Recent Advances in Enantioselective Pd-Catalyzed Allylic Substitution: From Design to Applications.

This Review compiles the evolution, mechanistic understanding, and more recent advances in enantioselective Pd-catalyzed allylic substitution and decarboxylative and oxidative allylic substitutions. For each reaction, the catalytic data, as well as examples of their application to the synthesis of more complex molecules, are collected. Sections in which we discuss key mechanistic aspects for high selectivity and a comparison with other metals (with advantages and disadvantages) are also included. For Pd-catalyzed asymmetric allylic substitution, the catalytic data are grouped according to the type of nucleophile employed. Because of the prominent position of the use of stabilized carbon nucleophiles and heteronucleophiles, many chiral ligands have been developed. To better compare the results, they are presented grouped by ligand types. Pd-catalyzed asymmetric decarboxylative reactions are mainly promoted by PHOX or Trost ligands, which justifies organizing this section in chronological order. For asymmetric oxidative allylic substitution the results are grouped according to the type of nucleophile used.

Development of and Recent Advances in Pd-Catalyzed Decarboxylative Asymmetric Protonation.

Decarboxylative asymmetric protonation (DAP) is a mild and efficient synthetic tool for the catalytic asymmetric formation of tertiary stereocenters adjacent to a carbonyl group. The development of the methodology from the initial racemic report to recent asymmetric examples is summarized. The discovery of an enantiodivergent Pd-catalyzed DAP, in which the choice of the achiral proton source determines the stereochemical outcome, is highlighted. Furthermore, the mechanism of Pd-catalyzed DAP, investigated since the initial report, is also discussed.

Preparation, anti-trypanosomal activity and localisation of a series of dipeptide-based vinyl sulfones.

An improved, Weinreb amide-based, synthesis of anti-trypanosomal lysine-containing vinyl sulfones is described incorporating, as a feature, diversity at the ε-lysine amino group. Members of this family demonstrated moderate to good efficacy as anti-trypanosomal agents and a fluorescent dansyl (19) derivative was used to investigate subcellular localisation of the compound class.