title: Chiral Integrated Catalysts Composed of Bifunctional Thiourea and Arylboronic Acid: Asymmetric Aza-Michael Addition of α,β-Unsaturated Carboxylic Acids.
abstract: The first intermolecular asymmetric Michael addition of nitrogen-nucleophiles to α,β-unsaturated carboxylic acids was achieved through a new type of arylboronic acid equipped with chiral aminothiourea. The use of BnONH2 as a nucleophile gives a range of enantioenriched β-(benzyloxy)amino acid derivatives in good yields and with high enantioselectivity (up to 90% yield, 97% enantiomeric excess (ee)). The obtained products are efficiently converted to optically active β-amino acid and 1,2-diamine derivatives.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University.
authors.forename: Noboru
authors.initials: N
authors.lastname: Hayama
authors.forename: Takumi
authors.initials: T
authors.lastname: Azuma
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
mesh_terms: D000596:Amino Acids / Q000138:chemical synthesis* / Q000737:chemistry; D001372:Aza Compounds / Q000737:chemistry*; D001897:Boronic Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D015394:Molecular Structure; D013237:Stereoisomerism; D013890:Thiourea / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D001372:Aza Compounds; D001897:Boronic Acids; D002264:Carboxylic Acids; D013890:Thiourea