title: Catalytic asymmetric synthesis of both enantiomers of 4‑substituted 1,4-dihydropyridines with the use of bifunctional thiourea-ammonium salts bearing different counterions.
abstract: Organoammonium salts composed of a Brønsted acid and an anilinothiourea promoted the Michael addition of ß-keto esters and α,ß-unsaturated aldehydes in the presence of primary amines to give functionalized 1,4-dihydropyridines enantioselectively. With the use of the different Brønsted acids such as DFA and HBF(4) with the same bifunctional thiourea, both enantiomers of 4-substituted 1,4-dihydropyridine were synthesized from the same starting materials.
authors.affiliation: Graduate School of Pharmaceutical Sciences, Kyoto University, Sakyo-ku, Kyoto, Japan.
authors.forename: Kohzo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Tsubasa
authors.initials: T
authors.lastname: Inokuma
authors.forename: Kiyosei
authors.initials: K
authors.lastname: Takasu
authors.forename: Yoshiji
authors.initials: Y
authors.lastname: Takemoto
mesh_terms: D000447:Aldehydes / Q000737:chemistry; D004095:Dihydropyridines / Q000138:chemical synthesis* / Q000737:chemistry*; D015394:Molecular Structure; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013237:Stereoisomerism; D013890:Thiourea / Q000737:chemistry*
chemical_list: D000447:Aldehydes; D004095:Dihydropyridines; D000644:Quaternary Ammonium Compounds; C038806:1,4-dihydropyridine; D013890:Thiourea