Dual Gold Catalysis: σ,π‐Propyne Acetylide and Hydroxyl‐Bridged Digold Complexes as Easy‐To‐Prepare and Easy‐To‐Handle Precatalysts

Abstract

A series of dinuclear gold σ,π-propyne acetylide complexes were prepared and tested for their catalytic ability in dual gold catalysis that was based on the reaction of an electrophilic π-complex of gold with a gold acetylide. The air-stable and storable catalysts can be isolated as silver-free catalysts in their activated form. These dual catalysts allow a fast initiation phase for the dual catalytic cycles without the need for additional additives for acetylide formation. Because propyne serves as a throw-away ligand, no traces of the precatalyst are generated. Based on the fast initiation process, side products are minimized and reaction rates are higher for these catalysts. A series of test reactions were used to demonstrate the general applicability of these catalysts. Lower catalyst loadings, faster reaction rates, and better selectivity, combined with the practicability of these catalysts, make them ideal catalysts for dual gold catalysis.

CO Extrusion in Homogeneous Gold Catalysis: Reactivity of Gold Acyl Species Generated through Water Addition to Gold Vinylidenes

“…By running the reaction with 1 equivalent of water and 5 mol % of dual activation catalyst 3, [8] we were able to isolate the product and to characterize it as the indene derivative 2 a (Scheme 2). By running the reaction with 1 equivalent of water and 5 mol % of dual activation catalyst 3, [8] we were able to isolate the product and to characterize it as the indene derivative 2 a (Scheme 2).…”

Unique distal size selectivity with a digold catalyst during alkyne homocoupling

“…Au(III) intermediates have been isolated and characterized [34][35][36] . Despite the great body of work reported in the literature for alkynes and gold, the reductive elimination of C sp bonds from Au(III) complexes has not been reported yet as far as we know 8 , and very few examples of stable Au(III)-diacetylide complexes appear in the literature 37,38 .…”

CO‐Extrusion in der homogenen Gold‐Katalyse: Reaktivität von Goldacyl‐Spezies, erzeugt durch Wasser‐Addition an Goldvinylidene

“…Bei unserer Untersuchung der dualen Gold-Katalyse in Anwesenheit von Wasser wurde für Substrat 1 a eine Trans- [8] waren wir in der Lage, das Produkt zu isolieren und als das Inden-Derivat 2 a zu charakterisieren (Schema 2). [9] Der Verlust eines Kohlenstoffatoms wurde zweifelsfrei durch eine Einkristall-Rçntgenstrukturanalyse bewiesen.…”