Abstract
The addition of secondary phosphine oxides to tetramesityldisilene and tetramesityldigermene results in the mild, partial reduction of the P(V) centre of the organophosphorus oxide to P(III) to yield disilyl and digermyl phosphinite derivatives and illustrates the potential of ditetrelenes to serve as mild reducing agents under ambient conditions. An analogous reaction happens with H-phosphonates. Mechanistic experiments, including deuterium labelling, kinetic isotope effect, and variable time normalization analysis experiments, reveal that the 1,3-PH addition likely proceeds through a stepwise reaction pathway with the organophosphorus oxide acting as the nucleophile toward the ditetrelene. Furthermore, a facile exchange between the R 2 PO moiety of the digermylphosphinite and the R 2 PO moiety of phosphine oxides was discovered and likely proceeds through a direct substitution mechanism.