Divergent Reactivity of Mixed-Ligand Manganese(I) Carbonyl–Isocyanide Complexes toward Primary Amines

The reactivity of the mixed-ligand carbonyl–isocyanide complexes fac-[Mn­(CNR)­(CO)₃(bipy)]⁺ (1a, R = Ph; 1b, R = xylyl; 1c, R = Me; 1d, R = CH₂Ph; 1e, R = tBu) with the primary amines NH₂Me and NH₂CH₂CH₂CH₂Br has been studied. Nucleophilic addition of the amine to a carbonyl ligand or to the isocyanide ligand may take place, depending on the nature of the amine, the substituent in the isocyanide ligand, and the reaction conditions; even replacement of a carbonyl ligand may occur. Thus, a variety of carbamoyl (2a–e), diaminocarbene (3a–d, 5a–d), N,O-heterocyclic carbene (6b), and amine (4b,c) complexes of manganese­(I) has been obtained and characterized by spectroscopic and/or X-ray diffraction methods.