Eluting the Tag

See allHide authors and affiliations

Science  06 Aug 2004:
Vol. 305, Issue 5685, pp. 754
DOI: 10.1126/science.305.5685.754d

Fluorous tagging has become an increasingly popular means of simplifying organic separations. The basis of the technique is that, like oil and water, hydrocarbons and fluorocarbons tend not to mix. After appending fluorocarbon chains or “tags” to organic compounds, the products can be isolated from the reaction mixture because they dissolve selectively in a fluorinated solvent. In practice, the separations are often done chromatographically with a somewhat exotic fluorinated silica gel as the solid phase; a polar organic liquid phase pushes the untagged compounds through first.

Matsugi and Curran show that the tagged and untagged compounds can also be separated using standard silica gels. The reaction mixture is deposited onto the silica, and an eluent of diethyl ether and perfluorinated hexanes (FC-72) efficiently pulls the tagged compounds through first and leaves the organic ones behind. The authors demonstrate the workup for a tin-mediated allylation and an amide coupling reaction. For the latter reaction, a single perfluorobutyl group suffices as a tag. — JSY

Org. Lett. 10.1021/ol049040o (2004).

Navigate This Article