Ninhydrin Adducts as Valid Synthon in Organic Synthesis: A Review

Ninhydrin (1,2,3‐indanetrione hydrate) is a powerful electrophile having enormousapplications in organic and bio‐organic sciences. In the last few years, reactivity of various ninhydrin adducts have been exploited extensively for the development of diverse organic scaffolds. The present review focuses on the applications of readily accessible ninhydrin adducts as building block towards the synthesis of a variety of compounds including N‐inserted compounds, spiro‐heterocycles, medium ring compounds, polycyclic molecules, propellanes, cycloadducts, allylic anions, axially chiral molecules etc. Interestingly, some of the compounds have profound biological activities and a few display important photophysical properties. Most of the reactions described here are simple and carried out with easily available starting materials under green conditions.