Acylation Cadmium

Barbier reaction Samarium(II) iodide, 270 Benzoannelation Chromium carbene complexes, 82 Dicarbonylcyclopentadienylcobalt, 96 Ethyl (Z)-3-bromoacryIate, 130 Grignard reagents, 138 Methyl acrylate, 183 Methyllithium, 188 Ruthenium(III) chloride, 268 Benzoin condensation Benzyltriethylammonium chloride, 239 3-EthyIbenzothiazolium bromide, 130 Benzoylation (see also Acylation) Cadmium, 60 Dibutyltin oxide, 95 Birch reduction Birch reduction, 32... 

Dialkylcadmium reagents are often useful alternatives to the more reactive Gngnard reagents in the preparation of ketones from acyl halides However, bis(trifluotomethyl)cadmium glyme is decomposed by acyl halides and does not give trifluoromethyl ketones [, 124] Nevertheless, this reaction can be used as a low-temperature source of difluorocarbene [S, 124] (equation 102)... 

Codeposition of silver vapor with perfluoroalkyl iodides at -196 °C provides an alternative route to nonsolvated primary perfluoroalkylsilvers [272] Phosphine complexes of trifluaromethylsilver are formed from the reaction of trimethyl-phosphme, silver acetate, and bis(trifluoromethyl)cadmium glyme [755] The per-fluoroalkylsilver compounds react with halogens [270], carbon dioxide [274], allyl halides [270, 274], mineral acids and water [275], and nitrosyl chloride [276] to give the expected products Oxidation with dioxygen gives ketones [270] or acyl halides [270] Sulfur reacts via insertion of sulfur into the carbon-silver bond [270] (equation 188)... 

The most common application of organocadmium compounds has been in the preparation of ketones by reaction with acyl chlorides. A major disadvantage of the use of organocadmium reagents is the toxicity and environmental problems associated with use of cadmium, and this has limited the recent use of organocadmium reagents. 

Reduction of RCOCI to RCHO. Sodium borohydride and this cadmium salt reduce acyl chlorides to aldehydes, but only in solvents such as DMF, DMA, and HMPT. DMF is essential, but the amount of DMF in the salt is sufficient. For the most part, yields are 50-90%. Aryl, alkyl, and benzylic halides do not react. Other functional groups (nitrile, nitro, ester, C=C) are also inert. 

OTHER ORGANOMETALLIC REAGENTS (see also Carbonylation, Fluorination, Reformatsky reaction) with acids and acyl derivatives with acid halides Benzylchlorobis(triphenyl-phosphine)palladium(II), 30 Cadmium, 60... 

From carboxylic acids or acyl derivatives From acyl chlorides Cadmium, 60... 

One of the best known reactions of dialkyl cadmium compounds is that with acyl halides which results in the formation of ketones. The reactions of (CF3)2Cd glyme with CH, COBr and C6HhCOC1 were the third class of reactions of the trifluoromethylating reagent examined. However, the mixed trifluoromethylalkyl or -aryl ketones were not observed. The organic products obtained were the acyl fluorides (95% yield) along with difluorocarbene. The latter could be stereospecifically trapped at temperatures as low as -78°C. The addition of either lithium or magnesium halides to the reaction mixture did not affect the outcome (106). 

Addition of cadmium alkyls to acyl chlorides yields the corresponding ketones. The method has been reviewed, and the experimental condi-... 

Mickler W, Reich A, Uhlemann E, and Bart HJ. Liquid membrane permeation of zinc, cadmium and nickel with 4-acyl-5-pyrazolones and (3-diketones. J Membr Sci 1996 119 91-97. 

O. R. 1-9, C. R. Hauser and B. E. Hudson, Jr., The Acctoacetic Ester Condensation and Related Reactions lV-4, S. M. McElvain, The Acyloins 11-4, W. S. Johnson, The Formation of Cyclic Ketones by Intramolecular Acylation VIII-2, D. A. Shirley, The Synthesis of Ketones from Acid Chlorides and Organometallic Compounds of Magnesium, Zinc, and Cadmium. ... 

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