title: Azlactone Reaction Developments.
abstract: Azlactones (also known as oxazolones) are heterocycles usually employed in the stereoselective synthesis of α,α-amino acids, heterocycles and natural products. The versatility of the azlactone scaffold arises from the numerous reactive sites, allowing its application in a diversity of transformations. This review aims to cover classical and recent applications of oxazolones, especially those involving stereoselective processes. After a short introduction on their structures and intrinsic reactivities, dynamic kinetic resolution (DKR) processes as well as reactions involving stereoselective formation of a new σ C-C bond, such as alkylation/allylation/arylation, aldol, ene, Michael and Mannich reactions will be exposed. Additionally, cycloadditions, Steglich rearrangement and sulfenylation reactions will also be discussed. Recent developments of the well-known Erlenmeyer azlactones will be described. For the most examples, the proposed mechanism, activation modes and/or key reaction intermediates will be exposed to rationalize both the final product and the observed stereochemistry. Finally, this review gives an overview of the synthetic utility of oxazolones.
authors.affiliation: Department of Chemistry, Federal University of Juiz de Fora, José Lourenço Kelmer, São Pedro, Juiz de Fora, Brazil.
authors.forename: Pedro P
authors.initials: PP
authors.lastname: de Castro
authors.affiliation: Department of Chemistry, Federal University of Juiz de Fora, José Lourenço Kelmer, São Pedro, Juiz de Fora, Brazil.
authors.forename: Arthur G
authors.initials: AG
authors.lastname: Carpanez
authors.affiliation: Department of Chemistry, Federal University of Juiz de Fora, José Lourenço Kelmer, São Pedro, Juiz de Fora, Brazil. giovanni.amarante@ufjf.br.
authors.forename: Giovanni W
authors.initials: GW
authors.lastname: Amarante
keywords: Erlenmeyer azlactone; azlactone; catalysis; oxazoles; oxazolones