Fluoroalkyl Iodides Research Articles

Studies on fluoroalkylation and fluoroalkoxylation. Part 28. Palladium(0)-induced addition of fluoroalkyl iodides to alkenes: an electron transfer process

In the presence of catalytic amounts of tetrakis(triphenylphosphine)palladium, fluoroalkyl iodides react readily with alkenes under mild conditions to give the corresponding adducts in high yields. Dichlorobis(triphenylphosphine)palladium or fluoroalkylbis(triphenylphosphine)palladium iodide fails to induce the reaction under the same conditions. Di-iodobis(triphenylphosphine)palladium, but not the fluoroalkylated complex of palladium, Pdl(PPh3)2RF, is formed in the reaction confirmed by X-ray photoelectron spectroscopy. The reaction can be partially suppressed by radical inhibitors, such as 2-nitro-2-nitrosopropane or di-t-butyl nitroxide, but no effects are observed by the presence of oxygen in air or p-dinitrobenzene [molar ratio p-DNB:Pd0= 1:1] unless an excess of p-DNB(10:1) was added. In the presence of diallyl ether, fluoroalkylated tetrahydrofuran derivatives are formed. All these results indicate that a radical-chain process initiated by single electron transfer from palladium(0) to iodide might be involved. Also, the formation of fluoroalkylbis(triphenylphosphine)palladium iodide is proved to proceed through a radical intermediate by e.s.r. trapping techniques.

Samarium diiodide initiated addition reaction of fluoroalkyl iodides to olefins

Samarium diiodide was found to be an effective initiator in the addition reaction of fluoroalkyl iodides to olefins.

ChemInform Abstract: Studies on Fluoroalkylation and Fluoroalkoxylation. Part 24. Magnesium‐ Induced Single Electron Transfer in Reactions of Fluoroalkyl Iodides with Alkenes and Alkynes.

AbstractThe magnesium‐catalyzed reaction of the fluoroalkyl iodides (I) with the alkenes (II) or the alkynes (V) yields the addition products (III) and (VI) respectively.

Solvent effects on the reaction of 4-chlorooctafluorobutyliodide with copper

A linear relationship between the differences of chemical shift in 19FNMR of IC F 2(CF 2) 3Cl and the donor number (DN) of various solvents has been found and the mechanism of the reaction of fluoroalkyl iodide with copper depends on the DN of the solvent used, which influences the product distribution in the reaction of fluoroalkyl iodide and copper with the mixture of olefin and iodobenzene in various solvents.

ChemInform Abstract: Studies on Fluoroalkylation and Fluoroalkoxylation. Part 16. Reactions of Fluoroalkyl Iodides with Some Nucleophiles by SRN1 Mechanism.

AbstractReaction of the fluoroalkyl iodides (I) with the anion of ethyl acetoacetate (II) gives the products (III) ‐ (VI).

Copper-induced telomerization of tetrafluoroethylene with fluoroalkyl iodides

In the presence of catalytic amounts of cooper, telomerization of tetrafluoroethylene with fluoroalkyl iodides can be carried out at 80-100°C. As compared with usual high-temperature (∼200 °C) telomerization process, the reaction time required is much shorter.

Studies on fluoroalkylation and fluoroalkoxylation. Part 24. Magnesium-induced single electrons transfer in reactions of fluoroalkyl iodides with alkenes and alkynes

Magnesium metal catalyses the radical reactions of perfluoroakyl iodides with alkenes and alkynes to give the corresponding adducts in high yields under mild conditions. The presence of 1,4-dinitrobenzene (p-DNB) or oxygen does not affect the reaction, but the reactions can be partially suppressed by hydroquinone and completely inhibited by 2-nitroso. 2-nitropropane in DMF. In THF fluoroalkene is obtained in addition to the normal adducts, and the reaction could be inhibited by p-DNB. All these results seem to show that a radical mechanism is involved in non-ethereal solvents. However, both radical addition and fluroalkyl Grignard reagent reactions are involved in THF. The formation of fluoroalkylmagnesium iodide is also found to proceed through a radical intermediate.

ChemInform Abstract: Iron‐Catalyzed Addition Reaction of Fluoroalkyl Iodides to Alkenes.

