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 acylradicals by photoredox-catalyzed iminyl-radical-mediated C–C bond cleavage. This redox-neutral protocol features excellent regioselectivity
Palladium-Catalyzed Synthesis of Aromatic Ketones and Isoindolobenzimidazoles<i>via</i>Selective Aromatic CH Bond Acylation
作者:Juyou Lu、Hao Zhang、Xiaowu Chen、Hongxia Liu、Yuyang Jiang、Hua Fu
DOI:10.1002/adsc.201200743
日期:2013.1.9
A convenient and efficient palladium-catalyzed synthesis of aromatic ketones and isoindolobenzimidazoles has been developed via selective aromatic CH bond acylation. The protocol uses palladium acetate as the catalyst, readily available carboxylicacids as the acylating reagents, trifluoroacetic anhydride as the activated agent of the acids, and the corresponding aromatic ketones and isoindolobenzimidazoles
activation of C–H bonds is very important for the construction of a variety of biologically active molecules. Supported alloy nanoparticles are of great interest in various catalytic applications due to the synergistic effects between different metals. Here, well-dispersed CuPd alloy nanoparticles supported on reduced grapheneoxide (rGO) were synthesized and found to be highlyefficient and recyclable
Ag1Pd1 nanoparticle-reduced graphene oxide (Ag1Pd1-rGO) nanocomposite was used as an efficient catalyst for the synthesis of aromaticketones via cross dehydrogenative coupling (CDC) reactions of 2-arylpyridines with aldehydes. The catalyst can be reused for 5 cycles without significantly losing its catalytic activity. On the basis of the obtained experimental evidence, we proposed a possible mechanism
Ag 1 Pd 1纳米粒子还原的氧化石墨烯(Ag 1 Pd 1 -rGO)纳米复合材料被用作通过2-芳基吡啶与醛的交叉脱氢偶联(CDC)反应合成芳族酮的有效催化剂。催化剂可重复使用5个循环,而不会明显丧失其催化活性。在获得的实验证据的基础上,我们提出了一种多相催化的可能机制。我们发现,负载型催化剂表现出一系列好处,包括非凡的催化活性,高可重复使用性和对各种底物的显着耐受性。