Planar-chiral 1,1′-diaminoferrocenes

Planar-chiral homologues of 1,1′-diaminoferrocene, which bear a single additional substituent adjacent to one of the amino groups, are prepared as racemic mixtures in a few steps and in good yields from ferrocene. Various substituents relevant to steric shielding, coordination and further functionalisation are used, giving access to ferrocene-based planar-chiral diimines and diamines as well as stable N-heterocyclic carbenes and tetrylenes by transformations analogous to procedures established for 1,1′-diaminoferrocene. Planar-chiral homologues of the important synthon 1,1′-diaminoferrocene, which bear a single additional substituent adjacent to an amino group, are efficiently synthesised on a gram scale.