Synthesis and crystal structures of novel optical active planar chiral cyclopalladated ferrocenylimine derived from L-phenylalaninol

摘要

Reaction of ligand (s)-1 with Li2PdCl4 leads to a chloro-bridged dimer of cyclometallated ferrocenylimine syn-(+)-(Rp,Sc,Rp,Sc)-2 with both planar and central chirality via C-H activation. Treatment compound 2 with PPh3 afford the stable cyclometallated compound (+)-(Rp,Sc)-3 in excellent yields (92%). Both complexes were fully characterized by IR, 1H NMR and specific rotations. X-ray analysis revealed that the absolute planar chirality at the ferrocenyl moiety and the central chirality at the C atom in syn-(+)-(Rp,Sc,Rp,Sc)-2 and (+)-(Rp,Sc)-3 are both retained during the -Cl-bridges cleavage step. In addition, compound 3 possess 1D helical chain structures with 21 screw axes along the b-direction.