Publications by authors named "Jérôme Marrot"

187 Publications

"Host in Host" Supramolecular Core-Shell Type Systems Based on Giant Ring-Shaped Polyoxometalates.

Angew Chem Int Ed Engl 2021 Mar 16. Epub 2021 Mar 16.

Institut Lavoisier de Versailles, CNRS, UVSQ, Université Paris-Saclay, Versailles, France.

Herein, we show how the chaotropic effect arising from reduced molybdate ions in acidified aqueous solution is able to amplify drastically weak supramolecular interactions. Time-resolved Small Angle X-ray Scattering (SAXS) analysis suggests that molybdenum-blue oligomeric species form huge aggregates in the presence of γ-cyclodextrin (γ-CD) which results in the fast formation of nanoscopic {Mo }-based host-guest species, while X-ray diffraction analysis reveals that the ending-point of the scenario results in an unprecedented three-component well-ordered core-shell-like motif. A similar arrangement was found by using preformed hexarhenium chalcogenide-type cluster [Re Te (CN) ] as exogenous guest. This seminal work brings better understanding of the self-assembly processes in general and gives new opportunities for practical applications in the design of complex multicomponent materials via the simplicity of the non-covalent chemistry.
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http://dx.doi.org/10.1002/anie.202102507DOI Listing
March 2021

Synthesis and chelation study of a fluoroionophore and a glycopeptide based on an aza crown iminosugar structure.

Carbohydr Res 2021 Mar 10;501:108258. Epub 2021 Feb 10.

Université de Poitiers, IC2MP, UMR CNRS 7285, Equipe "Synthèse Organique", Groupe Glycochimie, 4 rue Michel Brunet, 86073, Poitiers Cedex 9, France. Electronic address:

Capitalizing on a recently reported iminosugar-based aza-crown (ISAC) accessed by a double Staudinger azaWittig coupling reaction, we have expanded the structural diversity of this new family of sweet cyclam analogs. Replacement of the two secondary amines linking the iminosugar units by two amide bonds obtained a cyclodimerization by with BOP and DIPEA led to a macrocycle that did not demonstrate efficient Zn chelation unlike the parent ISAC. Introduction of two pyrene moieties on the secondary amines of the parent ISAC yielded a new fluoroionophore that selectively binds Hg in methanol.
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http://dx.doi.org/10.1016/j.carres.2021.108258DOI Listing
March 2021

Photoactive Organic/Inorganic Hybrid Materials with Nanosegregated Donor-Acceptor Arrays.

Angew Chem Int Ed Engl 2021 Apr 5;60(15):8419-8424. Epub 2021 Mar 5.

Sorbonne Université, CNRS, Institut Parisien de Chimie Moléculaire, IPCM, 4 Place Jussieu, 75005, Paris, France.

The synthesis of the first mesogenic donor-acceptor polyoxometalate (POM)-based hybrid is herein described. The structural and electronic properties of the hybrid compound were evaluated through combination of small- and wide-angle X-ray scattering, optical microscopy, electrochemistry and photoluminescence. In the solid state, the compound behaves as a birefringent solid, displaying a lamellar organization in which double-layers of POMs and bis(thiophene)thienothiophene organic donors alternate regularly. Noticeably, the sub-unit organizations in the composite are similar to that observed for the individual POM and organic donor precursors. Photophysical studies show that in the hybrid, the fluorescence of the organic donor unit is considerably quenched both in solution and in the solid state, which is attributed to occurrence of intramolecular charge-separated state.
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http://dx.doi.org/10.1002/anie.202014319DOI Listing
April 2021

Insight into the Ferrier Rearrangement by Combining Flash Chemistry and Superacids.

Angew Chem Int Ed Engl 2021 01 23;60(4):2036-2041. Epub 2020 Nov 23.

IC2MP UMR CNRS 7285, Equipe "Synthèse Organique", Université de Poitiers, 4 rue Michel Brunet, 86073, Poitiers cedex 9, France.

The transformation of glycals into 2,3-unsaturated glycosyl derivatives, reported by Ferrier in 1962, is supposed to involve an α,β unsaturated glycosyl cation, an elusive ionic species that has still to be observed experimentally. Herein, while combination of TfOH and flow conditions failed to observe this ionic species, its extended lifetime in superacid solutions allowed its characterization by NMR-based structural analysis supported by DFT calculations. This allyloxycarbenium ion was further exploited in the Ferrier rearrangement to afford unsaturated nitrogen-containing C-aryl glycosides and C-alkyl glycosides under superacid and flow conditions, respectively.
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http://dx.doi.org/10.1002/anie.202010175DOI Listing
January 2021

Synthesis, crystal structures and Hirshfeld surface analysis of 1,4-dibenzyl-6-methyl-1,4-di-hydro-quinoxaline-2,3-dione.

Acta Crystallogr E Crystallogr Commun 2020 Aug 24;76(Pt 8):1361-1364. Epub 2020 Jul 24.

