Iron(II) complexes featuring chiral PNNP diferrocene: Synthesis and characterization of potential hydrogenation catalysts

•Chiral PNNP biferrocene with either imine or amine nitrogen coordination sites were synthesized.•Only the imine-type formed dicationic iron complexes.•Complexes were active in hydrogenation and transfer hydrogenation reactions.

Chiral non-racemic PNNP biferrocene with either imine or amine nitrogen coordination sites were synthesized. Only the imine-type formed dicationic iron complexes of the type [Fe(PNNP)(NCMe)2][BF4]2 and [Fe(PNNP)(NCMe)(CO)][BF4]2. Some of these complexes were found to be active in hydrogenation and transfer hydrogenation reactions but their applicability is limited by moderate-to-low conversion and enantioselectivity.

Graphical abstractChiral non-racemic PNNP biferrocene ligands with either imine or amine nitrogen coordination sites were synthesized. Only the imine-type ligands formed dicationic iron complexes of the type [Fe(PNNP)(NCMe)2][BF4]2 and [Fe(PNNP)(NCMe)(CO)][BF4]2.Figure optionsDownload full-size imageDownload as PowerPoint slide