Recent advances in chiral NHC–gold complexes for asymmetric catalysis

Homogeneous gold catalysis has emerged as a prominent area of transition-metal catalysis; however, the development of efficient asymmetric gold catalysts remains a significant challenge. Because of the linear coordination mode of gold(I), the chiral ligand is positioned opposite the substrate-binding site, complicating the generation of a chiral environment around the metal center. On the other hand, the square planar geometry of gold(III) offers a promising alternative but its redox instability has hampered its use. In recent years, chiral N-heterocyclic carbenes (NHCs) have become a valuable alternative to more established phosphine-based chiral ligands. In this review, we summarize the recent advances in the development of chiral NHC–gold complexes reported from 2019 until today. Particular emphasis is placed on ligand design principles and their impact on catalytic performance in benchmark asymmetric transformations.