Iminophosphoranes: Synthesis, evolution of synthesis by 31P-NMR, DFT calculations and antioxidant activity

Abstract

New mono-iminophosphoranes and new bis-iminophosphoranes 3 were prepared by reaction of triphenylphosphine or tri-alkyl phosphite and azides 1. In order to reduce the reaction time and detect the phosphazides intermediates 2, the reactions of synthesis of iminophosphoranes 3 were evaluated by 31P-NMR spectroscopy. Two phosphazides intermediates 2 in the Z/E form were detected. Density Functional Theory (DFT) calculations were performed at B3LYP/6-311++G** and M062X/def2TZVP to determine the relative stability of Z/E intermediates. Antioxidant activities of iminophosphoranes 3 were evaluated by a 1,1-diphenyl-2-picryl hydrazyl (DPPH) test. The compounds were characterized on the basis of IR, NMR spectroscopy (1H, 13C and 31P) and by HRMS.