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Aryl triflates are selected as suitable electrophile coupling partners for the phosphorus-directed rhodium(III)-catalyzed direct C–H arylation of polyaromatic phosphines. We report herein simple conditions for the peri-C–H functionalization of polyarylphosphines, where a [Rh(III)Cl2Cp*]2 precatalyst is employed to provide a convenient access to polyarylated phosphines in up to 93% isolated yield. This synthetic approach tolerates a wide range of different aryl trifluoromethylsulfonate derivatives bearing either electron-donating (COMe, CN, CF3 or Cl) or electron-withdrawing substituents (Me, OMe) at the para-, meta- and ortho-positions, and includes bulky polyaromatic triflate substrates. We further describe access to a large class of polycyclic aromatic hydrocarbon phosphine ligands, their oxidized derivatives (i.e., their oxides and selenides), their coordination modes with Au(I) and Cu(I) coinage metal salts, and their use as efficient ligands for the atom-economic, gold-catalyzed oxidative cyclization of terminal alkynes with nitriles.

Cationic amidotitanocene complexes [Cp2 Ti(NPhAr)][B(C6 F5 )4 ] (Cp=η5 -C5 H5 ; Ar=phenyl (1 a), p-tolyl (1 b), p-anisyl (1 c)) were isolated. The bonding situation was studied by DFT (Density Functional Theory) using EDA-NOCV (Energy Decomposition Analysis with Natural Orbitals for Chemical Valence). The polar Ti-N bond in 1 a-c features an unusual inversion of σ and π bond strengths responsible for the balance between stability and reactivity in these coordinatively unsaturated species. In solution, 1 a-c undergo photolytic Ti-N cleavage to release Ti(III) species and aminyl radicals ⋅NPhAr. Reaction of 1 b with H3 BNHMe2 results in fast homolytic Ti-N cleavage to give [Cp2 Ti(H3 BNHMe2 )][B(C6 F5 )4 ] (3). 1 a-c are highly active precatalysts in olefin hydrogenation and silanes/amines cross-dehydrogenative coupling, whilst 3 efficiently catalyzes amine-borane dehydrogenation. The mechanism of olefin hydrogenation was studied by DFT and the cooperative H2 activation key step was disclosed using the Activation Strain Model (ASM).

International audience; We describe unsymmetrically substituted di-tert-butylated 1,1'-bis(phosphino)ferrocenes, with phosphino substituents R = [5-methyl]-2-furyl = Fu, and R' = phenyl (4a), i-propyl (4b). A modular synthetic approach was applied from the di-tert-butylated ferrocene platform (1), which lead to the formation of new diphosphines by using 1,1'bis(diiodo)-3,3'-bis(tert-butyl)ferrocene (2) as synthetic precursor. In contrast to the cousin non-alkylated unsymmetrically substituted diphosphino-ferrocenes which were reported up to now, these diphosphines showed strong (31 P, P')nonbonded (" ug-p e") nuclear spin-spin coupling. The strength of such internuclear spin-spin coupling constant (SSCCs) J PP' ranges between 17 and 35 Hz, and as such, are not associated to traditional " ug-b d" 4 J PP. The characterizations of these ferrocene derivatives by X-ray diffraction in the solid state, and by multinuclear NMR in solution, evidence that the strong SSCCs are attributable to the conformational constraint which is imposed to ferrocene backbone by the introduction of alkyl substituents on this platform. The molecular structures resolved in the solid-state showed long P…P u u l ep up to 6.9168(8) Å, while in solution a (P, P')-phosphorus lone-pair overlap clearly occurs. This testifies to a sufficient degree of rotational flexibility of the alkylated ferrocene backbone. We examined the coordination chemistry of these diphosphines towards coinage metals: Cu, Ag and Au. The constraint unsymmetrically substituted diphosphines 4a and 4b allowed the selective formation of dinuclear two-coordinate linear gold(I) complexes with strong Au…Au aurophilic interactions. They also lead to rare tetrahedral homoleptic d 10 monocationic complexes, with all the coinage metals, by structuring the encapsulation of the cation in a highly constraint environment where the stacking interactions of the (hetero)aromatic substituents of the phosphino groups are decisive. The resulting AA'XX' 31 P NMR signature in solution of the complexes was simulated and analyzed, as well as the stacking interactions between the pairs of furyl rings that were illustrated by noncovalent interactions (NCI) computation.

