Hypofluontes

With more electrophilic halogenated olefins, additions of tnfluoromethyl hypofluonte appear to go by radical processes [139] and give oligomeric products [140] or one-to-one adducts [141,142] (equation 4) depending on reaction conditions... 

Tnfluoromethyl hypofluonte will fluorinate Schiff bases, giving N,a,a-tn-fluoroatmnes and a-fluoroimines [144] and reacts with diazoketones to give adducts in modest yields [145] (equation 6) At-Substituted aziridines give nng opened products by 1,3 addition of fluonne on nitrogen and trifluoromethoxy on carbon [146] (equation 7)... 

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

Into a suspension of 8 g of sodium acetate m 400 mL of a solution of 1 part acetic acid and 10 parts fluorotnchloromethane is passed at -75 C a stream of fluonne diluted to 10% with nitrogen The reacuon is stirred with a Vibromixer A solution of 4-methylacetanilide (20 mmol) in a mixture of dichloromethane and fluorotnchloromethane cooled to -75 °C i s added to 20 mmol of acetyl hypofluonte as determined by titration with potassium iodide After 5 min the mixture is poured into water, and the orgamc layer is washed with sodium bicarbonate soluaon and dried over anhydrous magnesium sulfate After concentrauon and column chromatography over silica gel and elution with chloroform, 2-fluoro-4-methylacetanilide IS obtained m 85% yield... 

In contrast to molecular fluorine, trifluoromethyl hypofluonte has limited synthetic value for geminal fluorination of diazoketones owing to formation of complex mixtures [97]... 

Tnorganic and perfluoroorganic hypohalites add across olefimc bonds (equation 11 andTable 1) Thereactionsofhypofluontes have been included in a review on their chemistry [2J], In reactions of perfluoorganic hypofluontes, considerable fluonnation of the C=C bond may be observed With hypochlorites such as... 

A, [ F]fluorine diluted with an unreactive gas B, [ F]acetyl hypofluorite. For companson with F]F2, the radiocherracal yields obtained with acetyl hypofluonte need to be divided by 2... 

Isocyanides react with fluorine [75] to yield difluoromethylene lmmes, which tend to dimerize In an inert solvent, lmines accept fluorine from trifluoromethyl hypofluonte [76, 77] (equation 11)... 

In addition, fluorine [97, 98], trifluoromethyl hypofluonte [99,100], bisftri-fluoromethyl)peroxide [100, 101], trifluoromethyl disulfide [100], and xenon difluoride [102,103,104] react with phosphines to give the corresponding diflu-orophosphoranes in yields ranging from 25% to near quantitative. Phosphites are fluorinated by carbonyl fluoride [95, 96] or 2-hydroperfluoropropyl azide [7ft5J (equation 15). 

Vinyl acetates are also fluonnated by mixtures containing both acyl hy-pofluorite and perfluoroalkyl hypofluonte, obtained from fluorinatton of the carboxylic acid salts [16 /9] (equations 20 and 21)... 

Fluorine is well known for its ability to fluonnate selectively tertiary carbon-hydrogen bonds that are slightly activated by polar substituents Hypofluonte reagents also react with carbon-hydrogen bonds, both secondary and tertiary but tertiary bonds react better [6]... 

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