Dihydrooxazine oxides as key intermediates in organocatalytic Michael additions of aldehydes to nitroalkenes

Gokarneswar Sahoo; Hasibur Rahaman; Adám Madarász; Imre Pápai; Mikko Melarto; Arto Valkonen; Petri M Pihko

doi:10.1002/anie.201204833

Dihydrooxazine oxides as key intermediates in organocatalytic Michael additions of aldehydes to nitroalkenes

Angew Chem Int Ed Engl. 2012 Dec 21;51(52):13144-8. doi: 10.1002/anie.201204833. Epub 2012 Nov 13.

Authors

Gokarneswar Sahoo¹, Hasibur Rahaman, Adám Madarász, Imre Pápai, Mikko Melarto, Arto Valkonen, Petri M Pihko

Affiliation

¹ Department of Chemistry, Nanoscience Center, University of Jyväskylä, Finland.

PMID: 23150243
DOI: 10.1002/anie.201204833

Abstract

Pause and play: dihydrooxazine oxides are stable intermediates that are protonated directly, without the intermediacy of the zwitterions, in organocatalytic Michael additions of aldehydes and nitroalkenes (see scheme, R=alkyl). Protonation of these species explains both the role of the acid co-catalyst in these reactions, and the observed stereochemistry when the reaction is conducted with α-alkylnitroalkenes.