In comparison to mononuclear gold Lewis acid catalysts, digold complexes and dual-gold catalysis have illustrated a distinct and powerful potential for the activation of carbon-carbon multiple bonds. Herein, this concept is pushed further by designing novel tetranuclear gold(I) dicationic complexes structurally supported by strongly stabilizing constraint diphosphinoferrocenyl ligands and attractive closed-shell Au⋅⋅⋅Au aurophilic interactions. The use of a molecularly-defined tetranuclear dicationic aurophilic gold(I) precatalyst for the selectivity-challenging cycloisomerization of low-substituted 1,6-enynes favors the formation with high selectivity of strained azabicyclo[4.1.0]hept-4-enes - even in the complete absence of activating/orienting substituents on alkyne and olefin reactive functions. This selectivity is not achieved by the reported phosphine- and carbene-stabilized mono- and dinuclear cationic gold(I) complexes, including the ones formed from the same ligands. More importantly this selectivity differs also from nanoparticles and heterogeneous gold catalysts reported to date. DFT studies correlated to experimental mechanistic investigations support an unprecedented "cluster-like" reactivity from polynuclear cooperation at the origin of this peculiar selectivity where the aurophilic interactions preexist, and pre-organize, gold cluster reactive intermediates.

Dissolution of [(μ-Me2CO)3(NaTp*)2] (1) (Tp* = hydrido-tris(3,5-dimethyl-1-pyrazolyl)borate) in DMSO at room temperature leads to the growth of colourless crystals characterized as the new salt [Na2Tp*(μ-Me2SO)3(Me2SO)3] [NaTp* 2] (2). 2 crystallized in the trigonal space group R3 with Z = 3, a = 14.1227(2) Å, b = 14.1227(10) Å, c = 33.9685(2) Å, and V = 5867.35(17) Å3. Interestingly, anion and cation of 2 both contain the Tp* ligand. Moreover, the cationic moiety highlights an unusual sodium atom hexacoordinated by six DMSO molecules acting as O-bonded ligands. Three of which exhibit a bridging coordination mode and three are in terminal position. To the best of our knowledge, the framework of [Na2Tp*(μ-Me2SO)3(Me2SO)3] is unprecedented.

International audience; Ferrocene is unique among organometallic compounds, and serves notably as a versatile platform towards the production of ligands useful to promote transition metals chemistry. A general limiting aspect of the synthesis of ferrocene derivatives is the efficient access to sophisticated highly functionalized polysubstituted ferrocenes, i. e. bearing four or more substituents replacing hydrogen atoms on the cyclopentadienyl rings. These ferrocene derivatives can bear various functional or/and structuring spectator substituents. Their preparation involves synthetic difficulties resulting from the need of multiple functionalizations coexisting altogether, and satisfying functional group compatibility and high selectivity issues. In the last decades, our group initially designed highly functionalized polyphosphines and hybrid ligands (1,1',3,3'-tetrafunctionalized Fc) using dialkylated 1,1'-tert-butylferrocene as a scaffold, which opened the way to various new classes of hybrid compounds. Some of these original ferrocenes were used as ligands, promoting metal catalysed C–C and C–X bond formation (X = O, S, N, etc.). Thus, highly functionalized ferrocenes, which include notably (P,P,P,P)-, (P,P,N,N)-, (P,P,P')-, (P,P,B)-, (P,B)- and (N,B)-compounds were developed in which the heteroatoms coexist in a close proximity on a common ferrocene platform with a controlled conformation. The present review details the concepts attached to the synthesis of these highly functionalized ferrocene species, and illustrates their main features and applications related to organometallic chemistry directed towards organic synthesis by metal catalysis.

