Beyond conventional construction of the phthalimide core: a review

Abstract

Phthalimides are a privileged structural motif frequently found in natural products, pharmaceuticals and organic materials. The most common strategy for their synthesis involves the condensation of phthalic acids/anhydrides with primary amines. However, the target-oriented synthesis of functionalized phthalimides has presented long-standing challenges to the synthetic community. The present review emphasizes the different strategies exploited in the past decade (2010–2021) towards the construction of the phthalimide core beyond conventional routes, which are classified as: (1) the carbonylative cyclization of aromatic amides, (2) the carbonylative cyclization of o-dihaloarenes/o-haloarenes, (3) the cyclization of isocyanate/isocyanide with arenes, (4) cyclization involving maleimides and (5) miscellaneous synthesis. Most of the reactions discussed in this review involve readily available starting materials, cheap catalysts, and are one-pot processes that are environmentally benign with operational simplicity. Interesting mechanisms of representative transformations have also been highlighted. Some of the methodologies have been useful in the gram-scale synthesis of biologically active and fluorescent phthalimide frameworks.