title: Ionic nucleophilic catalysis of chiral ammonium betaines for highly stereoselective aldol reaction from oxindole-derived vinylic carbonates.
abstract: A new strategy for developing stereoselective bond-forming reactions is introduced; it takes advantage of the ionic nucleophilic catalysis of chiral ammonium betaines to utilize vinylic esters simultaneously as the enolate precursor and the acylating agent for coupling with electrophiles. Its synthetic utility is clearly demonstrated by the realization of a highly diastereo- and enantioselective aldol reaction from oxindole-derived vinylic carbonates.
authors.affiliation: Department of Applied Chemistry, Graduate School of Engineering, Nagoya University, Nagoya 464-8603, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Uraguchi
authors.forename: Kyohei
authors.initials: K
authors.lastname: Koshimoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Ooi
mesh_terms: D001622:Betaine / Q000737:chemistry*; D002254:Carbonates / Q000737:chemistry*; D002384:Catalysis; D007211:Indoles / Q000737:chemistry*; D007477:Ions / Q000737:chemistry; D015394:Molecular Structure; D000078183:Oxindoles; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D002254:Carbonates; D007211:Indoles; D007477:Ions; D000078183:Oxindoles; D000644:Quaternary Ammonium Compounds; C022960:2-oxindole; D001622:Betaine