Four free base aminoporphyrins were synthesized in two steps via regioselective anodic nucleophilic substitution with pyridine followed by ring opening of the electrogenerated pyridinium with piperidine. The X-ray crystallographic structure of the unstable 2-aminotetraphenylporphyrin was solved. Protonation of this latter compound leads to the stable diiminium porphyrin salt.

An expedient two-step synthesis produces in good yield polyaromatic heptacyclic (hetero)arylated o-substituted s-aryltetrazines (s-Tz) directly from diphenyl s-tetrazine. This methodology overcomes the steric limitations of classical Pinner-like syntheses encountered for o-functionalized s-Tz. A single step palladium-catalyzed N-directed C–H bond tetrahalogenation is followed by a Pd-catalyzed Suzuki (hetero)arylation that is achieved simultaneously on four sites. The single crystal X-ray diffraction structure of the resulting typical polyaromatic heptacyclic aromatic compound 3,6-bis(2,6-diphenyl)-1,2,4,5-tetrazine (3) is analyzed, together with R-functionalized peripheral phenyl derivatives [R = p-t-Bu (4), and m-OMe (10)]. Generally, stacking interactions between aromatic rings can be considerably stronger if electron-depleted rings are combined with electron-rich ones. Thus, electron-poor heteroaromatic aryltetrazines are expected to interact with electron-rich phenyl aromatic rings from reduced π⋯π repulsion, rendering the formation of stacking networks more favorable. Herein, despite the presence of strongly electron-deficient heteroaromatic tetrazine cores, the disruption of planarity between the various aromatic rings involved precludes the expected stacking arrangement. Thus, packing organization is driven by weak hydrogen bonding with C–H⋯N short contacts (or C–H⋯O when possible). These new heptaaromatics, which incorporate for the first time an electron-attracting nitrogen-rich core are easily modifiable from cross-coupling reactions, and constitute a relevant structural and electronical alternative to the well-known and high value class of hexaphenylbenzenes.

Crystallization of [(Ph3Sn)2SeO4] ⋅ 1.5H2O in methanol leads to the formation of [{(Ph3Sn)2SeO4} ⋅ CH3OH] n (1) which constitutes a new specimen of organotin(IV) selenate derivatives. In the solid state, complex 1 is arranged in polymeric zig-zag chains, composed of alternating Ph3Sn and SeO4 groups. In addition, pendant Ph3Sn ⋅ CH3OH moieties are branched along chains according to a syndiotactic organization and via Sn-O-Se connections. From a supramolecular point of view, intermolecular hydrogen bonds established between the selenate groups (uncoordinated oxygen) and the hydroxyl functions (CH3OH) of the pendant groups link the chains together.

We studied the electrochemical reduction based on gold electrode of a diazonium salt prepared from ethylenediamine. This is the first time where the covalent functionalization on the gold electrode of an alkyldiazonium salt, 2-aminoethane-1-diazonium chloride, is demonstrated. This step requires the preparation beforehand by diazotization of one amine group from ethylenediamine. The resulting electrodeposited ethylamine film was confirmed by spectroscopic characterizations from gold surface modification monitored by electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry (CV). The development of chemosensors based on such a covalent functionalization of a metal can reduce the chemical threats to human health along with drastically removing contaminants according to the green chemistry principles.

