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A copper-catalyzed site-selective fluorination of α-bromoamides possessing multiple reaction sites, such as primary and secondary alkyl-Br bonds, using inexpensive CsF is reported. Tertiary alkyl-F bonds, which are very difficult to synthesize, can be formed by this fluorination reaction with the aid of an amide group. Control experiments revealed that in situ generated CuF2 is a key fluorinating reagent that reacts with the tertiary alkyl radicals generated by the reaction between an α-bromocarbonyl compound and a copper(I) salt.

Although there are ways to synthesize ortho-pentafluoro-λ6-sulfanyl (SF5) pyridines, meta- and para-SF5-substituted pyridines are rare. We disclose herein a general route for their synthesis. The fundamental synthetic approach is the same as reported methods for ortho-SF5-substituted pyridines and SF5-substituted arenes, that is, oxidative chlorotetrafluorination of the corresponding disulfides to give pyridylsulfur chlorotetrafluorides (SF4Cl-pyridines), followed by chloride/fluoride exchange with fluorides. However, the trick in this case is the presence on the pyridine ring of at least one fluorine atom, which is essential for the successful transformation of the disulfides into m-and p-SF5-pyridines. After enabling the synthesis of an SF5-substituted pyridine, ortho-F groups can be efficiently substituted by C, N, S, and O nucleophiles through an SNAr pathway. This methodology provides access to a variety of previously unavailable SF5-substituted pyridine building blocks.

It was established here that cross-coupling of polyfluorinated 2-iodoanilines with arylacetylenes in MeCN in the presence catalytic amounts of Pd(PPh3)2Cl2, CuI and Et3N produces the corresponding 2-aminotolans although their yields are decreased from 98% to 40% with increasing fluorination of the substrates. It was shown that the 2-aminotolans with six or fewer fluorine atoms in their rings can be heterocyclised by heating in ethanol containing p-TSA to produce the corresponding polyfluorinated indoles. Cyclisation of tolans containing larger numbers of fluorine atoms in their rings proceeds most efficiently in the presence of KOH, resulting in 2-phenylindoles containing the current maximum of eight fluorine atoms.

An efficient and mild fluorination of vinyl azides for the synthesis of α-fluoroketones is described. The mechanistic studies indicated that a single-electron transfer (SET) and a subsequent fluorine atom transfer process could be involved in the reaction.

Gold-catalyzed reactions have witnessed an exponential growth in the past decade. When the unique modes of activation exhibited by gold species meet species with either fluorinated building blocks or fluorinating reagents, new opportunities arise for the development of new methodologies in fluoroorganic chemistry. Indeed, gold and fluorine truly formed a very fruitful partnership, and different types of reactivity emerged from their combination. This review gives an overview of such endeavors. The special properties imparted by fluorine to organic molecules have been exploited in gold-catalyzed processes, allowing for the generation of unprecedented fluorinated chemical entities. Thus, the interaction of gold salts with fluorinated building blocks has been revised. In a second section, recent developments in gold-catalyzed nucleophilic fluorinations have been covered. The development of new gold catalysts that stabilize the Au–F bond as well as recent mechanistic studies in the field raised the interest o...

Visible-light-induced arylthiofluoroalkylations of unactivated heteroaromatics and alkenes have been developed utilizing readily available arylthiofluoroalkyl sources. This method enables simultaneous installation of sulfur and fluoroalkyl moieties, two important functional groups, which demonstrates its potential use for late-stage modifications in the synthesis of functional molecules. This method can be easily utilized to fine-tune the properties of lead molecules in drug development by controlling the number of fluorine atoms in the reagents.

Reactions between XeF2, TiF4 and UV-irradiated elemental F2 in anhydrous HF yielded XeF5TiF5 (XeF6·TiF4), [XeF5]5[Ti10F45] (XeF6·2TiF4), and [XeF5][Ti3F13] (XeF6·3TiF4) upon crystallization. [XeF5]5[Ti10F45] crystallizes in two crystal modifications at low (α-phase, 150 K) and ambient (β-phase, 296 K) temperatures. The crystal structure determination of [XeF5]5[Ti10F45] reveals the largest known discrete decameric [Ti10F45]5− anion built from ten TiF6 octahedra, sharing vertices, in the shape of a double-star. [XeF5]+ cations are completely ordered in the α-phase, while one of three crystallographically unique [XeF5]+ cations is two-fold disordered in the β-phase. The anionic part of [XeF5][Ti3F13] is built from tetrameric Ti4F20 and octameric Ti8F36 units sharing vertices and alternatively linked into ([Ti3F13]−)∞ columns. The charge balance is maintained by [XeF5]+ cations which form secondary Xe⋯F contacts with fluorine atoms of ([Ti3F13]−)∞ groups. The main structural feature of XeF5TiF5 is an infinite chain of distorted TiF6 octahedra joined by cis vertices.

