Sulfoxonium ylides: simple compounds with chameleonic reactivity.

Sulfur ylides first disclosed in 1930 started to gain more attention in the 1960s, thanks mainly to the studies by Corey and Chaykovsky on their use for the preparation of strained rings. More recently, the chemistry of these compounds has experienced important growth, in part due to the similarity of their reactivities with diazo compounds. This short review provides an overview on the great assortment of reactions of sulfoxonium ylides, outlining a comparison between the chemistry of these ylides and their congeners: sulfonium ylides and diazo compounds. Insertion reactions, cyclisation reactions and ring-opening reactions are highlighted, giving particular attention to catalytic asymmetric methodologies.