A Systematic Study of the Effects of Complex Structure on Aryl Iodide Oxidative Addition at Bipyridyl-Ligated Gold(I) Centers

摘要

A combined theoretical and experimental approach has been used to study the unusual mechanism of oxidative addition of aryl iodides to [bipyAu(C2H4)](+) complexes. The modular nature of this system allowed a systematic assessment of the effects of complex structure. Computational comparisons between cationic gold and the isolobal (neutral) Pd-0 and Pt-0 complexes revealed similar mechanistic features, but with oxidative addition being significantly favored for the group 10 metals. Further differences between Au and Pd were seen in experimental studies: studying reaction rates as a function of electronic and steric properties showed that ligands bearing more electron-poor functionality increase the rate of oxidative addition; in a complementary way, electron-rich aryl iodides give faster rates. This divergence in mechanism compared to Pd suggests that Ar-X oxidative addition with Au can underpin a broad range of new or complementary transformations.