Octafluoro-4,4′-bipyridine and its derivatives: Synthesis, molecular and crystal structure

Reductive Coupling of (Fluoro)pyridines by Linear 3d‐Metal(I) Silylamides of Cr–Co: A Tale of C−C Bond Formation, C−F Bond Cleavage and a Pyridyl Radical Anion

“…In situ 1 H NMR analysis showed the formation of only one paramagnetic species ( δ SiMe3 =−15.20 ppm), which was subsequently identified as a rare low‐coordinate cobalt(II) fluoride ([K(18c6)][Co(F)(NR 2 ) 2 ] ( 5 ), Figure 4 right) [21] . The fate of the employed PFP was revealed by in situ 19 F NMR spectroscopy through the detection of considerable amounts of 4,4′‐octafluorobipyridine (4,4′‐Fbipy) [34] . 4,4′‐Fbipy is an uncommon perfluoro derivative of 4,4′‐bipyridine and its synthesis can be achieved by copper‐mediated cross coupling using zinc organyls under forcing conditions, [35] the reaction of PFB with hexaethyltriamidophosphite [34] or the unselective electrochemical reduction of PFB [36] .…”

“…[21] The fate of the employed PFP was revealed by in situ 19 FNMR spectroscopy through the detection of considerable amountsof4 ,4'-octafluorobipyridine (4,4'-Fbipy). [34] 4,4'-Fbipy is an uncommon perfluoro derivativeo f4 ,4'-bipyridine and its synthesis can be achieved by copper-mediated crossc oupling using zinc organyls under forcing conditions, [35] the reactiono fP FB with hexaethyltriamidophosphite [34] or the unselective electrochemical reduction of PFB. [36] Given our previouso bservation of the CÀF bond cleavage of fluorobenzene by the iron(I) compound [K(18c6)][Fe(NR 2 ) 2 ]t oy ield af luoroiron(II) and an aryliron(II) complex, [31] we speculated on arelated mechanism in the present case.…”

How do electron donating substituents affect the electronic structure, molecular topology, vibrational properties and intra- and intermolecular interactions of polyhalogenated pyridines?

“…Poly-and perfluoropyridines and their derivatives are building blocks widely employed in syntheses of pharmaceuticals and other bio-active molecules to enhance the lipophilicity or to achieve fluorine related unique biological activities. [1][2][3][4][5] Crystal engineering, often employs strongly electron donating substituents (such as, amino or hydroxyl groups) inserted in pyridine containing scaffolds; these substitutions -typically occurring in ortho-or para-position -impact structural, electronic, topological and vibrational features and allow to build peculiar super molecules with homo-and co-crystalline structures based on tenable p-p stacking and other kinds of intermolecular interactions. [6][7][8] On the other hand, intermolecular interactions impact the molecular properties, resulting in changes in spectra (e.g.…”

Synthesis of 2,3,5,6-tetrafluoro-pyridine derivatives from reaction of pentafluoropyridine with malononitrile, piperazine and tetrazole-5-thiol

“…In pharmacology, it is common to substitute hydrogen with fluorine atoms for increases the lipophilicity and biological activity of the compounds (Chambers et al 2008a , b ). Pentafluoropyridine one of the most important perfluoroheteroaromatic compounds have been used for the synthesis of various drug-like systems (Gutov et al 2010 ). These systems are highly active towards nucleophilic additions owing to the presence of electronegative fluorine atoms and the presence of the nitrogen heteroatom so all five fluorine atoms in pentafluoropyridine may be substituted by an appropriate nucleophile (Cartwright et al 2010 ; Chambers et al 2005 ).…”