Royal Society of Chemistry, Catalysis Science & Technology, 3(5), p. 1558-1567
DOI: 10.1039/c4cy01440e
Full text: Unavailable
We elucidate the role of the ligand in determining the ion pair structure of the [(NAC)Au(η2-3-hexyne)]+ BF4‒ [(NAC = Nitrogen Acyclic Carbene, also known as ADC = Acyclic Diamino Carbene)] catalysts and how the position of the anion influences their catalytic performances, giving a detailed relationship between the ion pairs structure, determined by 19F, 1H-HOESY NMR experiments and DFT calculations, and the catalytic activity in the intermolecular alkoxylation of alkynes. From our results, it is evident that if the anion is forced to be far from the catalytic site by ancillary ligand-anion hydrogen bonding interactions, the reaction slows down. On the contrary if the anion is located near the alkynes the reaction is accelerated, coherently with the proposed active role of the anion in catalysis. These results open new opportunities in ligands design for the gold-mediated reactions in which the anion plays an important role during the catalysis.