Nucleophilic catalysis of p-substituted aniline derivatives in acylhydrazone formation and exchange

Org Biomol Chem. 2021 Sep 7;19(33):7202-7210. doi: 10.1039/d1ob00871d. Epub 2021 Aug 13.

Abstract

Hydrazone bond formation is a versatile reaction employed in several research fields. It is one of the most popular reversible reactions in dynamic combinatorial chemistry. Under physiological conditions, hydrazone exchange benefits from the addition of a nucleophilic catalyst. We report a mechanistic study and superior performance of electron-rich p-substituted aniline derivatives as catalysts for efficient hydrazone formation and exchange in both protic and aprotic solvents. Rigorous kinetic analyses demonstrate that imine formation with 3-hydroxy-4-nitrobenzaldehyde and aniline derivatives proceeds with unprecedented third-order kinetics in which the aldehyde consistently shows a partial order of two. Computational investigations provide insights into the mechanisms of these transformations.

Publication types

  • Research Support, Non-U.S. Gov't