Emmanuel Magnier

Université de Versailles Saint-Quentin | UVSQ · Institut Pierre-Simon Laplace (IPSL)

Hypervalent iodine compounds are described with perfluoroalkyl chains and S‐perfluoromethyl sulfoximines as ligands of the halogen. The influence of these groups on the stability of the cyclic structure is studied. The crucial role of the trifluoromethyl chain is clearly highlighted as efficient ligand for the hypervalency. The structure and the re...

We report herein recent advances made by our group and others in the field of oxygen-centered radicals generated under photocatalysis. Thanks to the design of new O-radical precursors, these radicals can now be efficiently trapped by unsaturated systems in an intermolecular manner, via the formation of a new C–O bond. 1 Introduction 2 Reactions Inv...

We describe the preparation of S‐perfluoroalkyl benzodithiazole trioxides as radical perfluoroalkylating reagents. Their syntheses were performed on a multi‐gram scale by an oxidative cyclization connecting the nitrogen of a sulfoximine and a sulfur atom previously introduced in the ortho position of this group. The structures and properties of the...

Over the last years, methods devoted to the synthesis of asymmetric molecules bearing a perfluoroalkylated chain have been limited in number. Among them, only a few can be used on a large variety of scaffolds. This microreview aims at summarizing these recent advances in enantioselective perfluoroalkylation (-CF3 , -CF2 H, -Cn F2n+1 ) and highlight...

A selective access to perfluoroalkyl selenoxides, via Oxone® as oxidant or to selenones by using a Polyoxometalate‐based Ionic Liquid (POM‐IL) as a catalyst for the oxidation step is described. The reaction works with various perfluoralkyl chains and substituents with satisfactory to excellent yields. A two‐step one‐pot reaction from selenocyanates...

A selective access to perfluoroalkyl selenoxides, via Oxone® as oxidant or to selenones by using a Polyoxometalate‐based Ionic Liquid (POM‐IL) as a catalyst for the oxidation step is described. The reaction works with various perfluoralkyl chains and substituents with satisfactory to excellent yields. A two‐step one‐pot reaction from selenocyanates...

Site-selective trifluoromethylation of silyl dienol ethers derived from α,β-unsaturated aldehydes, ketones, and amides was achieved for the first time in the remote γ position. This photoredox catalyzed process is quite general to compounds bearing many functionalities and is applicable to the late-stage functionalization of biorelevant molecules....

This work shows why it is imperious to use an excess of butyllithium for a directed ortho‐lithiation of a trifluoromethyl sulfoximine. The analysis of mixtures of n‐BuLi and sulfoximine 1 in THF‐d8 using {1H, 6Li, 13C, 15N, 19F} NMR experiments at low temperatures reveal that a first deprotonation occurs that leads to dimeric and tetrameric N‐lithi...

This work shows why it is imperious to use an excess of butyllithium for a directed ortho‐lithiation of a trifluoromethyl sulfoximine. The analysis of mixtures of n‐BuLi and sulfoximine 1 in THF‐d8 using {1H, 6Li, 13C, 15N, 19F} NMR experiments at low temperatures reveal that a first deprotonation occurs that leads to dimeric and tetrameric N‐lithi...

Trifluorometylselenolation via C‐H activation is barely described in literature. In particular, no such vinylic functionalization has been yet described. Herein, a palladium‐catalyzed trifluoromethylselenolation of vinylic C‐H bonds is described. The 5‐methoxy‐8‐aminoquinoline has been used as auxiliary directing group to perform this reaction. The...

A general, scalable and easy to implement protocol is described for the coupling of thiosugars and various ortho‐functionalized S‐aryl S‐perfluoroalkyl sulfoximines. This dual photocatalysis methodology was developed with a commercial hydrogen atom transfer reagent and produced key structures that were transformed into original cyclic skeletons bea...

Trifluoromethyl tolueneselenosulfonate is a versatile reagent which can be reduced by iron powder to generate in situ trifluoromethylselenolate anion. This species can then react with alkyl bromide to perform SN2 reaction.

Available online-1-n-butyl-3-methylimidazolium selenocyanate ([bmim][SeCN]) proved to be a very efficient reagent for selenocyanation of alkyl halides. As part of an eco-friendly process, no organic solvents were used during the transformation and reaction times are reduced by using microwave as a heating source. The ionic liquid was carefully recy...

The first light-driven method for the α-trifluoromethoxylation of ketones is reported. Enol carbonates react with N-trifluoromethoxy-4-cyano-pyridinium, using the photoredox catalyst 4-CzIPN under 456 nm irradiation, affording the α-trifluoromethoxy ketones in ≤50% isolated yield and complete chemoselectivity. As shown by 29 examples, the reaction...

