A Unique (3+2) Annulation Reaction between Meldrum's Acid and Nitrones: Mechanistic Insight by ESI‐IMS‐MS and DFT Studies. Issue 16 (15th February 2018)

• Record Type: Journal Article
• Authors: Lespes, Nicolas; Pair, Etienne; Maganga, Clisy; Bretier, Marie; Tognetti, Vincent; Joubert, Laurent; Levacher, Vincent; Hubert‐Roux, Marie; Afonso, Carlos; Loutelier‐Bourhis, Corinne; Brière, Jean‐François
• Is Part Of: Chemistry. Volume 24:Issue 16(2018)
• Page Start: 4086
• Page End: 4093
• Publication Date: 2018-02-15
• Subjects: density functional calculations -- ion mobility -- mass spectrometry -- Meldrum's acid -- organocatalysis; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201705714
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: The fragile intermediates of the domino process leading to an isoxazolidin‐5‐one, triggered by unique reactivity between Meldrum's acid and an N ‐benzyl nitrone in the presence of a Brønsted base, were determined thanks to the softness and accuracy of electrospray ionization mass spectrometry coupled to ion mobility spectrometry (ESI‐IMS‐MS). The combined DFT study shed light on the overall organocatalytic sequence that starts with a stepwise (3+2) annulation reaction that is followed by a decarboxylative protonation sequence encompassing a stereoselective pathway issue. Abstract : Stuck in the middle : The intermediates of the domino process leading to an isoxazolidin‐5‐one, triggered by unique reactivity between Meldrum's acid and an N ‐benzyl nitrone in the presence of a Brønsted base, are determined thanks to the off‐line ESI‐IMS‐MS technique. A combined DFT study sheds light on the overall organocatalytic pathway that starts by a stepwise (3+2) annulation reaction and is followed by a decarboxylative protonation sequence (see scheme).