Frontispiece: Catalytic Gold Chemistry: From Simple Salts to Complexes for Regioselective C−H Bond Functionalization

Abstract

Sculptures showing Lord Vishnu of Hindu mythology performing the celestial wedding of Goddess Meenakshi with Lord Sundareswarar. These three Gods have been related in that order to gold catalysis, C−H activation and regioselectivity, the three underlying themes of this Review. An update about different types of gold catalysts, from simple to sophisticated ones, on C−H bond reactions and their regiochemical outcome together with catalytic applications of Au(I)‐ and Au(III)‐species for the regio‐ and site‐selective activation of challenging C−H bonds and potential applications in selective C−H bond activation is given in the Review article by C. Praveen, A. Dupeux and V. Michelet on page10495 ff.

Homogeneous Gold Catalysis for Regioselective Carbocyclization of Alkynyl Precursors

“…Accordingly, it leaves a space for another review focusing exclusively on gold catalyzed regioselective cyclization between alkynes and a tethered nucleophilic carbon. As part of our continuing journey in gold catalyzed approaches [70–88] along with highlighting their regiochemical outcomes, [32–36] we herein disclose the regioselective carbocyclization of alkynyl precursors enabled by catalytic gold chemistry.…”

“…Shortly afterwards, mechanistic underpinnings [15,16] along with the combined knowledge on relativistic effects, [17] π‐acidity, [18,19] redox character, [20] ligand effect [21,22] and frontier orbital models, [23,24] have stretched the boundaries of gold catalysis. Understanding these concepts opened the doors to several stereo‐, regio‐ and chemoselective reactions based on gold catalysis [25–36] . Moreover, bonding model of gold complexes [37–39] and organogold intermediates [40–43] have recently gained momentum in understanding the structure guided reactivity patterns.…”

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 eld, [11][12][13][14][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.…”

Gold-Catalyzed Cyclization of Alkynyl Heteroarenes with a Norbornene Bridge

“…8,9 Among the several metal catalysts used for the construction of heterocycles, gold is one of the most versatile catalysts that enables the activation of both C-H bonds and -systems. 10,11 The activation of alkynes by carbophilic Au catalysts facilitates reactions with various nucleophilic species for the synthesis of heteroaromatic rings. [12][13][14] When alkynes are tethered to electron-rich heteroaromatic rings that can serve as nucleophiles, cyclization reactions occur to provide polycyclic heteroarenes through -extension.…”