Transformation of Thiolatogold(I) to an Au Complex with an (Arylthio)silyl Ligand. Use of an (Aminosilyl)boronic Ester as a Silylene Precursor

The gold(I) thiolate complex [Au(SC6H4-4-OMe)-(PCy3)] reacts with an (aminosilyl)boronic ester, Et2N-SiPh2-BO(CMe2)(2)O, to afford a complex with an (arylthio)silyl [Au(SiPh2(SC6H4-4-OMe))(PCy3)]. In the solid state the molecule shows almost linear Si-Au-I-P coordination. DFT studies revealed that the reaction pathway involves an intermediate having an Au-S bond formed via initial association of the Si center of the substrate with the thiolate ligand. Reaction of H2SiPh2 with the thiolate complex also produces the silylgold complex in a lower yield.