Recent advances in spirocyclization of maleimides via transition-metal catalyzed C-H activation

In recent years, the maleimide scaffold has received a great deal of attention in C-H activation. Several types of products can be constructed using maleimides as a coupling partner. Alkylation, alkenylation, annulation, dehydrogenative annulation and spirocyclization are various reactions shown by maleimides in C-H activation. Thus, the maleimide scaffold has been extensively studied in the last few years in C-H activation owing to its unique reactivity. Among the diverse class of reactions of maleimides, spirocyclization is a less explored reaction. The spirocycles, in particular the spirosuccinimides are interesting candidates in drug discovery and materials chemistry. Therefore the method of spirocyclization of maleimides via C-H activation becomes an important strategy for the synthesis of a diverse array of spirosuccinimides. This review summarizes the reports available in this field from 2015-2023 and also highlights the scopes and prospects of this method.