Department of Computer and Electronic Engineering Technology, Sana'a Community College, Sana'a, Yemen.

The title quinoxaline mol-ecule, CHNO, is not planar, the dihedral angle angle between the mean planes of the benzene rings being 72.54 (15)°. In the crystal, mol-ecules are connected into chains extending parallel to (10) by weak C-H⋯O hydrogen bonds. Weak C-H⋯π inter-actions link the chains, forming a three-dimensional network structure. Hirshfeld surface analysis revealed that the most important contributions for the crystal packing are from H⋯H (48.7%), H⋯C/C⋯H (32.0%), H⋯O/O⋯H (15.4%), C⋯C (1.9%), H⋯N/N⋯H (1.1%) contacts.
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http://dx.doi.org/10.1107/S2056989020009895DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405587PMC
August 2020

Synthesis, crystal structure at 219 K and Hirshfeld surface analyses of 1,4,6-tri-methyl-quinoxaline-2,3(1,4)-dione monohydrate.

Acta Crystallogr E Crystallogr Commun 2020 Aug 17;76(Pt 8):1296-1301. Epub 2020 Jul 17.

Department of Pharmacy, University of Science and Technology, Ibb Branch, Ibb, Yemen.

The asymmetric unit of the title compound, CHNO·HO, contains a mol-ecule of 1,4,6-trimethyl-1,4-di-hydro-quinoxaline-2,3-dione and a solvent water mol-ecule. Four atoms of the benzene ring are disordered over two sets of sites in a 0.706 (7):0.294 (7) ratio while the N-bound methyl groups are rotationally disordered with occupancy ratios of 0.78 (4):0.22 (4) and 0.76 (5):0.24 (5). In the crystal, mol-ecules are linked by O-H⋯O and C-H⋯O hydrogen bonds into layers lying parallel to (10). The Hirshfeld surface analysis indicates that the most important contributions to the packing arrangement are due to H⋯H (51.3%) and O⋯H/H⋯O (28.6%) inter-actions. The mol-ecular structure calculated by density functional theory is compared with the experimentally determined mol-ecular structure, and the HOMO-LUMO energy gap has been calculated.
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http://dx.doi.org/10.1107/S2056989020009573DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7405578PMC
August 2020

Synthesis and photochromic behaviour of a series of benzopyrans bearing an N-phenyl-carbazole moiety: photochromism control by the steric effect.

Photochem Photobiol Sci 2020 Oct 11;19(10):1344-1355. Epub 2020 Aug 11.

Université Paris-Saclay, UVSQ, UMR CNRS 8080, Institut Lavoisier de Versailles, 45 av des Etats-Unis, 78035 Versailles, France.

Five new N-phenyl-carbazole benzopyrans bearing different substitutions on one of the phenyl rings at the sp3 carbon have been synthesized. Their molecular structures were investigated by X-ray and NMR analyses and through quantum chemical calculations. The photochromic mechanism under UV irradiation in toluene, consisting of the consecutive formation of transoid-cis (TC) and transoid-trans (TT) isomers, was studied by UV-vis spectral and kinetic analyses. These molecules have been specifically designed to ascertain the possibility of favouring the formation of the less thermodynamically stable TT at the photostationary state, upon exploiting steric hindrance effects on the diene part of the molecule. The spectrokinetic study allowed the estimation of most of the spectrokinetic parameters, such as molar extinction coefficients, quantum yields of UV colouration and visible photobleaching, and the rate constants of the fast and slow thermal bleaching processes. Peculiar effects of substituents with different donor strengths on one phenyl ring located at the 3-position were observed on the spectrokinetic properties.
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http://dx.doi.org/10.1039/d0pp00202jDOI Listing
October 2020

Access to Optically Pure Benzosultams by Superelectrophilic Activation.

Org Lett 2020 07 23;22(13):4944-4948. Epub 2020 Jun 23.

Université de Poitiers, UMR-CNRS 7285, IC2MP, Equipe Synthèse Organique, 4 rue Michel Brunet, TSA 51106, Poitiers 86073 Cedex 9, France.

Through superacid activation, -(arenesulfonyl)-aminoalcohols derived from readily available ephedrines or amino acids undergo an intramolecular Friedel-Crafts reaction to afford enantiopure benzosultams bearing two adjacent stereocenters in high yields with fully controlled diastereoselectivity. Low-temperature NMR spectroscopy demonstrated the crucial role played by the conformationally restricted chiral dicationic intermediates.
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http://dx.doi.org/10.1021/acs.orglett.0c01301DOI Listing
July 2020

Serendipitous Rediscovery of the Facile Cyclization of Z,Z-3,5-Octadiene-1,7-diyne Derivatives to Afford Stable, Substituted Naphthocyclobutadienes.

Chempluschem 2019 06 23;84(6):665-672. Epub 2019 Jan 23.

Department of Chemistry & Biochemistry and Materials Science Institute, 1253 University of Oregon, Eugene, Oregon, 97403-1253, United States.

