CuI-Catalyzed Coupling Reaction of β-Amino Acids or Esters with Aryl Halides at Temperature Lower Than That Employed in the Normal Ullmann Reaction. Facile Synthesis of SB-214857

2001 ◽  
Vol 3 (16) ◽  
pp. 2583-2586 ◽  
Author(s):  
Dawei Ma ◽  
Chengfeng Xia
Keyword(s):  
Amino Acids ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Facile Synthesis ◽  
Ullmann Reaction

Palladium-Catalyzed Direct C2-Arylation of Benzo[b]thiophenes with Electron-Rich Aryl Halides: Facile Access to Thienoacene Derivatives

Synlett ◽  
2017 ◽  
Vol 28 (20) ◽  
pp. 2812-2816 ◽  
Author(s):  
Fumiki Ichioka ◽  
Yuhei Itai ◽  
Yuji Nishii ◽  
Masahiro Miura
Keyword(s):  
Reaction System ◽  
Phenyl Group ◽  
Coupling Reaction ◽  
Direct Coupling ◽  
Aryl Halides ◽  
Facile Synthesis ◽  
Aryl Bromides ◽  
Palladium Catalyzed

Direct coupling reaction of benzo[b]thiophene and electron-rich aryl bromides was achieved under Pd2(dba)3/SPhos catalysis in the presence of NaOt-Bu. The reaction system was applied for the installation of 2-(methylthio)phenyl group onto thiophene-fused polyaromatic molecules, demonstrating facile synthesis of precursors for thienoacene derivatives.

Piperazine as an Inexpensive and Efficient Ligand for Pd-Catalyzed Homocoupling Reactions to Synthesize Bipyridines and Their Analogues

2019 ◽  
Vol 16 (1) ◽  
pp. 173-180
Author(s):  
Mingwei Chen ◽  
Jinyu Hu ◽  
Xiaoli Tang ◽  
Qiming Zhu
Keyword(s):  
Transition Metal ◽  
Oxidation State ◽  
Coupling Reaction ◽  
Aryl Halides ◽  
Metal Species ◽  
Good Substrate ◽  
Active Metal ◽  
Homocoupling Reaction ◽  
Catalytic Cycles ◽  
Reductive Homocoupling

Aim and Objective: The synthesis of bipyridines, especially 2, 2’-bipyridines, remains challenging because the catalytic cycle can be inhibited due to coordination of bipyridine to transition metal. Thus, the development of efficient methods for the synthesis of bipyridines is highly desirable. In the present work, we presented a promising approach for preparation of bipyridines via a Pd-catalyzed reductive homocoupling reaction with simple piperazine as a ligand. Materials and Methods: Simple and inexpensive piperazine was used as a ligand for Pd-catalyzed homocoupling reaction. The combination of Pd(OAc)2 and piperazine in dimethylformamide (DMF) was observed to form an excellent catalyst and efficiently catalyzed the homocoupling of azaarenyl halides, in which DMF was used as the solvent without excess reductants although stoichiometric reductant was generally required to generate the low-oxidation-state active metal species in the catalytic cycles. </P><P> Results: In this case, good to excellent yields of bipyridines and their (hetero) aromatic analogues were obtained in the presence of 2.5 mol% of Pd(OAc)2 and 5 mol% of piperazine, using K3PO4 as a base in DMF at 140°C. Conclusion: According to the results, piperazine as an inexpensive and efficient ligand was used in the Pd(OAc)2-catalyzed homocoupling reaction of heteroaryl and aryl halides. The coupling reaction was operationally simple and displayed good substrate compatibility.

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