Gold-Catalyzed Cross-Coupling and 1,2-Difunctionalization ­Reactions: A Personal Account

Abstract

In recent years, gold catalysis involving Au(I)/Au(III) redox cycle has gained significant attention. This account summarizes our contributions in the development of Au(I)/Au(III) catalysis focusing on cross-coupling reactions and 1,2-difunctionalization reactions of C-C multiple bonds. A special emphasis has been given towards understanding the mechanism of the reactions.

Gold-based enantioselective bimetallic catalysis

“…Considering that Au( iii ) complexes have square planar geometry, contrary to the linear geometry of Au( i ) complexes, the combination of these complexes with other metals is expected to provide new reactivities, and thus their application in multicatalysis is expected in the future. With the recent surge of gold-catalyzed cross-coupling reactions and 1,2-difunctionalization reactions of C–C multiple bonds 38 under Au( i )/Au( iii ) catalysis, 4 c ,9 a ,39 it is anticipated that a new multimetallic system based on gold redox catalysis would emerge though the concept is highly speculative at this time. Since the metals have varied transition states and the fact that reactivity can be tuned with the ligands/counterions, there could be multiple options to tune the reactivity and enantioselectivity, and hence the gold-based multicatalysis is expected to have tremendous potential.…”

Gold-catalyzed multicomponent reactions

“…Apart from the carbophilic properties, gold complexes show a unique mode of cross-coupling reactivity fuelled by an Au( i )/Au( iii ) redox cycle. 8 Taken together, gold, unlike other transition metals, offers unique reactivity and selectivity which were previously unattainable.…”

“…Over the last decade, various strategies have been developed to facilitate the challenging Au( i )/Au( iii ) redox cycle in order to achieve less accessible cross-coupling reactivity. 8 These strategies have been efficiently utilized in MCRs to achieve a diverse array of products. This section deals with the MCRs based on Au( i )/Au( iii ) redox catalysis.…”

Gold-Catalyzed Heck Reaction

“…Over the past 15 years, Au­(I)/Au­(III) redox catalysis has emerged as one of the most dynamic areas of research . A number of gold-catalyzed cross-coupling and 1,2-difunctionalization reactions have been developed by utilizing external oxidants, ,, photocatalysts, ,,, EBX reagents, ,, an electrochemical or ligand-enabled approach. ,, Even, very recently, our group and Shi’s group reported the first example of enantioselective Au­(I)/Au­(III) redox catalysis .…”