Hydroborative reduction of amides to amines mediated by La(CH2C6H4NMe2-o)3

Abstract

The deoxygenative reduction of amides to amines is a great challenge for resonance-stabilized carboxamide moieties, although this synthetic strategy is an attractive approach to access the corresponding amines. La(CH₂C₆H₄NMe₂-o)₃, a simple and easily accessible lanthanide complex, was found to be highly efficient not only for secondary and tertiary amide reduction, but also for the most challenging primary reduction with pinacolborane. This protocol exhibited good tolerance for many functional groups and heteroatoms, and could be applied to gram-scale synthesis. The active species in this catalytic cycle was likely a lanthanide hydride.