Synthesis, multinuclear NMR spectra, and x-ray structures of (Bu2PNP)-Bu-t(I)Bu-t(2) and EPR2NP(I)R-2 (E = Se, Te; R = Pr-i, Bu-t)

Two synthetic routes to bifunctional P(V)/P(V) compounds of the type EPR2NP(I)R-2 have been developed. The reaction of Li[(EPPr2NPPr2)-Pr-i-Pr-i] with one molar equivalent of I-2 produces (EPPr2NP)-Pr-i(I)Pr-i(2) (3a-I, E = Se; 3b-I, E=Te). Alternatively, the oxidation of Na[N((PBu2)-Bu-t)(2)] with I-2 in tetrahydrofuran (THF) generates the P(III)/P(V) compound (Bu2PNP)-Bu-t(1)Bu-t(2) (6'-I) which, on treatment with elemental selenium or tellurium in THF, yields (EPBu2NP)-Bu-t(I)Bu-t(2) (3a'-I, E=Se; 3b'-I, E=Te), The acyclic compounds 3a-I, 3a'-I, 3b-I, 3b'-I, and 6'-I have been characterized in solution by multinuclear (H-1, P-31, Se-77, and Te-125) NMR spectroscopy and in the solid state by X-ray structural determinations.