Synthesis of chiral palladium oxazolidine and imine complexes: Investigation the oxazolidine-imine conversion by DFT method

Abstract

Reaction of 2-pyridinecarboxaldehyde with l-Alaninol (as a chiral amine) or 2-amino-2-methyl-1-propanol (AMP) in the presence of PdCl2 produced the new and attractive palladium(II) complexes which were synthesized by in situ method. The presence of an extra methyl group in AMP other than l-Alaninol induced the different chelating mode and, therefore, several structurally different palladium complexes obtained. Correspondingly, the chiral amine with PdCl2 produced the imine product, (Iminol (1)), and an oxazolidine compound (Imizol (1′)) as minor product. Also, the use of AMP in formation of palladium complexes led to the synthesis of imine (Ampynol (2)) and oxazolidine (Ampyzol (3)) complexes. Besides utilizing of crystallization technique for the separation of the isomers, elemental analysis (CHN), FT-IR, 1H and 13C NMR spectroscopies were used for characterization of the synthesized compounds. In addition, structures of palladium complexes Iminol and Ampyzol were identified by single crystal X-ray diffraction method and investigation of the equilibrium between imine and oxazolidine complexes were carried out by DFT method.The in vitro studies revealed that the compounds have considerable cytotoxicity against human MCF-7 and HeLa cancer cell lines.