An unexpected cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates to construct 2,3-dihydrobenzofuran spirooxindoles
作者:Kuan Zhang、Huabin Han、Lele Wang、Ziying Zhang、Qilin Wang、Wenjing Zhang、Zhanwei Bu
DOI:10.1039/c9cc07114h
日期:——
An unexpected Michael addition-inspired ring-opening/closure cascade reaction of 3-hydroxyoxindoles with coumarin-3-carboxylates was developed to access new dihydrobenzofuran or dihydrobenzothiophene spirooxindoles in 68–98% yields. This reaction not only provides an expedient and convenient method to assemble dihydrobenzofuran spirooxindoles, but also establishes a new reaction mode of coumarin-3-carboxylates
Coumarin-3-formylpyrazoles have been synthesized and applied as 3-carbon synthons in reaction with 3-hydroxyoxindoles by using DABCO as the catalyst. A range of structurally diverse spiro-fused pentacyclic spirooxindoles, bearing a spirooxindole-γ-lactone and a 3,4-dihydrocoumarin substructure, could be smoothly obtained in good to excellent yields (up to 99%) with excellent diastereoselectivities
Enantioselective Construction of CF<sub>3</sub>-Containing Spirooxindole γ-Lactones via Organocatalytic Asymmetric Michael/Lactonization
作者:Zhong-Tao Yang、Jianhong Zhao、Wu-Lin Yang、Wei-Ping Deng
DOI:10.1021/acs.orglett.8b04039
日期:2019.2.15
A highly enantioselective Michael/lactonization cascade reaction of 3-hydroxyoxindoles with 3-trifluoroethylidene oxindoles was developed. The use of a cinchona-derived squaramide catalyst is essential in achieving high diastereo- and enantioselectivities. This reaction represents the first example of intramolecular amide C–N bondcleavage and lactonization of 3-hydroxyoxindoles with 3-trifluoroethylidene
Organocatalytic Asymmetric Michael/Cyclization Cascade Reactions of 3-Hydroxyoxindoles/3-Aminooxindoles with α,β-Unsaturated Acyl Phosphonates for the Construction of Spirocyclic Oxindole-γ-lactones/lactams
Enantioselective Michael/cyclization cascade reactions of 3-hydroxyoxindoles/3-aminooxindoles with α,β-unsaturatedacyl phosphonates by using a cinchonine derived squaramide as the catalyst were developed. A broad range of spirocyclic oxindole-γ-lactones/lactams could be obtained in moderate to excellent yields (up to 98%) with good to excellent diastereo- and enantioselectivities (up to >99:1 dr and
A novel Michael Addition and subsequent 4‐exo‐tet ring closure sequence with easily accessible N‐unsubstituted or N‐alkyl‐substituted oxindoles and phenyl vinyl selenone in aqueous basic conditions is described.