Phosphine-Free, Palladium-Catalyzed Arylation of Heterocycles through CH Bond Activation with Pivalic Acid as a Cocatalyst
作者:Dongbing Zhao、Weida Wang、Shuang Lian、Fei Yang、Jingbo Lan、Jingsong You
DOI:10.1002/chem.200802001
日期:2009.1.26
Ligand‐free C‐arylation: A general palladium‐catalyzed C‐arylation of N‐heterocycles with aryl bromides has been performed without the presence of phosphines, the aid of CuI, or other metal additives by using pivalic acid as a cocatalyst (see scheme).
A Palladium/Copper Bimetallic Catalytic System: Dramatic Improvement for Suzuki–Miyaura‐Type Direct CH Arylation of Azoles with Arylboronic Acids
作者:Bo Liu、Xurong Qin、Kaizhi Li、Xiyu Li、Qiang Guo、Jingbo Lan、Jingsong You
DOI:10.1002/chem.201001338
日期:2010.10.18
Bimetalliccatalyticsystem: Palladium/copperbimetallic‐catalyzed Suzuki–Miyaura‐type coupling has been disclosed for directCHarylation of azoles, instead of azole halides or pseudohalides, with arylboronicacids (see scheme).
Palladium-Catalyzed Direct Arylation of N-Heteroarenes with Arylsulfonyl Hydrazides
作者:Bo Liu、Jian Li、Feijie Song、Jingsong You
DOI:10.1002/chem.201201450
日期:2012.8.27
Hydrazides applied: A palladium‐catalyzed direct CH arylation of heteroarenes, with arylsulfonylhydrazides as the arylating reagents, has been developed (see scheme). The reaction is chemoselective, in that arylsulfonylhydrazides containing halogen substituents can be employed without participation of the halogen substituent in the reaction. The method offers a straightforward approach to a variety
solvent, an array of xanthenes, thiazole, pyrazine, and pyridazine are compatible with this new arylation approach. The broad substrate scope, mild reaction conditions, and use of water as reaction solvent make this procedure a practical and environmentally friendly method for the synthesis of compounds containing aryl‐heteroaryl motifs.
已经开发出一种高效的可见光促进的N-杂芳烃与芳基重氮盐在水中的“自由基型”偶联。在室温下将反应继续进行的[Ru(联吡啶)3 ]氯2 ⋅ 6 H 2O作为光敏剂,商用灯泡作为光源。在这些反应条件下,吡啶和各种取代的吡啶是有效的底物,仅形成具有不同区域选择性的单取代产物。使用甲酸水溶液作为溶剂,一系列的黄嘌呤,噻唑,吡嗪和哒嗪与这种新的芳基化方法兼容。广泛的底物范围,温和的反应条件以及使用水作为反应溶剂,使得该程序成为合成具有芳基-杂芳基基序的化合物的实用且环境友好的方法。
Double C−H Activation: The Palladium-Catalyzed Direct C-Arylation of Xanthines with Arenes
作者:Chandi C. Malakar、Dietmar Schmidt、Jürgen Conrad、Uwe Beifuss
DOI:10.1021/ol200065s
日期:2011.3.18
The novel Pd-catalyzedC(sp2)−H/C(sp2)−H cross-coupling of unactivated xanthines with unactivated arenes utilizing a combination of Ag(I) and O2 as oxidants exclusively yields C-8 arylated xanthines in a single synthetic operation.