Intermediates and Mechanisms of Gold(I)-Catalyzed Nucleophilic Addition Reactions

Abstract

Generally, gold(I) complexes interact with pi-bonds of alkenes, alkynes and allenes to initiate nucleophilic addition reactions. As the key intermediates in these reactions, there has been recent interest in the synthesis and study of cationic, two-coordinate gold pi-hydrocarbon complexes. However, few experimental studies have been focused on gold pi-heteroatom complexes. Moreover, gold(I)-catalyzed reactions may involve protic acids (H+), so it is significant to establish more detailed structure/activity relationships to determine the necessity of applying gold complexes. Previous literature at the outset of these studies focused on methodology explorations and computational investigations, but little experimental elucidation of mechanisms had been done. Alternatively, a “silver effect” is now considered to play a role in some gold(I)-catalyzed reactions, however the direct evidence for Au-Ag species in solution is limited.