(η6-Arene)tricarbonylchromium complexes derived from N,N-dimethylbenzylamine or from benzyl methyl thioether undergo a cyclomanganation reaction when treated with PhCH2−Mn(CO)5 in boiling heptane. The manganation process is selective and involves solely aromatic C−H bond activation that yields bimetallic and trimetallic compounds, respectively, when compounds such as [(η6-C6H5CH2R)Cr(CO)3] (R = N(CH3)2, SCH3) and the diamine [{η6-C6H4-1,3-[CH2N(CH3)2]}Cr(CO)3] are reacted. Cases of transmetalation reactions consisting of the transfer of a Mn(CO)4 moiety from one aromatic ligand to another are observed with free aromatic ligands and with chromium π-complexed ligands. Two examples of bimetallic and trimetallic compounds, [(2-η)-Mn{[η6-3,5-(CH3O)2-C6H2-CH2N(CH5)2]Cr(CO)3}(CO)4] (2) and [(4-η:6-η)-{Mn(CO)4}2{{η6-C6H2-1,3[CH2N(CH3)2]2}Cr(CO)3}] (6a), respectively, were characterized by X-ray diffraction analysis. Both complexes bear distorted Mn(CO)4 units with the ancillary amino ligand pointing away from the chromium.

The nucleophilic addition of PhLi to tetracarbonyl[3-methyl-2-{(η6-phenyl)tricarbonylchromium(0)}pyridine]rhenium(I) yields the air-stable (exo-benzoyl)(tricarbonyl)[3-methyl-2-{(η6-phenyl)tricarbonylchromium(0)-κ C 2‘}pyridine-κ N]rhenate(I) that has been isolated and characterized by X-ray diffraction analysis and other spectroscopic methods. A similar treatment applied to cyclomanganated (η6-arene)Cr(CO)3 analogues with a nucleophile such as MeLi provides a new route to the synthesis of ortho disubstituted (η6-acetophenone)Cr(CO)3 derivatives.