Enantioselective Nitroso Aldol Reaction Catalyzed by a Chiral Phosphine-Silver Complex
作者:Akira Yanagisawa、Yuqin Lin、Akihiro Takeishi、Kazuhiro Yoshida
DOI:10.1002/ejoc.201601143
日期:2016.11
R)-QuinoxP* = (–)-(R,R)-2,3-bis(tert-butylmethylphosphino)quinoxaline] as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol. Optically active α-aminooxy ketones with up to 99 % ee were regioselectively obtained in moderate to high yields by the in situ generated chiral silver enolates.
Chiral Silver Alkoxide Catalyzed Asymmetric Aldol Reaction of Alkenyl Esters with Isatins
作者:Akira Yanagisawa、Aiko Kawada
DOI:10.1055/a-1479-4694
日期:2021.7
aldol reaction of alkenyl esters with isatins was achieved using a DM-BINAP·AgOTf complex as the chiral precatalyst and N,N-diisopropylethylamine as the base precatalyst in the presence of methanol or 2,2,2-trifluoroethanol. Optically active 3-alkylated 3-hydroxy-2-oxindoles having up to 98% ee were diastereoselectively obtained in moderate to high yields not only from cyclic alkenyl esters but also
Catalytic Enantioselective Synthesis of Chiral Isatin Derivatives by an Aldol Approach
作者:Akira Yanagisawa、Naoyuki Kushihara、Takuya Sugita、Kazuhiro Yoshida
DOI:10.1055/s-0032-1316551
日期:2012.7
A catalytic enantioselective aldol reaction of alkenyl esters with isatins was achieved using an (S)-BINOL-derived chiraltin dibromide possessing a 4-tert-butylphenyl group at 3- and 3′-positions as the chiral pre-catalyst in the presence of sodium methoxide and methanol. Optically active 3-alkylated 3-hydroxy-2-oxindoles having up to 98% ee were diastereoselectively obtained in high yields not only