The Front Cover shows the introduction of fluorinated groups into molecules, which gives them interesting and sometimes unexpected physicochemical properties and reactivity. In this study, the configurational stability of fluoroalkyl sulfoxides (shown on the flyer) was investigated and the pKa value of the ‐CHF2 group was determined, which is very...

The enantiomeric separation of aryl trifluoromethyl and difluoromethyl sulfoxides was realized via chiral chromatography. The configurational stability of each set of enantiomers was then studied by thermal enantiomerization. The ΔG‡ values obtained cover a range of 38.2‐41.0 kcal.mol ‐1 at 214 °C, thus demonstrating their optical stability at room...

The first light-driven method for the alpha-trifluoromethoxylation of ketones is reported. Enol carbonates, in particular Boc derivatives, react with N-trifluoromethoxy-4-cyano-pyridinium triflimide (2a) using the photoredox-catalyst 4-CzIPN (5 mol-%) under irradiation at 456 nm affording the corresponding α-trifluoromethoxy ketones in up to 50% is...

The first light-driven method for the alpha-trifluoromethoxylation of ketones is reported. Enol carbonates, in particular Boc derivatives, react with N-trifluoromethoxy-4-cyano-pyridinium triflimide (2a) using the photoredox-catalyst 4-CzIPN (5 mol-%) under irradiation at 456 nm affording the corresponding α-trifluoromethoxy ketones in up to 50% is...

In this contribution, a new POM-based ionic liquid, namely (P6,6,6,14)4[W10O32], was fully characterized. Its viscosity and its very low dielectric constant make this hybrid ionic liquid suitable to be used as solvent for organic transformations. As proof of concept, this unique ionic liquid combining solvant and catalyst properties was tested for...

Ethynylbenziodoxol(on)e (EBX) cyclic hypervalent iodine reagents have become popular reagents for the alkynylation of radicals and nucleophiles, but only offer limited possibilities for further structure and reactivity fine‐tuning. Herein, we report the synthesis of new N ‐heterocyclic hypervalent iodine reagents with increased structural flexibili...

In this contribution, a new POM-based ionic liquid, namely (P6,6,6,14)4[W10O32], was fully characterized. Its viscosity and its very low dielectric constant make this hybrid ionic liquid suitable to be used...

The synthesis of molecules bearing (trifluoromethylselenyl)methylchalcogenyl groups is described via an efficient two-step strategy based on a metal-free photoredox catalyzed decarboxylative trifluoromethylselenolation with good yields up to 88% which raised to 98% in flow chemistry conditions. The flow methods allowed also to scale up the reaction...

This paper deals with the preparation and the characterization of four new ionic liquids resulting from the pairing of various polyoxotungstates or polyoxomolybdates with the cation trihexyltetradecylphosphonium. The physical properties measured by different techniques evidence that the viscosity and the rheological behaviors of such POM-based ioni...

We report herein a practical method to generate CF 3 Se ⁻ (and R F Se ⁻ ) anions from shelf-stable reagents under iodide activation. Metal-free nucleophilic trifluoromethylselenolations have been then performed with this in situ-generated anion. Perfluoroalkylselenolations have also been described.

The electroreduction of SF 6 is shown at ambient temperature in acetonitrile using an array of platinum microelectrodes to improve the electrical detection. Its half reduction potential occurs at −2.17 V vs Fc ⁺ /Fc. The exact number of electrons for the full consumption of sulfur hexafluoride was determined and this gas further quantitatively tran...

The direct trifluoromethylation of a variety of aliphatic alcohols using a hypervalent iodosulfoximine reagent affords the corresponding ethers in moderate to good yields (14‐72%). Primary, secondary and even tertiary alcohols, including examples derived from natural products, undergo this transformation in the presence of catalytic amounts of zinc...

α‐Trifluoromethylselenolated enones constitute valuable building‐blocks for further synthesis of innovative fluorinated compounds. Herein, we described an easy access to such compounds in green conditions through a Morita‐Baylis‐Hillman like reaction. These conditions have also been extended to higher fluorinated homologs.

A general protocol for the synthesis of S‑trifluoromethyl S‐arylsulfoximine thioglycosides has been reported. This protocol is based on a Pd‐catalyzed Migita cross‐coupling between o ‐iodo S‐trifluoromethyl S‑arylsulfoximines and a broad range of 1‐thiosugars. This method gives access to a series of functionalized S‑trifluoromethyl S‐arylsulfoximin...