The serendipitous isolation of very small amounts of two naphthocyclobutadiene (NCB) derivatives has led to the computational re-examination of the electrocyclization of Z,Z-3,5-octadiene-1,7-diyne as well as the experimental and computational study of diethynylindeno[2,1-a]fluorene derivatives that contain the 3,5-octadiene-1,7-diyne motif as part of a larger π-framework. In both cases the calculated potential energy surface strongly implicates two successive electrocyclic reactions to afford the antiaromatic products. With the octadienediyne fragment locked in the reactive conformation, the postulated diethynylindeno[2,1-a]fluorene intermediates afford the NCBs in modest to good yields. X-ray crystallography of four NCBs as well as NICS-XY scan calculations show that the paratropic motif is located primarily in the benzocyclobutadiene fragment within the larger π-scaffold.
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http://dx.doi.org/10.1002/cplu.201800605DOI Listing
June 2019

Engineering Structural Dynamics of Zirconium Metal-Organic Frameworks Based on Natural C4 Linkers.

J Am Chem Soc 2019 10 22;141(43):17207-17216. Epub 2019 Oct 22.

UMR 8004 CNRS, Ecole Normale Supérieure, Ecole Supérieure de Physique et de Chimie Industrielles de Paris, PSL Université , Institut des Matériaux Poreux de Paris , 75005 Paris , France.

Engineering the structural flexibility of metal-organic framework (MOF) materials for separation-related applications remains a great challenge. We present here a strategy of mixing rigid and soft linkers in a MOF structure to achieve tunable structural flexibility, as exemplified in a series of stable isostructural Zr-MOFs built with natural C4 linkers (fumaric acid, succinic acid, and malic acid). As shown by the differences in linker bond stretching and bending freedom, these MOFs display distinct responsive dynamics to external stimuli, namely, changes in temperature or guest molecule type. Comprehensive characterizations reveal a clear correlation between linker character and MOF dynamic behavior, which leads to the discovery of a multivariate flexible MOF. It shows an optimal combination of both good working capacity and significantly enhanced selectivity for CO/N separation. In principle, it provides a new avenue for potentially improving the ability of microporous MOFs to separate other gaseous and liquid mixtures.
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http://dx.doi.org/10.1021/jacs.9b07816DOI Listing
October 2019

Polyoxothiometalate-Derivatized Silicon Photocathodes for Sunlight-Driven Hydrogen Evolution Reaction.

ACS Omega 2018 Oct 22;3(10):13837-13849. Epub 2018 Oct 22.

Institut Lavoisier de Versailles (UMR-CNRS 8180), UVSQ, Université Paris-Saclay, 45 Avenue de Etats-Unis, 78000 Versailles, France.

Silicon photocathodes coated with drop-casted {MoS}-based polyoxothiometalate assemblies are demonstrated to be effective for sunlight-driven hydrogen evolution reaction (HER) in acid conditions. These photocathodes are catalytically more efficient than that coated with the parent thiomolybdate incorporating an organic ligand, as supported by a higher onset potential and a lower overvoltage at 10 mA cm. At pH 7.3, the trend is inversed and the beneficial effect of the polyoxometalate for the HER is not observed. Moreover, the polyoxothiometalate-modified photocathode is found to be also more stable under acid conditions and can be operated at the light-limited catalytic current for more than 40 h. Furthermore, X-ray photoelectron spectroscopy and atomic force microscopy measurements indicate that the cathodic polarization of both photocathodes leads to the release of a large amount of the deposited material into the electrolyte solution concomitantly with the formation of mixed valence species {Mo(IV) Mo(III) O S } resulting from the replacement of S sulfido ligands in the cluster by oxo O groups; these combined effects are shown to be beneficial for the photoelectrocatalysis.
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http://dx.doi.org/10.1021/acsomega.8b01734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6645094PMC
October 2018

Synthesis and glycosidase inhibition of conformationally locked DNJ and DMJ derivatives exploiting a 2-oxo-C-allyl iminosugar.

Org Biomol Chem 2019 08 18;17(30):7204-7214. Epub 2019 Jul 18.

Université de Poitiers, IC2MP, UMR CNRS 7285, Equipe "Synthèse Organique", Groupe Glycochimie, 4 rue Michel Brunet, 86073 Poitiers cedex 9, France.

A series of analogs of the iminosugars 1-deoxynojirimycin (DNJ) and 1-deoxymannojirimycin (DMJ), in which an extra five or six-membered ring has been fused to the C1-C2 bond have been prepared. The synthetic strategy exploits a key 2-keto-C-allyl iminosugar, easily accessible from gluconolactam, which upon Grignard addition and RCM furnishes a bicyclic scaffold that can be further hydroxylated at the C[double bond, length as m-dash]C bond. This strategy furnished DNJ mimics with the piperidine ring locked in a C conformation with all substituents in axial orientation when fused to a six-membered ring. Addition of an extra ring to DNJ and DMJ motif proved to strongly modify the glycosidase inhibition profile of the parent iminosugars leading to modest inhibitors. The 2-keto-C-allyl iminosugar scaffold was further used to access N-acetylglycosamine analogs via oxime formation.
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http://dx.doi.org/10.1039/c9ob01402kDOI Listing
August 2019

Site-Selective Debenzylation of C-Allyl Iminosugars Enables Their Stereocontroled Structure Diversification at the C-2 Position.

