Catalytic enantioselective aza-Henry reaction with broad substrate scope

Claudio Palomo; Mikel Oiarbide; Antonio Laso; Rosa López

doi:10.1021/ja056594t

Catalytic enantioselective aza-Henry reaction with broad substrate scope

J Am Chem Soc. 2005 Dec 21;127(50):17622-3. doi: 10.1021/ja056594t.

Authors

Claudio Palomo¹, Mikel Oiarbide, Antonio Laso, Rosa López

Affiliation

¹ Departamento de Química Orgánica I, Facultad de Química, Universidad del País Vasco, Apdo. 1072, 20080 San Sebastián, Spain. qoppanic@sc.ehu.es

PMID: 16351089
DOI: 10.1021/ja056594t

Abstract

In situ generated azomethines from readily available precursors react with nitromethane in the presence of 120 mol % of CsOH.H2O and 12 mol % of quinine- and cinchonidine-derived quaternary ammonium chlorides to provide the corresponding aza-Henry adducts in good yields and very high selectivities. It represents the first general enantioselective aza-Henry method for azomethines derived from enolizable aldehydes, giving rise to enantiomeric excesses above 94%. In addition, the reactions with nitroethane afforded high diastereo- and enantioselectivities (syn:anti up to 95:5; up to 98% ee for syn).