Pd-Catalyzed Tandem C–H Azidation and N–N Bond Formation of Arylpyridines: A Direct Approach to Pyrido[1,2-b]indazoles
摘要:
A novel Pd-catalyzed nitrogenation of arylpyridines via C-H azidation has been developed. Direct C-N and N-N formations are achieved for this N-atom incorporation transformation using azides as the N-atom source. This method provides an alternatively concise approach for the construction of bioactively important pyrido[1,2-b]indazoles.
A Pd(II)-catalyzed C-H phosphorylation reaction has been developed using heterocycle-directed ortho-palladation. Both H-phosphonates and diaryl phosphine oxides are suitable coupling partners for this reaction.
Room-Temperature Suzuki-Miyaura Coupling of Heteroaryl Chlorides and Tosylates
作者:Junfeng Yang、Sijia Liu、Jian-Feng Zheng、Jianrong Steve Zhou
DOI:10.1002/ejoc.201200918
日期:2012.11
Suzuki–Miyauracoupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroarylchlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2′
Ruthenium-Catalyzed<i>meta</i>-Selective C−H Mono- and Difluoromethylation of Arenes through<i>ortho</i>-Metalation Strategy
作者:Zhong-Yuan Li、Liang Li、Qi-Li Li、Kun Jing、Hui Xu、Guan-Wu Wang
DOI:10.1002/chem.201700354
日期:2017.3.8
Mechanistic studies indicate that a reaction pathway involving palladium‐initiated radical species is involved in the catalytic cycle. The new dual catalytic system consisting of compatible ruthenium(II) and palladium(0) complexes enables the key processes of C−H activation and mono‐/difluoromethyl‐radical formation to occur and achieves the meta‐selective functionalization efficiently. In addition, the present
A highly efficient and regioselectivedirectC–H trifluoromethylation of pyridine based on an N-methylpyridine quaternary ammonium activation strategy has been developed. A variety of trifluoromethylpyridines can be obtained in good yield and excellent regioselectivity by treating the pyridinium iodide salts with trifluoroacetic acid in the presence of silver carbonate in N,N-dimethylformamide. The