Asymmetric hydroxyamination of oxindoles catalyzed by chiral bifunctional tertiary aminethiourea: construction of 3-amino-2-oxindoles with quaternary stereocenters
作者:Li-Na Jia、Jun Huang、Lin Peng、Liang-Liang Wang、Jian-Fei Bai、Fang Tian、Guang-Yun He、Xiao-Ying Xu、Li-Xin Wang
DOI:10.1039/c1ob06413d
日期:——
Chiral bifunctional tertiary amine thiourea was applied to catalyze the asymmetric hydroxyamination of 3-subsituted oxindoles with nitrosobenzene to construct 3-amino-2-oxindoles with quaternary stereocenters in good yields (up to 91%) and enantioselectivities (up to 90% ee).
Sc takes action: The highly enantioselectivehydroxyaminationreaction of N‐unprotected 2‐oxindoles with nitrosoarenes has been realized using the Sc(OTf)3/L1 complex. The catalyst system exhibited remarkably broad substrate scope and high efficiency. This transformation is the first example of a chiral ScIII/enolate activating a nitrosoarene, and can be conducted on a gram scale without loss in the
Sc发挥作用:使用Sc(OTf)3 / L1络合物实现了N-未保护的2-氧吲哚与亚硝基芳烃的高度对映选择性羟基胺化反应。该催化剂体系表现出显着的底物范围和高效率。该转化是手性Sc III /烯酸酯活化亚硝基芳烃的第一个实例,并且可以以克级进行,而不会损失ee 值。