Phosphine-Free Palladium-Catalyzed Direct Arylation of Imidazo[1,2-a]pyridines with Aryl Bromides at Low Catalyst Loading
作者:Hai Yan Fu、Lu Chen、Henri Doucet
DOI:10.1021/jo300528b
日期:2012.5.4
Ligand-free Pd(OAc)2 was found to catalyze very efficiently the directarylation of imidazo[1,2-a]pyridines at C3 under very low catalyst concentration. The reaction can be performed employing as little as 0.1–0.01 mol % catalyst with electron-deficient and some electron-excessive aryl bromides.
The first Pd-catalyzed tandem cyclization of imidazo[1,2-a]pyridines with 2-chlorobenzaldehydes throughC–Harylation and acylation is presented for the efficient synthesis of novel 6H-benzo[b]imidazo[5,1,2-de]quinolizin-6-ones. The direct acylation reaction proceeded smoothly without the aid of directing groups and in the presence of air as a clean and free terminal oxidant.
提出了通过C–H芳基化和酰化反应,用2-氯苯甲醛将Pd催化的咪唑并[1,2- a ]吡啶串联环化反应,以有效合成新型6 H-苯并[ b ]咪唑并[5,1,2] -德〕喹6人。直接酰化反应在没有引导基团的帮助下并且在作为清洁和游离末端氧化剂的空气存在下顺利进行。
Ligand-free Pd-catalysed decarboxylative arylation of imidazo[1,2-a]pyridine-3-carboxylic acids with aryl bromides
作者:Uttam B. Karale、Saradhi Kalari、Jala Shivakumar、Vitthal B. Makane、Dattatraya A. Babar、Ritesh P. Thakare、Bathini Nagendra Babu、Sidharth Chopra、Haridas B. Rode
DOI:10.1039/c6ra12166g
日期:——
A facile ligand-free method for Pd(OAc)2 catalysed decarboxylative arylation of imidazo[1,2-a]pyridine-3-carboxylic acids with hetero(aryl) bromides has been developed. This method is applicable to variety of (hetero)aryl bromides as coupling partner....