The synthesis of mono-, di-, and trifluoromethyl aryl ethers by fluorodecarboxylation of the corresponding carboxylic acids is reported. AgF2 induces decarboxylation of aryloxydifluoroacetic acids, and AgF, either generated in situ or added separately, serves as a source of fluorine to generate the fluorodecarboxylation products. The addition of 2,6-difluoropyridine increased the reactivity of AgF2 , thereby increasing the range of functional groups and electronic properties of the aryl groups that are tolerated. The reaction conditions used for the formation of trifluoromethyl aryl ethers also served to form difluoromethyl and monofluoromethyl aryl ethers.

Stable and easily accessible benziodoxole reagents are used as fluorine source in reactions of aromatic and aliphatic diazocarbonyl compounds with a variety of alcohols, phenol, and carboxylic acids.

This review paper summarizes the recent progress of highly efficient copolymers with the fluorination strategy for photovoltaic applications. We first present a brief introduction of the fundamental principles of polymer solar cells, and then the functions of fluorine atoms on the polymer donor materials. Finally, we review the research progress of the reported copolymers by classification of the fluorinated acceptor units and donor units, respectively. The resulting structure–property correlations of these copolymers are also discussed which shall certainly facilitate widespread utilization of this strategy for constructing high-performance photovoltaic copolymers in the future.

RbCl and CsCl react with BrF3 yielding the corresponding decafluoridotribromates(III), MBr3F10 (M = Rb, Cs), which were structurally characterized for the first time. The Br3F10− anion is surprisingly not linear but contains a μ3-bridging fluorine atom and seems to be the first example of μ3-F bridging of Br atoms. The compounds are highly reactive and cannot be handled in glassware. As for the tetrafluoridobromates themselves, they are powerful oxidizers and thus suitable for the dry-chemical recycling of precious metals and additionally feature a significantly higher BrF3 content.

A novel layered aluminophosphate (TL-1) has been synthesized. Crystals grow as pseudo-hexagonal thin platelets and their whole morphology depends on the synthesis conditions. The structure was solved by single-crystal X-ray diffraction using charge flipping methods. The synthesized layered material, with composition [AlPO4F(H2O)]-(H10C4ON)4, crystallizes in the monoclinic space group P21/a with a=9.2282(5) A, b=6.9152(4) A, c=14.4615(9) A, β=101.57(1)°. The novel compound has corner sharing AlO3F2(H2O) octahedral chains running along [010], where fluorine atoms are at the shared apices, three oxygen atoms are shared with PO4 tetrahedra while the sixth oxygen pertain to an H2O molecule. The stability field of the novel material is enclosed in the HF/Al2O3 ratio ranging between 1 and 4 and the HF/morpholine ratio lower than 3. At temperature lower than 190 °C, the synthesis results is a pure aluminophosphate sample (low alumina/morpholine ratio). A treatment with H2CO3 leads to a complete morpholine removal, as shown by in situ Raman spectroscopy. Powder X-ray diffraction reveals that, after morpholine extraction, the material collapses. The collapse is irreversible.

Fluorination reactions of medicinal and biologically-active compounds will be discussed. Late stage fluorination strategies of medicinal targets have recently attracted considerable attention on account of the influence that a fluorine atom can impart to targets of medicinal importance, such as modulation of lipophilicity, electronegativity, basicity and bioavailability, the latter as a consequence of membrane permeability. Therefore, the recourse to late-stage fluorine substitution on compounds with already known and relevant biological activity can provide the pharmaceutical industry with new leads with improved medicinal properties. The fluorination strategies will take into account different fluorinating reagents, either of nucleophilic or electrophilic, and of radical nature. Diverse families of organic compounds such as (hetero)aromatic rings, and aliphatic substrates (sp(3), sp(2), and sp carbon atoms) will be studied in late-stage fluorination reaction strategies.

