Carboxylic Group-Assisted Proton Transfer in Gold-Mediated
Thiolation of Alkynes
- Publication date
- Publisher
Abstract
Combined
experimental and theoretical studies revealed a complex
mechanistic picture in which the carboxylic group-assisted proton
transfer from acetic acid to an alkyne molecule is the key step in
the unique gold-mediated alkyne transformation that leads to the formation
of <i>gem</i>-disubstituted vinyl gold complexes. The structures
of the complexes were unambiguously established using NMR spectroscopy
(in solution) and X-ray diffraction (in the solid state). ESI-MS study
of the reaction mixture revealed multiple gold-containing complexes
and clusters. Investigation of the MS<sup>2</sup> fragmentation patterns
of the selected ions suggested the involvement of gold acetylides
in the transformation. Further treatment of the complexes with protic
acid led to the discovery of a novel route for the gold-mediated alkyne
hydrothiolation