The carbon-carbon cross-coupling of phenyl s-tetrazine (Tz) units at their ortho-phenyl positions allows the formation of constrained bis(tetrazines) with original tweezer structures. In these compounds, the face-to-face positioning of the central tetrazine cores is reinforced by π-stacking of the electron-poor nitrogen-containing heteroaromatic moieties. The resulting tetra-aromatic structure can be used as a weak coordinating ligand with cationic silver. This coordination generates a set of bis(tetrazine)-silver(I) coordination complexes tolerating a large variety of counter anions of various geometries, namely, PF6−, BF4−, SbF6−, ClO4−, NTf2−, and OTf−. These compounds were characterized in the solid state by single-crystal X-ray diffraction (XRD) and diffuse reflectance spectroscopy, and in solution by 1H-NMR, mass spectrometry, electroanalysis, and UV-visible absorption spectrophotometry. The X-ray crystal structure of complexes {[Ag(3)][PF6]}∞ (4) and {[Ag(3)][SbF6]}∞ (6), where 3 is 3,3′-[(1,1′-biphenyl)-2,2′-diyl]-6,6′-bis(phenyl)-1,2,4,5-tetrazine, revealed the formation of 1D polymeric chains, characterized by an evolution to a large opening of the original tweezer and a coordination of silver(I) via two chelating nitrogen atom and some C=C π-interactions. Electrochemical and UV spectroscopic properties of the original tweezer and of the corresponding silver complexes are reported and compared. 1H-NMR titrations with AgNTf2 allowed the determination of the stoichiometry and apparent stability of two solution species, namely [Ag(3)]+ and [Ag(3)2]2+, that formed in CDCl3/CD3OD 2:1 v/v mixtures.

International audience; The synthesis, cyclic and rotating disk electrode voltammograms, UV-visible absorption and Xray diffraction analyses of cobalt(II) 10-phenyl-5,15-dip -tolylporphyrin (1-Co) are described. 1-Co was crystallized by slow diffusion of n-hexane into a concentrated CH2Cl2 solution. X-ray diffraction analyses reveals porphyrin aromatic cycle stacking in the crystal, C-H•••π interactions of the CH2Cl2 solvent with the π-system of one tolyl group and Co(II)•••π (porphyrin ring) interactions. The abstraction of 1.0 F/mol during the electrolysis at the first oxidation potential was followed by spectroelectrochemistry. It leads to the Co(II) → Co(III) transformation rather than the formation of the cation radical of the porphyrin ligand. These results were supported by comparison of the cyclic and rotating disc electrode voltammograms, of the UV-Visible absorption spectra, before and after electrolysis of 1-Co.

We studied the electrochemical reduction based on gold electrode of a diazonium salt prepared from ethylenediamine. This is the first time where the covalent functionalization on the gold electrode of an alkyldiazonium salt, 2-aminoethane-1-diazonium chloride, is demonstrated. This step requires the preparation beforehand by diazotization of one amine group from ethylenediamine. The resulting electrodeposited ethylamine film was confirmed by spectroscopic characterizations from gold surface modification monitored by electrochemical quartz crystal microbalance (EQCM) coupled to cyclic voltammetry (CV). The development of chemosensors based on such a covalent functionalization of a metal can reduce the chemical threats to human health along with drastically removing contaminants according to the green chemistry principles.

The synthesis and characterization of a range of bis(iminophosphoranyl)phosphide (BIPP) group 4 and coinage metals complexes is reported. BIPP ligands bind group 4 metals in a pseudo fac-fashion, and the central phosphorus atom enables the formation of d0–d10 heterobimetallic complexes. Various DFT computational tools (including AIM, ELF and NCI) show that the phosphorus–metal interaction is either electrostatic (Ti) or dative (Au, Cu). A bridged homobimetallic Cu–Cu complex was also prepared and its spectroscopic properties were investigated. The theoretical analysis of the P–P bond in BIPP complexes reveals that (i) BIPP are closely related to ambiphilic triphosphenium (TP) cations; (ii) the P–P bonds are normal covalent (i.e. not dative) in both BIPP and TP., The synthesis, characterization and computational analysis of a range of bis(iminophosphoranyl)phosphide (BIPP) group 4 and coinage metals complexes is reported. White phosphorus was used to install the central phosphorus atom.

