Chiral ferrocenylimine alcohols and corresponding reduced ferrocenyl secondary amine alcohols: synthesis, X-crystal structures and characterization

Four ferrocenylimine alcohol compounds, [Fe(η⁵-C₅H₅){η⁵-C₅H₄CH=NCH(R)CH₂OH}] (R = Et, (R)-HL1, (S)-HL1; R = Bn, (R)-HL2, (S)-HL2), were synthesized by condensation reaction from ferrocenecarboxaldehyde and different chiral aminoalcohols. Reduction of HL1 and HL2 with sodium borohydride afforded four corresponding ferrocenyl secondary amine alcohol compounds, [Fe(η⁵-C₅H₅){η⁵-C₅H₄CH₂–NHCH(R)CH₂OH}] (R = Et, (R)-HL3, (S)-HL3; R = Bn, (R)-HL4, (S)-HL4). The crystal structures of (R)-HL1, (S)-HL1, (R)-HL2 and (S)-HL3·HCl were determined by single crystal X-ray diffraction. In addition, all compounds HL1–4 were characterized by ¹H NMR, ¹³C NMR, FT-IR, and UV–Vis spectroscopies.