title: A dual arylboronic acid--aminothiourea catalytic system for the asymmetric intramolecular hetero-Michael reaction of α,β-unsaturated carboxylic acids.
abstract: A bifunctional aminoboronic acid has been used to facilitate for the first time the intramolecular aza- and oxa-Michael reactions of α,β-unsaturated carboxylic acids. The combination of an arylboronic acid with a chiral aminothiourea allowed for these reactions to proceed successfully in an enantioselective manner to afford the desired heterocycles in high yields and ee's (up to 96% ee). The overall utility of this dual catalytic system was demonstrated by a one-pot enantioselective synthesis of (+)-erythrococcamide B, which proceeded via sequential Michael and amidation reactions.
authors: Graduate School of Pharmaceutical Sciences, Kyoto University , Yoshida, Sakyo-ku, Kyoto 606-8501, Japan.
authors: Takumi
authors: T
authors: Azuma
authors: Akihiro
authors: A
authors: Murata
authors: Yusuke
authors: Y
authors: Kobayashi
authors: Tsubasa
authors: T
authors: Inokuma
authors: Yoshiji
authors: Y
authors: Takemoto
mesh_terms: D052117:Benzodioxoles / Q000138:chemical synthesis* / Q000737:chemistry; D001897:Boronic Acids / Q000737:chemistry*; D002264:Carboxylic Acids / Q000737:chemistry*; D002384:Catalysis; D020650:Combinatorial Chemistry Techniques; D003374:Coumarins / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D013237:Stereoisomerism
chemical_list: D052117:Benzodioxoles; D001897:Boronic Acids; D002264:Carboxylic Acids; D003374:Coumarins; C000597825:erythrococcamide B