Radical Addition Of Perfluoroalkyl Iodides Research Articles

Halogen-bond-mediated atom transfer radical addition of perfluoroalkyl iodides to alkynes under visible light irradiation

A halogen-bond-promoted atom transfer radical addition of alkynes with perfluoroalkyl iodides under visible light irradiation has been reported. Fluoroalkyl radicals can be generated by a visible-light-induced single electron transfer (SET) process with fluorinated iodides as halogen bond donors and organic bases as halogen bond acceptors. Subsequently fluoroalkyl radicals add to terminal alkynes to afford the corresponding iodoperfluoroalkylated products with high yields and broad substrate scope at room temperature. The resulting perfluoroalkylated alkenyl iodides can be further functionalized by cross-coupling reactions.

Synthesis of new bis(3-perfluoroalkyl-1H-pyrazole) polyoxyethylene

Free radical addition of perfluoroalkyl iodides to bis(propargyl) polyoxyethylene ethers 1, using AIBN as initiator, affords the corresponding EE/EZ and ZZ bis(perfluoroalkylallyliodo) ethers 2. Dehydroiodation of compounds 2 produces bis(perfluoroalkylpropargyl) polyoxyethylene ethers 3. Hydrate hydrazine react with dialkynes 3 gives the bis(perfluoroalkylpyrazol) ethers 4.

ChemInform Abstract: Radical Addition of Perfluoroalkyl Iodides to Alkenes and Alkynes Initiated by Sodium Dithionite in an Aqueous Solution in the Presence of a Novel Fluorosurfactant.

A new fluorinated anionic surfactant Cl(CF2)6O(CF2)2SO3N(C2H5)4 was prepared and characterized. The application of the fluorosurfactant allowed the fluoroalkylation to occur in the water without adding organic solvent. The addition of perfluoroalkyl iodides with olefins and alkynes under the initiation of Na2S2O4 in water in the presence of the fluorosurfactant gave the corresponding adducts in good to excellent yields. The fluorosurfactant was suitable for a radical addition process.

Radical Addition of Perfluoroalkyl Iodides to Alkenes and Alkynes Initiated by Sodium Dithionite in an Aqueous Solution in the Presence of a Novel Fluorosurfactant

AbstractA new fluorinated anionic surfactant Cl(CF2)6O(CF2)2SO3N(C2H5)4 was prepared and characterized. The application of the fluorosurfactant allowed the fluoroalkylation to occur in the water without adding organic solvent. The addition of perfluoroalkyl iodides with olefins and alkynes under the initiation of Na2S2O4 in water in the presence of the fluorosurfactant gave the corresponding adducts in good to excellent yields. The fluorosurfactant was suitable for a radical addition process.

ChemInform Abstract: Synthesis of Linear and Branched Perfluoroalkylated Carboxylic Acids by Radical Addition of Perfluoroalkyl Iodides to Unsaturated Fatty Acids.

ChemInform Abstract: Synthesis of Linear and Branched Perfluoroalkylated Carboxylic Acids by Radical Addition of Perfluoroalkyl Iodides to Unsaturated Fatty Acids.

Synthesis of novel perfluoroalkyl-containing polyethers

The synthesis of iodo(perfluoroalkyl)epoxides by radical addition of perfluoroalkyl iodides to allyl glycidyl ether and 1,2-epoxydec-9-ene is described. Dehydroiodination of additional products upon treatment with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) gives unsaturated products. The use of Bu 3SnH/Bz 2O 2 as a reduction reagent of iodo(perfluoroalkyl)allyl glycidyl ethers allows to save oxirane ring. Cationic polymerization of saturated or functional (with iodine or double bond) fluoroalkyl oxiranes under action of catalytic amount of BF 3 .Et 2O proceeds only on epoxide group. In case of poly(9-iod-10-(perfluoroalkyl)-1,2-epoxyalkane) iodine atoms are removed by standard zinc reduction.

New synthesis of polyfluoroalkyl racemic α-amino acids

We describe here a new synthesis of racemic α-amino acids containing polyfluorinated aliphatic long chain R F(CH 2) 3Y (R F = C 2F 5, C 6F 13, C 8F 17) (Y = CH(NH 2)COOH) based on Sörensen's method. The radical addition of perfluoroalkyl iodides R FI (R F = C 2F 5, C 6F 13, C 8F 17) at room temperature to ethyl-2-carbetoxy-2-phthalimido-pent-4-enoate 3 was first initiated by Et 3B/O 2. Then, the reduction of adducts 4a– c using Et 3B/O 2/Bu 3SnH leads to ethyl-2-carbetoxy-2-phthalimido-5-perfluoroalkyl-pentanoate 5a– c under mild conditions. Experimental conditions for optimisation of the iodoperfluoroalkylation step using Et 3B/O 2 were studied. Finally, deprotection of 5a– c gave the desired products 6a– c in good yields.

