Acid fluorides reaction with, carbonyl difluoride

A higher (62%) yield of benzoyl fluoride was obtained from the reaction of benzoic acid and COFj in the presence of sodium fluoride, by beating the charged vessel at 175 "C for 10 h. The presence of the highly electronegative fluorine atom in benzoyl fluoride clearly deactivates the carbonyl group for further reaction with carbonyl difluoride. 

Carbonyl difluoride reacts vigorously with water, to produce carbon dioxide and hydrogen fluoride [1756]. A similar reaction is observed with concentrated sulfuric acid, and it is completely absorbed by sodium hydroxide solution [1756]. Indeed, the reaction between COFj and D O at 0 C has been used to prepare DF in purities >99.5% and yields of 90% [1554], A recent ab initio study [677aa] of the mechanism and energetics of the gas-phase reaction of carbonyl difluoride with water indicates that the reaction proceeds through two transient intermediates - CFj(OH)j and FC(0)0H. The former dissociates to the latter and HF, and the FC(0)0H then dissociates into COj and HF, consistent with the overall stoicheiometry ... 

The reaction of trimethyl(perfluorophenyl)silanc with carbonyl centers occurs under mild reaction conditions, similar to those used for trimethyl(trifluoromethyl)silane. Acetyl fluoride in acetonitrile in the presence of catalytic amounts of potassium fluoride gives l-fluoro-l-(penta-fluoropheny )ethyl acetate (12) in 65% yield. When the bifunctional acid fluoride perfluoro-glutaryl difluoride reacts with trimethyl(perfluorophcnyl)silane in acetonitrile in the presence of potassium fluoride, the perfluorinated diketone perfluoro(l,5-diphenylpcntane-l,5-dione)... 

The reaction of 1,4-perfluoropentadiene with an excess of carbonyl difluoride, in the presence of CsF and CH CN at 180 C over 12 h, results in the production of a mixture of mono- and di-acid fluorides [628]. 

SF4 forms adducts with main group inorganic fluorides, and these have been variously described as simple Lewis acid-base systems (with SF4 behaving as the base) or as ionic systems such as [SFsJ [BF4] . The reactions of SF4 with organic molecules have been widely studied. The most important reaction is the conversion of a carbonyl group to a difluoride (equation 51). 

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