Palladium-catalyzed oxidative synthesis of aromatic ketones using olefins as acyl equivalents through selective ortho aromatic C-H bond activation
An efficient catalytic system has been developed for selective ortho-acylation of arenes by oxidative C-H bond activation using a palladium catalyst. Olefins were oxidized to the corresponding aldehydes/benzoyl radicals, which, on coupling with 2-phenylpy
Dual photoredox/palladium-catalyzed C-H acylation of 2-arylpyridines with oxime esters
An unprecedented dual photoredox/palladium-catalyzed iminyl-radical-mediated C-C bond cleavage and directed ortho C-H acylation of 2-arylpyridines by using oxime esters is described. Oxime esters can serve as efficient acyl sources through formation of the corresponding acyl radicals by photoredox-catalyzed iminyl-radical-mediated C-C bond cleavage. This redox-neutral protocol features excellent regioselectivity, a broad substrate scope, and good functional-group tolerance with respect to both components, giving a broad range of aryl ketones with generally good yields.
Ruthenium-Catalyzed Carbonylative Coupling of Anilines with Organoboranes by the Cleavage of Neutral Aryl C-N Bond
Herein, we report the first ruthenium-catalyzed Suzuki-type carbonylative reaction of electronically neutral anilines via C(aryl)-N bond cleavage. Without any ligand and base, diaryl ketones can be obtained in moderate to high yields by using Ru3/su
Replacing Pd(OAc)2 with supported palladium nanoparticles in ortho-directed CDC reactions of alkylbenzenes
Supported palladium nanoparticles are used as efficient catalysts for the synthesis of aromatic ketones via cross dehydrogenative coupling reactions of 2-arylpyridines with alkylbenzenes. The catalyst can be reused for five cycles without significantly losing activity. Mechanism research showed that alkylbenzenes were oxidized to their corresponding aldehydes and subsequently coupled with 2-arylpyridines to generate aryl ketones through a Pd0/PdII/PdIV catalytic cycle.
Bao, Yong-Sheng,Zhang, Dongling,Jia, Meilin,Zhaorigetu, Bao
supporting information
p. 2072 - 2077
(2016/04/19)
Palladium-catalyzed synthesis of aromatic ketones and isoindolobenzimidazoles via selective aromatic C-H bond acylation
A convenient and efficient palladium-catalyzed synthesis of aromatic ketones and isoindolobenzimidazoles has been developed via selective aromatic C-H bond acylation. The protocol uses palladium acetate as the catalyst, readily available carboxylic acids as the acylating reagents, trifluoroacetic anhydride as the activated agent of the acids, and the corresponding aromatic ketones and isoindolobenzimidazoles were obtained in good to excellent yields. This finding should provide a new and useful strategy for synthesis of aromatic ketones and isoindolobenzimidazoles.