To reconcile the urgent need to access well defined β-configured 2,6-di-deoxypyranose analogues for chemical biology, with the intrinsic α-selectivity of the native system, the directing role of fluorine at C2 has been explored. Localised partial charge inversion (C-H(δ+)→ C-F(δ-)) elicits a reversal of the substrate-based α-stereoselectivity, irrespective of the protecting group electronics.

Li2(OH)0.9F0.1Cl is prepared by melting mixtures of Li2O, LiOH, and LiX (X: Cl, F) at 350 °C for 0.5—1 h.

The present account summarises routes to organofluorine derivatives based on the chemistry of xanthates developed in the author's laboratory. It concerns mostly radical pathways, but a few ionic transformations are also discussed. The degenerative reversible transfer of xanthates allows radical addition even to unactivated alkenes and tolerates numerous functional groups, in particular common polar groups such as ketones, esters, amides, carbamates, nitriles etc. Since the fluorine atoms can be placed on the alkene or the xanthate partner or on both, this opens a convergent approach to a vast array of otherwise inaccessible organofluorine structures that could be of interest to the pharmaceutical and agrochemical industries and to materials science.

Carbazole preferentially reacts with the fluorine group of fluorinated iodoarenes to form iodinated N-arylcarbazole intermediates.

Multi-functionalized fluorinated arenes, especially those that are transformable fluorinated building blocks, are intriguing compounds in synthetic chemistry and for life science related applications. The development of straightforward and efficient approaches to these compounds is of significant importance and has, therefore, attracted much attention. This short review presents our recent progress on the fluoro-difunctionalization of arynes, which allows facile construction of a series of fluorinated arene building blocks bearing an ortho -iodine substituent as a coupling handle for further elaboration. 1 Introduction 2 Silver-Mediated Trifluoromethylation–Iodination of Arynes 3 Silver-Catalyzed Insertion of Aryne into R f –I Bonds 4 Diphenyliodonium-Catalyzed Fluorination of Arynes 5 Silver-Mediated Trifluoromethylthiolation–Iodination of Arynes 6 Summary and Outlook

The superior nucleofuge character of chlorine over fluorine was taken advantage of in the selective SN2′ substitution reaction of gem-chlorofluoropropenes, allowing for the clean formation of β-substituted monofluoroalkenes under metal-free conditions. Numerous N-, S-, O-, and C-nucleophiles behaved nicely in this system. Further synthetic transformations of selected monofluoroalkenes were also accomplished.

This account describes the endeavors made by our group concerning the synthesis of aziridines and azetidin(on)es and their use as novel building blocks for the preparation of nitrogen-containing organofluorine compounds. The majority of contributions, covered in the first part, comprises the study of fluorinated small-ring substrates, focusing on both their synthesis and their synthetic applicability for further transformations. These investigations revealed a pronounced effect of fluorine on the overall reactivity of small-ring azaheterocycles, often resulting in a different behavior compared with that of their nonfluorinated counterparts. In the second part, contributions are covered dealing with the transformation of nonfluorinated small rings into fluorinated target molecules upon treatment with fluorinated reagents. 1 Introduction 2 Synthesis and Reactivity of Fluorine-Containing Aziridines and Azetidines 2.1 Aziridines 2.2 Azetidines 3 Synthesis of Fluorine-Containing Nitrogen Compounds Starting from Nonfluorinated Aziridines and Azetidines 3.1 Aziridines 3.2 Azetidines 4 Conclusion and Outlook

Recent 19F-detected heteronuclear 2-D NMR experiments are summarized. They are devised for the determination of magnitude and sign of nJXF-couplings in multifluorinated compounds, where X is 1H, 13C, and/or 19F and n is the number of chemical bonds between the nuclei X and 19F. For the specific analysis of nJHF-couplings, 1H-detected NMR experiments are reviewed. The advantages and disadvantages of these experiments are discussed. The experiments are of interest to chemistry, biology, and medicine. Keywords: fluorine; multifluorinated; J-coupling; 19F; MRI; magnetic resonance spectroscopy; metabolism; screening; F–C correlation; E.COSY

Stable fluorinating reagent, IF5-pyridine-HF, was used for the polyfluorination of aryl alkyl sulfides. The introduction of three fluorine atoms with a concomitant migration of the arylsulfanyl group was achieved. Carrying out the reaction at 80 °C and presence of a methyl substituent on the aryl group were found to be effective for the polyfluorination. Trifluorinated products were also obtained from dithioketals by reaction with IF5-pyridine-HF. Tetrafluorination of phenyl benzyl ketone and dibenzyl ketone dithioketals was also achieved by reaction with IF5-pyridine-HF and Et3N-6HF.

