Synthesis of polyfluoroalkyl chlorosulfites and new polyfluoroalkylation reactions with their participation

Regularities were revealed of polyfluoroalkyl chlorosulfites synthesis by reaction of thionyl chloride with associates polyflorinated alcohol-triethylamine and of a new reaction with polyfluorinated alcohols (catalysis by amides), resulting in symmetrical simple polyfluoroalkyl ethers. New polyfluoroalkylation reactions of aliphatic (including polyfluorinated) alicyclic, benzyl alcohols, phenol, carboxylic acids and their salts with polyfluoroalkyl chlorosulfites through substitution of chlorosilfite moiety by halogen, alkoxy- (or polyfluoroalcoxy-), phenoxy-, and acyloxy-groups were studied. Novel synthesis approaches to Foligo- and polymeric materials with new properties were developed.     

Polyfluoroalkyl Chlorosulfites as New Polyfluorinating Agents

The interaction of polyfluorinated alcohols with triethylamine and the kinetics of the reaction of the resulting triethylamine complexes with thionyl chloride were studied, the mechanism of formation of polyfluoroalkyl chlorosulfites was considered, and the optimal reaction conditions were found. The alkylating power of polyfluoroalkyl chlorosulfites was studied in reactions with alkali metal halides (to obtain polyfluorohaloalkanes), in synthesis of acrylic and methacrylic acid esters, and in synthesis of polyfluoroalkyl ethers (with polyfluoroalkyl 1-adamantyl ethers as example).     

Synthesis of α-chloropolyfluoroalkyl ethers and acetals based on them

α-Chloropolyfluoroalkyl ethers were synthesized by the reaction of polyfluorinated alcohols H(CF₂CF₂) _n CH₂OH (n=1?3) with aliphatic aldehydes (ethanal, propanal, butanal) and hydrogen chloride. Yield of α-chloroethers decreases from 71 to 61% as the number of carbon atoms in the starting reactants increases. α-Chloropolyfluoroalkyl ethers react with polyfluorinated alcohols (n = 1?3) to form acetals in yield of up to 40–61%, and with methanol and ethanol, up to 98%.     

Synthesis and properties of di(polyfluoroalkyl) peroxydicarbonates

Synthesis of di(polyfluoroalkyl)peroxydicarbonates [X(CF₂) _n CH₂OC(O)O]₂, where X = H, F; n = 1, 2, 4, 6 (yield 80%) involves the step of the chloroformate formation (yield up to 93%) via the phosgenation of polyfluorinated alcohols followed by the reaction with sodium peroxide. The rate constant of monomolecular decomposition k _term was found to decrease as the polyfluoroalkyl groups were incorporated into the peroxide: it equaled 3.30 and 3.10 s⁻¹ for X = H, n = 2 and 4, respectively, and 7.36 s⁻¹ for di-n-butylperoxydicarbonate. The new peroxides are a source of the polyfluoroalkoxy radicals and nano-modifiers of the polymers to improve their heat resistance and light stability.     

Polyfluoroalkyl <Emphasis Type="Italic">N</Emphasis>-(trifluoromethylsulfonyl)amidosulfites,number one stable NH-containing amidosulfites

We prepared for the first time NH-containing amidosulfites, polyfluoroalkyl N-(trifluoro-methylsulfonyl) amidosulfites CF₃SO₂NHS(O)OR_F, by reaction of N-sulfinyl-trifluoromethanesulfonamide CF₃SO₂N=S=O with alcohols R_FOH. Amidosulfites were formed also in reaction of chlorosulfites R_FOS(O)Cl with trifluoromethanesulfonamide, with its sodium salt, and N-trimethylsilyl derivative.     

Synthesis of Polyfluorinated Ethers

Procedures for preparing polyfluorinated ethers H(CF₂CF₂) _n CH₂OR by alkylation of the corresponding telomeric alcohols H(CF₂CF₂) _n CH₂OH (n = 1–3) with alkyl halides and alkyl tosylates were examined.     

