Addition of Per(poly)fluoroalkyl Iodides to vinyl Cyclopropane Derivatives: Synthesis of Fluoroalkyl Substituted γ,δ-Unsaturated Carbonyl Compounds

In the presence of CrC13 /Fe bimetal couple,per(poly)fluoroalkyl iodides add to vinyl cyclopropane compounds giving addition-ring-opening products in good yields.

Novel Waterborne Fluorinated Polyurethane Containing Fluoroalkyl Side Chain:Synthesis,Characterization and Application on Cotton Fabric

A polyether diol poly[3-bromomethyl-3-tridecafluorooctyloxymethyloxetane]glycol(PFBOX 3) was prepared in 91% yield from ring opening polymerization of 3-bromomethyl-3-tridecafluorooctyloxymethyloxetane 2 which was derived from 3,3-dibromomethyloxetane 1 and 1H,1H,2H,2H-perfluorooctanol.The waterborne fluorinated polyurethane FPU was thus obtained by condensed polymerization of PFBOX 3 with isophoronediisocyanate(IPDI).The structure of FPU was characterized by Fourier transform infrared spectrometer(FTIR).FPU showed good thermal stability under 300℃.The surface properties of FPU were studied by applied on cotton fabric.The treated fabric surface showed excellent water repellent property as the contact angle reached 147°.On the other hand,the surface showed slightly oil repellent property as the contact angle for nujol droplet was 126°.

A Novel Aqueous Polyurethane Containing Short Fluoroalkyl Chains:Synthesis and Application on Cotton Fabrics

As very useful superficial modification agents, the common long perfluoroalkyl — containing agents are facing the ecological problems, such as persistence, bioaccumulation, and/or toxicity in the environment. In order to overcome the problems, we designed and synthesized a polyether diol containing short perfluoroalkyl side chains, which was condensed with diisocyanate to form fluorine-containing aqueous polyurethane. This aqueous polyurethane was applied on cotton fabrics by conventional pad-dry-cure process. The treated cotton fabrics showed good water repellent property with the contact angle reached 131°, and also possessed good washing durability.

Recent progress in carbene-catalyzed fluoroalkylation

The fluoroalkyl fragment plays a vital role in various fields such as pharmaceuticals and materials science, and has a significant impact on human life not only on the present but also in the future. The insertion of fluoroalkyl groups into the chemical skeletons can cause considerable alternations in the chemical, physical and biological properties of molecules, which has attracted numerous scientists from different fields. This review focuses on N-heterocyclic carbene(NHC)-catalyzed fluoroalkylation reactions, providing a detailed analysis and summary of the achievements in the past two decades. Many successful examples clearly indicate that NHCs can catalyze the tranformation of fluoroalkylation reagents with various electronic characteristics, whether electrophilic, nucleophilic, or radical precursors. Herein, the fluoroalkylation reactions are classified based on different catalytic modes of NHCs: Lewis base catalysis, Umploung catalysis, radical catalysis and others. Meanwhile, by refining and systematically studying the contribution of NHC catalysis in fluoroalkylation reactions, this review is expected to provide valuable insights and enlightenment for related fields.

Pentacoordinate Phosphoranes as Versatile Reagents in Fluoroalkylation Reactions

A general method for the synthesis of bench-stable bis(difluoromethyl)pentacoordinate phosphoranes has been developed.The reaction is rapid,operationally simple,and easily scalable.The pentacoordinate phosphoranes can generate both difluoromethyl radical(·CF_(2)H)and difluorocarbene(:CF_(2))intermediates.Thus,a variety of fluoroalkylation transformations havebeen achieved by·CF_(2)H,such asoxidativedifluoromethylation of electron-deficient heterocycles,nickel/photoredox dual-catalyzed difluoromethylation of aryl bromides,and photoredox difluoromethylation of alkenes,or by:CF_(2),such as gem-difluorocyclopropanation of alkenes,base-promoted difluoromethylation of heteroatom nucleophiles,Pd-catalyzed difluoromethylation of arylboronic acids,and Cu-mediated trifluoromethylation of aryl iodides(via:CF_(2) and recombined CF_(3)-).These fluoroalkylation methods have been successfully applied to late-stage fluoroalkylation of drugs and drug-like molecules.

