Sulfones: new reagents in organocatalysis

The development of new asymmetric methodologies that afford different structures in an enantioselective fashion is one of the most exciting goals for chemists nowadays. In this subject, lately, the use of sulfones has become a fast growing field. From the works of Tan and Shibata until the last works of Palomo, sulfones have demonstrated their versatility and power in organocatalytic asymmetric reactions. Moreover, the easy removal of sulfones with Mg or Hg/Na makes this group a perfect choice to afford easily naked alkyls. Remarkably, bissulfones can be used as nucleophiles or electrophiles, being vinyl sulfones excellent electrophiles, while bismethylensulfones derivatives such as fluoro are excellent nucleophiles. This double possibility has been studied by several research groups, leading to new methodologies that allow obtaining formally simple alkylation in an enantioselective fashion, by using organocatalysis. The aim of this tutorial review is to summarize the last trends in the use of sulfones in organocatalytic processes, giving a complete scenario of these new reagents.