Fluorination with xenon difluoride; Part IX. Reaction with phenylsubstituted sulphides

Fluorination of phenyl-methylsulphide with xenon difluoride yields phenyl-fluoromethylsulphide. Further fluorination leads to phenyl-difluoromethylsulphide. Reaction with cis-2,6-diphenyltetrahydro-1-thio-4-pyrone results in the dehydrogenated product 2,6-diphenyldihydro-1-thio-4-pyrone, while further reaction leads to 2,6-diphenyl-1-thio-4-pyrone; thiochroman-4-one yields thiochromen-4-one. No evidence for precursors of the products isolated at room temperature was found.     

Fluorination with xenon difluoride. Reaction with halogenated hydrocarbons

Filler and coworkers [1-5] have demonstrated the utility of xenon difluoride as a selective fluorinating agent for aromatic hydrocarbons in the liquid phase, while Mackenzie and coworker [6] have fluorinated aromatic compounds in the vapour phase. We have developed a fluorination reaction of phenyl substituted olefins resulting in high yields of vicinal difluorides [7,8] and trifluoroacetates, depending on the catalyst. In our continued interest in the use of xenon difluoride as a mild fluorinating agent for fluorination of organic compounds, we have tries to fluorinate some heterocyclic ring systems, e.g. imidazo-(1,2-b)-pyridazine, under conditions similar of those used for fluorination of phenyl substituted olefins [7,8,9] (room temperature, methylene chloride as solvent, hydrogen fluoride as catalyst). It is well known that heteroaromatic compounds are less reactive toward electrophilic substitution reactions then aromatic hydrocarbon systems. However, it has been shown that bromination of imidazo-(1,2-b) -pyridazine results in 3-bromo products [10], while in chlorination with phosphorus pentachloride [11], the entering order of chlorine atoms is at position 3 > 2, 7 > 8 > 6 (Radical reactions).     

Reaction of fluorochloronitroacetic and difluoronitroacetic acids with xenon difluoride

Conclusions Dihalodinitromethanes are formed in the reaction of difluoronitroacetic and fluorochloronitroacetic acids with xenon difluoride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 466–467, February, 1988.     

Fluorination with xenon difluoride. Reactions of phenyl-substituted olefins in the presence of trifluoroacetic acid

Trifluoroacetic acid-catalyzed liquid-phase fluorination with xenon difluoride of phenyl-substituted olefins, e.g. cis- and trans-1-phenylpropene and cis- and trans-stilbene, results in the formation of vicinal difluorides and fluoro-trifluoroacetates. The reaction is non-stereospecific. d,1-Erythro and d,1-threo fluoro-trifluoroacetates are formed in a highly regiospecific Markovnikov manner in 50% yield. The formation of β-fluorocarbonium ions is suggested.     

Reaction of the 3-nitrotriazole anion with xenon difluoride

Conclusions Xenon difluoride in acetonitrile is capable of oxidizing the anion of 3-nitro-1,2,4-triazole to form the corresponding radical.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 3, pp. 736–738, March, 1989.     

Fluorination of aromatic compounds with xenon difluoride in the presence of boron trifluoride etherate

Fluorination of benzene with the XeF₂—BF₃?Et₂O system in acetonitrile at low temperatures affords fluorobenzene in 18% yield, the conversion of benzene being 92%. The rest products are di-, tri-, tetra-, and polyphenyls with different fluorination pattern. Toluene and chloro- and bromobenzenes are fluorinated predominantly at the ortho and para positions. Fluorination of 4-nitroanisole affords 2-fluoro-4-nitroanisole in 73% yield.     

Reaction of carbonyl compounds with xenon difluoride in the presence of silicon tetrafluoride

Reaction of various carbonyl compounds with xenon difluoride in the presence of silicon tetrafluoride was investigated. Aromatic aldehyde, ketones, and α-ketoester react with xenon difluoride to give α,α-difluoroalkyl phenyl ethers. However, acid fluoride, ester, acid cyanide, α-ketocarboxylic acid, or thioester do not afford the corresponding products. In the case of cinnamaldehyde, fluorination was accompanied by intramolecular cyclization to afford fluorinated epoxide.     