STUDIES ON FLUOROALKYLATION AND FLUOROALKOXYLATION——A NOVEL METHOD OF FLUOROALKYLATION OF ALKENES CATALYSED BY ZINC

Ⅰ. INTRODUCTION Perfluoroalkylation of alkenes is one of the most important methods for industrial as well as laboratory syntheses of a variety of organofluorine compounds. It is usually induced by light, heat or radical initiators. A few of transition metals and their complexes have been shown to be able to catalyse the addition reaction

Synthesis of Fluoroalkylated Allylic-β-hydroxyesters and Fluoroalkylated ,β,γ-Epoxy Esters from Ethyl 3-Hydroxy-4-pentenoate

A sequential transformation of fluoroalkylated adducts obtained from ethyl 3-hydroxy-4-pentenoate with fluorinated iodides was reported. The dehydrohalogenation of adducts was favored to give fluoroalkylated unsaturated β-hydroxy esters in the presence of triethylamine. And intramolecular SN42 reaction products, fluoroalkylated β,γ-epoxy esters, were obtained in 10% aqueous sodium carbonate solution.

Recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides

Fluoroalkyl-containing organic compounds have exhibited wide applications in the field of pharmaceuticals,agrochemicals and materials science due to their outstanding properties such as biological activity,metabolic stability,lipophilicity,excellent chemical and thermal stability.Therefore,various synthetic strategies have been developed for the construction of fluoroalkyl-containing compounds,using highly active fluorinating reagents and fluorinated building blocks.Recently,the use of easily available and inexpensive trifluoroacetic anhydride(TFAA)and its anhydride analogues has attracted great attention to access numerous fluoroalkyl-containing compounds through cyclization and coupling reactions.In this review,we summarized the recent advances in the synthesis of fluoroalkylated compounds using fluoroalkyl anhydrides as reagents.This review aims to provide a reference for researchers on how to develop new synthetic straregies of fluorine-containing organic compounds and achieve kilograms or even tons preparation of fluorine-containing organic compounds using fluoroalkyl anhydrides.

Fluoroalkyl N-sulfonyl hydrazones:An efficient reagent for the synthesis of fluoroalkylated compounds

Fluoroalkyl N-sulfonyl hydrazones are versatile reagents that can be used to synthesize a wide range of diverse fluoroalkylated organic molecules.Although it has been known since 1975,the chemistry of fluoroalkyl N-sulfonyl hydrazones has recently only received great attention from the scientific community.Generally,they are used as either safe and bench-stable diazo precursors in carbene transfer reactions or as 1,3-dipoles in cycloaddition and cyclization reactions.Notably,fluoroalkyl N-sulfonyl hydrazones to replace toxic fluoroalkyl diazo compounds in carbene transfer reactions reduce the risk of rapid accumulation of explosive diazo compounds and improve functional group compatibility and substrate scope.Given the growing importance of fluoroalkyl N-sulfonyl hydrazones in chemical synthesis,a comprehensive review of this topic in the literature is essential to demonstrate their synthetic potential.In this review,we critically summarize and comprehensively analyze the publications in various literatures on the chemistry of fluoroalkyl N-sulfonyl hydrazones starting from 1990 to date.The classification of the different reactivity profiles of fluoroalkyl N-sulfonyl hydrazones and the efficiencies of similar types of reactions or substrates with fluoroalkyl diazo compounds are compared.

Synthesis and Structure Elucidation of New Spiro Compounds with Per（poly）fluoroalkyl Group

A series of spiro compounds have been synthesized via several steps. The structure of these compounds were confirmed by ^1H NMR, 13C NMR, IR, MS spectra and X-ray diffraction analysis. The possible mechanism to form these products was also proposed.

Synthesis of per(poly)fluoroalkyl substituted alkenes and alkynes——Utilizing potassium fluoride supported on alumina as a denydrohalogenating agent

Potassium fluoride on alumina was proved to be an efficient dehydrohalogenating agent for the synthesis of per(poly)fluoroalkyl substituted alkenes and alkynes. The reaction was simple, mild and the yields ranged from good to excellent.

