KI-Catalyzed Oxidative Cyclization of Enamines and t BuONO to Access Functional Imidazole-4-Carboxylic Derivatives.

A simple protocol for the noble-metal-free oxidative cyclization of enamines and ^t BuONO has been developed. This KI-mediated formal [4 + 1] cycloamination reaction provides a practical strategy for the synthesis of imidazole-4-carboxylic derivatives using ^t BuONO both as an aminating reagent and oxidant. The reaction features wide substrate scope and good functional tolerance for enamine compounds, even the unactivated ones.