title: Development of asymmetric reactions catalyzed by chiral organotin-alkoxide reagents.
abstract: Asymmetric catalysis under almost-neutral reaction conditions is key for the efficient synthesis of optically active polar molecules. We have developed catalytic enantioselective reactions of acyclic or cyclic alkenyl esters by using an (S)-BINOL-derived chiral tin-dibromide reagent that possesses a bulky aryl group at the 3 or 3' position as the chiral pre-catalyst in the presence of a sodium alkoxide and an alcohol, in which a chiral tin alkoxide bromide is generated in situ and recycled with the assistance of an alcohol. In this Personal Account, we describe three types of asymmetric transformation that proceed through a chiral tin enolate: 1) The asymmetric aldol reaction of alkenyl esters or unsaturated lactones with aldehydes or isatins; 2) the asymmetric three-component Mannich-type reaction of alkenyl esters and related cycloaddition reactions; and 3) the asymmetric N-nitroso aldol reaction of unsaturated lactones with nitrosoarenes.
authors: Department of Chemistry, Graduate School of Science, Chiba University, Inage, Chiba 263-8522, Japan. ayanagi@faculty.chiba-u.jp
authors: Akira
authors: A
authors: Yanagisawa
authors: Kazuhiro
authors: K
authors: Yoshida
mesh_terms: D000438:Alcohols / Q000737:chemistry; D000447:Aldehydes / Q000737:chemistry; D001965:Bromides / Q000737:chemistry; D002384:Catalysis; D061565:Cycloaddition Reaction; D004952:Esters; D007783:Lactones / Q000737:chemistry; D009284:Naphthols / Q000737:chemistry; D009947:Organotin Compounds / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D000438:Alcohols; D000447:Aldehydes; C406944:BINOL, naphthol; D001965:Bromides; D004952:Esters; D007783:Lactones; D009284:Naphthols; D009947:Organotin Compounds; C116609:3-hydroxybutanal