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.
Tuning of net architectures of Ni(<scp>ii</scp>) and Zn(<scp>ii</scp>) coordination polymers using isomeric organic linkers
作者:Shuang-De Liu、Bing-Chiuan Kuo、Yen-Wen Liu、Jing-Yi Lee、Kwun Yip Wong、Hon Man Lee
DOI:10.1039/c4ce01072h
日期:——
Ni(ii) and Zn(ii) coordination polymers with diverse net topologies were synthesized using isomeric organic linkers.
使用同分异构的有机连接剂合成了具有不同网络拓扑结构的Ni(II)和Zn(II)配位聚合物。
An unprecedented Pd-catalyzed decarboxylative coupling reaction of aromatic carboxylic acids in aqueous medium under air: synthesis of 3-aryl-imidazo[1,2-a]pyridines from aryl chlorides
An efficient and practical protocol for palladium-catalyzeddecarboxylative arylation of imidazo[1,2-a]pyridine-3-carboxylic acids with aryl chlorides has been developed. Note that the reaction could proceed smoothly without an additive in aqueous medium under an ambient atmosphere, and the addition of H2O could effectively promote the decarboxylative arylation. Particularly noteworthy is that these
已开发出一种有效,实用的方案,用于钯催化的咪唑并[1,2 - a ]吡啶-3-羧酸与芳基氯化物的脱羧芳基化反应。注意,在环境气氛下在水性介质中没有添加剂的情况下反应可以顺利进行,并且H 2 O的添加可以有效地促进脱羧芳基化。特别值得注意的是,这些结果代表了Pd催化的(杂)芳香族羧酸在水性介质中在空气中的P催化脱羧偶联反应的第一个实例,以及3-芳基-咪唑并[1,2- a]合成的第一个成功实例。吡啶使用廉价的各种芳基氯化物和杂芳基氯化物作为起始原料。
Magnetically recoverable nickel-palladium alloy nanocatalysts for direct C–H arylation reactions
in terms of the isolated product yields. The C–H arylationreactions were studied over a broad substrate scope (35 examples from 36 substrates) and gave the related biaryl products in good to excellent yields. Besides a broad substrate scope, the late-stage C–H arylation of zolimidine, a gastroprotective drug, was realized under the optimized reaction conditions. Moreover, the CoFe2O4-rGO/Ni20Pd80 nanocatalysts
新型磁性可回收纳米催化剂包含负载在还原氧化石墨烯 (rGO) 上的镍钯 (NiPd) 合金纳米粒子 (NPs),用钴铁氧体 (CoFe 2 O 4 ) NPs修饰,用于咪唑并吡啶、咪唑、茚茚的直接 C-H 芳基化和呋喃与芳基卤化物。为了制备所提出的催化剂,首先用合成的 CoFe 2 O 4 NPs 对rGO 纳米片进行改性,然后将获得的 CoFe 2 O 4 -rGO 纳米复合材料用作合成各种成分的双金属 NiPd 合金 NPs 的载体材料。得到的CoFe 2 O 4-rGO/NiPd 纳米催化剂通过许多先进的分析技术进行表征,包括 TEM、STEM-EDS、XRD、XPS 和 ICP-MS。接下来,为了优化反应条件,最初测试了具有不同合金成分的CoFe 2 O 4 -rGO/NiPd 纳米催化剂及其单金属对应物(CoFe 2 O 4 -rGO/Ni 和 CoFe 2 O 4 -rGO/Pd)咪唑并吡啶与溴苯的
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....