Cesium fluoroxysulfate

Eused-ring polycycHc fluoroaromatics can be made from the corresponding amino fused-ring polycycHc or from preformed fluoroaromatics, eg, 4-fluorophenyl-acetonitrile [459-22-3] (275). Direct fluorination techniques have been successfully appHed to polycycHc ring systems such as naphthalene, anthracene, benzanthracenes, phenanthrene, pyrene, fluorene, and quinoHnes with a variety of fluorinating agents xenon fluorides (10), acetyl hypofluorite (276), cesium fluoroxysulfate (277), and electrochemical fluorination (278,279). 

The white cesium fluoroxy sulfate precipitates from the reaction medium and may be kept for several months in the cold (0 to -15 °C) Metal surfaces can cause detonation of the reagent. The reaction scope of cesium fluoroxysulfate seems narrower than that of acetyl hypofluorite because of its limited solubility in organic solvents Cesium fluoroxysulfate has not been prepared with a fluorine-18 label. 

Fluororesorcinol can be prepared from derivatives of resorcinol and fluo-roxytrifluoromethane [15, 24] (equation 4) or by fluorination of resorcinol with cesium fluoroxysulfate [25] (equation 5). Reaction of acetyl hypofluorite with M-acetyl-O-methyltyrosine methyl ester provides a good route to 3-fluorotyrosine derivatives [26] (equation 6). 

Cesium fluoroxysulfate reacts with derivatives ot porphyrin to give i-fluoro-porphynns accompanied by polyfluorinated products [35, 36]... 

Both enol acetates and enols are fluormated by cesium fluoroxysulfate at room temperature in either acetonitnie or methylene chloride solutions (Table 2, entries 1,2 and 6)... 

The aryl tin compounds are better substrates for fluorination because they give high yields of fliiorinated aromatics and they may be fluorinated with acetyl hypofluorite, cesium fluoroxysulfate, or fluorine [52, 54 (equation 28). Aryl boronic esters react with cesium fluoroxysulfate to produce fluoroaromatics [55] (equation 29). 

Aerosol Fluorination of Dimethoxymethane, 111 Fluorination with Cesium Fluoroxysulfate... 

Pd salts and CC14 in the presence of K2CO3,362 or (3) RuH PPluV363 Primary alcohols RCH2OH can be directly oxidized to acyl fluorides RCOF with cesium fluoroxysulfate.364 Lactones can be prepared by oxidizing diols in which at least one OH is primary.365... 

Room-temperature reactions of 1.1-diphenyl-substituted alkenes in dichloromethane with cesium fluoroxysulfate give addition-elimination products, e.g. formation of 1, while the reaction with norbornene gives only 7-fluoronortricyclene and 7-mi-fluoronorbornene.6-7... 

Fluorination of Alkenes 2 by Cesium Fluoroxysulfate (NuH =. YleOH) General Procedure 8... 

Phenyl-substituted acetylenes 6 react with cesium fluoroxysulfate in methanol with a regioselectivity which is dependent on the structure of the acetylene.12... 

Cesium fluoroxysulfate reacts with various substituted benzene derivatives in acetonitrile at room temperature, and a Hammett correlation parameter r>+ = —3.5 has been established.1- ... 

The reaction of 17/ -estradiol (14) with cesium fluoroxysulfate and boron trifluoride-diethyl ether complex in acetonitrile gives the 2-fluoro and 4-fluoro isomers in a 1 1 ratio,17 while the reaction with the hexamethyl ether of gossypol fails under a variety of conditions.21... 

The course of the reaction of methyl-substituted benzene derivatives with cesium fluoroxysulfate in acetonitrile at 35-40 C strongly depends on the structure of the molecule. Toluene (16, R1 = R2 = H) and other alkyl-substituted benzenes 16 and 17 are mainly functionalized on the side chain, while 1,3.5-trimethylbenzene (18) gives mainly ring-substituted products 24 however. 1.2.4,5-tetramethylbenzene (19) and hexamethylbenzene again give mainly or exclusively side-chain products.25... 

Cesium fluoroxysulfate reacts with ketones, diketones and enol acetates to give monofluoro products,27 28 e.g. formation of 22, 23 and 24. but barbituric acid is converted into 5.5-di-fluorobarbituric acid.29... 

