Synthesis of organophosphorus compounds containing different Y,C,Y-chelating ligands. Crystal structure of P ← N intramolecularly coordinated diselenoxophosphorane
reported. While the presence of ligands L2,3 afforded the synthesis of dichlorophosphines L2PCl2 (2) and L3PCl2 (3), the use of ligand L1 resulted to the isolation of O → P coordinated 1-chloro-7-(t-butoxymethyl)-3H-2,1-benzoxaphosphole (1) as the result of the cyclization type reaction of dichlorophosphines L1PCl2. The hydrolysis of compounds 1–3 as well as the preparation of phosphanes L2PH2 (7), L3PH2
(Ar=[C6H3(CH2NMe2)2-2,6]) 3 undergoes hydride abstraction on treatment with trityl cation to give the stabilized phosphenium ion [ArPH]+BF4−, 4a. The same cation was prepared by reaction of 3 with BrCCl3 (4b) and also by lithiation of 3 followed by treatment with I2 (4c). ArLi reacts with PX3 (X = Cl or Br) to give the stabilized phosphenium ion [ArPX]+X− which affords 3 by LiAlH4 reduction. In contrast, DIBAL-H reduction