We report herein a novel photoredox‐catalyzed synthesis of allylic trifluoromethanes. The use of sulfilimino iminium as source of trifluoromethyl radical proves crucial to achieve high selectivity. Importantly, both styrene derivatives and unactivated alkenes are for the first time suitable partners for this process. The mild reaction conditions ar...

The synthesis of sulfilimines and sulfoximines is a topic widely developed in the literature. This chapter focuses on the very specific cases of a fluorine atom or a perfluoroalkyl chain directly bonded to the sulfur atom. The access to these species needs peculiar methodologies that are summarized in this text. Applications and postfunctionalizati...

The Cover Feature shows the combination of flow chemistry and photoredox catalysis for the hydroper­fluoroalkylation of alkenes and alkynes. Organic dye (Rhodamine B) and green light promote this safe and scalable transformation. Perfluorinated sulfilimino iminiums, readily accessible reagents through a one‐pot multigram procedure, are used as sour...

A metal‐free visible‐light‐promoted regioselective trifluoromethylselenolation of electron‐rich heteroarenes has been developed using C–H functionalization. This eco‐friendly, atom‐economical, and easy‐to‐operate protocol provides direct access to a wide range of functionalized SeCF3‐containing heteroarenes in high yields, and is amenable to contin...

S-trifluoromethyl sulfoximine and S-trifluoromethyl sulfilimino iminiums are important reagents for the electrophilic or radical late-stage introduction of the CF3 group. We disclose in this article a reappraisal of our previous methodologies and their adaptation to a large scale. More than 30 g of the key sulfoximine 4 and 40 g of S-trifluoromethy...

In this Review, we highlight recent advances in the understanding and design of N‐functionalized pyridinium scaffolds as single electron, redox‐triggered functional group transfer reagents. We provide a selection of representative methods that demonstrate reactivity and fundamental advances in this emerging field. Reactivity of these reagents can b...

In this Review, we highlight recent advances in the understanding and design of N‐functionalized pyridinium scaffolds as single electron, redox‐triggered functional group transfer reagents. We provide a selection of representative methods that demonstrate reactivity and fundamental advances in this emerging field. Reactivity of these reagents can b...

Electrophilic trifluoromethylation is at the forefront of methodologies available for the installation of the CF3 moiety to organic molecules; research in this field is largely spurred by the availability of stable and accessible trifluoromethylation reagents, of which hypervalent iodine and sulfoximine based compounds have emerged as two prominent...

We report herein a novel photoredox‐catalyzed hydrotrifluoromethylation of unsaturated systems under continuous flow. This metal‐free method is easily broadened to other perfluoroalkyl groups (RF = CF3, CFCl2, CF2Br, C4F9) thanks to the use of sulfilimino iminiums as sources of ·RF radicals. The mild reaction conditions are compatible with unactiva...

We report herein an efficient four-component photoredox-catalyzed reaction. Under the optimized conditions using [Ru(bpy)3(PF6)2] as the photocatalyst, a wide range of terminal and internal alkenes can efficiently undergo azidoalkoxy-trifluoromethylation in the presence of Umemoto's reagent, carbonyl compound, and TMSN3, giving rise to original and...

Alkoxyl radicals are highly reactive species which rapidly react by hydrogen atom transfer (HAT) or β-fragmentation to afford a carbon-centered radical. We discuss herein how these RO· radicals can be efficiently trapped in an intermolecular manner by styrene derivatives when they are generated by photoredox catalysis from the corresponding N-alkox...

A simple and efficient protocol for the oxidation of trifluoromethyl, mono- and difluoromethyl sulfides to the corresponding sulfoxides without over-oxidation to sulfones, using TFPAA prepared in situ from trifluoroacetic acid and 15% H2O2 aqueous solution was developed. The methodology is suitable for a wide range of aromatic and aliphatic substra...

We report here the preparation of unprecedented analogs of 1,2-benzothiazine and benzoisothiazole incorporating the S-trifluoromethyl sulfoximine group in their core. Starting from a stable precursor, cyclization occurs via a catalytic controlled process. The choice of the catalyst is crucial for selectivity towards the 5- or the 6-membered ring. I...

Correction for ‘Modulation of the mechanical energy storage performance of the MIL-47(V IV ) metal organic framework by ligand functionalization’ by Pascal G. Yot et al. , Dalton Trans. , 2019, DOI: 10.1039/c8dt04214d.

We describe herein the photoredox‐initiated 1,2‐difunctionalization of alkene derivatives with N ‐chloro S ‐fluoroalkyl sulfoximines yielding novel fluoroalkyl sulfoximine scaffolds. The reaction is proposed to proceed through an atom‐transfer radical addition (ATRA) mechanism involving the generation of fluorinated nitrogen‐centered sulfoximidoyl...

