Synthesis of Spirocyclopropane Scaffolds: A Review

Abstract This review highlights different synthetic strategies for preparing a spirocyclopropane moiety, covering the literature from 1989 to 2024. The spirocyclopropane moiety is a structural scaffold that is used to access synthetic libraries of highly functionalized spirocarbo- and heterocyclic molecules. The review showcases different routes for the synthesis of spirocyclopropanes that utilize distinct precursors and methodologies, including cascade reactions, cyclopropanation, Michael-initiated ring closure (MIRC), and one-pot and multicomponent synthesis. These discussions are organized around the oxindole core, which include isatin, oxindole, 3-chlorooxindole, and 3-alkenyl oxindoles. Additionally, this review explores various ylides and other techniques. The goal of this review is to provide a background for synthetic chemistry researchers to develop new ideas and novel synthetic routes to spirocyclopropanes. 1 Introduction 2 Synthesis of Spirocyclopropanes from 3-Chlorooxindole Derivatives 3 Synthesis of Spirocyclopropanes from Isatin Derivatives 3.1 Synthesis of Spirocyclopropanes from Alkylidene Oxindole Derivatives 3.2 Synthesis of Spirocyclopropanes from Diazooxindole Compounds 4 Synthesis of Spirocyclopropanes from 1,3-Diones 5 Synthesis of Spirocyclopropanes from N-Ylides 6 Synthesis of Spirocyclopropanes from S-Ylides 7 Miscellaneous Syntheses of Spirocyclopropanes 8 Conclusion 9 List of Abbreviations