Migratory Insertion of CO into a Au–C Bond

Abstract

A MeDalPhos-ligated gold(III) metallafluorene complex, generated via C–C oxidative addition of biphenylene, reacts with CO to produce 9-fluorenone. Experimental and computational studies show that this proceeds via a hitherto unknown migratory insertion of CO into a Au(III)–C bond. This process is more energetically challenging compared to other M–C bonds, but once achieved, the product is comparatively stable with respect to retro-carbonylation. Exploiting migratory insertion of CO into Au–C bonds may extend the range of products that are accessible using gold chemistry.

Gold‐Catalyzed 1,2‐Dicarbofunctionalization of Alkynes with Organohalides**

“…Using this strategy, our group, [19] and groups of Amgoune/Bourissou, [20] and Shi, [21] developed a range of 1,2‐difunctionalization reactions of alkenes (Scheme 1c). Recently, Bower/Russell also employed this strategy to demonstrate the feasibility of CO migratory insertion in a stoichiometric manner [22] . Subsequently, Gandon/Patil disclosed a gold‐catalyzed Heck reaction of alkenes using iodoarenes as coupling partners [23] .…”

Gold–Manganese Bimetallic Redox Coupling with Light

“…The Au­(I)/Au­(III) redox couple chemistry represents the state-of-the-art in gold chemistry research. − Compared with Pd(0)/Pd­(II) ( 1/2 E = 0.91 V versus SCE), the couple of Au­(I)/Au­(III) holds a very high redox potential of 1.41 V, and thus strong oxidants, such as PhI­(OAc) 2 and Selectfluor, are usually required for gold-mediated redox processes , (Figure a, left part). Despite this, gold-catalyzed oxidative C–C coupling has been esteemed as one reliable platform owing to its excellent functional group compatibility. − In the past decade, ligand-promoted oxidative addition of Ar–X has become a new avenue to produce Au­(III)-complexes − (Figure a, right part). Very recently, external excitation with either light − or electricity − is becoming an alternative route to achieve a valent change of gold.…”

Gold-Catalyzed Heck Reaction

“…16 Recently, in a stoichiometric study, the Toste, 17 Bourissou, 18 20 Bourissou/Amgoune, 21 Tilset, 22 and Bower/Russell. 23 Despite these stoichiometric studies, until now there is no report on the gold-mediated migratory insertion and β-hydride elimination steps in catalytic fashion. Herein, we disclose the first example of gold-catalyzed Heck reaction where the catalytic cycle involves the key migratory insertion and β-hydride elimination steps (Scheme 1c).…”

“…Recently, in a stoichiometric study, the Toste, Bourissou, and Nevado groups showcased the feasibility of β-hydride elimination in Au­(III)–difluoroalkyl, Au­(III)–alkyl, and Au­(III)–formate complexes, respectively. Similarly, the feasibility of migratory insertion of C–C or C–O multiple bonds into Au­(III)–H, Au­(I)–Si/Au­(III)–C, Au­(III)–O, and Au­(III)–C bonds are shown by the research groups of Bochmann, Bourissou/Amgoune, Tilset, and Bower/Russell . Despite these stoichiometric studies, until now there is no report on the gold-mediated migratory insertion and β-hydride elimination steps in catalytic fashion.…”

“…16 Recently, in a stoichiometric study, the Toste, 17 Bourissou, 18 20 Bourissou/Amgoune, 21 Tilset, 22 and Bower/Russell. 23 Despite these stoichiometric studies, until now there is no report on the gold-mediated migratory insertion and β-hydride elimination steps in catalytic fashion.…”