An overview of the most significant radical-based synthetic methods currently available for the preparation of trifluoromethylthiolated compounds is presented. 1 Introduction 2 Early Work: Photochemical Reactions Under UV Irradiation 2.1 Reactions Involving CF3SH 2.2 Reactions Involving CF3SCl 2.3 Reactions Involving CF3SSCF3 3 Reactions Involving...

A general efficient one-pot synthesis of S-perfluoroalkylated NH-sulfoximines from sulfides has been developed using phenyliodine diacetate (PIDA) and ammonium carbamate. Remarkable rate enhancement with trifluoroethanol was observed, presumably due to H-bonding effects. These mild and metal-free conditions are compatible with -CH2 F, -CFCl2 , -CF2...

We report herein a novel photoredox‐catalyzed approach for ether synthesis, involving alkoxyl radicals generated from N‐alkoxypyridinium salts. A wide range of alkenes are smoothly difunctionalized in an anti‐Markovnikov fashion, affording various functionalized alkyl alkyl ethers. Notably, this mild process tolerates a large number of functional g...

We report herein a novel photoredox‐catalyzed approach for ether synthesis, involving alkoxyl radicals generated from N‐alkoxypyridinium salts. A wide range of alkenes are smoothly difunctionalized in an anti‐Markovnikov fashion, affording various functionalized alkyl alkyl ethers. Notably, this mild process tolerates a large number of functional g...

We report herein the preparation of ortho‐vinylaryl S‐trifluoromethylated sulfoximines through cross‐coupling reactions. Two efficient palladium‐catalyzed procedures (Stille and Suzuki) were developed, with use of ortho‐iodo aryl sulfoximines as substrates, to give various vinyl derivatives in good yields. The difference in reactivity of the fluori...

The search for original perfluorinated moieties is a very modern and attractive challenge. Among the emergent groups, the S-perfluoroalkylated sulfoximines are very peculiar because of their structural diversity and promising properties. A literature survey shows that interest in these molecules is strongly increasing. This short review summarizes...

Organofluorine compounds have attracted special attention in the field of drug discovery because of their unique properties, which make them important in biomedicinal research. Great attention has been given to novel methodologies that offer promising convenient synthetic protocols to prepare various organofluorine compounds. This chapter highlight...

The trifluoromethylthio group is of rising interest in medicinal, agrochemical, and materials chemistry. Although several strategies for the introduction of this functional group have been described, new synthetic methods are needed. A novel ionic liquid, 1-n-butyl-3-methylimidazolium trifluoromethylthiolate, has been developed and is herein report...

Lignin chemical demethylation in ionic liquids was investigated using pure lignin-model monomers and dimer together with dioxan isolated lignins from poplar, miscanthus and maize. Different methylimidazolium ionic liquids (ILs) were compared, according to two different heating processes, microwave irradiation and conventional heating in sealed tube...

Fluoroalkyl amino reagents 1a and 2a have been developed from commercially available trifluoromethyl trifluorovinyl ether via a hydroamination reaction with diethylamine or dimethylamine. These reagents can be activated by treatment with a Lewis acid and subsequently used as a mono- or dielectrophile for the introduction of the fluoro(trifluorometh...

A facile, and totally regioselective one pot approach to synthesize 5,7-diiodo-3-substituted-isocoumarins is described. This reaction was realized using copper iodide as the catalyst under mild reaction conditions. The methodology was used to design a wide variety of compounds and was tolerant to a large number of functions. Interestingly, among th...

The aim of this article is to highlight the benefit of the presence of the fluorine atom for health compounds. This element, almost absent in organic natural compounds, brings remarkable properties to molecules. This has allowed chemists to design and synthesize new drugs, much more efficient and selective for all the diseases. The fluorine atom is...

We describe the first gram scale preparation of the reagent dichlorotrifluoromethoxyacetic acid. This stable compound is obtained in five steps starting from the cheap diethylene glycol. The reactivity of the sodium salt of this fluorinated acid was also tested and allowed the preparation of new amides.

The “chlorination/fluorination” technique for aliphatic trifluoromethyl ether synthesis was investigated and a range of products with various functional groups was prepared. The results were compared with oxidative desulfurization-fluorination of xanthates with the same structure.

Reported herein is the use of S-perfluoroalkyl sulfilimino iminiums as a new source of RF radicals under visible-light photoredox catalysis (RF =CF3 , C4 F9 , CF2 Br, CFCl2 ). These shelf-stable perfluoroalkyl reagents, readily prepared on gram scale from the corresponding sulfoxide using a one-pot procedure, allow the efficient photoredox-induced...