Quantitative knowledge of the fluorinating strength of electrophilic N–F reagents is of crucial importance for rational design and optimization of novel reagents and new reactions. Herein, we report the first systematic computation of fluorinating potentials of 130 electrophilic N–F reagents in two commonly used solvents dichloromethane and acetonitrile in terms of the N–F bond heterolysis energies as expressed by the fluorine plus detachment (FPD) values. The calculated FPD scales of 130 N–F reagents cover a range from 112.3 to 290.4 kcal mol–1 and 110.9 to 278.4 kcal mol–1 in dichloromethane and acetonitrile, respectively. This comprehensive FPD database provides a valuable quantitative guide for studying the influence of structural variation on the fluorinating strength of the N–F reagents, opening a door to the rational design of novel reagents with appropriate fluorinating strength for specific purposes. It is demonstrated that the FPD values can reproduce the reactivity order for electrophilic N–F r...

Fluorinated derivatives of radicamine A and radicamine B have been synthesized from D-arabinose-derived cyclic nitrone. Structure–activity relationship studies showed that glycosidase inhibition of these fluorinated derivatives was significantly influenced by the position of the fluorine atom. C-7 or C-11 fluorination of the aromatic ring decreased α-glucosidase inhibition of the derivatives, whereas C-8 or C-10 fluorination preserved glycosidase inhibitory activities.

A direct fluorination of 1-(2,2-dibromovinyl)benzene derivatives using wet tetra-n-butylammonium fluoride (TBAF·3H2O) as either a base or a fluorine source in toluene was accomplished, which provided (Z)-1-(2-bromo-1-fluorovinyl)benzene compounds in up to 81% yields with high regioselectivities. This reaction results strongly depend upon the reaction conditions. The mechanism of this reaction was investigated as well.

Chiral phosphoric acid-catalyzed enantioselective aza-Friedel–Crafts reaction of trifluoromethyl benzoxazinones with pyrroles is reported. Under mild conditions, a range of enantioenriched dihydrobenzoxazinones bearing trifluoromethylated quaternary stereocenters could be obtained in good to excellent yield and ee. A remarkable fluorine effect is observed, and preliminary mechanistic studies combined with theory calculations suggest that triple-hydrogen-bonding interactions hold the transition structure rigidly and allow the bulky substituents of the catalyst to influence the enantioselectivity.

Gem-aminofluorination of diazocarbonyl compounds has been achieved for the first time. This reaction proceeds under mild conditions and does not require any transition-metal promoter or catalyst. Treatment of diazoesters with N-fluorobenzenesulfonimide (NFSI), which serves as both a fluorine and nitrogen source, results in the facile construction of C–N and C–F bonds, providing aminofluorination products in moderate to excellent yields. Kinetic studies and DFT calculations have provided valuable insight into the potential mechanism for this novel N–F bond insertion.

A method for the highly site-selective C–N bond-formation reaction of halogenated fluorobenzenes with carbazoles is described. The selectivity of iodine and fluorine atoms on the aromatic ring of fluorinated iodobenzenes was initially determined with a copper–N,N-diisopropylethylamine catalytic system. By changing the position of the iodine atom on the aromatic ring from the 3- or 4-position to the 2-position, the preferred coupling site was switched from the iodine atom to the fluorine atom. Steric hindrance of the fluorinated iodobenzenes is responsible for the selectivity switch. After elucidating the reaction mechanisms of these reaction processes, a metal-free method for the highly site-selective C–N bond-formation reaction of halogenated fluorobenzenes with carbazoles was revealed through C–F bond activation. The metal-free system is able to handle a range of halogenated groups. Thus, a broad range of chlorinated, brominated, and iodinated N-arylated carbazoles were generated, which are widely useful in organic chemistry.

The low-temperature fluorination of the n = 2 Ruddlesden–Popper phase La2SrCr2O7 yields La2SrCr2O7F2 via a topochemical fluorine insertion reaction. The structure-conserving nature of the fluorination reaction means that the chromium centers of the initial oxide phase retain an octahedral coordination environment in the fluorinated product, resulting in a material containing an extended array of apex-linked Cr4+O6 units. Typically materials containing networks of octahedrally coordinated Cr4+ centers can only be prepared at high pressure; thus, the preparation of La2SrCr2O7F2 demonstrates that low-temperature topochemical reactions offer an alternative synthesis route to materials of this type. Neutron diffraction, magnetization, and μ+SR data indicate that La2SrCr2O7F2 undergoes a transition to an antiferromagnetic state below TN ≈ 140 K. The structure–property relations of this phase and other Cr4+ oxide phases are discussed.

