The reactivity of arylphosphine oxides under Bouveault-Blanc reaction conditions

Treatment of tertiary arylphosphine oxides with alkali metal/alcohol reagent system lead to the corresponding cyclohexyl-substituted phosphine oxides. This transformation makes use of the inexpensive sodium as the electron donor and an alcohol as the proton source, and provides an attractive alternative to reactions mediated by expensive transition metals. Under optimized conditions numerous mono- and diaryl substituted phosphine oxides were transformed into the corresponding mono- and dicyclohexyl-substituted phosphine oxides in good yields. Furthermore, the formation of 1,2-bis(phosphinoyl)cyclohexanes or unknown 5,10-dialkyltetradecahydrophosphanthrene 5,10-dioxides as side products was observed, which are hardly accessible by other procedures.

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