Diborane heterolysis and P( v ) reduction by Ph 3 P[double bond, length as m-dash]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 P[double bond, length as m-dash]O bond of the phosphine oxide to magnesium.