title: Direct asymmetric organocatalytic Michael reactions of alpha,alpha-disubstituted aldehydes with beta-nitrostyrenes for the synthesis of quaternary carbon-containing products.
abstract: [reaction: see text] Direct asymmetric catalytic Michael reactions have been performed using chiral-amine/acid bifunctional catalysts. Performed with 0.3 equiv of (S)-(+)-1-(2-pyrrolidinylmethyl)pyrrolidine and 0.3 equiv of trifluoroacetic acid as the catalyst, the reaction of alpha,alpha-dialkylaldehydes with (E)-beta-nitrostyrene provided the alpha,alpha-dialkyl Michael products in up to 96% yield with up to 91% ee. With respect to enantioselectivity, l-proline was a poor catalyst of this class of Michael reactions.
authors.affiliation: The Skaggs Institute for Chemical Biology and the Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, California 92037, USA.
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Mase
authors.forename: Rajeswari
authors.initials: R
authors.lastname: Thayumanavan
authors.forename: Fujie
authors.initials: F
authors.lastname: Tanaka
authors.forename: Carlos F
authors.initials: CF
authors.lastname: Barbas
mesh_terms: D000447:Aldehydes / Q000138:chemical synthesis*; D000588:Amines / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D011392:Proline / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013237:Stereoisomerism; D013343:Styrenes / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D000588:Amines; D013343:Styrenes; C011955:beta-nitrostyrene; D002244:Carbon; D011392:Proline