Org Lett 2019 06 30;21(12):4821-4825. Epub 2019 May 30.

Université de Poitiers , IC2MP , UMR CNRS 7285, Equipe "Synthèse Organique", Groupe Glycochimie, 4 rue Michel Brunet , Poitiers 86073 Cedex 9 , France.

A C-2 regioselective debenzylative cycloetherification/reductive elimination sequence applied to perbenzylated C-allyl iminosugars is described. This NIS/TMSOTf-triggered deprotection was successfully applied to five-, six-, and seven-membered C-allyl iminosugars including 1,2 cis and 1,2 trans stereoisomers. It allows rapid introduction of structural diversity at the key C-2 position in a stereoselective manner exploiting the anchimeric assistance of the intracyclic N-benzyl group, giving access to the 2-acetamido and 2-fluoro d-gluco configured C-allyl iminosugars and to the epimeric d-manno derivative.
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http://dx.doi.org/10.1021/acs.orglett.9b01712DOI Listing
June 2019

Excellent Semiconductors Based on Tetracenotetracene and Pentacenopentacene: From Stable Closed-Shell to Singlet Open-Shell.

J Am Chem Soc 2019 Jun 3;141(23):9373-9381. Epub 2019 Jun 3.

UMR CNRS 8180 , UVSQ, Institut Lavoisier de Versailles, Université Paris-Saclay , 45 Avenue des Etats-Unis , 78035 Versailles Cedex , France.

Designing stable open-shell organic materials through the modifications of the π-topology of molecular organic semiconductors has recently attracted considerable attention. However, their uses as an active layer in organic field-effect transistors (OFETs) are very limited, and the obtained hole and electron charge mobilities are around 10 cm V s. Herein, we disclose the synthesis of two peri-fused materials, so-called tetracenotetracene (TT) and pentacenopentacene (PP), which have low band gaps of 1.79 and 1.42 eV, respectively. Their ground state natures have been investigated by different experiments including steady state absorption, electron spin resonance, superconducting quantum interfering device, and variable-temperature NMR along with DFT calculations. TT and PP have closed-shell and singlet open-shell structures in their ground state, respectively, and possess high stability. Their biradical characteristics were found to be 0.50 and 0.64. The origin of the open-shell character of PP is related to the concomitant opening of two tetracenes with the recovering of two extra aromatic sextets and a small HOMO-LUMO energy gap (gap <1.5 eV). Thanks to the high stability, thin film OFET devices could be fabricated. In TG-BC configuration PP shows a remarkably high hole mobility of 1.4 cm V s, while TT exhibits a hole mobility of 0.77 cm V s. In the configuration of BG-TC, ambipolar behaviors for both were obtained with hole and electron mobilities of 0.21 and 0.01 cm V s for PP and 0.14 and 0.006 cm V s for TT.
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http://dx.doi.org/10.1021/jacs.9b03488DOI Listing
June 2019

A Fused Hexacyclic Ring System: Diastereoselective Polycyclization of 2,4-Dienals through an Interrupted iso-Nazarov Reaction.

Angew Chem Int Ed Engl 2019 07 24;58(29):9969-9973. Epub 2019 Jun 24.

Institut Lavoisier Versailles, Université de Versailles-St-Quentin-en-Yvelines, Université Paris Saclay, UMR CNRS 8180, 78035, Versailles cedex, France.

We report an unprecedented domino polycyclization from readily available 2,4-dienals and cyclic α,β-unsaturated imines that is initiated by an iso-Nazarov reaction. This Brønsted acid promoted reaction enables the concomitant formation of four bonds, three cycles, and four contiguous stereogenic centers to yield elaborated structures in a single operation. A range of fused hexacyclic molecules is obtained in a highly diastereoselective manner.
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http://dx.doi.org/10.1002/anie.201903860DOI Listing
July 2019

An unprecedented {NiSiW} hybrid polyoxometalate with high photocatalytic hydrogen evolution activity.

Chem Commun (Camb) 2019 Apr;55(29):4166-4169

Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles Saint-Quentin en Yvelines, Université Paris-Saclay, 45 Avenue des Etats-Unis, 78035 Versailles Cedex, France.

A unique polyoxometalate complex made up of a tetradecanuclear nickel bisphosphonate cluster capping a {SiW9} unit has been characterized. This stable compound exhibits a high hydrogen evolution reaction photocatalytic activity under visible light irradiation via a reductive quenching mechanism.
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http://dx.doi.org/10.1039/c9cc01269aDOI Listing
April 2019

Green synthesis of new chiral 1-(arylamino)imidazo[2,1-]isoindole-2,5-diones from the corresponding α-amino acid arylhydrazides in aqueous medium.

