Diphenyl(N-alkyl-N-diphenylphosphinylmethyl)carbamoylmethylphosphine Oxides: Synthesis and NMR Spectroscopy Study

摘要

Modified tridentate carbamoylmethylphosphine oxides Ph2P(O)CH2N(R)CH2P(O)Ph-2 (R = Et, i-Pr, Bu, Oct) were synthesized by the reaction of phosphorylated amines Ph2P(O)CH2NHR (R = Et, i-Pr, Bu, Oct) with diphenylphosphinylacetic acid in the presence of diisopropylcarbodiimide or by reacting with diphenylphosphinylacetyl chloride. According to the H-1, C-13{H-1}, P-31{H-1} NMR spectroscopy data, in CDCl3 solutions, the modified carbamoylmethylphosphine oxides exist in two conformers in the ratio of approximately 1.3:1 (R = Et), 1.5 : 1 (R = i-Pr) or 1 : 1 (R = Bu, Oct).