Reactions of Polyfluorinated Telomeric Alcohols with ε-Caprolactam

The possibility of preparing fluorinated oligomeric derivatives of -aminocaproic acid by reaction of polyfluorinated telomeric alcohols H(CF₂CF₂) _n CH₂OH (n = 1-4) with -caprolactam under conditions of homogeneous catalysis (triethylamine, dimethylformamide) was examined. The thermal stability of the oligomers was studied in relation to the fluorine content.     

Catalytic phosphorylation of polyfluoroalkanols. 15. Catalytic phosphorylation of α-polyfluoroalkylbenzyl alcohols by bis(polyfluoroalkyl) chlorophosphates

The catalytic phosphorylation of -polyfluoroalkylbenzyl alcohols by bis(polyfluoroalkyl) chlorophosphates is a convenient method for the synthesis of various bis(polyfluoroalkyl)(-polyfluoroalkylbenzyl) phosphates, including those having donor substituents in the benzene ring. It was shown that in the series of p-methyl--trifluoromethylbenzyl phosphates p-CH₃C₆H₄CH-(CF₃)OP(O)XY (where X, Y=Cl, CF₃CH₂O), the ability to act as O-alkylating agents with respect to polyfluorinated alcohols is a common characteristic, and the alkylating ability increases symbatically with increase in the overall electron-acceptor strength of the X and Y substituents at the phosphorus atom.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 878–886, April, 1990.     

Iridium‐Catalyzed Intermolecular Asymmetric Dearomatization of β‐Naphthols with Allyl Alcohols or Allyl Ethers

An Ir‐catalyzed intermolecular asymmetric dearomatization reaction of β‐naphthols with allyl alcohols or allyl ethers was developed. When an iridium catalyst generated from [Ir(COD)Cl]₂ (COD=cyclooctadiene) and a chiral P/olefin ligand is employed, highly functionalized β‐naphthalenone compounds bearing an all‐carbon‐substituted quaternary chiral center were obtained in up to 92 % yield and 98 % ee . The direct utilization of allyl alcohols as electrophiles represents an improvement from the viewpoint of atom economy. Allyl ethers were found to undergo asymmetric allylic substitution reaction under Ir catalysis for the first time. The diverse transformations of the dearomatized product to various motifs render this method attractive.     

Features of reactions of phthalic anhydride with polyfluorinated alcohols

Polyifluoroalkyl mono- and diesters of phthalic acid were obtained by the reaction of phthalic anhydride with polyfluorinated alcohols. The structure of the polyfluoroalkyl phthalates was studied using IR and ¹H, ¹³C NMR spectroscopy. The nature of the associative interactions between cyclohexanone and polyfluorinated alcohols was revealed.     

Oxovanadium(V)-Catalyzed Deoxygenative Coupling Reaction of Alcohols with Trimethylsilyl Enol Ethers in the Presence of MS3A

Oxovanadium(V)-catalyzed deoxygenative coupling reaction of allyl alcohols with trimethylsilyl enol ethers was demonstrated to afford γ,δ-unsaturated carbonyl compounds in one-step. The catalytic deoxygenative coupling reaction of allyl alcohols proceeded smoothly with both aromatic and aliphatic trimethylsilyl enol ethers. This catalytic deoxygenative coupling system could be applied to the deoxygenative coupling reaction of benzyl alcohols with trimethylsilyl enol ethers, providing the corresponding carbonyl compounds. Furthermore, a gram-scale catalytic synthesis of the γ,δ-unsaturated carbonyl compound was successfully performed to validate the scalability of this catalytic deoxygenative coupling reaction.     