Cesium fluoroxysulfate in acetonitrile medium at 35 C converts primary alcohols and alkyl and aryl aldehydes into acid fluorides in high yields.i" Hammett correlation analysis of the fluorination of various benzene-substituted aldehydes gives the reactivity constant31 q = —0.38. It has been shown that solvent polarity plays an extremely important role in the conversion of aldehydes into fluorides the conversion is almost quantitative in acetonitrile, but completely stopped in dichloromethane, hexane or tetrahydrofuran. The presence of ni-... 

Trialkylaryltin derivatives 30 are converted into fluoro-substituted derivatives 31. 37-38 (4-Mcth-oxyphenyl)trimethylsilane (32) in acetonitrile gives 4-fluoroanisole and (3-fluoro-4-meth-oxyphenyl)trimethylsilane in the ratio 1 2. A -Methyldiethanol esters of arylboronic acids 33 (l-aryl-5-methyl-2,8-dioxa-5-azonia-l-boranuidabicyclo[3.3.0]octanes) are converted into tluoroaromatic compounds with cesium fluoroxysulfate in acetonitrile in the presence of 1,3-dinitrobenzene at room temperature.39-40 Regiospecific synthesis of 2-fluoro-3-0-methyles-trone in 27 % yield occurs upon fluorination of the corresponding arylboronic acid with cesium fluoroxysulfate.41... 

Regioselective fluorodestannylation of alkenyl and heteroaryl molecules to give 34 can be achieved under mild conditions with cesium fluoroxysulfate, while x-fluoro ketones, e.g. 35, are formed when the tin group is attached to the benzylic position.42 The pyrrole ring in indole derivatives is also successfully fluorinated using this method, e.g. formation of 36.42-45... 

The regiospecific fluorofunctionalization of steroids using 4-trimethylstannyl derivatives, e.g. 37, with cesium fluoroxysulfate has been described.46... 

The fluorination of pyridine with cesium fluoroxysulfate in the presence of sodium tetrafluoro-borate in acetonitrile at 0-5 C gives 1-fluoropyridinium tetrafluoroborate (3).42... 

Room-temperature fluorination of aromatic compounds with cesium fluoroxysulfate is generally run in the presence of a polar solvent like acetonitrile and a catalyst like boron trifluoride. Thus benzene yields fluorobenzene (22). 

Cesium fluoroxysulfate, CsSO.,f (1). Mol. wt. 247.97, stable solid at - I O, stable in CHyCN for about a day. The reagent is prepared by reaction of cesium sulfate in water with fluorine.1... 

FLIJORINATTON Acetyl hypofluoritc. Cesium fluoroxysulfate. (Diethylamino)-sulfur trifluoride. 

Benzotriazole can be chlorinated at the N(l) position by NaOCl (85H(23)2225). 1-Chlorobenzotriazole - a rather stable crystalline compound that has found application in organic synthesis as a selective chlorinating reagent and mild oxidant. A-Fluorination of benzotriazole with cesium fluoroxysulfate gives 1-fluorobenzotriazole in 25% yield (91T7447). 

Xenon difluoride and xenon hexafluoride fluorinate pyridine to give a mixture of 2- and 3-fluoropyridines along with 2,6-difluoropyridine (76JFC(7)179). Cesium fluoroxysulfate at room... 

The Role of Reagent Structure in the Mild Introduction of a Fluorine Atom into Organic Molecules Xenon Difluoride, Cesium Fluoroxysulfate and F-TEDA Case ... 

Addition of cesium fluoroxysulfate to olefins gives vicinalfluoroalky l sulfates with low regio- and stereoselectivity [762, 165] (equations 12 and 13) Reactions of this reagent with olefins in methanol or acetic acid give vicinalfluoroalkyl methy l ethers or acetates, respectively [164, 165 166] (equation 14), with a predominance... 

Fluoroxytrifluoromethane (trifluoromethyl hypofluorite) and acetyl hypofluonte are the most commonly used neutral hypofluorites, cesium fluoroxysulfate is an inorganic anionic fluoroxy derivative... 

Cesium fluoroxysulfate [5, 61 is prepared by reacting fluorine with cesium sulfate in aqueous solution [20, 21] (equation 3). 

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