Reduction of Schiff Bases with Isopropyl Alcohol and Aluminum Isopropoxide in the Presence of Raney Nickel

Article abstract of DOI:10.1021/jo00211a026

The reduction of several N-alkyl and N-aryl ketimines to the corresponding secondary amines is described.The reaction, which generally proceeds in high yield, is effected by isopropyl alcohol and aluminium isopropoxide in the presence of Raney nickel.In the absence of the nickel catalyst, that is, under the Meerwein-Ponndorf-Verley conditions, the reaction takes a different route and N-isopropylamines are formed at preference to the direct reduction products.Without the aluminum alkoxide the reduction proceeds only for a small percentage.This reaction, besides offering a new method for the synthesis of secondary amines, represents the first example where the couple aluminum alkoxide/Raney nicel is used in catalytic transfer hydrogenation reactions.