Fluorous separation

Fluorous separations rely on the strong and selective affinity interaction between fluorous molecules and fluorous separation media. The separation medium can be fluorous solvents which are immiscible with common or-... 

THE ROLE OF FLUORINE COMPOUNDS IN CLEAN SYNTHESIS 3.1. Fluorous separation technologies... 

Table 7.1). Perfluorinated polyethers can also be used as the fluorous phase. However, perfluorinated aromatics are usually miscible with organic solvents and therefore are not used in FBS. It should also be noted that fluorous solvents have a low solubility in water and therefore aqueous-fluorous separations can also be achieved. 

This procedure is very convenient for parallel synthesis and avoids the tedious chromatographies that are usually needed to separate spent Mitsunobu reagents from desired products. If excess reagents are used, then they can also be removed by the fluorous separation. But the reagents are soluble in THF, and large excesses are not... 

Scheme 16.35. Integration of microfluidic and "online" fluorous separation.

On reaching the stage of fluorous separation, three methods are usually used for the rapid separation of fluorous compounds from the reaction mixture fluorous hquid-phase extraction, fluorous solid-phase extraction [6], and fluorous HPLC [7]. 

Fluorous separation is based on the fact that fluorophilic molecules have an affinity for fluorous media under certain condition, while non-fluorous ones do not have such affinity. Fluorous media can differentiate such affinity, therefore, can rapidly separate fluorous compounds from the rest The choice of the method depends on the nature of the components in the mixture to be separated and the purpose of the synthesis. 

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