Vinylogous michael addition of 3-alkylidene-2-oxindoles to beta,gamma-unsaturated alpha-keto esters by bifunctional cinchona alkaloids
Title | Vinylogous michael addition of 3-alkylidene-2-oxindoles to beta,gamma-unsaturated alpha-keto esters by bifunctional cinchona alkaloids |
Publication Type | Journal Article |
Year of Publication | 2020 |
Authors | Jaiswal, MK, Kumar, R, Singh, S, Jain, S, Vanka, K, Singh, RP |
Journal | European Journal of Organic Chemistry |
Volume | 2020 |
Issue | 35 |
Pagination | 5690-5694 |
Date Published | SEP |
Type of Article | Article |
ISSN | 1434-193X |
Keywords | 3-Alkylidene-2-oxindoles, Asymmetric synthesis, beta, gamma-Unsaturated alpha-keto esters, Michael adduct, Vinylogous Michael addition |
Abstract | A highly enantioselective vinylogous Michael addition of 3-alkylidene-2-oxindoles with beta,gamma-unsaturated alpha-keto esters using a bifunctional tertiary-amine thiourea catalyst is demontsrated. The challenging Michael reaction with the beta,gamma-unsaturated alpha-keto esters has been accomplished due to the synchronized H-bond guided dual activation of vinylogous nucleophile and electrophile by catalyst. The reaction afforded product in high yield while resulting in excellent stereocontrol (> 19:1E/Zand upto 99 %ee). |
DOI | 10.1002/ejoc.202000835, Early Access Date = SEP 2020 |
Type of Journal (Indian or Foreign) | Foreign |
Impact Factor (IF) | 2.889 |
Divison category:
Physical and Materials Chemistry
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