Ferrocenylamines 2. Reductive methylation of secondary ferrocenylamines and ferrocenylaldimines: Synthesis, characterization of [(N-methyl-N-aryl)amino]methylferrocenes, 1-[(N-methyl-N-phenyl)amino]ethylferrocene and crystal structures of [(η5-C5H5)Fe(η5-

The reactions of ferrocenylaldimines (II) [(η5-C5H5)Fe(η5-C5H4CHdouble bond; length as m-dashNC6H4-R)] (R = 4-CH3O (a), 4-CH3 (b), H (c), 4-Cl (d), 3-Cl (e), 4-NO2 (f), 3-NO2 (g)) and ferrocenylketimine (I) [(η5-C5H5)Fe (η5-C5H4CH3Cdouble bond; length as m-dashNC6H5)] with sodium borohydride in ethanol or lithium aluminum hydride in THF resulted in secondary ferrocenylamines 3, 4. Reductive methylation of 3 (or II) and 4 with aqueous formaldehyde and sodium cyanoborohydride all gave out corresponding N-methylated tertiary ferrocenylamines 5 [(η5-C5H5)Fe(η5-C5H4CH2N(CH3)C6H 4-R)] (R = same as above mentioned) and 2, respectively, in good yields. All these tertiary ferrocenylamines 3–5 were characterized structurally. The crystal structures of 3d and 5a were also determined. Compound 3d is monoclinic, space group P2(1)/n, with a = 9.7585(14) Å, b = 11.5267(17) Å, c = 13.0830(19) Å and β = 97.969(2)°. Compound 5a is orthorhombic, space group Pccn, with a = 13.752(2) Å, b = 22.095(3) Å, c = 10.6421(16) Å.