Asymmetric Cross [10+2] Cycloadditions of 2‐Alkylidene‐1‐indanones and Activated Alkenes under Phase‐Transfer Catalysis
作者:Yang Yang、Ying Jiang、Wei Du、Ying‐Chun Chen
DOI:10.1002/chem.201904930
日期:2020.2.6
have been employed in diverse challenging higher-order cycloaddition reactions. Here, the first chemoselective and asymmetric cross [10+2] cycloaddition reaction between activated 2-alkylidene-1-indanones and a variety of electron-deficient alkenes has been developed, relying on the in situ generation of dearomative 1-hydroxyl isobenzofulvene anion intermediates under the catalysis of a newly designed
An efficient organocatalytic Michael-aldol cascade reaction for the asymmetric synthesis of spirocyclic oxindole derivatives fused with tetrahydrothiophenes has been developed through a formal [3+2] annulation strategy.
A highlydiastereoselective and regioselective [2+2]-cycloaddition reaction of 3-ylideneoxindoles has been accomplished using visible light photocatalysis. This visible light photocatalytic protocol allows an expedient access to diversely functionalized and structurally constrained oxindolederivatives containing two spirocycles and four stereogenic centers, including two all-carbon quaternary centers
Catalytic Asymmetric Michael Addition/Cyclization of Isothiocyanato Oxindoles: Highly Efficient and Versatile Approach for the Synthesis of 3,2′-Pyrrolidinyl Mono- and Bi-spirooxindole Frameworks
作者:Yi-Ming Cao、Fang-Fang Shen、Fu-Ting Zhang、Rui Wang
DOI:10.1002/chem.201204114
日期:2013.1.21
A‐spiro‐ing to greatness: The catalytic asymmetric Michael addition/cyclization of isothiocyanato oxindoles has been realized. This versatile approach provides an easy and highly efficient way to access not only the enantioselective synthesis of 3,2′‐pyrrolidinyl spirooxindole frameworks, but also the construction of enatiomerically enriched bi‐spirooxindoles containingthreecontiguous stereocenters
A novel asymmetric nucleophilic epoxidation for alpha-ylideneoxindole esters has been successfully devised, resulting in enantioenriched spiro compounds with two new contiguous stereocenters. The employed (S)-alpha,alpha-diphenylprolinol functions as a bifunctional catalyst, creating a complex H-bond network in conjunction with a substrate and an oxidant.