Beilstein J Org Chem 2018 26;14:2923-2930. Epub 2018 Nov 26.

Laboratoire de Synthèse Organique Asymétrique et Catalyse Homogène, (UR 11ES56) Université de Monastir, Faculté des Sciences de Monastir, avenue de l'environnement, 5000 Monastir, Tunisie. ; Tel: (+216) 73.

New chiral 1-(arylamino)imidazo[2,1-]isoindole-2,5-dione derivatives were obtained in good to excellent yields via the cyclocondensation of 2-formylbenzoic acid and various α-amino acid arylhydrazides using water as the solvent in the presence of sodium dodecyl sulfate as the surfactant and under simple and minimum manipulation, without purification. The reaction is totally diastereoselective and gives access to the nitrogenated tricyclic core with a relative stereochemistry.
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http://dx.doi.org/10.3762/bjoc.14.271DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6278760PMC
November 2018

A robust zirconium amino acid metal-organic framework for proton conduction.

Nat Commun 2018 11 22;9(1):4937. Epub 2018 Nov 22.

Institut des Matériaux Poreux de Paris, FRE 2000 CNRS, Ecole Normale Supérieure, Ecole Supérieure de Physique et de Chimie Industrielles de Paris, PSL Research Université, 75005, Paris, France.

Proton conductive materials are of significant importance and highly desired for clean energy-related applications. Discovery of practical metal-organic frameworks (MOFs) with high proton conduction remains a challenge due to the use of toxic chemicals, inconvenient ligand preparation and complication of production at scale for the state-of-the-art candidates. Herein, we report a zirconium-MOF, MIP-202(Zr), constructed from natural α-amino acid showing a high and steady proton conductivity of 0.011 S cm at 363 K and under 95% relative humidity. This MOF features a cost-effective, green and scalable preparation with a very high space-time yield above 7000 kg m day. It exhibits a good chemical stability under various conditions, including solutions of wide pH range and boiling water. Finally, a comprehensive molecular simulation was carried out to shed light on the proton conduction mechanism. All together these features make MIP-202(Zr) one of the most promising candidates to approach the commercial benchmark Nafion.
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http://dx.doi.org/10.1038/s41467-018-07414-4DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6250719PMC
November 2018

Evidence of Phosphonium-Carbenium Dication Formation in a Superacid: Precursor to Fluorinated Phosphine Oxides.

Angew Chem Int Ed Engl 2019 Jan 28;58(5):1355-1360. Epub 2018 Dec 28.

IC2MP-UMR CNRS 7582-, Université de Poitiers, 4 rue Michel Brunet TSA 51106, 86073, Poitiers cedex 9, France.

Unambiguously confirmed by low-temperature in situ NMR experiments, X-ray diffraction and vibrational spectroscopy, phosphonium-carbenium superelectrophiles are shown to be generated in strong acidic conditions. Representing crucial intermediates, their exploitation allows for the synthesis of unprecedented fluorinated (cyclic) phosphine oxides.
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http://dx.doi.org/10.1002/anie.201811032DOI Listing
January 2019

Bicapped Keggin polyoxomolybdates: discrete species and experimental and theoretical investigations on the electronic delocalization in a chain compound.

Dalton Trans 2018 Aug 24;47(31):10636-10645. Epub 2018 May 24.

Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles Saint-Quentin en Yvelines, Université Paris-Saclay, 45 Avenue des Etats-Unis, Versailles 78035 Cedex, France.

Three monomeric polyoxometalates [M(CHN)][α-PMoMoOZn(CHN)]·2HO (M-PMoZn, M = Fe, Co, Ru) with {Zn(bpy)} units capped on reduced α-Keggin polyanions and [M(bpy)] counter-ions were synthesized under hydrothermal conditions. The 1D polymer [N(CH)][Ru(CHN)][α-PMoMoO] (Ru-PMo) was prepared by a similar strategy, in the absence of 2,2'-bpy ligands. In this chain capped reduced Keggin anions are linked via Mo-O-Mo bridges and are surrounded by both tetrabutylammonium cations and [Ru(bpy)] counter-ions. The compounds were characterized in the solid state by single crystal and powder X-ray diffraction and IR spectroscopy and in solution by P NMR spectroscopy. P diffusion ordered NMR spectroscopy (DOSY) indicates that the diffusion coefficient of the dissolved species of Ru-PMo corresponds to a dimeric structure. Magnetic susceptibility measurements performed on Ru-PMo show the existence of antiferromagnetic interactions between the d electrons of the six Mo centers, with a singlet spin ground state. However, attempts to fit the data in the 2-300 K temperature range with Heisenberg Hamiltonians adapted for 0 or 1D systems suggest that these electrons are delocalized. Density Functional Theory (DFT) and Wave Function Theory (WFT) calculations indicate a migration of the electrons of the capping Mo centers into the PMo units at high temperature, allowing the rationalization of the experimental observations.
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http://dx.doi.org/10.1039/c8dt01313fDOI Listing
August 2018

Anderson-Type Polyoxometalates Functionalized by Tetrathiafulvalene Groups: Synthesis, Electrochemical Studies, and NLO Properties.

