Fluoroketones, hydration

Zinc metalloproteases can be inhibited by fluoroketones. This inhibition should stem from complexation of the monoanion of the fluoroketone hydrate with zinc. Thus, S-amido and peptidyl fluoroketones inhibit carboxypeptidase and microbial... 

Stabilisation of the tetrahedral forms of fluoroalkyl ketones The presence of a fluoroalkyl group in a position of a carbonyl strongly enhances its electrophilicity, and hence its reactivity, towards nucleophiles. The anionic tetrahedral intermediates are stabilised by the electron-withdrawing group Rf (Fig. 20) [69,70]. This phenomenon is illustrated by the ability of fluoroketones to afford stable hydrates in aqueous medium. 

Ab initio calculations have been performed to evaluate the ease of hydration and the charge densities of the carbonyl of fluoroketones that are carboxyesterase... 

The strong inductive effect of fluoroalkyl groups has a corresponding additive acidifying effect on alcohols (Table 4.2). For instance, perfluoro-t-butanol is of the same order of acidity as acetic acid. The hydrates of fluoroketones are also remarkably acidic [10]. 

A second class of catalysts comprises perfluorinated ketones such as hexafluoro-acetone [38] and perfluoro-2-octanone ]39]. This class of catalyst is assumed to reversibly form peroxyhemihydrates when exposed to hydrogen peroxide ]40] the latter are the active oxygen-transfer agents. Oxygen transfer to the substrate is accompanied by formation of the ketone s hydrate, which, in equilibrium, regenerates the fluoroketone catalyst. 

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