Alkyl Formates as Transfer Hydroalkylation Reagents and Their Use in the Conversion of Imines to Alkylamines

Easily accessible via a simple esterification of alcohols with formic acid, alkyl formates are used as a novel class of transfer hydroalkylation reagents, CO2 acting as a traceless linker. As a proof-of-concept, their reactivity in the transfer hydroalkylation of imines is investigated, using a ruthenium-based catalyst and LiI as promoter to cleave the C−O σ–bond of the formate scaffold. Providing tertiary amines, the reaction displays a reverse and complementary regioselectivity compared to previously reported transfer hydroalkylation strategies.