Polyfluoroalkyl chloro- and fluorosulfites

The first example of polyfluoroalkyl chlorosulfite esters have been prepared in good yield by reaction of the corresponding polyfluoroalcohol-triethylamine adducts with excess SOCl₂. The polyfluoroalkyl chlorosulfites are easily converted to the fluorosulfite derivatives (～75%) by reactions with ClF. The polyfluoroalkyl chloro- and fluorosulfites are found to much more thermally stable than their corresponding unfluorinated analogs. The nmr spectra indicate that chemically equivallent groups attached to the α-alkyoxy carbon of these halosulfites are magnetically nonequivallent as a consequence of their asymmetric sulfhur atoms.     

Base-Mediated Claisen Rearrangement of CF3-Containing Bisallyl Ethers

We have previously clarified that the strongly electron-withdrawing CF₃ group nicely affected the base-mediated proton shift of CF₃-containing propargylic or allylic alcohols to afford the corresponding α,β-unsaturated or saturated ketones, respectively, which was applied this time to the Claisen rearrangement after O-allylation of the allylic alcohols with a CF₃ group, followed by isomerization to the corresponding allyl vinyl ethers via the proton shift, enabling the desired rearrangement in a tandem fashion, or in a stepwise manner, the latter of which was proved to have attained an excellent diastereoselectivity with the aid of a palladium catalyst.     

Rapid and Slow Generation of 1‐Trifluoromethylvinyllithium: Syntheses and Applications of CF3‐Containing Allylic Alcohols,Allylic Amines,and Vinyl Ketones

1‐(Trifluoromethyl)vinylation is accomplished in two protocols by the in situ generation of thermally unstable 3,3,3‐trifluoroprop‐1‐en‐2‐yllithium ( 1 ): 1) a rapid lithium–halogen‐exchange reaction of 2‐bromo‐3,3,3‐trifluoroprop‐1‐ene ( 2 ) takes effect with sec‐BuLi at ?105 °C to generate vinyllithium 1 , which reacts with more reactive electrophiles, such as aldehydes and N‐tosylimines before its decomposition, to afford 2‐(trifluoromethyl)allyl alcohols and N‐[2‐(trifluoromethyl)allyl] sulfoamides in good yield; 2) treatment of 2 with nBuLi at ?100 °C causes a slow lithium–halogen exchange of 2 , which gives rise to a mixture of 1 and nBuLi. Vinyllithium 1 is preferentially trapped with less reactive electrophiles, such as N,N‐dimethylamides in the presence of BF₃?OEt₂, to afford 1‐(trifluoromethyl)vinyl ketones in good yield. Versatility of the products toward syntheses of CF₃‐containing ring‐fused cyclopentenones is also demonstrated by the Pauson–Khand reaction and the Nazarov cyclization.     

Synthesis of di(polyfluoroalkyl) ethers

New procedures for preparing di(polyfluoroalkyl) ethers by reactions of polyfluoropropyl chlorosulfonites with polyfluorinated alcohols were tested.Translated from Zhurnal Prikladnoi Khimii, Vol. 77, No. 9, 2004, pp. 1573–1574.Original Russian Text Copyright © 2004 by Rakhimov, Nalesnaya, Vostrikova.     

Synthése d'époxydes et d'éthers glycidiques á chaîne chlorofluorée

Epoxides of general formula

(II, V) (R_F,Cl = Cl ; CF₃ ; Cl(CFClCF₂)_n?) are prepared from chlorohydrines R_F,ClCCl₂CH₂CHClCH₂OH (I).These chlorhydrines are monoadducts of carbon tetrachloride 1,1,1 trichlorotrifluoroethane, telomers Cl(CFClCF₂)_nCCl₃, with allyl alcohol.Reactions of these epoxides with lithium aluminium hydride and/or sulfuric acid lead to corresponding secondary alcohols and/or diols. Glycidyl ethers of (I) and (II,n) with epichlorhydrin could not be obtained. However, epichlorhydrin reacts with the more acidic chlorofluorinated alcohol CFCl₂CF₂CH₂OH. Thus, the glycidyl ether

is prepared.     

