Enantioselective C−H Functionalization Reactions under Gold Catalysis

Abstract

Transition metal-catalyzed enantioselective functionalization of ubiquitous CÀ H bonds has proven to be promising field as it offers the construction of chiral molecular complexity in a step-and atom-economical manner. In recent years, gold has emerged as an attractive contender for catalyzing such reactions. The unique reactivities and selectivities offered by gold catalysts have been exploited to access numerous asymmetric transformations based on gold-catalyzed CÀ H functionalization processes. Herein, this review critically highlights the major advances and discoveries made in the enantioselective CÀ H functionalization under gold catalysis which is accompanied by mechanistic insights at appropriate places.

Asymmetric gold catalysis enabled by specially designed ligands

“…Within the domain of ligand-induced asymmetric catalysis, enantioselective gold(I) catalysis has flourished significantly in recent years. [36][37][38][39][40][41][42][43][44] However, it is important to note that the initial development in this field was sluggish, stemming from the geometrical constraints associated with linear Au(I) complexes. The linear geometry of gold complexes positions the chiral ligand at 180°from the reaction site, thus making the enantioinduction arduous.…”

Gold-catalyzed cyclization and cycloaddition in natural product synthesis

“…It has been a decade since our previous review on the application of gold catalysis in the synthesis of complex natural products. 10 While there have been excellent reviews in this field, 11–15 the majority have focused on the broader spectrum of gold-catalyzed transformations per sue, including gold( i )/( iii ) catalysis, 16,17 small-ring formation, 18 conversion of strained compounds, 19 photochemical reactions, 20 medium-ring formation, 21 1,2-migration, 22 oxidation, 23 nitrene/carbene transfer, 24 C–H functionalization, 25,26 hydroarylation, 27 and cycloisomerization. 28 In the subsequent sections, we will emphasize some notable progresses, methodologies, and strategies employed in gold-catalyzed transformations that have enabled the efficient construction of intricate scaffolds within natural products.…”

Ligand-Enabled Sustainable Gold Catalysis

“…There have been reviews that focus on optimization studies and reactivities in gold catalysis; , however, a thematic review on the development of homogeneous sustainable gold catalysis at a ppm level has remained highly sporadic in the literature. , In light of our long-standing interest in the development of homogeneous gold catalysis, − herein, we would like to present a comprehensive perspective summarizing all the reports that employ catalyst loadings ≤ 0.1 mol %. A special emphasis on the roles of electronic and steric effects of ligands to achieve high turnover numbers (TONs) and turnover frequencies (TOFs) are given for a better understanding for the readers.…”