AbstractThe fluoroalkyl iodides (I) are coupled with the alkenes (II) in the presence of iron as a catalyst to give the products (III).

Studies on fluoroalkylation and fluoroalkoxylation. Part 16. Reactions of fluoroalkyl iodides with some nucleophiles by S RN1 mechanism

Fluoroalkyl iodides , XCF 2CF 2I (X=ClCF 2CF 2, Cl(CF 2) 4) ( 1 ), react readily with the anion of ethyl acetoacetate ( 2 ) in DMF to give ▪ ( 3 ), XCF 2CF 2H ( 4 ), (CH 3CO) 2CHCO 2Et ( 5 ) and the dimer of the anion ( 6 ). The reaction can be partly suppressed with 1,4-dinitrobenzene(p-DNB) and the radical intermediate can be trapped by diallyl ether (DAE) to give the tetrahydrofuran derivatives. Anions of acetylacetone and malonitrile react also with 1 in the presence of DAE to yield the five-membered ring compounds. All these results seem to indicate that the reaction is a radical chain process induced by electron transfer. In the case of XCF 2CF 2I (X=Cl,I), tetrafluoroethylene and 6 , instead of 3 and 4 , are produced, showing the occurrence of β-fragmentation of the 2-halotetrafluoroethyl radical in the initiation step.

Palladium (0)-catalyzed addition reaction of fluoroalkyl iodides with alkynes

Palladium (0)-catalyzed addition reaction of fluoroalkyl iodides with alkynes

Studies on fluoroalkylation and fluoroalkoxylation. Regioselective synthesis of fluoroalkylated imidazoles

High yields of 4-fluoroalkylimidazoles are obtained regioselectively by the reactions of an imidazole anion and fluoroalkyl iodides or bromides under mild conditions; an SRN1 mechanism is proposed.

Iron-catalyzed addition reaction of fluoroalkyl iodides to alkenes

Fluoroalkyl iodides react with alkenes in the presence of catalytic amounts of iron to give the corresponding adducts in good yields, the influence of solvent on the reaction is discussed and a SET initiated radical chain mechanism is proposed.

Studies on fluoroalkylation and fluoroalkoxylation: 8. Palladium(0)-catalyzed addition reaction of fluoroalkyl iodides with alkynes

Fluoroalkyl iodide RfI [RF=(CF2)nCl, n=2, 4, 6; CF3(CF2)n, n=1, 3; H(CF2)4] reacted with alkyne (CH≡CC4H9; CH≡CSiMe3; CH≡CC6H5) in the presence of catalytic amounts of tetrakis (triphenylphosphine) palladium (0) to give a mixture of E and Z-fluoroalkylated adduct. The reaction could not be catalyzed by dichloro-bis(triphenylphosphine)palladium (II) and fluoroalkyl complex of palladium (II). 2-Nitro-2-nitrosopropane partly suppressed the reaction. It is believed that the reaction proceeds through a free radical intermediate rather than fluoroalkyl complex of palladium (II).

ChemInform Abstract: A New Addition of Fluoroalkyl Iodides to Alkenes Catalysed by Raney Nickel.

AbstractUnter Katalyse von Raney‐Nickel addieren sich die Iodide (II) an terminale Alkene (I) unter Bildung der Iodide (III).

Studies on fluoroalkylation and fluoroalkoxylation. Palladium(0)-catalyzed addition of fluoroalkyl iodides to olefins

Polyfluoroalkyl iodide R_fI (R_f=CI(CF_2)_4, H(CF_2)_4, CF_3(CF_2)_5, CF_3CF_2) reacted with olefin in the presence of catalytic amounts of palladium (0) without solvent at 10～100℃ to give adduces in excellent yields. The tetrahydrofuran derivatives were obtained in the reaction of diallyl ether with fiuoroalkyl iodides, indicating that a radical intermediate may be involved.

