Reactions of 1,1,3,3-tetrakis(dimethylamino)-1λ5,3λ5-diphosphete with diphenylchlorophosphane and methyl iodide

1,1,3,3-Tetrakis(dimethylamino)-1λ⁵,3λ⁵-diphosphete, 1, reacts with diphenylchlorophosphane to yield 1,1,3,3-tetrakis(dimethylamino)-4-diphenylphosphanyl-1,2-dihydro-3λ⁵-1,3]diphosphetium chloride, 2, or, depending on the reaction conditions, the isomer compound 3. The cation of 2 is deprotonated by LiNSi(CH₃)₃]₂ to give the diphenylphosphanyl-substituted derivative of 1, i.e., compound 4. Methyl iodide adds to 1 to form 1,1,3,3-tetrakis(dimethylamino)-4-methyl-1,2-dihydro-3λ⁵-1,3]diphosphetium iodide, 6. Deprotonation of 6 with n-butyllithium leads to the monomethyl derivative of 1, i.e., compound 7. Physical properties, NMR spectra, and mass spectra of compounds 2–4, 6, and 7 are described. The results of the X-ray structural analysis of 6 are reported and discussed. © 1996 John Wiley & Sons, Inc.