International audience; Di-tert-butylated-bis(phosphino)ferrocene ligands bearing phosphino substituents R (R=phenyl, cyclohexyl, isopropyl, mesityl, or furyl) allow tuning the selective formation of Au(I) halide complexes. Thus, dinuclear linear twocoordinate, but also rare mononuclear trigonal three-coordinate and tetrahedral four-coordinate complexes were formed upon tuning of the conditions. Both Au(I) chloride and rarer Au(I) iodide complexes were synthesized, and their X-ray diffraction analysis are reported. The significance of the control of structure and nuclearity in Au(I) complexes is further illustrated herein by its strong effect on the efficiency and selectivity of gold-catalysed cycloisomerization. Cationic linear digold(I) bis(dicyclohexylphosphino) ferrocenes outperform other catalysts in the demanding regioselective cycloisomerization of enyne sulphonamides into cyclohexadienes. Conversely, tetrahedral and trigonal cationic monogold(I) complexes were found incompetent for enyne cycloaddition. We used the two-coordinate linear electron-rich Au(I) complex 2b (R=Cy) to extend the scope of selective intramolecular cycloaddition of different 1,6-enyne sulfonylamines with high activity and excellent selectivity to the endo cyclohexadiene products.

Click chemistry at a tetrazine core is useful for bioorthogonal labeling and crosslinking. Introduced here are two new classes of doubly clickable s-aryl tetrazines synthesized by Cu-catalyzed cross-coupling. Homocoupling of o-brominated s-aryl tetrazines leads to bis(tetrazine)s structurally characterized by tetrazine cores arranged face-to-face. [N]8 π-stacking interactions are essential to the conformation. Upon inverse electron demand Diels-Alder (iEDDA) cycloaddition, the bis(tetrazine)s produce a unique staple structure. The o-azidation of s-aryl tetrazines introduces a second proximal intermolecular clickable function that leads to double click chemistry opportunities. The stepwise introduction of fluorophores and then iEDDA cycloaddition, including bioconjugation to antibodies, was achieved on this class of tetrazines. This method extends to (thio)etherification, phosphination, trifluoromethylation and the introduction of various bioactive nitrogen-based heterocycles.

International audience; In this work, new receptors built on the porphyrin scaffold were synthesized for halophenols recognition. A quinolyl group was introduced on the porphyrin's periphery as binding site, to form two series of molecules based on two distinct porphyrin frames and which were obtained in free base and zinc forms. The binding between these porphyrin based receptors and halophenols (2,3,4,6tetrachlorophenol, 2,4,6-trichlorophenol or 2,4,6-tribromophenol) was studied. As established by 1 H NMR spectroscopy, the binding constants are in the range of two-digit numbers, which value is correlated with the porphyrin structure (substitutive pattern, form of the free base or Zn II complex) and the pKa of the respective phenol. These data, supplemented by a X-ray structure of one adduct complex, indicate a single interaction between the phenolic proton and the nitrogen of the quinolyl group. The binding with p-nitrophenol was tested for comparison. The association constant increases at a scale of one order of magnitude. This net stabilization of the adduct complex in this case is explained by additional hydrogen bonds implying the nitro function, as also witnessed by X-ray diffractometry.

The polymeric organotin(IV) selenate complex [(Me3Sn)3(SeO4)(OH)]n (1) has been isolated as single crystals from the reaction of [(Me2NH2)2SeO4] and Me3SnCl in methanol. In the solid state, compound 1 was characterized by X-ray diffraction analysis, Fourier transform-infrared spectroscopy, and elemental analysis. 1 crystallizes in the orthorhombic system space group Pbca with a=11.0231(2) Å, b=16.3461(3) Å, c=20.9945(4) Å, α=β=γ=90°, V=3782.89(12) Å3, and Z=8. Its structure can be described as a polymeric zigzag chain based on Me3Sn moieties linked by tridentate selenate anions. Pendant (Me3Sn)2OH groups are also connected to the chain, according to a syndiotactic organization, and via Sn-O-Se bonds. Intermolecular OH···O hydrogen bonds and long Se-O···Sn distance interactions promote the association of chains together and lead to the propagation of a three-dimensional network. In addition, the behavior of 1 in solution (methanol) was also studied by multinuclear nuclear magnetic resonance spectroscopy and mass spectrometry.

