Imidazopyridine and pyrimidinopyridine systems from perfluorinated pyridine derivatives

Synthesis of some fluorinated thiazolopyridine from pentafluoropyridine and 4-phenylsulfonyl tetrafluoropyridine

“…Identification of 3j-3p was done by 19 F NMR analysis, in which the resonance attributed to fluorine located ortho to ring nitrogen had a chemical shift in the range of À82.4 to À92.4 ppm, similar to the shift observed for the 3a. The corresponding resonance for the fluorine located meta to ring nitrogen occured at the range of À137.4 to À147.5 ppm similar to the analogous system (Cartwright et al, 2007(Cartwright et al, , 2010.…”

“…In recent years, we and others have described synthesis of some bipyridyl bridged compounds (Ranjbar-Karimi et al, 2011a, b), macrocycles (Sandford, 2003) and ring-fused systems (Barone et al, 2005;Sandford et al, 2005;Hargreaves et al, 2007;Ranjbar-Karimi et al, 2011a, b;Sandford, 2003;Ranjbar-Karimi et al, 2012;Ranjbar-Karimi and Mousavi, 2010) from reaction of pentafluoropyridine and derivatives with some appropriate nucleophiles and binucleophiles (N, O, S nucleophiles) for example Sandford et al reported synthesis of some dipyridoimidazole and imidazopyridine derivatives from highly fluorinated pyridine systems, 2-aminopyridine derivatives, and amidines respectively (Cartwright et al, 2007(Cartwright et al, , 2010. Previously we reported the use of ultrasound irradiation for reaction of pentafluoropyridine with mono-and bidentate Nnucleophiles (Ranjbar-Karimi et al, 2011a).…”

Pyrido[3,2-b][1,4]oxazine and pyrido[2,3-b][1,4]benzoxazine systems from tetrafluoropyridine derivatives

“…For example, penta-and tetrafluoropyridine derivatives have been used as substrates in annelation reactions involving reaction with appropriate difunctional nucleophiles to give various tetrahydro-pyridopyrazine [2], imidazopyridine [3], dipyridoimidazole [4], furopyridine [5] and thienopyridine systems [6] that are very difficult heterocyclic scaffolds to access by conventional reported methodologies.…”

Reactions of dibromotetrafluorobenzene derivatives with sodium phenoxide salts. Competing hydrodebromination and SNAr processes

“…Solutions to problems of regioselectivity of reactions, functionalisation and a mechanistic rationale for these processes continue to evolve and perfluoroaromatic systems have been used in the synthesis of, for example, polyfluorinated macrocyclic systems [5][6][7][8][9], peptides [10], solid phase organic systems [11], polycyclic derivatives [12][13][14][15][16][17] and, furthermore, in life-science applications [18].…”