Inorg Chem 2018 Apr 22;57(7):3742-3752. Epub 2018 Mar 22.

Institut Lavoisier de Versailles , UMR 8180, Université de Versailles Saint-Quentin en Yvelines, Université Paris-Saclay , 45 Avenue des Etats-Unis , CEDEX 78035 Versailles , France.

Three polyoxometalates (POMs) functionalized by tetrathiafulvalene (TTF) molecules have been synthesized by a coupling reaction between the Anderson-type POMs [MnMoO{(OCH)CNH}] or [AlMoO(OH){(OCH)CNH}] and the TTF carboxylic acid derivative (MeS)TTF(S-CH-COH). The monofunctionalized TTF-AlMo POM contains one TTF group covalently grafted on an Al Anderson platform. The symmetrical TTF-MnMo-TTF POM possesses two TTF groups grafted on each side of a Mn Anderson derivative while the asymmetrical TTF-MnMo-SP POM contains a TTF and a spiropyran groups. These three trianionic species have been characterized by elemental analysis, H and C NMR, FT-IR spectroscopy, ESI-MS spectrometry, and single-crystal X-ray diffraction (for TTF-MnMo-TTF). In the solid state, the grafted TTF molecules of TTF-MnMo-TTF POMs interact via S···S and π···π interactions and form chains. The electrochemical properties of the complexes reflect the contributions of both the inorganic POM and the TTF moieties. Despite adsorption of the oxidized hybrid species on the Pt grid working electrode, UV-vis-NIR spectroelectrochemical investigations evidence peaks characteristic of the oxidation of the TTF units. Finally, hyper-Rayleigh scattering (HRS) measurements show that the three novel TTF derivatives exhibit β values between 20 and 37 × 10 esu. Moreover it is observed that the oxidation of the TTF moieties by Fe ions increases the NLO response. These values are in the order of magnitude of that found for the well-known 4-dimethylamino- N-methyl-4-stilbazolium (DAS) cation (β = 60 × 10 esu).
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http://dx.doi.org/10.1021/acs.inorgchem.7b02976DOI Listing
April 2018

In Situ Generation of Cyclopentadienol Intermediates from 2,4-Dienals. Application to the Synthesis of Spirooxindoles via a Domino Polycyclization.

Org Lett 2018 02 22;20(3):792-795. Epub 2018 Jan 22.

Institut Lavoisier Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines, Université Paris Saclay , 45 Avenue des États-Unis, Versailles 78035 Cedex, France.

An efficient domino polycyclization combining different classes of pericyclic reactions leads to complex spiroxindoles under mild conditions. This domino process represents a rare example of an in situ formation of cyclopentadienol derivatives from an interrupted iso-Nazarov electrocyclization of 2,4-dienals and their use in [4 + 2] cycloaddition reactions. According to the reaction conditions, different polycyclic architectures are obtained in good yields and excellent diastereoselectivities.
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http://dx.doi.org/10.1021/acs.orglett.7b03934DOI Listing
February 2018

From α-Bromomethylbutenolide to Fused Tri(Tetra) Cyclic Dihydrofurandiones through Barbier Reaction-Heck Arylation Sequence.

Molecules 2017 Dec 8;22(12). Epub 2017 Dec 8.

Institut Lavoisier de Versailles, Université Paris-Saclay, UVSQ, CNRS, 78035 Versailles, France.

A Barbier reaction-Heck arylation sequence from α-bromomethylbutenolide to fused tri and tetracyclic lactones has been developed. The first step involving a Barbier reaction enabled installing -bromoaromatics in α-ylidene γ-lactones. The latter substrates were subjected to intramolecular Heck reaction conditions which selectively afforded 6,5,5 or 6,6,5 fused ring systems depending on the nature of the base employed.
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http://dx.doi.org/10.3390/molecules22122171DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6149967PMC
December 2017

Aminocatalyzed Synthesis of Enantioenriched Phenalene Skeletons through a Friedel-Crafts/Cyclization Strategy.

J Org Chem 2018 01 4;83(2):1019-1025. Epub 2018 Jan 4.

Institut Lavoisier de Versailles, UMR CNRS 8180, Université de Versailles-St-Quentin-en-Yvelines , 45 Avenue des États-Unis, Versailles 78035 Cedex, France.

