TY - JOUR
T1 - Synthesis of N-Arylpyrazoles by Palladium-Catalyzed Coupling of Aryl Triflates with Pyrazole Derivatives
AU - Onodera, Shunsuke
AU - Kochi, Takuya
AU - Kakiuchi, Fumitoshi
N1 - Funding Information:
This work was supported in part by JSPS KAKENHI (JP17K19126, JP16H04150, and JP15H05839; Middle Molecular Strategy). T.K. is also grateful for support by JSPS KAKENHI (JP16H01040; Precisely Designed Catalysts with Customized Scaffolding). S.O. is also grateful for support by the research grant from Keio Leading-Edge Laboratory of Science & Technology.
Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/5/17
Y1 - 2019/5/17
N2 - A method for the synthesis of N-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C-N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives 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 product, 1-aryl-3-trimethylsilylpyrazole, also served as a great template for the syntheses of N-arylpyrazole derivatives, as demonstrated by regioselective halogenation at the 3-, 4-, and 5-positions of the pyrazole ring.
AB - A method for the synthesis of N-arylpyrazoles by palladium-catalyzed coupling of aryl triflates with pyrazole derivatives is described. Using tBuBrettPhos as a ligand, the palladium-catalyzed C-N coupling of a variety of aryl triflates including ortho-substituted ones with pyrazole derivatives 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 product, 1-aryl-3-trimethylsilylpyrazole, also served as a great template for the syntheses of N-arylpyrazole derivatives, as demonstrated by regioselective halogenation at the 3-, 4-, and 5-positions of the pyrazole ring.
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U2 - 10.1021/acs.joc.9b00673
DO - 10.1021/acs.joc.9b00673
M3 - Article
C2 - 31026163
AN - SCOPUS:85065790020
SN - 0022-3263
VL - 84
SP - 6508
EP - 6515
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
IS - 10
ER -