. Oxidizing agents such as benzoquinone, Mn02, or 02, along with palladium acetate, have been used to convert conjugated dienes to l,4-diacetoxy-2-alkenes (1,4 addition). ... 

Primary (R = H) and secondary aromatic amines react with alkenes in the presence of thallium(III) acetate to give vie- diamines in good yields. " The reaction is not successful for primary aliphatic amines. In another procedure, alkenes can be diaminated by treatment with the osmium compounds R2NOSO2 and R3NOSO (R = t-Bu)," analogous to the osmium compound mentioned at 15-51. The palladium-promoted method of 15-51 has also been extended to diamination. " Alkenes can also be diaminated indirectly by treatment of the aminomercurial compound mentioned in 15-51 with a primary or secondary aromatic amine. 

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. ... 

Thallium(III) acetate Acetic acid, thallium (3+) salt (8,9) (2570-63-0)... 

Monoalkylthallium(III) compounds are unstable (73, 79), and very few examples of this class have been isolated. A number of alkylthallium diacetates have been obtained either from oxythallation of olefins with thallium-(III) acetate (see below) or from exchange reactions such as that shown in Eq. (11) (74, 75). Only four alkylthallium dihalides have been isolated so far, namely a neopentylthallium dihalide (60) [Eq. (12)] and the isomeric 2-, 3-, and 4-pyridiomethylthallium dichlorides (20) [Eq. (13)]. Monoaryl-and monovinylthallium(III) derivatives are considerably more stable than... 

The major problem encountered in the oxidation of olefins by thallium-(III) acetate is the formation of mixtures of products that are frequently... 

Formation of mixtures of products in these reactions can be attributed largely to the properties of the acetate group. The reactions of a number of cycloalkenes with thallium(III) salts have been investigated in some detail and the results obtained have served both to elucidate the stereochemistry of oxythallation and to underline the important role assumed by the anion of the metal salt in these oxidations. The most unambiguous evidence as to the stereochemistry of oxythallation comes from studies by Winstein on the oxythallation of norbornene (VII) and norbornadiene (VIII) with thal-lium(III) acetate in chloroform, in which the adducts (IX) and (X) could be precipitated from the reaction mixture by addition of pentane 128) (Scheme 11). Both by chemical means and by analogy with the oxymercuration... 

The same conclusion was drawn from the results obtained from careful studies of the stereochemistry of the glycol products formed on oxidation of cyclohexene with thallium(III) acetate 3, 83). When dry acetic acid was employed as solvent the product was mainly the tranr-diacetate (XI) in moist acetic acid, however, the mixture of glycol mono- (XII) and diacetates (XIII) which was obtained was mainly cis. These results have been interpreted in terms of initial trans oxythallation, ring inversion. 

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). 

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