A series of enantioenriched phenalene-derived compounds were accessed by a Friedel-Crafts/cyclization strategy. Starting from α,β-unsaturated aldehydes and 2-naphthol derivatives, high levels of enantioselectivity were obtained through iminium-enamine catalysis. The catalytic system composed of a diphenylprolinol silyl ether organocatalyst and triethylamine as a base was applied to a combination of diversely functionalized substrates. The obtained phenalene-derived architectures are promising building blocks for reaching natural products and exhibit fluorescence properties.
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http://dx.doi.org/10.1021/acs.joc.7b02629DOI Listing
January 2018

High Oxygen Reduction Reaction Performances of Cathode Materials Combining Polyoxometalates, Coordination Complexes, and Carboneous Supports.

ACS Appl Mater Interfaces 2017 Nov 27;9(44):38486-38498. Epub 2017 Oct 27.

Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences , 100190 Beijing, China.

A series of carbonaceous-supported precious-metal-free polyoxometalate (POM)-based composites which can be easily synthesized on a large scale was shown to act as efficient cathode materials for the oxygen reduction reaction (ORR) in neutral or basic media via a four-electron mechanism with high durability. Moreover, exploiting the versatility of the considered system, its activity was optimized by the judicious choice of the 3d metals incorporated in the {(PW)M} (M = Co, Ni) POM core, the POM counterions and the support (thermalized triazine-based frameworks (TTFs), fluorine-doped TTF (TTF-F), reduced graphene oxide, or carbon Vulcan XC-72. In particular, for {(PW)Ni}/{Cu(ethylenediamine)}/TTF-F, the overpotential required to drive the ORR compared well with those of Pt/C. This outstanding ORR electrocatalytic activity is linked with two synergistic effects due to the binary combination of the Cu and Ni centers and the strong interaction between the POM molecules and the porous and highly conducting TTF-F framework. To our knowledge, {(PW)Ni}/{Cu(ethylenediamine)}/TTF-F represents the first example of POM-based noble-metal-free ORR electrocatalyst possessing both comparable ORR electrocatalytic activity and much higher stability than that of Pt/C in neutral medium.
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http://dx.doi.org/10.1021/acsami.7b10989DOI Listing
November 2017

Nonconventional Three-Component Hierarchical Host-Guest Assembly Based on Mo-Blue Ring-Shaped Giant Anion, γ-Cyclodextrin, and Dawson-type Polyoxometalate.

J Am Chem Soc 2017 10 5;139(41):14376-14379. Epub 2017 Oct 5.

Institut Lavoisier de Versailles UMR 8180, UVSQ, Université Paris-Saclay , 78035 Versailles, France.

In this communication, we report on a noteworthy hybrid supramolecular assembly built from three functional components hierarchically organized through noncovalent interactions. The one-pot synthesis procedure leads to the formation of large Mo-blue ring-shaped anion {Mo}, which contains the supramolecular adduct based on the symmetric encapsulation of the Dawson-type [PWO] anion by two γ-cyclodextrin units. Such a nanoscopic onion-like structure, noted [PWO]@2γ-CD@{Mo} has been characterized by single-crystal X-ray diffraction, thus demonstrating the capability of the giant inorganic torus to develop relevant supramolecular chemistry, probing the strong affinity of the inner and outer faces of the γ-CD for the polyoxometalate surfaces. Furthermore, interactions and behavior in solution have been studied by multinuclear NMR spectroscopy, which supports specific interactions between γ-CD and POM units. Finally, the formation of this three-component hybrid assembly from one-pot procedure, in water and using nearly stoichiometric conditions, is discussed in terms of the driving forces orchestrating this highly efficient multilevel recognition process.
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http://dx.doi.org/10.1021/jacs.7b08058DOI Listing
October 2017

Polyoxometalate, Cationic Cluster, and γ-Cyclodextrin: From Primary Interactions to Supramolecular Hybrid Materials.

J Am Chem Soc 2017 09 1;139(36):12793-12803. Epub 2017 Sep 1.

Institut Lavoisier de Versailles, UMR 8180, UVSQ, Université Paris-Saclay , 78035 Versailles, France.

Herein, we report on a three-component supramolecular hybrid system built from specific recognition processes involving a Dawson-type polyoxometalate (POM), [PWO], a cationic electron-rich cluster [TaBr(HO)], and γ-cyclodextrin (γ-CD). Such materials have been investigated using a bottom-up approach by studying the specific interactions between γ-CD and both types of inorganic units. Their ability to interact has been investigated in the solid state by single-crystal X-ray diffraction (XRD) and in solution using multinuclear NMR methods (including DOSY, EXSY, and COSY), electrospray ionization mass and UV-vis spectroscopies, electrochemistry, and isothermal titration calorimetry experiments. Single-crystal XRD analysis reveals that POM:γ-CD constitutes a highly versatile system which gives aggregates with 1:1, 1:2, and 1:3 stoichiometry. Surprisingly, these arrangements exhibit a common feature wherein the γ-CD moiety interacts with the Dawson-type POMs through its primary face. We present also the first structural model involving an octahedral-type metallic cluster with γ-CD. XRD study reveals that the cationic [TaBr(HO)] ion is closely embedded within two γ-CD units to give a supramolecular ditopic cation, suitable to be used as a linker within extended structure. Solution study demonstrates clearly that pre-associations exist in solution, for which binding constants and thermodynamic parameters have been determined, giving preliminary arguments about the chaotropic nature of the inorganic ions. Finally, both building blocks, i.e., the ditopic supramolecular cation {[TaBr(HO)]@2CD} and the Dawson-type anion, react together to give a three-component, well-ordered hybrid material derived either as a supramolecular hydrogel or single crystals. The solid-state structure shows an unprecedented helicoidal tubular chain resulting from the periodic alternation of POM and supramolecular cation, featuring short hydrogen-bonding contacts between the electron-poor POM and electron-rich cluster. The 1D tubular ionic polymer observed in the single crystals should make it possible to understand the long-range ordering observed within the hydrogel hybrid material. The supramolecular chemical complementarities between the γ-CD-based ditopic cation and POM open a wide scope for the design of hybrid materials that accumulate synergistic functionalities.
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http://dx.doi.org/10.1021/jacs.7b07317DOI Listing
September 2017

