N‐Carboxyanhydrides (NCAs): Unorthodox and Useful Reagents for Amide Synthesis

Abstract

AbstractN‐Carboxyanhydrides (NCAs) are compounds derived from the addition of a carboxylic acid to an isocyanate, and are known to form amides readily with the release of CO2 as a by‐product. NCAs have been known for over 120 years, but despite their lengthy history, have remained so far overshadowed by more traditional approaches to amide bond formation. In this review, the potential utility of NCAs in the context of amide bond formation is reviewed and their preparation, reactivity and practical application are also discussed.