Enantioselective construction of multifunctionalized spirocyclohexaneoxindoles through organocatalytic Michael–Aldol cyclization of isatin derived alkenes with linear dialdehydes
Asymmetric Synthesis of Spiro-3,3′-cyclopropyl Oxindoles via Vinylogous Michael Initiated Ring Closure Reaction
作者:Abhijit Manna、Harshit Joshi、Vinod K. Singh
DOI:10.1021/acs.joc.2c02402
日期:2022.12.16
A novel organocatalytic cascade approach for the synthesis of spiro-cyclopropyl oxindole derivatives has been developed. The methodology is based on asymmetric vinylogous Michael addition of 4-nitroisoxazole derivatives to N-Boc isatylidene malonates followed by intramolecularalkylation. Its remarkable stereocontrol, wide substrate scope, and scalability highlight this new developed strategy. Moreover
Metal-Free Regioselective Oxa-Michael Approach to Access Spirooxindole-Fused Tetrahydrofuran/Tetrahydropyran through [3 + 2]/ [4 + 2] Spirocyclization of Methyleneindolinones with Haloalcohols
作者:Amol T. Savekar、Ramesh A. Gaikwad、Suresh B. Waghmode
DOI:10.1021/acs.joc.4c00659
日期:2024.7.5
An efficient one-pot metal-free, base-catalyzed method has been developed for the regioselective [3 + 2]/[4 + 2] annulation reactions of electrophilic methyleneindolinones with haloalcohols to furnish spirooxindole derivatives under mild reaction conditions. This reaction afforded the corresponding products with two contiguous stereocenters including a quaternary center in good to excellent yield (up
开发了一种高效的一锅法无金属碱催化方法,用于亲电子亚甲基二氢吲哚酮与卤代醇的区域选择性[3 + 2]/[4 + 2]环化反应,在温和的反应条件下提供螺吲哚衍生物。该反应以良好至优异的产率(高达 95%)提供具有两个连续立体中心(包括四元中心)的相应产物,具有中等至良好的非对映选择性(高达 12.5:1 dr )和完全区域选择性。
Phosphine- and Nitrogen-Containing Lewis Base Catalyzed Highly Regioselective and Geometric Selective Cyclization of Isatin Derived Electron-Deficient Alkenes with Ethyl 2,3-Butadienoate
作者:Xiu-Chun Zhang、Shu-Hua Cao、Yin Wei、Min Shi
DOI:10.1021/ol1031798
日期:2011.3.4
An interesting phosphine-containing Lewis base catalyzed highly regioselective [3 + 2] cycloaddition and a novel nitrogen-containing Lewis base catalyzed highly geometric selective [4 + 2] cycloaddition of isatin derived alpha,beta-unsaturated diesters with alpha-allenic ester have been disclosed to give the corresponding cyclic products in good to excellent yields under mild conditions. A plausible reaction mechanism has also been proposed on the basis of previous literature and our own investigation.