Heteroleptic Dirhodium(II) Complexes with Redox‐Active Ferrocenyl Ligands: Synthesis, Electrochemical Properties, and Redox‐Responsive Chemoselectivity in Carbene C−H Insertion

A series of original heteroleptic dirhodium(II) complexes (4 a–j) formula [Rh2(OAc)3(L)], where L is a redox-active ferrocenecarboxylate ligand, has been prepared. These have characterised by NMR, mass spectrometry and cyclic voltammetry. All show quasi-reversible redox behaviour for the ferrocenyl unit. The latter can be selectively oxidised [N(4-C6H4Br)3]+BF4−. Four selected 4 a, b, f i, evaluated as catalysts intramolecular decomposition diazo compound 5. ratio between aromatic substitution product 6 aliphatic C−H insertion 7 increases (up to 19 % increase) when using in situ generated form a+BF4− i+BF4−). This shows that oxidation ligand an effect on chemoselectivity dirhodium-catalysed decomposition, thus electronic properties complex tuned without exchanging ligands.