The reaction of perfluoroalkanesulfinates——Ⅶ.Fenton reagent-initiated addition of sodium perfluoroalkanesulfinates to alkenes

The addition of sodium perfluoroalkanesulfinates (R_FSO_2Na) to various olefins (CH_2=CHR) initiated by Fenton reagent (Fe^(2+)-H_2O_2) in the presence of sodium azide gave the adduets R_FCH_2- CHN_3R in good yield.A radical mechanism was proposed based on the EPR and other evidences. The adducts were readily reduced through catalytic hydrogenation to give the corresponding amines R_FCH_2CH(NH_2)R in high yield.The reaction represents a convenient and effective route to these useful organofluorine compounds.

The reaction of perfluoroalkanesulfinates——The study on perfluoroalkanesulfinates as perfluoroalkylation reagents

The reactions for introducing perfluoroalkyl groups into organic compounds have extensively studied.Most of these perfluoroalkylation reactions are realized by using thecommonly used perfluoroalkylating reagents RI,through addition to various olefins andacetylenes,initiated by means of photolysis,pyrolysis,free radical initiators and differentcatalysts,such as the main group metals,transition metals or their complexes in lower oxida-tion states,NaSOand Ph（OAc）, etc. Recently,perfluoroalkanesulfonyl halide was used to effect perfluoroalkylation,thusthe addition of perfluorosulfonyl chloride with olefin or acetylene was initiated by light orheat,and the perfluoroalkanesulfonyl bromides and iodides can effect the perfluoroalkylationthrough their spontaneous addition to some unsaturated compounds,and in other cases,through actinic,thermal or peroxide initiation.These reactions can be visionalized as

The reaction of perfluoroalkanesulfinatesIV.Perfluoroalkyl radical addition to olefins initiated by single electron oxidation of perfluoroalkanesulfinate

Sodium perfluoroalkanesulfinates [Cl(CF_2)n SO_2 Na (1), a, n=4; b, n=6; c, n=8] with the reduction potentials about 0.95-1.00V could be oxidized readily with various oxidizing agents such as Mn (OAc)_3·2H_2O, Ce(SO_4)_2, HgSO_4 and Co_2O_3 to generate perfluoroalkyl radicals which added to the olefins RCH=CHR′to give two kinds of adducts, namely RCH (R_f) CHXR′(3, X=H; 4, X=OAc), with good yields depending upon the solvent system used. Different oxidizing agents showed slight variation on the yields of the adducts. The reaction time could be greatly shortened at higher temperature. Thus, this reaction provides a new way for introducing a perfluoroalkyl group into olefinic compounds.

Perfluoroalkylation of benzo crown ethers with sodium perfluoroalkanesulfinates in the presence of oxidant

Using Ce(SO4)2 or Mn(OAc)3 as oxidant, dibenzo crown ethers such as dibenzo-18-crown-6 (1) and dibenzo-24-crown-8 (5) and benzo-12-crown-4 (7) reacted smoothly with sodium perfluoroalkanesulfinates (2a-2e) to give the corresponding perfluoroalkylated products (3,4,6,7) in good yields with two isomers obtained in the case of dibenzo crown ethers. This provides a facile synthesis of perfluoroalkyl-containing crown ethers.

Bis-perfluoroalkylation of aromatic compounds with sodium perfluoroalkanesulfinates

Bis-perfluoroalkylation of aromatic compounds such as dimethoxybenzenes (2, 4, 6), anisole (8), pyridine (10) and quinoline (13) was accomplished by reaction with excess sodium perfluoroalkanesulfinates, RFSO2Na (1), in the presence of Mn(OAc)3·2H2O under mild conditions. The reaction provides a facile method for the synthesis of bis-perfluoroalkylated aromatic compounds.

The Reaction of Sodium Perfluoroalkanesulfinate with PCl_3

The reaction between sodium perfluoroalkanesulfinate(1)(Rf=a,Cl(CF_2)_4;b, Cl(CF_2)_6;c,Cl(CF_2)_8;d,n-C_6F_(13);e,n-C_8F_(17);f,H(CF_2)_4OCF_2CF_2)and phosphorus trichloride in acetonitrile at 0℃ resulted in the formation of an unstable intermediate,which was hydrolysed directly with aqueous sodium hydro- xide solution to give the corresponding perfluorocarboxylic acid in good yield.

PERFLUOROALKANESULFONYL IODIDE GENERATED FROM THE REACTION OF PERFLUOROALKANESULFINATE SALT WITH IC1

The reaction between perfluoroalkanesulfinate salts(1)[R_fSO_2M R_f=a,Cl(CF_2)_4;b,Cl(CF_2)_6;c,Cl(CF_2)8;d,n-C_6F_(13);e,n-C_8F_(17);M-Na;K; Hg(I)]and iodine monochloride in dichloromethane at low temperature(e.g. -30--50℃)resulted in the formation of the corresponding perfluoroalkane- sulfonyl iodides(2),which were identified by their 19_F NMR spectra.The perfluoroalkanesulfonyl iodides generated in situ reacted smoothly with olefins to forum 1:1 adducts with good yields.Thus,these reactions provide another method for the synthesis of the very unstable perfluoroalkanesulfonyl iodide.

The reaction of perfluoroalkanesulfinate——A novel method for the preparation ofperfluorocarboxylic acid and the coupling product perfluoroalkane

Oxidation of perfluoroalkanesulfinate usually resulted in the formation of the correspon-ding sulfonyl derivatives,thus reaction with hydrogen peroxide or halogen（Cl,Br,I）gavesulfonic acid or sulfonyl halides.However in comparison with alkanesulfinate the perfluo-ro analog was shown to be relatively inert toward oxidizing agents.

Studies on the reaction of cupric(Ⅱ)perfluoroalkanesulfinate

Reaction of aqueous solution of sodium perfluoroalkanesulfinate with cupric sulphate gave a high yield of cupric perfluoroalkanesulfinate,which decomposed slowly in the air on exposure to light to give perfluorocarboxylic acid.The reaction between cupric perfluoroalkanesulfinate and olefins in the presence of potassium iodide and excess CuSO_4 in ether at low temperature(-30 to-20℃)for- med two kinds of adducts,namely the normal adducts,R_fSO_2CH_2CHIR(2)and the adducts resulting from the loss of SO_2 moiety,R_f CH_2CHIR(3)in yields ranging from morderate to good.These results were identical with that of the addition of perfluoroalkanesulfonyl iodide to olefins.A radical reac- tion mechanism is proposed.

Perfluoroalkylation of aromatic compounds with perfluoroalkyl radical generated from the oxidation of sodium perfluoroalkanesulfinate

Sodium perfluoroalkanesulfinates [R_fSO_2Na(1), Rf=CI(CF_2)_n; a, n=4; b, n=6; c, n=8] on oxidation with various single eletron oxidizing agents, such as Mn (OAc)_3·2H_2O and Ce (SO_4)_2, yielded perfluoroalkyl radicals capable of perfluoroalkylating aromatic compounds to give a mixture of o-and p-monoperfluoroalkylated products. Thus, this reaction provides a new method for the synthesis of o-and p-monoperfluoroalkyl substituted aromatic compounds.