Diborane Heterolysis and P(V) Reduction by Ph3P=O Coordination to Magnesium

Reaction of a magnesium diboranate complex with triphenylphosphine oxide provides a terminal magnesium boryl, which is itself a potent reagent for the deoxygenative reduction of Ph3PO. Computational analysis with density functional theory (DFT) indicates that B–B bond activation results from initial coordination of the PO bond of the phosphine oxide to magnesium.