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.

Oxazolones or azlactones are among the most-common starting materials for the synthesis of quaternary amino acids. Since the seminal works of Steglich and co-workers until the recent examples from Ooi and co-workers, azlactones have been the focus of intense research. Oxazolones are also widely used in organometallic chemistry; however, with the "renaissance" of organocatalysis, this reagent has emerged as an important starting material for a broad range of new organocatalytic asymmetric methodologies. In this Focus Review, we aim to cover all of these new organocatalytic methodologies. We begin by discussing the dynamic kinetic resolution reactions developed with azlactones. Then, we disclose the organocatalytic rearrangements. Finally, we focus on the use of oxazolones as nucleophiles in organocatalytic processes.

The synthesis of spiro compounds via a Michael-Michael-aldol reaction is reported. The reaction affords spirooxindole derivatives in good yields and in almost diastereo- and enantiopure form. Moreover, the reaction works with several heterocycles such as oxindoles, benzofuranones, pyrazolones or azlactones rendering the final spiro compounds in good yields and excellent stereoselectivities.

In biology enzyme concentrations are continuously regulated, yet for synthetic catalytic systems such regulatory mechanisms are underdeveloped. We now report how a substrate of a chemical reaction induces the formation of its own catalyst from a dynamic molecular network. After complete conversion of the substrate, the network disassembles the catalyst. These results open up new opportunities for controlling catalysis in synthetic chemical systems.

An efficient synthesis of spiropyrazolones based on organocatalysis is described. The reaction between pyrazolones, enolizable aldehydes and enals is catalyzed by secondary amine catalysts and affords the final spiro compounds bearing four contiguous chiral centers in good yields and excellent diastereo- and enantioselectivities.

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The synthesis of spiro compounds through a Michael–Michael–aldol reaction is reported. The reaction affords spiropyrazolone derivatives in good yields, in almost diastereo‐ and enantiopure form, and is catalyzed by diphenylprolinol derivatives. The reaction showed strong nonlinear effects. Remarkably, when a catalyst with 70 % ee is used, the reaction still affords the final spiro compound in almost diastereo‐ and enantiopure form.

The first highly diastereo- and enantioselective organocatalytic synthesis of 2,2-disubstituted-2H-oxazol-5-ones is described. The addition of oxazolones to maleimides is promoted by bifunctional thiourea catalysts, which afford the corresponding 2,2-disubstituted-2H-oxazol-5-ones with total regio- and stereocontrol.