Synthesis, Characterization Of Three Tertiary Ferrocenylbenzylamines And Their Cyclometallations (M=Hg, Pd)

Condensation of acetylferrocene and series substituted benzyl amines in ether at room temperature resulted in ferrocenylaldimines [(η⁵-C₅H₅)Fe[η⁵-C₅H₄C(CH₃)=N CH₂C₆H₄-R)],R=4-MeO(a),4-Me(b),H(c) in moderate yields. Reduction of these imines with sodium borohydride in methanol or lithium aluminum hydride in THF produced quantitative secondary ferrocenylamines [(η⁵-C₅H₅)Fe[η⁵-C₅H₄CH(CH₃) NHCH₂C₆H₄-R)], R=4-MeO(a), 4-Me(b), H(c). Reductive methylation of secondary ferrocenylamines as mentioned above with sodium cyanoborohydride, formaldehyde in acetic acid gave out the corresponding tertiary ferrocenylamines [(η⁵-C₅H₅)Fe [η⁵-C₅H₄CH(CH₃)N(CH₃)CH₂C₆H₄-R)], R=4-MeO(a), 4-Me(b), H(c).Ortho-mercuration of these tertiary amines afforded orthomercurated complexes in which an intramolecular N-Hg coordination pattern was observed. Cyclopalladation of these amines led to racemic cyclopalladated complexes in low yields. The stereoselective C-H activation was observed. The structures the compounds as mentioned before were characterized by elemental analysis, IR and 1H-NMR. In addition, the structures of three cyclopalladated complexes and one mercurated complex were also confirmed by X-Ray single crystal diffraction.