International audience; We provide efficient synthetic access to heteroaryl sulfones in two-steps using a simple palladium-1,1'-bis [(diphenyl)phosphanyl]ferrocene catalyst to form in high yields variously functionalized heteroaromatic thioethers. Pyridinyl-containing substrates can be subsequently selectively oxidized into sulfones and NH-sulfoximines by using very mild oxidation conditions with a high functional group tolerance. In the palladium catalyzed C-S coupling of heteroaromatic thiols, reactivity limitation is attached with electron-deficient thiols. We show that this limitation can be resolved by the successful use of 2-bromoheteroarenes in the C-S coupling. We established herein that this choice of heteroaryl electrophilic reagent in palladium-catalyzed C-S bond formation allows overcoming palladium dithiolate out-of-cycle resting state inertness. This was illustrated in the stoichiometric reactivity study of the palladium dithiolate formed from 4-trifluoromethylbenzen-1-thiol-isolated and characterized by multinuclear NMR and XRD-with both 2-chloropyridine and 2-bromopyridine.

International audience; The reaction of N,N,N′,N′-tetramethyl guanidine, NHC(N(CH3)2)2 (TMGD) and CdBr2·4H2O in ethanol led to the formation of [TMGDH][CdBr3] (1), which crystallizes in the monoclinic space group Cc with Z=4, a=8.9079(7) Å, b=18.5810(14) Å, c=8.1637(6) Å, β=107.953(3)°, and V=1285.44(17) Å3. In the crystal lattice, 1 is organized in one-dimensional anionic chains of CdBr4 tetrahedra sharing two corners. To our knowledge, this is the first evidence of such a coordination geometry described for a bromocadmate derivative. The negative charges are compensated by monoprotonated N,N,N′,N′-tetramethyl guanidinium cations (TMGDHs), which are in N-H hydrogen bonding interaction with the terminal bromide atoms of the anionic chain. The title compound was also characterized by middle and far-infrared spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The elemental analysis corroborates as well the X-ray elucidation. Multinuclear solution nuclear magnetic resonance (NMR) spectroscopic measurements (1H, 13C{1H}) were conducted in D2O.

International audience; Herein we report the synthesis of new ditopic ligands, which consist of a phenoxy group and N,N,N'trisubstituted amidines linked by a methylene spacer (L1-L4). Their coordination chemistry has been studied/investigated with Zn(II) and Al(III). Alkane elimination route between the phenol-amidine proligands (L1H-L4H) and Et2Zn led to dinuclear complexes [(L1-L4)ZnEt]2 (1a-4a) in which the Zn centers are chelated by phenoxyamidine ligands and bridged through the oxygen atom of the phenoxy groups. Salt metathesis reaction between two equivalents of the sodium amidine phenate L1Na and ZnCl2 led to a bis-chelate chiral spiro-complex (L12Zn) 1a'. Analogous alkane elimination route between AlMe3 and the phenol-amidine proligands L1H-L4H allowed the preparation of the mononuclear complexes [(L1-L4)AlMe2] (1b-4b). The phenoxyamidine-Al and Zn complexes have been characterized by NMR spectroscopy, elemental analysis and/or high resolution ESI-MS. The solid state structures of the proligands [L1H2][Br] and L2H as well as of six complexes have been established by single crystal X-ray diffraction analysis. Fluxional properties of the proligands L1H-L2H and of the complexes 1a and 2b have been investigated by VT NMR experiments. In the presence of an alcohol source, complexes 1a-4a and 1b-4b were used as initiators for the controlled ring-opening polymerization (ROP) of rac-lactide to afford atactic polylactic acid (PLA).

Click chemistry at a tetrazine core is useful for bioorthogonal labeling and crosslinking. Introduced here are two new classes of doubly clickable s-aryl tetrazines synthesized by Cu-catalyzed cross-coupling. Homocoupling of o-brominated s-aryl tetrazines leads to bis(tetrazine)s structurally characterized by tetrazine cores arranged face-to-face. [N]

International audience; A new class of tritopic ferrocene-based ambiphilic compound has been prepared by assembling diphosphino- and boryl-substituted cyclopentadienides at iron. The presence of five sterically demanding substituents on the ferrocene platform induces conformation constraints, as apparent from XRD and NMR data, but does not prevent chelating coordination to platinum. The Lewis acid moiety is pendant in both the free ligand and the platinum complex.

