Carbonylative Cross-Electrophile Coupling between Aryl Bromides and Aryl Triflates Enabled by Palladium and Rhodium Cooperative Catalysis and CO as Reductant

Abstract

Ketones are among the most useful functional groups in organic synthesis. Here, we report a carbonylative crosselectrophile coupling reaction that utilizes carbon monoxide gas as both carbonyl source and reductant. The use of Pd/Rh cooperative catalysis enables the carbonylative coupling of easily accessible aryl triflates and aryl bromides. Unlike previous carbonylative cross-electrophile coupling reactions, the method does not require addition of a stoichiometric metal reductant. Notably, density functional theory (DFT) calculations and isotope-labeling indicate that CO serves as the reductant.

Palladium-catalyzed multi-component Heck alkynylcarbonylation of unactivated alkenes for synthesis of β,γ-alkynoates

“…At present, there are two ways to temporarily avoid these challenges: (1) performing the Pd-catalysed multi-component carbonylation reaction of alkyl halides using carbon radicals as a trigger 6 and (2) using a bi-metallic catalysis pathway (Scheme 1B). 7 In addition, the priority binding of olefins instead of CO to C–Pd( ii )–X species can be accomplished via the Pd-catalysed intra-molecular Heck cyclisation–carbonylation reaction; however, this reaction usually realises intra-molecular transformations. 8,9…”

Site-selective carbonylation of arenesviaC(sp2)–H thianthrenation: direct access to 1,2-diarylethanones

“…In order to overcome these limitations, alternative methods have gradually been discovered, such as the direct C–H functionalization reaction of arenes 14 and alternative organometallic reagents. 8 Rueping and Zhu, 15 Gong, 16 Hu, 17 Lian, 18 and others 19 have achieved considerable progress in the field of carbonylative Negishi-type reactions, independently. However, the required organic halides are often not available and generally cannot be accessed in high selectivity from complex arenes.…”