Lewis acid catalyzed annulation of spirocyclic donor–acceptor cyclopropanes with <i>exo</i>-heterocyclic olefins: access to highly functionalized bis-spirocyclopentane oxindole frameworks
作者:Kuldeep Singh、Sourav Pramanik、Trevor A. Hamlin、Biplab Mondal、Dinabandhu Das、Jaideep Saha
DOI:10.1039/c9cc03393a
日期:——
Lewisacidcatalyzedhighly efficient [3+2] annulation of spirocyclic Donor–Acceptorcyclopropanes (DACs) with exo-heterocyclic olefins is reported to furnish various biologically relevant dispiro-2,3-dioxopyrrolidine[cyclopentane]oxindole and dispiropyrazolone[cyclopentane]oxindole frameworks. This report highlights the use of oxindole-activated spiro-DACs as potential synthons to access complex dispirocarbocyclic