Organocatalytic tandem enantioselective Michael-cyclization of isatin-derived β, γ-unsaturated α-ketoesters with 3-hydroxy-4H-chromen-4-one or 2-hydroxy-1, 4-naphthoquinone derivatives. Issue 87 (8th September 2016)

• Record Type: Journal Article
• Authors: Yin, Shao-Jie; Zhang, Shao-Yun; Zhang, Jun-Qi; Sun, Bing-Bing; Fan, Wei-Tai; Wu, Bing; Wang, Xing-Wang
• Is Part Of: RSC advances. Volume 6:Issue 87(2016)
• Page Start: 84248
• Page End: 84254
• Publication Date: 2016-09-08
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c6ra17400k
• Languages: English
• ISSNs: 2046-2069

Abstract

Abstract : An efficient tandem Michael-cyclization has been reported to provide two types of enantio-enriched spiro-oxindole derivatives in high yields with excellent stereoselectivities. Abstract : The enantioselective formal [3 + 3] annulation reaction of isatin-derived β, γ-unsaturated α-ketoesters with 3-hydroxy-4 H -chromen-4-ones or 2-hydroxy-1, 4-naphthoquinone was successfully implemented under catalysis of quinine-derived bifunctional tertiary amine-thiourea catalysts. The efficient tandem Michael-cyclization has provided facile access to optically active spiro[oxindole-pyrano[3, 2- b ]chromenone] and spiro[oxindole-benzo[ g ]chromene-dione] derivatives in high yields with excellent diastereo- and enantioselectivities.