Synthetic Approaches to Access Indolin-3-ones

Indolin-3-one constitutes an important core in naturally occurring bio-active alkaloids, dyes, and synthetic compounds. Though endowed with an interesting biological profile, this core received comparatively less attention than its well-explored isomer indolin-2-one. Herein, we review the synthetic strategies for constructing this oxygenated indole motif during the past decade (2014-2024). The metal-mediated and metal-free methods have been covered, with a discussion of the key reactions and the mechanistic scenario prevailing in the strategies. This one-stop platform will undoubtedly enrich the researchers and help expand the research domain in this area.