The study gives a vivid example of unusual chemical reactivity associated with organogold complexes. Using modern physical methods and computational studies, the authors propose a reaction mechanism in which a molecule of acetic acid serves as a proton shuttle, transferring the hydrogen atom between the reaction centers.
The study was carried out using both theoretical and experimental approaches. Dedicated labelling of the reagents allowed observation of molecular reorganizations. Variation of reaction conditions helped to estimate key factors governing the transformation. In addition, computational study of the reaction provided the models of certain intermediate steps, which were invisible for experimental investigation. The theoretical data obtained were in excellent agreement with the experiment, and the researchers proposed a reaction mechanism in which a molecule of acetic acid served as a proton shuttle, transferring the hydrogen atom and mediating the reaction.
As for now, the main goal is to "introduce gold catalysis as a valuable practical tool in fine organic chemistry, competitive with other transition metal catalysts", says Prof. Valentine P. Ananikov.
The article "Carboxylic Group-Assisted Proton Transfer in Gold-Mediated Thiolation of Alkynes" by Sergey S. Zalesskiy, Victor N. Khrustalev, Alexandr Yu. Kostukovich, and Valentine P. Ananikov was published in Organometallics (The Journal of the American Chemical Society).
Reference: Organometallics, 2015; DOI: 10.1021/acs.organomet.5b00210
Online link: http://doi.org/10.1021/acs.organomet.5b00210