Chloride cerium, reaction with

Cerium chloride in aqueous phase would undergo double decomposition reactions with many soluble salts of other metals e.g. ... 

With this end in view, phenyldimcthylsilyl tri-n-butylstannane was added under the influence of zero-valent palladium compound with high regioselectivity and in excellent yield to the acetylene 386 to give the metallated olefin 387 (Scheme 56). The vinyl lithium carbanion 388 generated therefrom, was then converted by reaction with cerium(lll) chloride into an equilibrium mixture (1 1) of the cerium salts 389 and 390 respectively. However, the 1,2-addition of 389 to the caibonyl of 391, which in principle would have eventually led to ( )-pretazettine, did not occur due to steric reasons — instead, only deprotonation of 391 was observed. On the other hand, 390 did function as a suitable nucleophile to provide the olefinic product 392. Exposure of 392 to copper(II) triflate induced its transformation via the nine membered enol (Scheme 55) to the requisite C-silyl hydroindole 393. On treatment with tetrafluoroboric acid diethyl ether complex in dichloromethane, compound 393 suffered... 

CARBONYL ADDITIONS, CERIUM(III) CHLORIDE-PROMOTED, 76, 237 Carbonyl compounds, reactions with organolithiums or Grignard reagents, 76, 228 Carboxylic acid amides, 77, 27 Cells, storage of, 76, 80 Centrifugation, 76, 78... 

Chromates, vanadates, and cerium salts give colour reactions with the reagent and should therefore be absent. Iron salts give a yellow colour with hydrogen peroxide, but this is eliminated by the addition of syrupy phosphoric acid. Fluorides bleach the colour (stable [TiF6]2 ions are formed), and large amounts of nitrates, chlorides, bromides, and acetates as well as coloured ions... 

The interaction of bis(pyridinium)cerium hexachloride with Na[Cp] was claimed to produce Ce(Cp)4 and similar reactions afforded the indenyl and fluorenyl complexes. Tris(cyclopentadienyl)cerium chloride and bis(indenyl)cerium dichloride were also claimed. This work is not repeatable and the Ce(Cp)4 has been shown to be Ce(Cp)3(THF). 

Ethereal solvents such as tetrahydrofuran (THF) and dimethoxyethane (DME) are employed in the reactions, with THF generally being preferred. Usually, THF freshly distilled from potassium or sodium with benzophenone is used. Use of hot THF is not recommended, because on addition to cerium chloride a pebble-like material, which is not easily suspended, may be formed. 

The action of n-butyllithium in THF at low temperature leads to the anion. After reaction with an electrophilic compound, e hydrolysis can generally be carried out in polar solvents (acetone, alcohols, acetonitrile) in the presence of mercury(II) chloride or oxide and water.In other cases, NBS, - chloramine T, cerium(IV) ammonium nitrate, n-tributyltin hydride, trialkyloxonium tetrafluorobor-ate, thallium nitrate or photochemistry can be used. Desulfurization by Raney nickel gives hydro-carbons. ... 

The reaction with CeOj was incorrectly reported as yielding CeCl [360]. Cerium(IV) oxide reacts with phosgene to initially form cerium(lll) oxide chloride, which can then react with further phosgene (see Section 9.3.1). Thus, the stoicheiometry of the two possible overall reactions is [307,1088,2042] ... 

Stannous chloride, SnCl2, is. usually used for the reduction of iron(III) to iron(II) for titrating with cerium(r or dichromate. The reaction is rapid in the presence of chloride (hot HCl). When iron samples (e.g , ores) are dissolved (usually in hydrochloric acid), part or all of the iron is in the -f-3 oxidation state and must be reduced. The reaction with stannous chloride is... 

A common interpretation of this reaction invokes the use of the cerium(lll) chloride as a Lewis acid that bonds to the carbonyl system, to make 1,2-addition favored. However, lanthanoid ions are known to preferentially bind to alcohols rather than carbonyl groups.6 Additionally, if the cerium did bind with the carbonyl, one would expect that as dilution with methanol was increased, the observed regioselectivity, presumably due to this complexation, should be reduced. However, experimental results do not support this hypothesis. Since cerium complexation with methanol would result in increased acidity of the methanolic proton, the following scheme appears to be the more likely course of the reaction. 

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