Fluorine-containing heterocumulenes. 19. Synthesis and reactions of 2-perfluoro-tert-butyl-3,3-diphenyloxaziridine

Conclusions A method is proposed for the production of N-perfluoro-tert-butyldiphenyloxaziridine. Its cycloaddition to electrophilic and nucleophilic dipolarophiles, leading to the synthesis of fluorine-containing oxadiazolidinones, dioxazolidine, and a uniquely stable aziridinone, was investigated.For Communication 18, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1788–1791, August, 1979.The authors thank P. V. Petrovskii and A. I. Lutsenko for recording and interpreting the¹³C NMR spectrum.     

Fluorine-containing imines. Communication 6. Reaction of hexafluoroacetone perfluoropivaloylimine with dimethylantline and dimethylbenzylamine

Conclusions Hexafluoroacetone perfluoropivaloylimine reacts with dimethylaniline as a C-alkylating agent and with dimethyIbenzylimine and triethylamine as a hydride-ion acceptor: the reactions are accompanied by the ejection of perfluoro-tert-butyl anions, which leads to the formation of isocyanates.See [1] for Communication 5.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2022–2024, September, 1987.     

Fluorine-containing imines. 5. Reactions of acylimines of hexafluoroacetone and perfluoroalkyl isocynates with methylenebisdimethylamine

Conclusions In reactions with hexafluoroacetone acylimines, perfluoroalkyl isocyanates and imidoyl fluoride, methylenebisdimethylamine serves a source of dimethylaminomethylene, hydride ion, and dimethylamino group.For communication 6, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1814–1817, August, 1987.     

Electronic factors in reactions of sulfinylamines with dienes

By means of the frontier MO approach, using the MNDO method, it has been shown that the (4+2)-cycloaddition of N-sulfinylalkylamines and N-sulfinylpolyfluoroalkylamines to 1,3-butadiene and isoprene proceeds under normal electronic conditions. The -electron stabilization energies of the transition state of the reactions have been estimated. An interpretation is given for the high reactivity of the N-sulfinylpolyfluoroalkylamines and the regioselectivity of their reactions with isoprene.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 28, No. 3, pp. 258–261, May–June, 1992.The author wishes to thank participants in the Republic Seminar on Quantum Chemistry (May 19–21, 1992) for valuable discussion of this work.     

Fluorine-containing heterocumulenes 15. Bis(trifluoromethyl)ketene N-(benzenesulfonyl)imine in reactions with vinyl ethyl ether and phenylacetylene

Conclusions We have examined the cycloaddition of vinyl ethyl ether and phenylacetylene to bis (trifluoromethyl) ketene N-(benzenesulfonyl) imine, which forms fluorine-containing azetidines, azetines, and cyclobutenes.For communication 14, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 880–883, April, 1978.     

New results of the reactions with hexafluoroacetone and related compounds

The reaction of hexafluoroacetone (HFA) with CN- and SCN-compounds of main group and transition elements is described. The cyclic addition reactions to the CN-moiety is catalyzed by base, preferentially triethylamine. Of particular interest are the adducts of HFA with (SCN)₂ and Hg(SCN)₂. They are precursors for various new compounds containing six- membered rings. The elimination of oxygen by the reaction of HFA with N=WCl₃ may be considered as a new Wittig type reaction. The dimer of hexafluorothioacetone inserts into its SC bond the carbon atom of an isonitrile group to yield five-membered rings. PCl₅ adds to (CF₃)₂CC(CN)₂, prepared from HFA and CH₂(CN)₂, to form a six-membered phosphorus containing ring.Hexafluoroacetone (HFA) was first prepared in 1941 [1]. It is easily available either by the reaction of hexachloroacetone and anhydrous hydrogen fluoride in the presence of a catalyst [2] or by the isomerisation of hexafluoropropenoxide in the presence of a Lewis acid [3,4]. We have prepared HFA using hexachloroacetone, anhydrous HF and a CrO_x catalyst. The reaction proceeds well at 350°C. By-products, which are formed in small amounts, are the very toxic chloropentafluoroacetone and perfluoropropionic acid fluoride. The chloropentafluoroacetone is easily separated by distillation and the perfluoropropionic acid fluoride is removed by treating the crude product with water. Very pure hexafluoroacetone is obtained by distillation of the HFA · H₂O adduct from concentrated sulfuric acid.     

氟催化废弃硅基还原剂与CO2还原转化反应

CO2是最重要的可再生碳源之一.为了将CO2转化为有用的有机化合物,我们研究了二种模型硅基"废"材料—乙硅烷和硅粉的反应活性.在这些反应中,氟盐的催化活性最高,在常压、在质子源水和硅基还原剂的存在下,CO2可转化为甲酸.原位NMR和动力学分析表明,含氢硅烷和五配位的硅物种分别是反应中间物和活性物种.     

Cycloaddition-elimination reactions of 5-imino-1,2,4-dithiazolidin-3-ones with heterocumulenes

5-Benzylimino-1,2,4-dithiazolidin-3-one ( 2a ) reacts with heterocumulenes (isocyanates, isothiocyanates, ketenes) with elimination of carbonyl sulfide, yielding the heterocycles 6–8 . The thiadiazolidine 6a , obtained from 2a and phenyl isocyanate, underwent similar reactions but under milder conditions, indicating that phenyl isocyanate is a better leaving group than carbonyl sulfide.     