A simple and effective method for fluoroalkylation——the addition of fluoroalkyl iodide to olefins in the presence of hydrogen peroxide

Addition of fluoroalkyl iodides to olefins in the presence of hydrogen peroxide(H_2O_(?)) in acetone,acetonitrile or ethanol gave the corresponding 1:1 adducts in good yields.Reaction of fluoroalkyl iodide with diallyl ether(DAE)yielded tetrahydrofuran derivatives,p-Hydroquinone (p-HQ)can partly suppress the reaction.A radical initiation mechanism is proposed.

Synthesis of 5-Fluoroalkyl Isoxazolidines via 1,3-Dipolar Cycloaddition of Ethyl 2-Hydropolyfluoroalk-2- enoates with Nitrones

Dipolar cycloaddition reactions of ethyl 2-hydropolyfluoroalk-2-enoates (1) with some nitrones were de-scribed. The reaction of 3,4-dihydroisoquinoline N-oxide (2) with 1 took place readily in methylene chloride at room temperature to give the corresponding 5-fluoroalkylisoxazolidines regioselectively as a mixture of two di-astereoisomers (trans and cis) in high yields, while longer reaction time and higher temperature were needed in the case of non-cyclic nitrones. Under similar conditions the reaction of quinoline N-oxide (14) with 1 did not give the expected adducts and a ring-opening product was obtained.

Direct synthesis of per(poly)fluoroalkylmethyl-substituted electrophilic cyclopropane derivatives

A convenient and direct per(poly)fluoroalkylmethyl-introducing cyclopropanation reaction was described. In the presence of CrCl3/Fe, per(poly)fluoroalkyl iodides reacted with diethyl allylmalonate and its analogs to give per(poly)fluoroalkylmethyl-substituted electrophilic cyclopropane derivatives in high yields. This reaction was considered to proceed by two steps: radical addition followed by cyclopropanation.

Synthesis of Fluoroalkylated Heterocycles via the Reaction of 3-（1-Hydropolyfluoroalkenyl）-l-oxo-2,4,1-benzoxazines with Dinucleophilic Reagents

The reaction of 3-（1-hydropolyfluoroalkenyl）-1-oxo-2,4,1-benzoxazines 1 with some dinucleophiles was investigated. 7-Fluoroalkyl-2,3-dihydro- 1,4-diazepine[ 1,2-d]quinazolin- 11-ones 2, 2-fluoroalkylisoxazolo[3,2-b]quinazolin-9-ones 3 and 2-fluoroalkylbenzoimidazoles 4 were obtained from the reaction of 1 with 1,2-diaminoethane, hydroxylamine hydrochloride and 1,2-diaminobenzene respectively.

A facile synthesis of per (poly )fluoroalkyl substituted α-amino acid derivatives

Initiated by CrCl3/Fe redox couple, per(poly)fluoroalkyl iodides added to methyl a-acetylamino acrylate, giving B-per(poly)fluoroalkyl a-amino acid derivatives in good yields.

Selective Ni-catalyzed cross-electrophile coupling of alkynes,fluoroalkyl halides,and vinyl halides

We report a Ni-catalyzed three-component cross-electrophile coupling of alkynes with alkenyl halides and fluoroalkyl halides to generate fluoroalkyl-incorporated 1,3-dienes.This mild and operationally simple protocol is distinguished by its broad substrate scope and excellent chemo-,regio-,and stereo-selectivity,offering a new and organometallic agent-free platform for the construction of fluoroalkyl-incorporated diene motifs.Preliminary mechanistic studies have been conducted to probe the potential reaction pathway.

Syntheses of fluoroalkyl derivatives of two biologically active oligopeptides

Fluoroalkyl derivatives of two biologically active oligopeptides [(m-CF3)Tyr(1)]-Leu-enkephalin, [(m-C2F4Cl)Tyr(1)]-Leu-enkephalin and [(m-COCF2Cl)Tyr(2)]-melanocyte-stimulating hormone releasing hormone have been synthesized. Studies on the activities of these peptides are underway.