palladium-catalyzed coupling of aryl triflates with pyrazolederivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C–N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazolederivatives proceeded efficiently to give N-arylpyrazole products in high yields. 3-Trimethylsilylpyrazole was found to be an excellent pyrazole substrate for the coupling, and the corresponding
Copper-catalyzed reactions of α,β-unsaturated <i>N</i>-tosylhydrazones with diaryliodonium salts to construct <i>N</i>-arylpyrazoles and diaryl sulfones
作者:Lian-Mei Chen、Chuang Zhou、Jing Li、Jun Li、Xiao-Qiang Guo、Tai-Ran Kang
DOI:10.1039/d2ob01338j
日期:——
Herein, an economical copper-catalyzed reaction of α,β-unsaturated N-tosylhydrazones with diaryliodoniumsalts to construct both N-arylpyrazoles and diaryl sulfones has been developed. Both the p-toluenesulfonyl anion and the 3-arylpyrazole intermediates were formed in situ from N-tosylhydrazones. Subsequently, the former reacted rapidly with diaryliodoniumsalts to give diaryl sulfones and aryl iodide