An Easy Three Step Synthesis of Perfluoroalkylated Amphetamines.

AbstractFor Abstract see ChemInform Abstract in Full Text.

An easy three step synthesis of perfluoroalkylated amphetamines

A general synthesis of perfluoroalkylated amphetamines is presented. Initially, 1-aryl-1-iodo-2-(perfluoroalkyl)ethylenes are prepared by radical addition of perfluoroalkyl iodides to arylacetylenes. Key step of the reaction sequence is the following dehydroiodination in the presence of n-BuLi to give 1-perfluoroalkyl-2-arylacetylenes in situ, which are reacted with secondary amines to produce perfluoroalkylated enamines in a new one pot procedure. Final hydrogenation yields the desired products in good yields. By using N, N-dibenzylamine or N-benzylamines the corresponding primary and secondary perfluoroalkylated amines are easily available.

Synthesis of (Polyfluoroalkyl)cyclopentenes as Model Compounds for Fluorophilic Cyclopentadienes

Nucleophilic opening of the epoxide ring in 6-oxabicyclo[3.1.0]hexane (1) with ethenylmagnesium bromide was employed for the preparation of 2-ethenylcyclopentan-1-ol (2). Radical addition of perfluoroalkyl iodides 3 to alcohol 2 afforded (polyfluoroiodoalkyl)cyclopentanols 4, which were deiodinated with tributylstannane to (polyfluoroalkyl)cyclopentanols 5, followed by dehydration with Nafion-H to the target (polyfluoroalkyl)cyclopentenes 6, which are potential intermediates for fluorous chemistry. Attempts to synthesize (polyfluoroalkyl)cyclopentadienes or bis(polyfluoroalkyl)cyclopentadienes failed due to the exclusive formation of unexpected side product, polyfluoroiodoalkanol 7, in the course of radical addition of perfluoroalkyl iodides 3 to ethenylcyclopentenol (8) or diethenylcyclopentanediol (9), respectively.

A Facile Synthesis of Perfluoroalkyl Vinyl Iodides and Their Palladium-Mediated Cross-Coupling Reactions1

Catalytic amounts of zinc, as low as 10 mol %, in the presence of trifluoroacetic acid (TFA) initiate the radical addition of perfluoroalkyl iodides to terminal alkynes with high regio- and stereoselectivities. Palladium-mediated cross-coupling of these (E)-perfluoroalkyl vinyl iodides allows for a facile synthesis of potentially useful fluoroorganic intermediates.

Application of trimethylvinylsilane as a convenient synthetic precursor of (Perfluoroalkyl)ethenes: An unusual fluoride-induced elimination-desilylation coupled reaction

A convenient and effective method for the preparation of perfluoroalkylated ethenes is described. First, the free radical addition of perfluoroalkyl iodides to trimethylvinylsilane in the presence of AIBN gave iodoethylsilane intermediates (F(CF(2))(n)()CH(2)CHISiMe(3), n = 4 (1), 6 (2), 8 (3), 10 (4); 94-99%). Then an unusual dehydrohalogenation-desilylation reaction was effected by tetrabutylammonium fluoride, and finally the product isolation (F(CF(2))(n)()CH=CH(2) (5-8), 62-87%) was facilitated using a fluorous phase separation technique. This novel approach can also be applied to adjust short C(2) hydrocarbon units to functionalized fluorinated segments (e.g., HOCH(2)(CF(2))(8)CH=CH(2) (11), 71%). All structures were verified by state-of-the-art multinuclear one- and two-dimensional NMR experiments involving both homo- ((19)F-(19)F) and heteronuclear ((1)H-(13)C, (19)F-(13)C) correlations based on the GMQFCOPS and inverse (1)H and/or (19)F detected GHSQC, GHMQC sequences with broad-band adiabatic (13)C decoupling.

Kinetics of homopolymerization of fluorinated acrylates, 5. Influence of the spacer between the fluorinated chain and the ester group

The synthesis of various fluorinated acrylates CH2CHCOO(CH2)pCnF2n+1 and their kinetics of radical homopolymerization are presented. The fluoroacrylated monomers have been prepared in two steps by acrylation of the corresponding halogenated alcohols produced by radical addition of perfluoroalkyl iodides(CnF2n+1I) to ω-hydroxylated alkenes. The fluorinated acrylates differ from each other in the nature (branched or linear) and the length (n ranging from 1 to 8) of the fluorinated chain and in the nature of the spacer between this fluorinated chain and the ester group (p ranging from 1 to 11). The kinetics of polymerization led to the determination of kp2/kte. These values were compared with those of commercially available fluorinated acrylates and were found to depend upon both the spacer length and the nature of the fluorinated group.

