Phosphine-Catalyzed Enantioselective γ-Addition of 3-Substituted Oxindoles to 2,3-Butadienoates and 2-Butynoates: Use of Prochiral Nucleophiles
作者:Tianli Wang、Weijun Yao、Fangrui Zhong、Guo Hao Pang、Yixin Lu
DOI:10.1002/anie.201307757
日期:2014.3.10
first phosphine‐catalyzed enantioselective γ‐addition with prochiral nucleophiles and 2,3‐butadienoates as the reaction partners has been developed. Both 3‐alkyl‐ and 3‐aryl‐substitutedoxindoles could be employed in this process, which is catalyzed by a chiral phosphine that is derived from an amino acid, thus affording oxindoles that bear an all‐carbon quaternary center at the 3‐position in high yields
Michael Addition of Oxindoles to N-(2-tert-Butylphenyl)maleimides: Efficient Desymmetrization for the Synthesis of Atropisomeric Succinimides with Quaternary and Tertiary Stereocenters
作者:Giorgio Bencivenni、Nicola Di Iorio、Lorenzo Soprani、Simone Crotti、Emanuela Marotta、Andrea Mazzanti、Paolo Righi
DOI:10.1055/s-0036-1588408
日期:——
Abstract The desymmetrization of N-(2-tert-butylphenyl)maleimides was realized by means of a Michael reaction of N-(tert-butoxycarbonyl)-3-phenyloxindoles leading to the corresponding axially chiral succinimides in high yields. The use of a squaramide cinchonidine organocatalyst was fundamental to achieve the simultaneous remote control of the stereogenic axis and adjacent quaternary and tertiary stereocenters