Tite T, Sabbah M, Levacher V, Brière J.-F * Normandie Université, Université de Rouen, and Centre National de la Recherche Scientifique, Mont Saint Aignan, France
Organocatalysed Decarboxylative Protonation Process from Meldrum’s Acid: Enantioselective Synthesis of Isoxazolidinones.
Chem. Commun. 2013;
49: 11569-11571
Key words
decarboxylative protonation - isoxazolidinones - Meldrum’s acids
Significance
An organocatalytic approach for the synthesis of isoxazolidinones 3 is reported by the Brière group. The methodology is a tandem process promoted by the quinidine-derived catalyst A. An initial formal [3+2]-cycloaddition process couples 5-substituted Meldrum’s acids 1 and nitrones derived from sulfonamides 2. Then, an asymmetric decarboxylative protonation takes place via a putative stepwise mechanism. The desired products are generally obtained with good yields and with modest to good enantioselectivities.
Comment
Asymmetric protonation reactions are a fascinating topic in organic chemistry. In this area, decarboxylative protonation processes have attracted the interest of the scientific community due to the elegant in situ generation of the reacting enolate upon release of carbon dioxide (see Review below). Based on this concept, the authors present a novel straightforward approach to the synthesis of isoxazolidinones, which are useful precursors for β2-amino acids.
Review
J. Blanchet, J. Baudoux, M. Amere,
M.-C. Lasne, J. Rouden Eur. J. Org. Chem.
2008, 5493–5506.