3-Fluoro-5-nitro-1-(pentafluorosulfanyl)benzene was prepared by three different ways: as a byproduct of direct fluorination of 1,2-bis(3-nitrophenyl)disulfane, by direct fluorination of 4-nitro-1-(pentafluorosulfanyl)benzene, and by fluorodenitration of 3,5-dinitro-1-(pentafluorosulfanyl)benzene. The title compound was subjected to a nucleophilic aromatic substitution of the fluorine atom with oxygen, sulfur and nitrogen nucleophiles affording novel (pentafluorosulfanyl)benzenes with 3,5-disubstitution pattern. Vicarious nucleophilic substitution of the title compound with carbon, oxygen, and nitrogen nucleophiles provided 3-fluoro-5-nitro-1-(pentafluorosulfanyl)benzenes substituted in position four.

Elemental fluorine was successfully added across the double bond of various α,β-unsaturated carbonyl compounds. A necessary ingredient is a presence of alcohol in the solvent mixture. Unlike all other halogen's addition to olefins, fluorine adds itself in a syn mode specificity. The vic difluoro products were easily dehydrofluorinated to form the corresponding α-fluoro carbonyl derivatives.

The Kinugasa reaction, applied to propargylic gem-difluorides, allows a very direct and efficient synthesis of new exoalkylidene β-lactams with a fluorine in the vinylic position.

Addition reactions of perfluoroalkyl radicals to ordinary or polyfluorinated alkenes have been frequently used to synthesize perfluoroalkylated organic compounds. Here ethyl/methyl 2-bromo-2,2-difluoroacetate, diethyl (bromodifluoromethyl)phosphonate, [(bromodifluoromethyl)sulfonyl]benzene, and ethyl 2-bromo-2-fluoroacetate were involved in Na2S2O4-mediated radical additions to vinyl ethers in the presence of alcohols to give difluoro or monofluoroacetyl-substituted acetals or corresponding difluoromethylphosphonate- and (difluoromethylphenyl)sulfonyl-substituted alkyl acetals. This methodology has also been applied as a key step in the synthesis of hitherto unknown 3,3-difluoro-GABA, completing the series of isomeric difluoro GABAs. Comparison of the pKa values of 3-fluoro- and 3,3-difluoro-GABA with that of the fluorine free parent compound showed that introduction of each fluorine lead to acidification of both the amino and the carboxyl functions by approximately one unit.

An efficient, regioselective synthesis of fluorine-substituted arylboronic esters was achieved through fluorine-controlled C–H borylation of arenes with diboron catalyzed by a PSiN–platinum complex. The promising utility of the PSiN–platinum catalyst and its unique regioselectivity were demonstrated for the first time, which would complement the well-developed Ir-catalyzed C–H borylation.

Crystals of (II) and (III) are characterized by single crystal XRD, IR spectroscopy, UV/VIS diffuse reflectance spectroscopy, second harmonic generation (SHG) measurements, and DFT calculations.

The halogen exchange reaction of aliphatic fluorine compounds with organic halides as the halogen source was achieved. Treatment of alkyl fluorides (primary, secondary, or tertiary fluorides) with a catalytic amount of titanocene dihalides, trialkyl aluminum, and polyhalomethanes (chloro or bromo methanes) as the halogen source gave the corresponding alkyl halides in excellent yields under mild conditions. In the case of a fluorine/iodine exchange, no titanocene catalyst is needed. Only C-F bonds are selectively activated under these conditions, whereas alkyl chlorides, bromides, and iodides are tolerant to these reactions.

Fluorinated ketones are intriguing compounds in synthetic chemistry and life science-related fields. The development of efficient methodologies to obtain these compounds is of significant importance and has therefore attracted considerable attention. This Minireview highlights recent progress made in the synthesis of fluorine-containing ketones, with an emphasis on those methods in which the construction of carbonyl groups is synergetic with distal (β-, γ-, δ-, etc.) incorporation of fluorine atoms or fluorinated groups.

