Chromium-catalyzed reductive alkylation of N-heteroarenes using alkyl formates as transfer hydroalkylation reagents

Abstract

Alkyl formates are employed as transfer hydroalkylation reagents in the reductive alkylation of N-heteroarenes to saturated azacycles. This is achieved using a well-defined chromium catalyst and LiI as a promoter via the cleavage of the C−O σ-bond of the formate, generating a hydride nucleophile and an alkyl electrophile. The reaction produces volatile CO₂ as the only byproduct, making the method atom-efficient and environmentally friendly.