Synthesis, characterization of [{(N-methyl-N-benzyl)amino}methyl]-ferrocenes and their cyclopalladated complexes:: Crystal structure of σ-Pd[(η5-C5H5)Fe(η5-C5H3CH2N(CH3)CH2C6H4NO2-4)]Cl(PPh3)

Condensation of aminomethylferrocene (1) and substituted benzaldehydes resulted in aldimines 2a-c which followed by reduction with sodium borohydride to give 3a-c. N-methylation of 3a-c with HCHO/NaCNBH3/HOAc led to 4a-c. Treatment of 4a-c with sodium palladium tetrachloride in the presence of sodium acetate afforded cleanly cyclopalladated 5a-c in which configurations consisted of the RNRC, SNSC. The preferable activation Of C-Ferrocenyl-H bond over C-Phenyl-H bond was also observed. All compounds 2-5 were characterized by elemental analysis, IR and H-1 NMR. In addition, the molecular structure of 5c was confirmed by single crystal X-ray diffraction. The possible mechanism for the formation of 5 was also discussed. (c) 2006 Elsevier B.V. All rights reserved.