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).
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
Palladium-Catalyzed Desulfitative CH Arylation of Heteroarenes with Sodium Sulfinates
作者:Bo Liu、Qiang Guo、Yangyang Cheng、Jingbo Lan、Jingsong You
DOI:10.1002/chem.201102644
日期:2011.11.25
Desulfitative CHarylation: Palladium‐catalyzed desulfitative CHarylation of heteroarenes with sodium sulfinates has been disclosed to construct aryl–heteroaryl bonds without the need for any extra ligands (see scheme).
Smooth Metal‐Free Photoinduced Preparation of Valuable 8‐Arylxanthines
作者:Havall Othman Abdulla、Ahmed A. Amin、Carlotta Raviola、Till Opatz、Stefano Protti、Maurizio Fagnoni
DOI:10.1002/ejoc.201900638
日期:2020.3.15
A set of 8‐arylxanthines was prepared under metal‐free conditions and in aqueous solvents from arylazosulfones and caffeine or theophylline. Notably, the process took place by simply exposing the reaction vessel to visible or solar light, and unreacted xanthine could be easily recovered during the purification step.