Some of the title compounds including estradiol derivative (IV) are prepared in a regioselective manner from α-diazocyclohexanone units following the two-step sequence A)-B).

This microreview is divided into four parts: introduction, benzylic monofluorination, benzylic difluorination and summary. Each procedure (base-mediated, transition-metal-catalyzed, radical-initiated benzylic fluorination) is described for the cases of both electrophilic and nucleophilic fluorine sources, with the exception of radical-initiated benzylic difluorination, which is described only in the case of electrophilic fluorine in the literature. Moreover, specifically for radical-initiated fluorination, the procedures are further classified according to the nature of the radical initiators used.

With CsF as the fluorine source in combination with BuI as an electrophile, a series of the desired title compounds is available under conditions A)—C), i.e.

This paper presents a metal-free method for highly site-selective C–N bond-forming reaction of polyhalogenated pyridines and pyrimidines. The preferred coupling site can be tuned from the fluorine group bearing the N-heterocyclic ring to the chlorine group when changing from the pyridine ring to the pyrimidine ring. A wide array of halogenated pyridines preferentially reacted with amines at the fluorine group of the pyridine ring to generate monosubstituted halogenated pyridines with high selectivities. Different halogen atoms at various positions were produced by the pyridine ring that performed well under mild conditions. Halogenated pyrimidines underwent highly selective coupling at the chloride group with a wide range of amines having broad substrate applicability and moderate to good yields. The selectivity of the polyfluoropyridines in the developed reaction system was also tested, and the result indicated that the reaction occurred site-selectively at the ortho-position of the nitrogen ring. This reaction accommodated a wide range of halogenated groups. Thus, a wide range of chloro-, bromo-, iodo-, and fluoropyridines were generated, which have a wide utility for organic synthesis.

The chemistry of the lanthanides is mostly dominated by compounds in the oxidation state +III. Only few compounds of Ce, Pr, and Tb are known with the metal in the +IV oxidation state. Removal of the last f-electron on praseodymium +IV would lead to a closed-shell system with formal oxidation state V. In this work we investigated the stability of the PrF5 molecule by theory and matrix-isolation techniques through the reaction of laser-ablated praseodymium atoms with fluorine in excess of neon, argon, krypton, or neat fluorine. Besides the known PrF3 molecule, unreported IR bands for PrF4 could be observed, and there is evidence for the formation of PrF and PrF2 but not for the formation of PrF5.

The [XeOXeOXe]2+ cation provides an unprecedented example of a xenon(II) oxide and a noble-gas oxocation as well as a rare example of a noble-gas dication. The [XeOXeOXe]2+ cation was synthesized as its [μ-F(ReO2F3)2]− salt by reaction of ReO3F with XeF2 in anhydrous HF at −30 °C. Red-orange [XeOXeOXe][μ-F(ReO2F3)2]2 rapidly decomposes to XeF2, ReO2F3, Xe, and O2 when the solid or its HF solutions are warmed above −20 °C. The crystal structure of [XeOXeOXe][μ-F(ReO2F3)2]2 consists of a planar, zigzag-shaped [XeOXeOXe]2+ cation (C2h symmetry) that is fluorine bridged through its terminal xenon atoms to two [μ-F(ReO2F3)2]− anions. The Raman spectra of the natural abundance and 18O-enriched [XeOXeOXe]2+ salts are consistent with a centrosymmetric (C2h) cation geometry. A proposed reaction pathway leading to [XeOXeOXe][μ-F(ReO2F3)2]2 consists of a series of oxygen/fluorine metathesis reactions that are presumably mediated by the transient HOXeF molecule. Quantum-chemical calculations were used to aid in the v...

The development of an enantioselective palladium-catalyzed 1,1-fluoroarylation of unactivated aminoalkenes is described. The reaction uses arylboronic acids as the arene source and Selectfluor as the fluorine source to generate benzylic fluorides in good yields with excellent enantioselectivities. This transformation, likely proceeding through an oxidative Heck mechanism, affords 1,1-difunctionalized alkene products.

A method for direct synthesis of tetrasubstituted fluoroarenes via nickel-catalyzed [2+2+2] cycloaddition is presented. The reaction combines one molecule of 1,1-difluoroethylene with two molecules of alkynes and involves sequential cleavage of the CF and CH bonds in difluoroethylene. The catalytic cycle is established by reduction of the intermediary NiII fluoride with a triethylborane-based borate.