Reaction of 1,2-diamines with 4-hydroxycoumarin. Synthesis of 1,4-diazepin-5-ones

1,4-diazepin-5-ones were obtained from 4-hydroxycoumarin and substituted 1,2-diamines by heating in 2-methyl-1-propanol.     

Some reactions with krypton difluoride and xenon fluorides

The VF₅XeF_x (x being 2,4 and 6) system was sistematically investigated. Besides XeF_2^·.VF₅ (1) and 2XeF_6^·.VF₅ (2), new adducts XeF_6^·.VF₅ and XeF_6^·.2VF₅ were also isolated. The obtained adducts were characterized by following mass balance throughout the experiment, by Raman and IR spectroscopy, by recording the melting point - composition diagram, etc.The results of reactions in a system with some binary fluorides (e.g. TiF₄, MnF₂, CrF₃) and KrF₂ are also discussed.     

Reaction of polyhalopyridines 4. Reaction of mercaptopolychloropyridines with fluorine-containing xenon compounds

A method has been developed for the perfluoroalkylation of mercaptopolychloropyridines by the thermolysis of xenon(II) perfluoroalkanecarboxylates, obtained by the reaction of xenon difluoride and aperfluoroalkanecarboxylic acids, in the presence of the appropriate thiol. Perfluoroalkylthio derivatives of polychloropyridines have been synthesized. The fluorosulfonyl derivatives of tetrachloropyriidne and of tetrachloropyridine N-oxide were obtained by the action of XeF₂ on mercaptotetrachloropyridine dissolved in aqueous HF.For Communication 3 see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 58–62, January, 1994.     

Reactions of xenon difluoride. Part 6. Some reactions of phosphorus,arsenic and iodine compounds

The reaction of XeF₂ with some organo-phosphorus, -arsenic and-iodine compounds is described. The products were identified by fluorine nmr spectroscopy and the conditions under which fluorine exchange occurs were briefly investigated. Organoiodine (III) difluorides are suitable for the conversion of Ph₂Te to Ph₂TeF₂; the decomposition of RIF₂liberates IF and fluoroalkane.     

Reaction of 1,4-dibromo-1,2-butadiene with primary amines

Conclusions Starting with 1,4-dibromo-1,2-butadiene we synthesized bis(1-bromo-1,2-butadienyl)-N-(-hydroxyethyl)amine, which was reacted with primary amines to give 2,6-diethynyl-1-N-alkyl-4-N-(-hydroxyethyl)piperazines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2579–2582, November, 1975.     

Autocatalytic condensation of 1,2-orthoesters of sugars with 2,3-dihydroxy-1,4-naphthoquinone (isonaphthazarin)

The autocatalytic glycosylation of isonaphthazarine and its derivatives with 1,2-orthoesters of D-glucose and maltose in chlorobenzene has been studied. It has been established that the ratio of mono- and bisglycoside forms depends on the acidity of the glycosylated hydroxy group and its steric accessibility. Free monoglycosides of 2,3-dihydroxy-1,4-naphthoquinone have been synthesized by deacetylation with sodium methoxide in methanol.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Branch, USSR Academy of Sciences, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 477–482, July–August, 1989.     

Autocatalytic condensation of 1,2-orthoesters of sugars with 2,3-dihydroxy-1,4-naphthoquinone (isonaphthazarin)

The autocatalytic glycosylation of isonaphthazarine and its derivatives with 1,2-orthoesters of D-glucose and maltose in chlorobenzene has been studied. It has been established that the ratio of mono- and bisglycoside forms depends on the acidity of the glycosylated hydroxy group and its steric accessibility. Free monoglycosides of 2,3-dihydroxy-1,4-naphthoquinone have been synthesized by deacetylation with sodium methoxide in methanol.     

Regioselective Synthesis of 4-Aryl-1,3-dihydroxy-2-naphthoates through 1,2-Aryl-Migrative Ring Rearrangement Reaction and their Photoluminescence Properties

4-Aryl-1,3-dihydroxy-2-naphthoates having the less accessible 1,2,3,4-tetrasubstituted naphthalene scaffold and that show photoluminescence emission from solid state as well as in solutions, were selectively synthesized from brominated lactol silyl ethers through the 1,2-aryl-migrative ring rearrangement reaction.