Recent Advances in Asymmetric Gold Catalysis

The first decade of the 21 century evidenced the explosive growth of homogeneous gold catalysis. The unique versatility and efficiency of gold metal complexes are clearly indicated by the numerous reports regarding their application in various organic transformations. Key to the success of homogeneous gold catalysis is the ability of gold(I) and gold(III) to act as soft carbophilic Lewis acids towards C C multiple bonds. This high carbophilicity translates to a relatively low oxophilic character and a kinetically labile carbon-metal bond, which allows efficient catalyst turnover. In addition, the high oxidation potential between gold(I) and gold(III) makes the gold catalysts inert from air oxidation. Therefore, compared with other transition metal catalysts, gold complexes could catalyze reactions under very mild conditions (tolerates air or moisture), giving excellent chemoselectivity, wide functional group compatibility and high efficiency. However, despite its high efficiency in alkyne and allene activation, gold catalysts, like many other transition metal complexes, inherit some limitations that prevent them from being “perfect.” Two clearly identified challenges in gold catalysis are a) rather poor thermal stability due to disproportionation of the metal cation and b) difficulty in asymmetric transformations. In the past several years, efforts have been made by various research groups to overcome these challenges. Significant progress has been made, which has given this very hot topic in catalytic research strong momentum for an even more promising future. Major breakthroughs in asymmetric gold catalysis are certainly expected in the coming decade and this Minireview, by highlighting recent advances, aims to facilitate progress in this fascinating field of research.