Kinetics of homopolymerization of fluorinated acrylates, 5. Influence of the spacer between the fluorinated chain and the ester group

The synthesis of various fluorinated acrylates CH2CHCOO(CH2)pCnF2n+1 and their kinetics of radical homopolymerization are presented. The fluoroacrylated monomers have been prepared in two steps by acrylation of the corresponding halogenated alcohols produced by radical addition of perfluoroalkyl iodides(CnF2n+1I) to ω-hydroxylated alkenes. The fluorinated acrylates differ from each other in the nature (branched or linear) and the length (n ranging from 1 to 8) of the fluorinated chain and in the nature of the spacer between this fluorinated chain and the ester group (p ranging from 1 to 11). The kinetics of polymerization led to the determination of kp2/kte. These values were compared with those of commercially available fluorinated acrylates and were found to depend upon both the spacer length and the nature of the fluorinated group.

Synthesis and polymerization of novel fluorinated morpholino acrylates and methacrylates

The synthesis of four fluorinated acrylates and methacrylates bearing a morpholino group in the lateral chain was achieved in four steps in very high yield: the radical addition of perfluoroalkyl iodides on to allyl acetate followed by an alkaline cyclization led to fluorinated epoxides. These compounds reacted with an excess of morpholine and yielded morpholinofluorinated alcohols that, condensed with acrylic or methacrylic anhydride, produced the expected fluorinated acrylic or methacrylic monomers, respectively. The behaviour in homopolymerization of such new olefins involved the study of the square of the propagation rate constant to the termination rate constant ratio ( k p 2 k te ) by two different methods. The poor reactivity of these monomers has been shown by a GC kinetic study and also by the calculation of the yield. The values of k p 2 k te show that they are two-hundred-times less reactive than usual fluorinated acrylic monomers. We finally propose a reactivity scale for such fluorinated monomers.

Cloud point and pour point measurements of long chain hydrofluorocarbons solutions in a paraffin oil

Long chain hydro-fluorocarbons CF 3(CF 2) n (CH 2) m CH 3 ( n=3, 5, 7; m=7, 11, 13, 15, 17), synthesised by free radical addition of perfluoroalkyl iodides R FI to linear 1-alkenes, showed interesting surface-active properties in a non- aqueous medium [M. Napoli, C. Fraccaro, A. Scipioni and P. Alessi, J. Fluorine Chem., 51 (1991) 103]. Pursuing the research on the physical properties of these compounds, a series of measurements of cloud point (ASTM D 2500-81) and pour point (ASTM D 97-66) was done with solutions of these hydro-fluorocarbons in a paraffin oil and the measured values were then plotted against w/w concentration. An increase of the cloud point and pour point values of paraffin, depending on the length of the perfluoroalkyl group, was generally observed.

Synthese linearer und verzweigter perfluoralkylierter Carbonsäuren durch radikalische Addition von Perfluoralkyliodiden an ungesättigte Fettsäuren

Synthesis of Linear and Branched Perfluoroalkylated Carboxylic Acids by Radical Addition of Perfluoroalkyl Iodides to Unsaturated Fatty AcidsLinear and branched perfluoroalkylated carboxylic acids, i.e. 6a, 11a, 12a, 15a and 16a, are easily available by tin(II) chloride/silver(I) acetate‐initiated free radical additions of perfluoroalkyl iodides to unsaturated carboxylic acids 1a–3a followed by tributylstannan reduction of the respective addition products. The unsaturated perfluoroalkylated carboxylic acids 7a can be obtained by regioselective base‐catalyzed elimination of HI from the addition products.

Addition of perfluoroalkyl iodides to 4-pentenol and its derivatives: one-pot preparation of 2-[( F-alkyl)methyl]tetrahydrofurans

Depending on the nature of the alkaline medium, the radical addition of perfluoroalkyl iodides to 4-pentenol gives a mixture of 5-( F-alkyl)-4-pentenol and 2-[( F-alkyl)- methyl]tetrahydrofuran, or the latter alone.

ChemInform Abstract: Triethylborane‐Induced Stereoselective Radical Addition of Perfluoroalkyl Iodides to Acetylenes.

AbstractThe alkynes (I) react with the perfluoroalkyl iodides (II) in the presence of triethylboron to form exclusively the iodo olefines (III) bearing the iodide and the perfluoroalkyl substituent in trans‐position.

Triethylborane-induced stereoselective radical addition of perfluoroalkyl iodides to acetylenes

Treatment of terminal or internal acetylenes bearing a variety of substituents with perfluoroalkyl iodides in the presence of a catalytic amount of triethylborane provides the corresponding perfluoroalkenes in good to excellent yields. The addition of perfluoroalkyl iodides to olefins is also described.