Synthesis and Crystal Structures of Novel Optical Active Planar Chiral Cyclopalladated Ferrocenylimine Derived from L-phenylalaninol

Abstract

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 μ-Cl-bridges cleavage step. In addition, compound 3 possess 1D helical chain structures with 2₁ screw axes along the b-direction.

Keywords:

• L-phenylalaninol
• crystal structure
• ferrocenylimine
• planar chiral palladacycle

This work was supported by the National Natural Science Foundation of China (20572102) and the Natural Science Foundation of Henan Province (611021800).