Studies on sulfinatodehalogenation. XX. Sodium dithionite-initiated addition of per- and polyfluoroalkyl iodides to cyclic enol ethers and chemical conversions of the products

Per- and polyfluoroalkyl iodides [R_FI, R_F=Cl(CF₂)₄, 1a ; Cl(CF₂)₆, 1b ; Cl(CF₂)₈, 1c ; n-C₆F₁₃, 1d ; n-C₈F₁₇, 1e ] reacted with cyclic enol ethers such as 2,3-dihydrofuran (2) and 3,4-dihydro-2H-pyran (3) in aqueous acetonitrile in the presence of sodium dithionite and sodium bicarbonate at room temperature (10–15°C) to give the corresponding 2-(F-alkyl) hemiacetals in high yields. The adducts were oxidized with Ce(NH₄)₂(NO₃)₆ in acetonitrile or reduced with LiAlH₄ in ether to form the corresponding 2-(F-alkyl)lactones or diols respectively in good yields. In the presence of p-toluenesulfonic acid, the adducts were refluxed in benzene and CH₃CN to produce the corresponding 2,3-dihydro-4-(F-alkyl) furan and 3,4-dihydro-5-(F-alkyl)-2H-pyran. This is a new and effective method for preparing these useful organofluorine compounds.     

The Cp2ZrCl2-catalyzed cycloalumination of functionally substituted olefins with triethylaluminum

Reactions of functionally substituted olefins (allylamines, sulfides and ethers, homoallylic alcohols and amines, as well as vinyl ethers) with Et₃Al in the presence of Cp₂ZrCl₂ as a catalyst were studied. Cycloalumination of allylamines occurs with high regioselectivity to furnish after subsequent deuterolysis 4-deutero-2-(deuteromethyl)butyl-substituted amines. Cycloalumination of alkyl allyl sulfide is accompanied by a side process of the C-S bond cleavage. In the case of allyl and vinyl ethers, no cycloalumination products are formed under the reaction conditions. However, the reactions with homoallylic alcohol and amine after deuterolysis gave the corresponding dideutero-containing compounds in good yields.     

Synthesis of low molecular weight perfluoro oxymethylene vinyl ethers

Perfluoro oxymethylene vinyl ethers have been formed by a multi-step synthesis. The key intermediates are low molecular weight perfluoropolyether (PFPE) fluoroformates CF₃O(CF₂O)_nCOF (I) n=1-6 obtained from the photo-oxidation of perfluoro propene (HFP) in perfluorohexane. Under certain conditions the light-mediated fluorination of PFPE fluoroformates (I) gives PFPE hypofluorites CF₃O(CF₂O)_nCF₂OF (II), which can be added to sym dichlorodifluoroethene to form the dichloro adduct CF₃O(CF₂O)_nCF₂OCFClCF₂Cl (III) which, after dechlorination, gives the desired vinyl ethers CF₃O(CF₂O)_nCF₂OCFCF₂ (IV). Every reaction step has to be properly controlled as far as the reaction variables are concerned. A mechanistic scheme is presented that is consistent with the observed experimental data.     

Selective tetrahydropyranylation of alcohols and phenols using titanium(IV) salophen trifluoromethanesulfonate as an efficient catalyst

Titanium(IV) salophen trifluoromethanesulfonate, [Ti^IV(salophen)(OSO₂CF₃)₂], as a catalyst enables selective tetrahydropyranylation of alcohols and phenols with 3,4‐dihydro‐2H‐pyran. Using this catalytic system, primary, secondary and tertiary alcohols, as well as phenols, were converted to their corresponding tetrahydropyranyl ethers in high yields and short reaction times at room temperature. Investigation of the chemoselectivity of this method showed discrimination between the activity of primary alcohols in the presence of secondary and tertiary alcohols and phenols. This heterogenized catalyst could be reused several times without loss of its catalytic activity. Copyright © 2016 John Wiley & Sons, Ltd.