Reaktionen eines Tetraalkoxyhydro‐spirophosphorans

Abstract

Das Hydrophosphoran HP[OC(CF3)2C(CF3)2O]2 wird durch Dimethylsulfoxid zu einem Hydroxyphosphoran oxidiert, welches leicht silyliert werden kann. Chlor und Brom ergeben die entsprechenden Halogenspirophosphorane; FP[OC(CF3)2C(CF3)2O]2 wird aus FCl2P[OC(CF3)2 C(CF3)2O] und Li2[OC(CF3)2C(CF3)2O] erhalten. In Gegenwart von Triethylamin reagiert HP[OC(CF3)2C(CF3)2O]2 mit Benzylbromid bzw. Acetylchlorid zu RP[OC(CF3)2C(CF3)2O]2 (R  PhCH2, MeC(O)). Trimethylphosphin setzt sich in einer Säure‐Base‐Reaktion um zu dem thermisch instabilen Me3PH+{P[OC(CF3)2C(CF3)2O]2}−. Die Hydrolyse der Stammverbindung ergibt phosphorige Säure und Perfluorpinakol.

Chiral Hypervalent, Pentacoordinated Phosphoranes

“…Moreover, the treatment of the hydrophosphorane 181 with trimethylphosphine gave a thermally unstable phosphonium salts 189. Hydrophosphorane 181 undergoes fast hydrolysis affording phosphorous acid and perfluoropinacol [125] (Scheme 70). Later on, spirophosphoranes 177 were also used as substrates in a new method for the solid phase synthesis of oligopeptides.…”

“…The synthesis and reactivity of the hydrophosphorane 181 derived from perfluoropinacol was described as early as 1983 [125]. It was found that it could be rapidly oxidized by dimethyl sulfoxide to form the hydroxyphosphorane 182, and then silylated to the derivative 183.…”

“…Moreover, the treatment of the hydrophosphorane 181 with trimethylphosphine gave a thermally unstable phosphonium salts 189. Hydrophosphorane 181 undergoes fast hydrolysis affording phosphorous acid and perfluoropinacol [125] …”