Carbonyl fluoride iodide

Carbonyl fluoride iodide, COFI, is a colourless liquid close to its boiling temperature of 

4 C under normal conditions. Its odour is described as being similar to that of phosgene. 

As with a number of the other unsymmetrical halides, carbonyl fluoride iodide was flrst reported in the FIAT review of German science (1939-1945) [1196a,1751]. The compound was prepared by Kwasnik [1196a, 1751] from the reaction of iodine]V) fluoride with carbon monoxide according to  

The reaction takes place in a rotating autoclave over eight hours, and under a partial pressure of carbon monoxide of 12 MPa. After bleeding off the carbonyl difluoride co-product and the excess of carbon monoxide, the COFI was removed by distillation at about 26.7 kPa, foliowed by a further distillation in vacuo over antimony powder to give a yield of 12% for COFI (based on IF ). The material is suitably stored in quartz vessels cooled with dry ice [1196,1751]. 

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Carbonyl fluoride iodide decomposes at temperatures as iow as -20 C with evolution of diiodine. It is reported to be hydrolysed by water (within thirty minutes), and is rapidly and completely absorbed by aqueous sodium hydroxide solution [1196,1751], When exposed to liquid COFI at normal temperatures, quartz and glass are reported to become coated with a yellow substance [1196]. 

Allyltin difluoroiodide, formed in situ by the oxidative addition of stannous fluoride to allyl iodide, is found to react with carbonyl compounds to give the corresponding homoallylic alcohols in excellent yields under mild reaction conditions (9). 

Tris(dimethylamino)sulfonium difluo-rotrimethylsilicate, 336 Xenon(II) fluoride, 345 Alkyl bromides Potassium permanganate, 258 Sodium bromide, 46 Tetraethylammonium bromide, 46 Alkyl iodides Aluminum iodide, 17 Potassium permanganate, 258 Sodium iodide, 46 Tetraethylammonium iodide, 46 Alkynes (see also Acetylenic carbonyl compounds, Diynes, Enynes, Propar-gyl alcohols)... 

Fluoride ion first becomes coordinated with the silicon atom of tin reagent 33. Further coordination with the carbonyl oxygen atom of substrate 34 leads to an especially activated hypervalent silicon species 35.21 from which a stannyl anion is eliminated. I Ialogen-metal exchange between the tin anion and inyhc iodide 36 produces vinylic anion 37, which attacks in an intramolecular way the carbonyl group that has been activated through silicon coordination. Aqueous workup leads to alcohol 38. 

This cyclization is a reaction developed by Mori, who carried out a series of investigations with tin reagent 33. Fluoride is a much more reactive anion for initiation than any of the other halides, although it often leads to decomposition of the starting materials. In the case of vinylic or aryl halogen compounds the iodides are easier to transform than the bromides, and chlorides are unrcactive. The carbonyl group can be derived from either an aldehyde or a ketone, and even esters are sufficiently electrophilic.22... 

Carbonylation of aryl iodides in the presence of cesium fluoride at 80 °C in propionitrile gives aroyl fluorides in quantitative yields923. 

When Me3SiSnBu3 is treated with CsF, the fluoride anion should coordinate to the silyl group and not the stannyl group to produce a hypervalent silicate, and as a result, a stannyl anion would be generated.282 The stannyl anion reacts with vinyl iodide to produce a vinyl anion via a halogen-metal exchange and it reacts with the carbonyl group intramolecularly (Equation (113)). Aryl halides or allyl halides are also used in similar cyclizations.283,284... 

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