Enantioselective synthesis of quaternary 3-aminooxindoles via organocatalytic asymmetric Michael addition of 3-monosubstituted 3-aminooxindoles to nitroolefins.
An enantioselective synthesis of quaternary 3-aminooxindoles with 3-monosubstituted 3-aminooxindoles as nucleophiles is first presented. A Michael addition reaction of 3-monosubstituted 3-aminooxindoles to nitroolefins has been developed with a bifunctional thiourea-tertiary amine as a catalyst to afford a range of 3,3-disubstituted oxindoles bearing adjacent quaternary-tertiary centers in good results (up to 98% yield, >99:1 dr, and 92% ee). We also demonstrate the potential synthetic utility of this methodology by a transformation of the product into a spirocyclic oxindole compound.
National Engineering Research Center of Chiral Drugs, Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041, China.
Bao-Dong
BD
Cui
Wen-Yong
WY
Han
Zhi-Jun
ZJ
Wu
Xiao-Mei
XM
Zhang
Wei-Cheng
WC
Yuan
D000475:Alkenes / Q000138:chemical synthesis* / Q000737:chemistry; D000588:Amines / Q000737:chemistry*; D002384:Catalysis; D007211:Indoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D009574:Nitro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D000078183:Oxindoles; D013237:Stereoisomerism
D000475:Alkenes; D000588:Amines; D007211:Indoles; D009574:Nitro Compounds; D000078183:Oxindoles; C022960:2-oxindole