Stoichiometric to catalytic reactivity of the aryl cycloaurated species with arylboronic acids: insight into the mechanism of gold-catalyzed oxidative C(sp²)–H arylation

Abstract

The aryl cycloaurated species are established as reliable models for understanding the gold(iii)-catalyzed oxidative cross-couplings between arenes and arylboronic acids.

Au(iii)-aryl intermediates in oxidant-free C–N and C–O cross-coupling catalysis

“…The bond lengths in 3a are similar to those reported for the related cyclometalated [Au(ppy)Cl 2 ] 18 a and [Au(tpy)Br 2 ] 21 complexes. Specifically, the Au–I distances are longer than the analogous Au–Cl and Au–Br ones, consistent with bigger and more labile iodine atoms.…”

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

“…[192] The reaction is initiated by the oxidation of the Au I precatalyst to form the catalytically active Au III species. [195] Their experiments provided direct evidencef or the CÀHa ctivation, Au/B transmetalation,a nd biaryl reductive elimination steps. Further,i odine(III)-mediated oxidation of Au I to Au III would initiate the next catalytic cycle.…”

Cyclometalated Gold(III) Complexes: Synthesis, Reactivity, and Physicochemical Properties

“…[92] Complex 56 proved to be highly robust so that ten successive cycles could be performed with overall turnover numbers of > 800. [95] Thes toichiometric reaction of 101 a or 101 b with phenylboronic acid in the presence of KF delivered the desired cross-coupling product 102 in excellent yield. [93,94] In 2015, Youa nd co-workers described the utilization of the cyclometalated [(C^N)Au(X)(Y)] complexes 101 a and 101 b to study the mechanism of the gold-catalyzed oxidative C À Ha rylation of 2-aryl pyridines with aryl boronic acids (Scheme 28).…”