Silver-Mediated Cα(sp3)-H Functionalization of Primary Amines: An Oxidative C-N Coupling Strategy for the Synthesis of Two Different Types of 1,2,4,5-Tetrasubstituted Imidazoles

A new silver(I)-mediated C-alpha(sp3)-H bond functionalization of primary amines and subsequent oxidative C-N cross-coupling reaction has been demonstrated. This protocol provides a simple, highly efficient, and straightforward approach to form significantly diverse 1,2,4,5-tetrasubstituted imidazoles. In this course of the reaction, a stoichiometric amount of Ag2CO3 was employed. Upon completion of reaction, the silver species was successfully recycled and reused without any loss of activity. Good to excellent yields of the products were readily achieved by using this selective oxidative C-N coupling, which was promoted by a crucial silver(I) salt.