Addition reactions of compounds with the P(:O)H group to fluorinated ketimines

Abstract

N, N′-Disubstituted derivatives of 5,6-benzo-2 H-2-oxo-1,3,2-diazaphosphorinan-4-one ( 2–6), 1,3,5-trimethyl-2 H-2-oxo-1,3,5-triaza-2 λ 4-phosphorinan-4,6-dione ( 12), phenylphosphinic acid ( 14) and dimethylphosphine oxide ( 16) have been added across the CN double bond of phenyltrifluoromethylketimine ( 1) in the presence of catalytic quantities of triethylamine, leading to the formation of N, N′-disubstituted derivatives of 5,6-benzo-2-(1-amino-1-phenyl-2,2,2-trifluoroethyl)-2-oxo-1,3,2-diazaphosphorinan-4-one ( 7–11), 2-(1-amino-1-phenyl-2,2,2-trifluoroethyl)-1,3,5-trimethyl-2-oxo-1,3,5-triaza-2λ 4-phosphorinan-4,6-dione ( 13), phenyl-(1-amino-1-phenyl-2,2,2-trifluoroethyl)phosphinic acid ( 15) and dimethyl-(1-amino-1-phenyl-2,2,2-trifluoroethyl) phosphine oxide ( 17), respectively. Addition of N, N′-disubstituted derivatives of 5,6-benzo-2 H-2-oxo-1,3,2-diazaphosphorinan-4-one ( 2–4) and ( 21) and of 1,3,5-trimethyl-2 H-2-oxo-1,3,5-triaza-2 λ 4-phosphorinan-4,6-dione ( 12) across the CN double bond of bis(trifluoromethyl)ketimine ( 20) resulted in N, N′-disubstituted derivatives of 5,6-benzo-2-(1-amino-1-trifluoromethyl-2,2,2-trifluoroethyl)-2-oxo-1,3,2-diphosphorinan-4-one ( 22–25) and 2-(1-amino-1-trifluoromethyl-2,2,2-trifluoroethyl)-1,3,5-trimethyl-2-oxo-1,3,5-triaza-2λ 4-phosphorinan-4,6-dione ( 26), respectively. The compounds were characterised by 1H, 13C, 19F and 31P NMR spectroscopy, mass spectrometry, elemental analysis and a single-crystal X-ray structure analysis in the case of compound 22. The heterocycle displays an envelope conformation. The structure shows one intermolecular hydrogen bond, leading to the formation of centrosymmetric dimers.