Aminophosphines derived from morpholine and N-methylpiperazine: Synthesis, oxidation reactions and transition metal complexes

The synthesis, derivatization and coordination behavior of N-diphenylphosphinomorpholine (1) and N-diphenylphosphinopiperazine (2) is described. Ligands 1 and 2 react with elemental sulfur or selenium to give the corresponding chalcogenides in good yield. Reaction of 1 with paraformaldehyde leads to the insertion of methylene into P–N bond to give phosphine oxide, Ph2P(O)CH2NC4H8O in quantitative yield. Treatment of 2 with [Pd(COD)Cl2] produces both the mononuclear [PdCl2{(Ph2PNC4H8O)-κP}2] and the chloro-bridged dinuclear complex, [(OC4H8NPh2P)Pd-(μ-Cl)Cl]2 whereas the similar reaction of 2 with [Pt(COD)Cl2] affords only the mononuclear complex [PtCl2{(Ph2PNC4H8O)-κP}2]. Interestingly, ligand 2 reacts with Mo(0), W(0), Ru(II), Pd(II), Pt(II) and Au(I) derivatives to furnish exclusively mononuclear complexes. The molecular structures of Ru(II) and Pd(II) dimer have been confirmed by X-ray studies.

The synthesis, derivatization and metal complexes of morpholine and N-methylpiperazine derived tertiary phosphines are described.Figure optionsDownload as PowerPoint slide