Organofluorine chemistry: promising growth areas and challenges

Abstract

Currently, the chemistry of organofluorine compounds is a leading and rapidly developing area of organic chemistry. Fluorine present in a molecule largely determines its specific chemical and biological properties. This thematic issue covers the trends of organofluorine chemistry that have been actively developed in Russia the last 15 – 20 years. The review describes nucleophilic substitution and heterocyclization reactions involving fluorinated arenes and quinones and skeletal cationoid rearrangements in the polyfluoroarene series. The transformations involving CF3-substituted carbocations and radical cations are considered. Heterocyclization and oxidative addition reactions of trifluoroacetamide derivatives and transformations of the organic moiety in polyfluorinated organoboranes and borates with retention of the carbon – boron bond are discussed. Particular attention is devoted to catalytic olefination using freons as an efficient synthetic route to fluorinated compounds. The application of unsymmetrical fluorine-containing N-heterocyclic carbene ligands as catalysts for olefin metathesis is demonstrated. A variety of classes of organofluorine compounds are considered, in particular, polyfluorinated arenes and 1,2-diaminobenzenes, 1-halo-2-trifluoroacetylacetylenes, α-fluoronitro compounds, fluorinated heterocycles, 2-hydrazinylidene-1,3-dicarbonyl derivatives, imines and silanes. The potential practical applications of organofluorine compounds in fundamental organic chemistry, materials science and biomedicine are outlined. The bibliography includes 1019 references.

Aromatic SNF-Approach to Fluorinated Phenyl tert-Butyl Nitroxides

“…The use of organofluorine compounds has had a huge impact on the main areas of modern chemistry, such as the development of new functional materials and pharmaceuticals with unique properties [1][2][3][4]. The ever-increasing importance of fluorine organic compounds brings the development of new directed and high-performance synthetic methods to the forefront [5]. The chemistry of stable organic radicals is among the scientific fields where the need for the creation of new methods for the synthesis of fluorinated compounds is ripe.…”

Reactions of 3-aryl-1-(trifluoromethyl)prop-2-yn-1-iminium salts with 1,3-dienes and styrenes

“…Analogous intermolecular reactions of CF 3 -substituted iminium groups with electron-rich (hetero)aromatics are known [18,24]. Furthermore, 1-(trifluoromethyl)indenes have recently been generated by cationic cyclization of β-aryl trifluoromethyl enones under superacid conditions [42][43][44].…”

“…Cis-annelated cyclobutene 18 ( 1 H NMR: 3 J H,H = 3.8 Hz for the angular protons) and the iminium-substituted primary cycloadduct are not expected to undergo a fast ring opening under moderate thermal conditions, because the orbital-symmetry-allowed concerted conrotatory process [47,48] would create a strained cis,trans-dihydrobenzo [8]annulene ring system. Cyclobutenes resulting from a [2 + 2] cycloaddition of electrophilic alkynes and alkenes under moderate thermal conditions have been isolated also from the reaction of CF 3 -free propyn-iminium salts with cyclic enol ethers [49] and of other very electrophilic alkynes (i.e., Lewis acid-activated acetylenic esters [50], 1-(trifluoroacetyl)-3-haloacetylenes [44] and 4-chloro-2oxobut-3-ynoic esters [51][52][53] with unactivated alkenes (including cyclohexene [51], which did not react with 1a). For the 3-arylpropyn-1-iminium ions 1, a charge delocalization can be assumed, which is described by the resonance structure of a 1-aryl-3-aminoallenyl cation, hence their electronic structure shows a certain analogy to the triphenylpropargyl/triphenylallenyl cation.…”

Cu(I)- and Pd(0)-Catalyzed Arylation of Oxadiamines with Fluorinated Halogenobenzenes: Comparison of Efficiency

“…The spectrum of their activities is impressive: they are used as non-steroid anti-inflammatory drugs, antibiotics, and anticancer agents; additionally, some of them possess anxiolytic, antipsychotic, and neurotropic activities [2][3][4]. Thus, great attention is paid to the elaboration of modern synthetic approaches to various fluorine-containing compounds [5,6]. Also of interest are bioactive fluoro-and trifluorosubstituted pyridines possessing aminoalkyl substituents [7,8].…”

“…19 F-NMR (376.4 MHz, CDCl 3 ) δ -113.05 (ddd, 3 J HF = 11.8 Hz, 3 J HF = 8.9 Hz, 4 J HF = 6.8 Hz). MS (MALDI-TOF+): Calculated for C 22 H 31 F 2 N 2 O 3 [M + H] 409.230, found 409.244.N,N -(((oxybis(ethan-2,1-diyl))bis(oxy))bis(propane-3,1-diyl))bis(2-fluoroaniline)(6). Obtained according to method B from trioxadiamine 1 (0.5 mmol, 110 mg), 2-bromofluorobenzene (1.25 mmol, 218 mg) in the presence of Pd(dba) 2(11 mg) and BINAP(14 mg).…”