Cesium fluoride catalyst

Carbonyl fluoride, COF2, and oxygen difluoride react in the presence of cesium fluoride catalyst to give bis(trifluorylmethyl)trioxide [1718-18-9] CF OOOCF (31). CF OOF has been isolated from the reaction in the presence of excess OF2 (32). 

Fluoroncytrifluoromethane is prepared in a process that uses cesium fluoride as a catalyst for the reaction between fluorine and carbon monoxide [/ij (equation 1) Bisfluoroxydifluoromethane is prepared in a similar manner from carbon dioxide [id], Fluoroxymethane was prepared recently [14]... 

Especially for large-scale work, esters may be more safely and efficiently prepared by reaction of carboxylate salts with alkyl halides or tosylates. Carboxylate anions are not very reactive nucleophiles so the best results are obtained in polar aprotic solvents45 or with crown ether catalysts.46 The reactivity order for carboxylate salts is Na+ < K+ < Rb+ < Cs+. Cesium carboxylates are especially useful in polar aprotic solvents. The enhanced reactivity of the cesium salts is due to both high solubility and minimal ion pairing with the anion 47 Acetone is a good solvent for reaction of carboxylate anions with alkyl iodides48 Cesium fluoride in DMF is another useful... 

Diphenylsilane catalyzed by various salts promotes the 1,2-reduction of cinnamaldehyde.318 Cesium fluoride catalysis is particularly effective.320 It is possible to stop these reactions at the silyl ether stage.73,320 The 1,2-reduction of citral is accomplished in high yield with diphenylsilane and Wilkinson s catalyst (Eq. 262) 435 Interestingly, the trialkylsilanes, ethyldimethylsilane and triethylsilane, give high yields of the 1,4-reduction product whereas diisopropylsilane gives a 1 1 mixture of 1,2- and 1,4-reduction (Eq. 263)435... 

Indoleboronic acid 96 was employed by Neel to prepare bis(indolyl)maleimides such as 109 [119]. However, since the standard Suzuki conditions failed (triflate 108 apparently decomposing under the reaction conditions), the use of a phosphine-free Pd catalyst [120] and cesium fluoride [121] was necessary and gave 109 in an acceptable yield of 55%. 

Oxygen dilluoride reacts with carbonyl fluoride, COF2, in the presence of a catalyst, cesium fluoride, to form bis(trifluorylmethyl)trioxide, CF3OOOCF3 (Solomon, Irvine J. 1980. Kirk-Othmer Encyclopedia of Chemical Technology, ed., Vol. 3, pp 773-75. New York John Wiley Sons). The overall reaction is as follows ... 

The addition of chlorine monofluoridc across the C = 0 bonds in difluorophosgene, per-fluoroacyl fluorides, and perfluoroketones with the formation of hypochlorites occurs only in the presence of the catalysts potassium fluoride, rubidium fluoride, cesium fluoride80,81 or the strong Lewis acids hydrogen fluoride, boron trifluoride, or arsenic(V) fluoride.82 The cesium fluoride catalyzed reactions are carried out in an autoclave for 2-3 hours at — 20"C or left overnight.80... 

In spite of the fact that cesium fluoride is very expensive and needs care in handling (very hygroscopic ), it is the reagent of choice for several reactions where halogens and fluorosulfonate groups have to be replaced by fluorine in aromatic and heterocyclic compounds. Cesium fluoride is more reactive than potassium fluoride and also possesses greater solubility. Often a phase-transfer catalyst is added to aid and enhance the reaction rate and yield of the products. 

Reaction of organosUanes with lactones and enonesf Certain carbanions, generated by desilylation, have been found to react not only with aldehydes and ketones, but also with some lactones and a,/ -enones. Cesium fluoride or tetrabutylam-monium fluoride supported on silica can be used as catalysts. 

Thus, for our present purposes a similar approach was followed using Suzuki cross-coupling reactions as the key steps in the synthesis of our target compounds. Symmetrically substituted compounds were synthesized in a twofold Suzuki crosscoupling reaction from commercially available p-substituted phenylboronic acids or esters and 4,4 -dibromobiphenyl or 4,4 -biphenyl-bis-boronic acid ester and a p-substituted arylhalide, respectively, using tetrakis (triphenylphosphino) palladium as catalyst together with cesium fluoride as base in dry tetrahydrofurane as shown in Scheme 8.1. The desired products were obtained in respectable yields after heating at reflux for 50 h. 

Cesium fluoride—Celite as catalyst for oxidation by atmospheric oxygen 789... 

Carboxylic acid fluorides undergo addition to fluoroalkenes in the presence of a fluoride ion catalyst, e.g. antimony(V) fluoride to give products 1, or cesium fluoride to give products 2 ... 

When activated by anionic catalysts [potassium fluoride, cesium fluoride, tctraalkylammonium fluorides, tris(dimethylamino)sulfonium difluorotrimethylsilicate, phosphazenium, hexa-methylpiperidinium and cobaltoccnium fluorides, tetrabuiylammonium difluoro(triphenyl-silyl)silicatc. the complex tetrakis(dimethylamino)ethene/pcrfluoropropene, ammonium (and phosphonium) periluorocyclobuianc ylides], trimethyl(perfluoroalkyl)silanes will generate C-Rp bonds from carbon-halogen bonds. 

Thionyl tetrafluoride and pentafluorosulfur hypofluorite can be prepared by the fluorination of thionyl fluoride. The product distribution obtained upon fluorination appears to be dependent not only upon the reaction conditions, but on whether a source of fluoride ion is present. Fluorination of thionyl fluoride over a hot platinum gauze or in a Monel pressure reactor produces thionyl tetrafluoride, whereas fluorination in the presence of cesium fluoride or a silver fluoride catalyst jdelds pentafluorosulfur hypofluorite. The role of the fluoride ion in the fluorination has not been conclusively established however, the avail-... 

Color reactions Boric acid (hydroxyquinones). Dimethylaminobenzaldehyde (pyrroles). Ferric chloride (enols, phenols). Haloform test. Phenylhydrazine (Porter-Silber reaction). Sulfoacetic acid (Liebermann-Burchard test). Tetranitromethane (unsaturation). Condensation catalysts /3-Alanine. Ammonium acetate (formate). Ammonium nitrate. Benzyltrimethylammonium chloride. Boric acid. Boron trilluoride. Calcium hydride. Cesium fluoride. Glycine. Ion-exchange resins. Lead oxide. Lithium amide. Mercuric cyanide. 3-Methyl-l-ethyl-2-phosphoiene-l-oxlde. 3-Methyl-1-phenyi-3-phoipholene-1-oxide. Oxalic acid. Perchloric acid. Piperidine. Potaiaium r-butoxIde. Potassium fluoride. Potassium... 

A study of the Knoevenagel condensation of cyclohexanone and benzaldehyde with three active-methylene components showed that rubidium fluoride and cesium fluoride are more effective catalysts than potassium fluoride and that lithium fluoride... 

Rubidium fluoride, RbF. Supplier Amer. Potash and Chem. Corp. Catalyst for the Knoevenagel reaction, see Cesium fluoride. 

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