Gold(I)-Catalyzed Activation of Alkynes for the Construction of Molecular Complexity

Identifier:  imarina:9389633

Handle: https://hdl.handle.net/20.500.11797/imarina9389633

Authors:  Dorel, Ruth; Echavarren, Antonio M

Abstract:
Gold(I) complexes are the most effective catalysts for the electrophilic activation of alkynes under homogeneous conditions, and a broad range of versatile synthetic tools have been developed for the construction of carbon-carbon or carbon-heteroatom bonds. The properties of gold (I) complexes can be easily tuned sterically or electronically depending on the ligand, consequently modulating their reactivity in the activation of alkynes, alkenes, and allenes. Reactions catalyzed by gold (I) are similar to those catalyzed by other electrophilic metal complexes or even BrOønsted acids and resemble carbocation-mediated processes. However, gold (I) provides unique control on complex transformations by very selectively activating alkynes and by stabilizing the key carbocationic intermediates by weak, but still significant, metal to carbene πback-donation. Additionally, the structural characteristics of linear two-coordinated gold (I) complexes, in which the ligand is very distant from the nucleophilic addition site to the πbound substrate, explains the slow development of general enantioselective transformations of alkynes.