Reported herein is the use of S-perfluoroalkyl sulfilimino iminiums as a new source of RF radicals under visible-light photoredox catalysis (RF=CF3, C4F9, CF2Br, CFCl2). These shelf-stable perfluoroalkyl reagents, readily prepared on gram scale from the corresponding sulfoxide using a one-pot procedure, allow the efficient photoredox-induced oxyper...

We report herein the first use of N-trifluoromethylthiosaccharin as the source of SCF3 radical under photoredox catalysis. This allowed an efficient and general visible-light-mediated carbotrifluoromethylthiolation of alkenes. Under the optimized conditions using fac-Ir(ppy)3 as the photocatalyst, various N-aryl acrylamides as well as a wide range...

Methyl 3-(dimethylamino) acrylates containing trifluoromethylsulfenyl-, trifluoromethylsulfinyl-, and trifluoromethylsulfonyl groups were synthesized and their utility demonstrated by reactions with aliphatic and aromatic amidines to produce 2,5–substituted 4(3H)-pyrimidones. Cyclization reactions of enaminones with urea or thiourea led to 5-substi...

A novel photoredox-mediated tandem three-component process afforded a wide variety of CF3-containing phthalans and isoindolines in respectable yields and with moderate to excellent diastereoselectivity

The introduction of a double or triple bond to the nitrogen atom of S-perfluoroalkyl sulfoximines is described. We propose a simple catalytic system based on copper iodide for the reaction with bromoalkenes and bromoalkynes, and based on copper dichloride for the coupling with terminal alkynes. The fluorinated chain was varied from perfluorobutyl t...

A novel photoredox-mediated tandem three-component process afforded a wide variety of CF3-containing phthalans and isoindolines in respectable yields and with moderate to excellent diastereoselectivity.

Stability and sorption of Metal-Organic Frameworks (MOFs) towards water are critical in many applications, and can a priori be modulated through the introduction of suitable organic functional groups on their backbone. We report here the preparation of a series of Zr(iv)-based MOFs functionalized with alkyl and perfluoroalkyl groups and their chara...

N-substituted S-perfluoroalkylated sulfoximines were synthesized from the NH sulfoximines either by a copper coupling reaction with aryl halides or by a reaction with electrophilic substrates. The procedure allowed the preparation of N,N’-bridged bis sulfoximines and of thioureas. The potential of these new sulfoximines was evaluated in different c...

A mild and simple three-component procedure for the direct vicinal halotrifluoromethylation of styrenes and aliphatic alkenes has been developed in the presence of [Ru(bpy)3](PF6)2 as a photosensitizer and Umemoto's reagent as the CF3 source. The multicomponent method offers the advantage of short reaction time, moderate to good yields, and mild re...

The transformation of internal as well as terminal alkenes proceeds with high regioselectivity and low to moderate E/Z-selectivity.

An efficient and convenient method is described that allows the synthesis of a set of difluoromethyl sulfoximines, as well as chlorofluoromethyl sulfoxides, sulfones, and sulfoximines. Our procedure does not require metals or nonrecommended freons, and it gives rise to an original route to Hu's reagent. Unprecedented chlorofluoromethyl sulfoximines...

A new ionic liquid [bdmim][F] has been prepared and fully characterized. Its potential as a fluoride source for the desulfurization–fluorination process has been evaluated with success. The carbon–sulfur double bond of xanthates and thiocarbonates has been difluorinated to give rise to small libraries of halogenated ketals and thioketals.

L’atome de fluor est exceptionnel tant les propriétés conférées aux molécules par sa présence sont intéressantes. En quelques années, l’introduction douce et sélective d’un ou de plusieurs atomes de fluor à l’aide de réactifs stables et non toxiques a connu un essor remarquable.Cet article décrit les avancées récentes en listant tour à tour les mét...

The fluorine atom is remarkable since properties conferred by its presence in molecules are of great interest. During recent years, the smooth and selective introduction of one or several fluorine atoms with non-toxic and stable reagents has grown exponentially. This article describes the new reactions and reagents and particularly the mono- and pe...

The separation ability of branched alkane isomers (nHEX, 3MP, 22DMB) of the flexible and functionalized microporous iron(III) dicarboxylate MIL-53(Fe)-(CF3)2 solid is evaluated through a combination of breakthrough experiments (binary or ternary mixtures), adsorption isotherms, X-ray diffraction temperature analysis, quasi-elastic neutron scatterin...