Reactions of Hg(OTeF5)2 with excess amounts of NSF3 at 0 °C result in the formation of NSF3 adducts having the compositions [Hg(OTeF5)2·N≡SF3]∞ (1), [Hg(OTeF5)2·2N≡SF3]2 (2), and Hg3(OTeF5)6·4N≡SF3 (3). When the reactions are carried out at room temperature, oxygen/fluorine metatheses occur yielding the F2OSN- derivatives [Hg(OTeF5)(N═SOF2)·N≡SF3]∞ (4) and [Hg3(OTeF5)5(N═SOF2)·2N≡SF3]2 (5). The proposed reaction pathway leading to F2OSN- group formation occurs by nucleophilic attack by a F5TeO- group at the sulfur(VI) atom of NSF3, followed by TeF6 elimination. Tellurium hexafluoride formation was confirmed by (19)F NMR spectroscopy. The NSF3 molecules are terminally N-coordinated to mercury, whereas the F2OSN- ligands are N-bridged to two mercury atoms. The compound series was characterized by low-temperature single-crystal X-ray diffraction and low-temperature Raman spectroscopy. Several structural motifs are observed within this structurally diverse series. These include the infinite chain structures of the related compounds, 1 and 4; 2, a dimeric structure which possesses an (HgO(μ))2 ring at its core; 3, a structure based on a cage comprised of a (HgO(μ))3 ring that is capped on each face by μ(3)-oxygen bridged F5TeO- groups; and 5, a dimeric structure possessing two distorted (Hg3O2N) rings that are formally derived from 3 by replacement of a F5TeO- group by a F2OSN- group in each ring. Quantum-chemical calculations were carried out to gain insight into the bonding of the μ(3)-oxygen bridged teflate groups observed in structure 3. Compounds 1-5 represent a novel class of neutral transition metal complexes with NSF3, providing the first examples of NSF3 coordination to mercury. Compounds 4 and 5 also provide the only examples of F2OSN- derivatives of mercury that have been characterized by single-crystal X-ray diffraction.

A new compound CsRb 2 Sb 4 F 15 ( I ) has been synthesized, and its crystal structure (monoclinic syngony: a = 7.9863(3), b = 28.594(1), c = 8.0319(3) A, β = 116.60(1), space group P 2 1 / c ) has been determined. The structure of I is composed of complex [Sb 2 F 7 ] − and [SbF 4 ] − anions and Cs + and Rb + cations, which link structural units into a framework through ionic bonds. The isostructural character of the compounds CsRb 2 Sb 4 F 15 ( I ) and Cs 3 Sb 4 F 15 ( II ) has been established. It has been demonstrated that fluorine ions diffusion is a predominant type of ionic motions in the fluoride sublattice of the compound I above 420 K. The comparison of ionic conductivities in K 3 Sb 4 F 15 , Cs 3 Sb 4 F 15 , and CsRb 2 Sb 4 F 15 complexes has been performed. The factors determining the value of ionic conductivity in these compounds have been discussed.

This Communication describes a successful olefin cross-metathesis with tetrafluoroethylene and its analogues. A key to the efficient catalytic cycle is interconversion between two thermodynamically stable, generally considered sluggish, Fischer carbenes. This newly demonstrated catalytic transformation enables easy and short-step synthesis of a new class of partially fluorinated olefins bearing plural fluorine atoms, which are particularly important and valuable compounds in organic synthesis and medicinal chemistry as well as the materials and polymer industries.

The importance of fluorinated compounds in pharmaceutical, agrochemical, and material chemistry has led to the development of numerous methods for electrophilic and nucleophilic fluorination. Radical fluorination represents an interesting complementary approach, but it had been limited due to the paucity of selective radical fluorinating agents. The recent uncovering of easier to handle atomic fluorine sources has led to significant advances in radical fluorination in the past few years. This review presents the newly developed methods for fluorination involving radicals as reactive intermediates. 1 Introduction 2 Atomic Fluorine Sources 2.1 Fluorine as a Selective Radical Fluorinating Agent 2.2 Fluoroxy Reagents 2.3 XeF2 2.4 N–F Reagents as Atomic Fluorine Sources 3 Methodologies for Radical Fluorination 3.1 Decarboxylative Fluorination 3.2 Fluorination of Alkenes 3.3 Fluorination of Boronic Acid Derivatives 3.4 C(sp3)–H Fluorination 3.5 C–C Bond Activation 4 Conclusion