Fluorine-containing imines. 1. New cycloaddition reactions of acylimines of fluoroketones

Conclusions Acylimines of fluoroketones react with nitriles and aromatic aldehydes to form 1,4-cycloadducts, and with difluorocarbene give 1,2- and 1,4-cycloadducts, with the latter predominating.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1826–1830, August, 1979.     

Fluorine-containing 3-arylhydrazono-2,4-dioxobutanoates in reactions with difunctional nucleophiles

3-Arylhydrazono-4-polyfluoroalkyl-2,4-dioxobutanoates reacted with hydrazines to give ethyl 4-aryldiazeno-3-polyfluoroalkyl-1H-pyrazole-5-carboxylates, while analogous reactions of ethyl 3-arylhydrazono-4-pentafluorophenyl-2,4-dioxobutanoates resulted in the formation of 4-aryldiazeno-3-pentafluorophenyl-1,2-dihydropyridazine-5,6-diones or 6-aryl-7,8,9,10-tetrafluoro-2-phenyl-2,4a,6,10b-tetradropyridazo[4,3-c]cinnoline-3,4-diones, depending on the conditions. Cyclocondensation of ethyl 3-arylhydrazono-4-polyfluoroalkyl(or pentafluorophenyl)-2,4-dioxobutanoates with ethylenediamine led to 3-[1-arylhydrazono-2-oxo-2-polyfluoroalkyl(or pentafluorophenyl)ethyl]-5,6-dihydropyrazin-2(1H)-ones, and 3-[1-arylhydrazono-2-oxo-2-polyfluoroalkyl(pentafluorophenyl)ethyl]benzoxazin-2-ones were formed in the condensation with o-aminophenol. Pentafluorophenyl-substituted heterocycles were found to undergo intramolecular ring closure to give 3-hetaryl-substituted 1-aryl-5,6,7,8-tetrafluoro-1,4-dihydrocinnolin-4-ones. The reactions of ethyl 3-arylhydrazono-4-pentafluorophenyl-2,4-dioxobutanoates with o-aminobenzenethiol gave 3-[7-(2-aminophenylsulfanyl)-1-aryl-5,6,8-trifluoro-4-oxo-1,4-dihydrocinnolin-3-yl]benzothiazin-2-ones; 8a-hydroxy-11,12,13,14-tetrafluoro-10-(4-methoxyphenyl)-2,3,4,5,6,7,8a,10-octahydropyrazino[1′,2′:4,5][1,4]diazepino[6,7-c]cinnolin-8-one was isolated in the condensation of ethyl 3-(4-methoxyphenylhydrazono)-4-pentafluorophenyl-2,4-dioxobutanoate with N-(2-aminoethyl)ethane-1,2-diamine.     

Reactions of group IV organometallic compounds : XXIX. Insertion reactions of (trimethylsilylmethylene)phosphorane with heterocumulenes. Inhibition of Wittig type reactions

A reaction of (trimethylsilylmethylene)dimethylphenylphosphorane, PhMe₂PCHSiMe₃ (I), with phenyl isocyanate affords a 2/1 insertion product, which results from insertion of phenyl isocyanate into both the CSi and CH bonds of I. By way of contrast, a reaction of isothiocyanate and carbon disulfide with I affords 1/1 products by insertion of these heterocumulenes into the CSi bond of I. In these reactions, Wittig-type elimination of dimethylphenylphosphine oxide or sulfide did not occur because of irreversible migrations of the trimethylsilyl group to the anionic centers of the Zwitterionic intermediates.     

Fluoride-catalyzed hydroalkoxylation of hexafluoropropene with 2,2,2-trifluoroethanol

Trifluoroethoxylation of hexafluoropropene with 2,2,2-trifluoroethanol (TFE) were conducted using an alkali metal fluoride catalyst to produce CF₃CHFCF₂OCH₂CF₃. KF exhibited the highest yield and selectivity of CF₃CHFCF₂OCH₂CF₃, whereas LiF and NaF were inactive for the trifluoroethoxylation reaction. The same reaction also proceeded well in the presence of RbF or CsF, but yielded large amounts of olefinic and high molecular weight side products, implying that the size of alkali metal cation or the degree of MF dissociation plays an important role in determining the activity and the product composition. FT-IR and NMR experiments revealed that CsF interacts with TFE more strongly than KF through a hydrogen bonding. The experimental and spectroscopic results suggest that the degree of MF dissociation should be in the medium range for the selective production of CF₃CHFCF₂OCH₂CF₃ in high yield and selectivity.     

Hexafluoroacetone as protecting and activating reagent: reactions of hexafluoroacetone with α-keto acids

Hexafluoroacetone and α-keto acids react to give 5,5-bis(trifluoromethyl) substituted 2(5H)-furanones and/or 2,2-bis(trifluoromethyl)-1,3-dioxolan-4-ones depending upon the substituent pattern of the side chain of the acid. A fluoroanalogue of the natural product zymonic acid was obtained from ethyl 3,3,3-trifluoropyruvate and 2-oxosuccinic acid in one step.     

Condensation of perfluoroisobutylene with acetonitrile

Conclusions Perfluoroisobutylene condenses with acetonitrile in the presence of CsF.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 209–210, January, 1982.