Synthesis of Fluorinated 3,6-Dihydropyridines and 2-(Fluoromethyl)pyridines by Electrophilic Fluorination of 1,2-Dihydropyridines with Selectfluor®

Abstract

<jats:p>New fluorinated 3,6-dihydropyridines were obtained by the electrophilic fluorination of 1,2-dihydropyridines with Selectfluor®. These 3-fluoro-3,6-dihydropyridines were easily converted to corresponding pyridines by the elimination of hydrogen fluoride under mild conditions. A new approach to the synthesis of methyl 2-(fluoromethyl)-5-nitro-6-arylnicotinates by the fluorination of 3-fluoro-2-methyl-5-nitro-3,6-dihydropyridines or 1,2-dihydropyridines with Selectfluor® has been developed.</jats:p>

Synthesis and Evaluation of Self-Assembling Properties of 3-(3,5-Difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium Iodides

“…The electrophilic fluorination of aromatic heterocyclic systems has been less studied than the fluorination of arenes. However, a number of heterocycles, including 1,2-dihydropyridines [27], quinolines [28] and indoles [29,30] were modified either by direct fluorination or by fluorodecarboxylation using mainly Selectfluor ® or N-fluorobenzenesulfonimide. The last step-treatment of dialkyl 2,4-diacetyl-2,4-difluoro-3-(pyridin-3-yl)pentanedioates 3 with an excess of methyl iodide-led to quaternization of the pyridine moiety and formation of target compounds-3-(3,5-difluoro-3,5-bis((alkoxy)carbonyl)-2,6-dioxoheptan-4-yl)-1-methylpyridin-1-ium iodides 4 with 56 and 43% yields, respectively.…”

Photoactivated Pyridine Directed Fluorination through Hydrogen Atom Transfer

“…The literature on pyridine fluorination displays a wide variety of approaches over any systemic pattern. Several procedures involve the fluorination of the pyridine ring itself, 3 whereas another approach employs a neat deprotonation protocol to access the fluorination of para-benzylic sites. 4 However, there exist two papers of interest to our present study.…”