Ring-opening fluorination

Akiyama, Y., Hiramatsu, C., Fukuhara, T., and Kara, S. 2006. Selective introduction of a fluorine atom into carbohydrates and a nucleoside by ring-opening fluorination reaction of epoxides. Journal of Fluorine Chemistry, 127 920-23. 

F-Labcled compounds are also available, via the ring-opening fluorination of cyclic sulfates, using tetraincthylammonium fluoride prepared from tetramethylammonium hydroxide and F-containing aqueous hydrogen fluoride. ... 

Anhydrous hydrogen fluoride itself is not recommended for ring-opening fluorinations of simple epoxides as it causes polymerization, rearrangement and other side reactions. With simple epoxides, low to moderate yields of fluorohydrins can be obtained when anhydrous hydrogen fluoride is diluted with organic solvents. 

The hydrogen fluoridc/pyridine reagent, which is commercially available, was introduced for the ring-opening fluorination of simple epoxides by Olah in 1978. However, the reagent was used as early as 1960 by Bergstrom for the synthesis of fluoro steroids. ... 

Mixtures of alkylamines with hydrogen fluoride were introduced by Jullien - in the 1960s for the ring-opening fluorination of epoxides, and have since become a valuable source of the fluoride ion. 

Ring-Opening Fluorination of Simple Epoxides with Diisopropylamine Trishydroflnondc General Procedure ... 

Syininetiic epoxides are opened with high antiisyn selectivitics w ith triethylamine trishydrofluoride. as shown by the ring-opening fluorination of cis- and /ro//.s-2.3-dipentyloxiranc to give syn- and imii-5. respectively. 

Alkali metal fluorides are, in general, not much used for the ring-opening fluorination of epoxides. However, the oligomerization of trifluoro(trifluoromethyl)oxirane induced by cesium fluoride is of some importance for the preparation of fluorinated polymeric ethers 1. ... 

Tris(dimethylamino)sulfonium difluorotrimethylsilicate [TASF(Me)] has found very little use in the ring-opening fluorination of epoxides. From the experimental conditions that were successfully applied in one ease (THF. reflux. 4d). it can be concluded that TASF(Mc) is not very reactive towards epoxides. 

There are no examples for the preparative ring-opening fluorination of higher-membered cyclic ethers, but it has been observed that 1-fluoropyridinium triflatc gives a low yield of some fluorinated ring-opened addition products with tetrahydrofuran and dioxane. ... 

Ring opening (fluorination, chlorination, or amination) of epoxides are usually facilitated when performed in ILs... 

Ring-opening fluorination of 2,3-epoxy-alcohols is one of the most important ways of introducing fluorine atoms into functionalized organic compounds (Scheme 12.12). Sc(OTf)3 could act as an efficient catalyst in ring-opening fluorination of 2,3-epoxyalcohols by ammonium hydrogen fluorides [20]. 

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