Gold coordinated to neutral phosphines (R 3 P), Nheterocyclic carbenes (NHCs) or anionic ligands is catalytically active in functionalizing various CÀ H bonds with high selectivity. The sterics/electronic nature of the studied CÀ H bond, oxidation state of gold and stereoelectronic capacity of the coordinated auxiliary ligand are some of the associated selectivity factors in gold-catalyzed CÀ H bond functionalization reactions. Hence, in this review a comprehensive update about the action of different types of gold catalysts, from simple to sophisticated ones, on CÀ H bond reactions and their regiochemical outcome is disclosed. This review also highlights the catalytic applications of Au(I)-and Au(III)species in creating new opportunities for the regio-and siteselective activation of challenging CÀ H bonds. Finally, it also intends to stress the potential applications in selective CÀ H bond activation associated with a variety of heterocycles recently described in the literature.

Merging the latest advances in the field of gold catalysis and the efficiency of hexafluoro-2propanol (HFIP), a gold-catalyzed orthogonal tandem reaction has been developed to access carbocyclic ketone on naphthalene substrates. The methodology involved a cycloisomerization/nucleophilic addition and a C!O rearrangement. The HFIP solvent most probably acted as a Lewis-acid on isochromene derivatives, through hydrogen donor bond activity. A large range of acenaphthylene carbaldehyde has been engaged in this process coupling gold catalysis and Lewis-acid behavior of HFIP leading to cyclic ketones with a yield ranging from 15 to 91% (27 compounds). The mechanism was investigated, and the reaction most presumably occurred via a classical cyclization process followed by a [Au]-HFIP interaction for the final rearrangement. The interest of such transformation was demonstrated by performing it on a gram-scale. Moreover, a post-functionalization bromination was performed, as well as the isomerization of some functionalized ketones leading to full trans derivatives with a yield ranging from 78 to 90% yields.

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.

The palladium-catalyzed synthesis of bis-heterocyclic spirocycles containing both pyrroline and indoline motifs is reported. Di-tert-butyldiaziridinone is used to functionalize palladacycles generated in situ via domino Narasaka−Heck/C−H activation reactions. The reaction is readily scalable, and the spirocyclic products can undergo deprotection, reduction, and (3 + 2) cycloadditions, highlighting their synthetic utility. Additionally, kinetic isotope effect experiments support a turnover-limiting C−H functionalization step in the catalytic cycle.