A novel silane reagent for the chemoselective reductive functionalization of amides

The reductive functionalization of amides has emerged as a transformation of great interest in recent years: the ubiquitous nature and robustness of the amide functionality make it an attractive handle for late-stage functionalization of complex molecules. ¹ Several protocols for the reductive functionalization of amides have been disclosed recently, exploiting the high Lewis basicity of amides to enable chemoselective functionalization. ^2-4 However, these methods often rely on precious metal catalysis, cryogenic temperatures or hazardous activating agents. Herein we present the synthesis, characterization and application of a novel silyl sulfonate reagent, which acts in tandem as both an amide activator and reducing agent. This reagent enables selective, transition metal-free access to iminium ion intermediates from amides, which can then be functionalized with a range of organometallic nucleophiles