Carboxylic acids as enabling directing groups in C−H activation and functionalization: A decade review

Over the last decade, carboxylic acids have drawn profound interest in synthetic chemistry, due to its exceptional adaptability as traceless directing groups (TDGs) in the construction of complex organic molecules in the realm of C−H activation. The chameleonic nature of such privileged functionality startles each time in portraying its diversity by either trace elimination of acid group or by inherent annulation which makes an aura of distinction from other conventional DGs. In this review, the recent developments of carboxylic acid as a directing group (DG) are emphasized from the year 2017 with apparent late-stage applications. In view of synthetic chemistry context and substrate scope, innovative avenues are addressed along with multiple approaches in utilising carboxylic acids as efficient DGs.