375-60-0Relevant articles and documents
A scalable and regioselective synthesis of 2-difluoromethyl pyridines from commodity chemicals
Desrosiers, Jean-Nicolas,Kelly, Christopher B.,Fandrick, Daniel R.,Nummy, Larry,Campbell, Scot J.,Wei, Xudong,Sarvestani, Max,Lee, Heewon,Sienkiewicz, Alexander,Sanyal, Sanjit,Zeng, Xingzhong,Grinberg, Nelu,Ma, Shengli,Song, Jinhua J.,Senanayake, Chris H.
, p. 1724 - 1727 (2014/04/17)
A scalable de novo synthesis of difluoromethyl pyridines from inexpensive materials is reported. The pyridyl subunit is built around the difluoromethyl group rather than a late stage introduction of this moiety. This user-friendly approach allows access to a diverse range of substitution patterns on all positions on the ring system and on the difluoromethyl group.
Multiple pathways in cyclodextrin-catalyzed hydrolysis of perfluoroalkylamides
Granados, Alejandro,De Rossi, Rita H.
, p. 3690 - 3696 (2007/10/02)
The hydrolysis of p-nitroanilide of perfluoroalkanoic acids, CF3(CF2)nCO-, with n = 1, 2, 3, 5, 6, and 7, 1a-f, was studied in the presence of β-cyclodextrin (CD). All reactions were catalyzed by CD through the formation of a 1:1 and 1:2 inclusion complexes. The association equilibrium constants for the 1:1 complexes were dependent on the number of carbons of the fluoroalkyl chain, whereas those of the 1:2 complexes were almost independent. These results indicate that, in the former case, the perfluoroalkyl chain is included, while in the latter, the CD unit encloses the aryl ring. For compounds 1a,b both complexes were more reactive than the substrate itself. The ratio of the reaction of complexed to uncomplexed substrate had its highest value for 1a in the case of the 1:1 complex, and for 1b, the 1:2 complex. This is attributed to the geometry of the complexes. Although compounds 1c-e reacted at the same rates in the free or 1:1 complexed form, CD accelerated the reactions because of an increase of the pKa of the substrate, which results in a higher concentration of the neutral reactive substrate at the same pH. Compound 1f formed aggregates even at 10-6 M concentration, and CD-induced deaggregation resulted in catalysis of the reaction.
REACTIONS OF PERFLUOROACYL FLUORIDES WITH COMPLEXES OF ALUMINUM HALIDES
Bil'dinov, I. K.,Podsevalov, P. V.,Deev, L. E.
, p. 1915 - 1919 (2007/10/03)
The occurrence of halogenodefluorination reactions under the influence of AlHlg3 is explained by the high strength of the Al-F bond that forms.However, thermodynamically stable complexes of perfluoroacyl halides and aluminum halides prevent their full conversion.By substituting the AlHlg3 by the tetrahalogenoaluminates of metals of groups I and II it is possible to replace the F atom by the atoms of other halogens with quantitative yields.A nucleophilic substitution mechanism, accompanied by rearrangement of the intermediate, is proposed for this reaction.The reactivity of the MAlHlg4 does not depend on the nature of the halogen and is determined by the crystal lattice energy.With the AlHlg3-alkyl halide system as halogenodefluorinating agent it is possible to synthesize perfluoroacyl halides with high yields with the reagents in the stoichiometric ratio.The catalytic effect of the alkyl halides is explained by the displacement of the equilibrium RFCOHlg*AlHlg3 ->FCOHlg + AlHlg3 toward the formation of the final products.
