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Cercosporin-Photocatalyzed [4+1]- and [4+2]-Annulations of Azoalkenes Under Mild Conditions
Published on: July 17, 2020
Selective Fluorination of 4-Substituted 2-Aminopyridines and Pyridin-2(1 H)-ones in Aqueous Solution
Gang Zhou1, Yawei Tian1, Xiaoming Zhao1
1School of Chemical Technology and Engineering, State Key Laboratory of Pollution Control and Resource Reuse , Tongji University , 1239 Siping Road , Shanghai 200092 , P. R. China.
Abstract:
Fluorination of 2-aminopyridines and pyridin-2(1 H)-ones in the presence of Selectfluor, water, and chloroform under mild conditions has been realized. This method gives fluorinated pyridines in good to high yields with high regioselectivities. The electron-deficient pyridine system is activated by an amino or hydroxyl group at C2. The regioselectivity of the fluorination reaction is strongly dependent upon the substituent pattern in the 2-aminopyridine or pyridin-2(1 H)-one. The transformation of the 3-fluoro-substituted pyridine derivative into fluorinated zolimidine was achieved as well.
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