Gold-Mediated Insertion of Oxygen into Silicon–Silicon Bond: An Original Au(I)/Au(III) Redox Sequence

The diphosphine–disilane i Pr 2 ( o -C 6 H 4 )SiMe 2 SiMe 2 ( o -C 6 H 4 )P i Pr 2 reacts with AuCl(SMe 2 ) via coordination of the two phosphines and oxidative addition of the σ-Si–Si bond. The ensuing bis(silyl) gold(III) complex has been unequivocally authenticated by NMR spectroscopy at −60 °C. Upon heating, it evolves cleanly to give a disiloxane gold(I) complex that has been fully characterized, including by X-ray diffraction analysis. Oxidation of the disilane proceeds via an original Au(I)/Au(III) redox sequence. According to 18 O labeling experiments, both water and dioxygen are competent oxygen sources. Oxidative addition of the σ-Si–Si bond to form a bis(silyl) gold(III) complex seems to be a prerequisite for the disilane → disiloxane conversion to occur.