Studies on fluoroalkylation and fluoroalkoxylation. Part 10. Electron-transfer induced reactions of perfluoroalkyl iodides and the dialkyl malonate anion and β-fragmentation of the halotetrafluoroethyl radical

Fluoroalkyl iodides, XCF 2CF 2I (X=F, perfluoroalkyl group) ( 1 ), react readily with malonic ester anion ( 2 ) in DMF to give ▪ ( 3 ), 1-hydroperfluoroalkane ( 4 ) and dimer of the anion ( 5 ). The reaction is accelerated by UV irradiation and partly suppressed by p-DNB. Diallyl ether (DAE) can trap the radical intermediates to afford five-membered ring products. Interestingly, in the case of 1 ( X = Cl, I ) the same reaction mainly yielded tetrafluoroethylene and 5 instead of 3 and 4 . The radical intermediate XCF 2CF · 2 ( X=Cl ) can also be trapped by DAE to yield tetrahydrofuran derivatives. All these results can be rationalized in terms of the S RN1 mechanism.

A new addition of fluoroalkyl iodides to alkenes catalysed by raney nickel

Addition of fluoroalkyl iodides to alkenes can be catalysed by Raney nickel under mild conditions to give adducts in good yields; a single electron transfer initiated free radical chain mechanism is suggested.

Radical addition of fluoroalkyl iodides to vinyltrimethylsilane in the presence of copper and stereospecific synthesis of corresponding olefins

Fluoroalkyl iodide R F(R F=(CF 2) nCl, n=6(1a); 4(1b); 2(1c); CF 3(CF 2) 5 (1d); H(CF 2) 4 (1e); (CF 2) 4O(CF 2) 2SO 2F(1f) reacted readily with vinyltrimethylsilane(CH 2CHSiMe 3(2)) in the presence of catalytic amounts of copper in acetonitrile to give adduct (R FCH 2CHISiMe (3)) in good yield. Under the same conditions, α,ω-fluoroalkylene diiodide(I(CF 2) nI, n=6(4a); n=4(4b)) reacted with 2 to form mono-adduct(I(CF 2) nCH 2CHISiMe 3(5)) and bis-adduct (Me 3SiICHCH 2(CF 2) nCH 2CHISiMe(6)). The ratio of 5 to 6 depends on the amounts of 2 used. The reaction can be suppressed by hydroquinone and inhibited partially with p-dinitrobenzene. All the results seem to indicate that the reaction is a radical chain process induced by electron transfer. Stereospecific synthesis of trans-fluoroalkylvinylsilane(R FCHCHSiMe (7)) can be achieved by the reaction of 3 and diethylamine. On treatment of 3 with potassium hydroxide a trans- and cis-mixture of 7 was formed, which can be converted to pure trans-7 on treatment with a small amount of bromine in metylene chloride.

Reactive scattering of a supersonic deuterium atom beam : D+Br2, CF3I, C2F5I, C3F7I

Reactive scattering of D atoms with Br2, CF3I, C2F5I and C3F7I molecules has been studied at an initial translational energy E = 5·3 kJ mol-1 using a supersonic beam of D atoms seeded in He. Deuterium halide product is scattered in the backward direction with respect to the incident D atoms, with substantial energy disposed into product translation in all cases. The fraction of the total available energy which is disposed into product translation, is greater for the fluoralkyl iodides than for Br2 and decreases slightly along the series CF3I, C2F5I, C3F7I. These results demonstrate that the reaction of D atoms with fluoroalkyl iodides occurs only in collisions at small impact parameters with strong repulsion between the reaction products. The potential energy surfaces for the reactions of the fluoroalkyl iodides are similar to that for the D + Br2 reaction but involve the release of a still greater proportion of the reaction exoergicity in the exit valley of the surface. Only a small fraction, if any, of ...

Laser photolysis of perfluoroalkyl iodides

A new method is presented for the simultaneous determination of the quantum yields of excited and unexcited iodine atoms produced by photodissociation of alkyl and fluoroalkyl iodide molecules, and for the determination of the rate constants of the subsequent recombination processes. The method involves taking simultaneous oscillograph traces of the 1313 and 580 nm luminescence signals of the material being studied, produced during molecular photodissociation by neodymium laser harmonics. These constants were determined for CF3I, 1–C3F7I, and (CF3)3CI molecules using the radiation of the fourth harmonic (266 nm) with a pulse energy of 0.4–0.8 J. The results significantly altered the estimate, based on previous investigations, of the possible population inversion in the active medium of a Q-switched iodine laser.