Gold‐Catalyzed Cross‐Coupling Reactions: An Overview of Design Strategies, Mechanistic Studies, and Applications

Abstract

Transition-metal-catalyzed cross-couplingr eactions are central to many organic synthesis methodologies. Traditionally,P d, Ni, Cu, and Fe catalysts are used to promote these reactions. Recently,m any studies have showedt hat both homogeneous and heterogeneous Au catalysts can be used for activating selective cross-coupling reactions.H ere, an overview of the past studies, current trends, andf uture directions in the field of gold-catalyzed coupling reactions is presented.D esign strategiest oa ccomplish selective homocoupling and cross-coupling reactions under both homogeneous and heterogeneous conditions, computational and ex-perimental mechanistic studies, and their applicationsi nd iverse fields are critically reviewed. Specific topics covered are:o xidant-assisted and oxidant-free reactions;s train-assisted reactions;d ual Au and photoredoxc atalysis;b imetallic synergistic reactions;m echanismso fr eductivee limination processes;e nzyme-mimicking Au chemistry;c lustera nd surface reactions;a nd plasmonic catalysis. In the relevant sections, theoretical and computational studies of Au I /Au III chemistry are discussed and the predictionsf rom the calculationsa re compared with the experimental observations to derive useful design strategies.A. Nijamudheen earnedh is PhD from IACS, Kolkata,i n2 015. Currently,h ei sapostdoctoral researcher atF loridaS tate University.H is researchi nterests are in computational catalysis, solar energym aterials, and beyond Li-ion battery technologies.Ayan Dattai sc urrently aP rofessor at IACS, Kolkata.H is research interests include theoretical and computational studieso ft ransitionmetal-catalyzed reactions,o pto-electronic properties of organic and solid-statem aterials, and the design of renewableenergymaterials. He has won several awards including the DST-SERB Distinguished Investigator Award (DIA) in 2019.

Modular and Selective Arylation of Aryl Germanes (C−GeEt3) over C−Bpin, C−SiR3 and Halogens Enabled by Light‐Activated Gold Catalysis

“…For example, none of these methods allow to assemble richly decorated small molecules in the presence of C−iodine bonds, which owing to their pronounced halogen bonding are receiving increasing interest in medicinal and materials chemistry . In this context, oxidative gold catalysis has emerged as a powerful alternative to construct C –C bonds in the presence of aromatic C−halogen, including C−I bonds via the coupling of Ar−FG with ArH (see Figure ) . However, intramolecular competitions of for example, C−Bpin vs. C−SiMe 3 or C−GeR 3 vs. C−SiR 3 functionalizations are—with the exception of ArH=indole and ArF n —not yet possible for a wide range of substrates due to incompatibilities with the strong stoichiometric oxidant that is mechanistically necessary to re‐oxidize Au I to Au III .…”

Non-covalent Interactions Directed Rearrangement of Lactones to Pyrones: A Computational Study on the Mechanistic Insights of Solvent Assisted Gold(I) Catalyzed Reactions

“…Gold (Au) catalyzed reactions have emerged as a key source for carrying out unprecedented cycloisomerization reactions for the past few decades due to the propensity of gold to bond with heteroatoms like -O, -N, -S [1] and has vast number of applications [2]. Au has a propensity to act as a soft and carbophilic Lewis acid and to activate C-C πbonds.…”

Insights into the Mechanism of Gold(I) Oxidation with Aryldiazonium Salts

“…The success of the application of aryldiazoniums alts in the oxidative addition of Au I came alongw ith the development of photoredox catalysis. [14,15] The mechanistic studies carried out so far indicate that aryl radicals are involvedinthese processes. Initially,b oth light and ap hotosensitizer wereu sed to generate the aryl radicals, but later,i tw as observed that in some instances the photosensitizer was not necessary and that even nucleophiles, bases,o rs imple heatinga re enough to generate aryl radicals (Scheme 1).…”