Asymmetric Nitroaldol Reactions of Nitroalkanes with Isatins Catalyzed by Bifunctional Cinchona Alkaloid Derivatives
作者:Mei-Qiu Li、Jin-Xin Zhang、Xiao-Fei Huang、Bin Wu、Zhao-Min Liu、Jian Chen、Xiang-Dong Li、Xing-Wang Wang
DOI:10.1002/ejoc.201100824
日期:2011.9
The enantioselective nitroaldolreactions of isatins with nitroalkanes were smoothly carried out by organocatalysis. A C6′-OH cinchona alkaloid derivative bearing a C9-OBn group exhibited outstanding catalytic efficiency as an acid–base bifunctional catalyst for the nitroaldolreaction of isatins with nitromethane, providing 3-hydroxy-3-(nitromethyl)indolin-2-ones in good yields (90–98 %) and with
hybrid-type squaramide-fused aminoalcohol (SFAA) catalysts were synthesized, and their catalytic efficiency in the enantioselective nitro-aldol reaction of various isatins with nitromethane has been described. This transformation afforded chiral 3-substituted 3-hydroxyoxindoles in excellent chemical yields (up to 99 %) with high enantioselectivities (up to 95 % ee). The resulting chiral 3-hydroxyoxindoles can
Biscinchona alkaloid catalysed Henry reaction of isatins: Enantioselective synthesis of 3-hydroxy-3-(nitromethyl)indolin-2-ones
作者:Parvathaneni Sai Prathima、Keesara Srinivas、Kodicherla Balaswamy、Racha Arundhathi、Gajjaia Narsimha Reddy、Balasubramanian Sridhar、Mandapati Mohan Rao、Pravin R. Likhar
DOI:10.1016/j.tetasy.2011.11.008
日期:2011.12
The direct catalytic enantioselective Henry (nitroaldol) reaction of isatins with nitromethane has been developed in the presence of a biscinchona alkaloid as a chiral organocatalyst. The resulting Henry adducts bearing C3-quaternary stereocentres were obtained in high yields (up to 94%) with high enantioselectivities (up to 97% ee). (C) 2011 Elsevier Ltd. All rights reserved.