Deciphering minimal antigenic epitopes associated with Burkholderia pseudomallei and Burkholderia mallei lipopolysaccharide O-antigens.

Nat Commun 2017 07 24;8(1):115. Epub 2017 Jul 24.

Institut de Chimie IC2MP, CNRS-UMR 7285, Équipe Synthèse Organique, Groupe Glycochimie, Université de Poitiers, 4, rue Michel Brunet, Poitiers, 86073, France.

Burkholderia pseudomallei (Bp) and Burkholderia mallei (Bm), the etiologic agents of melioidosis and glanders, respectively, cause severe disease in both humans and animals. Studies have highlighted the importance of Bp and Bm lipopolysaccharides (LPS) as vaccine candidates. Here we describe the synthesis of seven oligosaccharides as the minimal structures featuring all of the reported acetylation/methylation patterns associated with Bp and Bm LPS O-antigens (OAgs). Our approach is based on the conversion of an L-rhamnose into a 6-deoxy-L-talose residue at a late stage of the synthetic sequence. Using biochemical and biophysical methods, we demonstrate the binding of several Bp and Bm LPS-specific monoclonal antibodies with terminal OAg residues. Mice immunized with terminal disaccharide-CRM197 constructs produced high-titer antibody responses that crossreacted with Bm-like OAgs. Collectively, these studies serve as foundation for the development of novel therapeutics, diagnostics, and vaccine candidates to combat diseases caused by Bp and Bm.Melioidosis and glanders are multifaceted infections caused by gram-negative bacteria. Here, the authors synthesize a series of oligosaccharides that mimic the lipopolysaccharides present on the pathogens' surface and use them to develop novel glycoconjugates for vaccine development.
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http://dx.doi.org/10.1038/s41467-017-00173-8DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524647PMC
July 2017

Review on Bioorganometallic Chemistry and New Outcomes in the Synthesis and Substitution of Tetracarbonyl(pyrrolylimine) Complexes of Rhenium with Organophosphorus Ligands.

Curr Top Med Chem 2017 Jul 19. Epub 2017 Jul 19.

IPCM,UMR 8232, Université Paris 06, CNRS, F-75005, Paris. France.

: After a short review dealing with bioorganometallic chemistry, the synthesis of tetracarbonyl (pyrrolylimine) complexes of rhenium bearing chirality on the pyrrolyl ligands was reported.The reactivity of these compounds towards the substitution of one carbonyl ligand with triphenyl phosphine, tricyclohexyl phosphine and trimethyl phosphite was studied. The rhenium becoming a stereogenic center in that transformation, the resulting tricarbonyl species were obtained as mixtures of diastereomers, with diastereomeric excesses varying from 8 to 84%, according to the reaction conditions and the relative steric hindrances of the pyrrolylimine and the organophosphorus ligands. These bioorganometallics are potential CO releasing molecules that could be used in the field of medicinal chemistry.
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http://dx.doi.org/10.2174/1568026617666170719171010DOI Listing
July 2017

Cationic polycyclization of ynamides: building up molecular complexity.

Org Biomol Chem 2017 May;15(20):4399-4416

Laboratoire de Chimie Organique, Service de Chimie et PhysicoChimie Organiques, Université libre de Bruxelles (ULB), Avenue F. D. Roosevelt 50, CP160/06, 1050 Brussels, Belgium.

Polycyclization reactions are among the most efficient synthetic tools for the synthesis of complex, polycyclic molecules in a single operation from simple starting materials. We report in this manuscript a full account on the discovery and development of a novel cationic polycyclization from readily available ynamides. Simple activation of these building blocks under acidic conditions enables the generation of highly reactive activated keteniminium ions, which triggers an unprecedented cationic polycyclization yielding highly substituted polycyclic nitrogen heterocycles possessing up to seven fused cycles and three contiguous stereocenters.
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http://dx.doi.org/10.1039/c7ob00850cDOI Listing
May 2017