Multisite solid (NHC)NN-Ru-catalysts for cascade reactions: Synthesis of secondary amines from nitro compounds

Supported ruthenium complexes based on electron-rich (NHC)NN-pincer-type ligands selectively catalyze the formation of substituted amines from nitroaromatics and carbonyl compounds through a series of consecutive steps which involves the reduction of nitro group to amine, the formation of an imine or iminium ion intermediate, followed by in situ reduction to an alkylated amine of higher order in a single operation. Solid complexes result active and recyclable catalysts and no deactivation was observed after repeated recycling.