Recent advances in the synthesis of C2-spiropseudoindoxyls

Compared with the numerous reviews on the construction of C3 spirooxindoles, few reviews have examined the synthesis of structurally analogous C2-spiropseudoindoxyl derivatives. This scaffold has attracted substantial attention from synthetic chemists because of its relevance to medicinal chemistry. This review summarizes the recent progress in the synthesis of many heterocycle and carbocycle fused spiropseudoindoxyl compounds. The article is divided into sections according to the type of catalysis, including metal catalysis, high-iodine reagent mediation, and organic catalysis. We also discuss challenges and future directions based on the progress in the field. We believe that this review will update researchers focused on the synthesis of C2-spiropseudoindoxyl compounds and will encourage further growth in this field.