Enantioselective organocatalytic vinylogous aldol-cyclization cascade reaction of 3-alkylidene oxindoles with <i>o</i>-quinones
作者:Yun-Jie Tsou、Ren-You Guan、Jeng-Liang Han
DOI:10.1039/d1ob00888a
日期:——
bifunctional squaramide catalysed asymmetric vinylogous aldol-cyclization cascade reaction between 3-alkylidene oxindoles and o-quinones. A wide range of enantioenriched spirocyclic o-quinone analogues with a quaternary stereocenter could be smoothly synthesized in good to excellent yields (up to 99%) with high enantioselectivities (up to 99%).
Enantioselective Organocatalytic Three-Component Vinylogous Michael/Aldol Tandem Reaction among 3-Alkylidene oxindoles, Methyleneindolinones, and Aldehydes
作者:Jing-Xiang Xu、Yi-Syun Jiang、Chih-Hao Chen、Nadaraj Sathishkumar、Kai-Ti Chu、Ming-Hsi Chiang、Hsin-Tsung Chen、Jeng-Liang Han
DOI:10.1021/acs.joc.1c02180
日期:2022.1.7
We reported a one-pot enantioselective three-component vinylogous Michael/aldol tandem reaction of prochiral 3-alkylidene oxindoles with methyleneindolinones and aldehydes using bifunctional organocatalysts. A variety of enantioenriched 3,3-disubstituted oxindoles 3 and spirolactones 4 were generated in moderate yields (up to 78%) with high stereoselectivities (up to >20:1 dr, >99% ee). Intriguingly
Asymmetric vinylogous aldol addition of alkylidene oxindoles on trifluoromethyl-α,β-unsaturated ketones
作者:Simone Crotti、Giada Belletti、Nicola Di Iorio、Emanuela Marotta、Andrea Mazzanti、Paolo Righi、Giorgio Bencivenni
DOI:10.1039/c8ra06615a
日期:——
A novel vinylogous aldoladdition of alkylidene oxindole with 1-trifluoromethyl-3-alkylidene-propan-2-ones is presented. The reaction, catalyzed by a bifunctional tertiary amine, provides an efficient application of the vinylogous reactivity of oxindoles for the preparation of enantioenriched trifluoromethylated allylic alcohols.