Decarboxylative fluorination

Another reaction specific to XeF2 is decarboxylative fluorination. It was postulated that the intermediate here contains the rare O—Xe bond318. Several fluorides including tertiary bicyclo ones319 have been prepared by this route. It should be noted that tertiary fluorides could also be obtained from the corresponding iodides (equation 187), resembling the reaction of iodoadamantanes with F2198. Reactions with anions have also been reported. 

Decarboxylative fluorination, presumably via intermediate acyl hypofluorites, has been achieved in low yield by passing a dilute stream of fluorine in nitrogen into aqueous solutions of sodium carboxy-lates. A somewhat more promising method, tolerant of aryl groups, ketones and ethers, involves reaction of a dichloromethane solution of the acid with xenon difluoride and hydrogen fluoride (equation 23). 7... 

A second and may be more important point is their low thermal stability which may open a new way for decarboxylative fluorination of various acids - a subject which we have started to explore not a long ago (figure 8). 

Figure 8. Thermal stability and decarboxylative fluorination of acids...

The decarboxylative fluorination of a wide range of aliphatic carboxylic acids with Selectfluor is achievable under silver catalysis (Scheme 4.83) [87]. 

Common silver compounds such as silver nitrate catalyzed the decarboxylative fluorination of carboxylic acids (Schane 7.23 and Example 7.10) [36]. Selectfluor served as the fluorine source for this chanistry, and simply refluxing the reagents in acetone/water mixtures generated good to excellent yields of the fluorinated compounds. Not only was the reaction successful in the presence of water, but also water was a critical component of the... 

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