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
Asymmetric α-amination reaction of alkenyl trifluoroacetates catalyzed by a chiral phosphine–silver complex
作者:Akira Yanagisawa、Ryoji Miyake、Kazuhiro Yoshida
DOI:10.1039/c3ob42111b
日期:——
The asymmetric α-amination of alkenyltrifluoroacetates with dialkyl azodicarboxylates catalyzed by the DTBM-SEGPHOS·AgOTf complex takes place in the presence of 2,2,2-trifluoroethanol with almost quantitative yield and high ees of up to 97%.