Quantitative Evaluation of the Stability of <i>gem</i>-Diaurated Species in Reactions with Nucleophiles
                                
                                    
                                        作者:Alexander Zhdanko、Martin E. Maier                                    
                                    
                                        DOI:10.1021/om400083f
                                    
                                    
                                        日期:2013.3.25
                                    
                                    The reactivity of diaurated species toward nucleophiles was investigated. The reaction yields vinyl gold species and is described as simple S(N)2 ligand exchange at gold. Using suitably strong nucleophiles, equilibrium constants were determined to measure the stability of various diaurated species. On the basis of these equilibrium constants the influence of ligand and the nature of vinyl cores on the stability were analyzed. These results have direct implication for gold catalysis: it was demonstrated that vinyl gold intermediates bind the catalytic LAu+ species generally stronger than an alkyne (the substrate) by a factor of 10(6)-10(9). This demonstrates that the formation of diaurated species from vinyl gold intermediates is thermodynamically favored in a catalytic reaction.