Efficient and Highly Chemoselective Direct Reductive Amination of Aldehydes using the System Silane/Oxorhenium Complexes

This work reports a novel method for direct reductive amination of aldehydes with silanes catalyzed by several high-valent oxorhenium(V) and oxorhenium(VII) complexes. The catalytic system PhSiH3/ReIO2(PPh3)(2) (2.5 mol%) was very efficient for the synthesis of secondary amines and highly chemoselective, tolerating a wide range of functional groups such as -NO2, -CF3, -SO2R, -CO2R, -F, -Cl, -Br, -I, -CN, -OH, -OCH3, -SCH3, -NCOR, and double bonds. This novel method was also employed in the synthesis of tertiary amines with moderate yields.