Synthesis, reactivity and properties of versatile gem-bis[(trifluoromethyl)sulfonyl] functionalized organic molecules

Abstract

Incorporation of fluorinated functionalities is a valuable strategy to improve both chemical and biological properties of organic compounds. In this context, much attention is being focused on the trifluoromethanesulfonyl (triflyl) group (SO2CF3), due to its potent electron-withdrawing effect and mild lipophilicity. Consequently, different protocols have been developed over the years to prepare triflones, which are organic molecules bearing the triflyl functionality. The electron-withdrawing effect of the triflyl group also makes compounds bearing gem-bis(triflyl)methyl group (Tf2CH) strongly acidic. Several one-pot reactions, in combination with a derivation step in some cases, merged under simple reaction conditions for the straightforward formation of divergent fluorosulfonyl-decorated cyclic scaffolds from simple starting materials, providing a convenient access to an under-explored structural space. In this way, cyclobutenes, heterocycles, and non-cyclic products have been easily prepared without the requirement for either a catalyst or an additive. This article reviews reactions between differently functionalized alkynes, alkenes and allenes with Tf2C=CH2 (generated in situ from a shelf-stable betaine) to afford cyclic and acyclic bis(triflyl)-functionalized organic molecules with novel chemical structures.