The reaction between ethylamine and oxalic acid in water in a 1:1 molar ratio afforded the title salt, C2H8N+·C2HO4 −·0.5C2H2O4. The hydrogen oxalate anions interact through hydrogen bonding and are organized into a chains propagating along the c-axis direction. The chains are connected to the neighbouring cations and oxalic acid molecules by N—H...O and O—H...O hydrogen bonds and N...O dipole–dipole contacts, leading to a supramolecular three-dimensional network.

International audience; A general challenging issue in the synthesis of hemilabile ferrocene ligands is the access to highly functionalized ferrocene starting materials. These can bear donor/acceptor atoms, additional functional and structuring spectator substituents, but the preparation of such species poses general synthetic difficulties. We report herein alternative synthetic routes to hybrid ferrocene donors such as tert-butylated phosphanylcarboxylic acids and their corresponding aldehydes. These hybrid ambiphilic species that combine Brønsted-acidic and Lewis-basic functional moieties in their structure were characterized by multinuclear NMR and single-crystal X-ray diffraction analysis. In the solid state, the mutual arrangement of functional groups at the ferrocene unit is highly dependent on hydrogen bonding interactions despite the structural hindering effect of the tert-butyl groups introduced. The ligands were converted to gold(I) complexes and phosphane selenides to further monitor the properties and mutual influence of the functional groups in the prepared compounds.

The reaction of bis(2-methyl-1H-imidazol-3-ium) oxalate, [C4H7N2]2[C2O4], and bis(triphenyltin) oxalate, [(Ph3Sn)2(C2O4)], in methanol at room temperature yielded the formation of 2-methyl-1H-imidazol-3-ium catena-O,O′-oxalatotriphenylstannate, [C4H7N2][Ph3Sn(C2O4)] (1), which crystallizes in the monoclinic space group P21/c with Z=8, a=16.9334(14) Å, b=17.3251(14) Å, c=14.5114(10) Å, β=90.590(2)°, and V=4257.0(6) Å3. The oxalate ligand of 1 displays a bridging coordination mode and thus links two SnPh3 moieties through an axial coordination leading to the propagation of infinite polymeric chains along the c axis. All Sn(IV) atoms exhibit a trigonal bipyramid geometry. The negative charge of [Ph3Sn(C2O4)]- moieties is compensated by the presence of surrounding noncoordinating 2-methyl-1H-imidazol-3-ium cations. From a supramolecular point of view, the Sn-based chains are connected to one another through N-H···O hydrogen bond interactions involving oxalate ligands of distinct strands and doubly by the [C4H7N2]+ cations. The topology of the resulting crystal packing can be described as a two-dimensional layer network.

Reaction of dimethyl N-cyanodithioiminocarbonate, NCNC(SCH3)2 (L), and SnPh3Cl led to the formation of [ClPh3SnNCNC(SCH3)2] (1) which crystallizes in the monoclinic space group C2/c with Z=8, a=19.152(2) Å, b=12.8659 (16) Å, c=19.063(3) Å, β=108.608(3) and V=4451.6(10) Å3. The structure of 1 consists of a SnPh3 moiety trans-coordinated in apical positions by one L ligand, N-coordinated, and one chlorine atom involving a trigonal bipyramid geometry around the Sn(IV) atom. To our knowledge, this is the first isolation of a discrete triorganotin(IV) complex with a N-cyanodithioiminocarbonate adduct. The structural characterization of 1 was completed by infrared and nuclear magnetic resonance spectroscopy, and elemental analysis which confirm the X-ray elucidation.

Porphyrins provide an extremely flexible synthetic scaffold for numerous applications such as artificial photosynthesis, photodynamic therapy, molecular recognition, oxidation/reduction catalysts and molecular materials.[1] The fusion of one or several hydrocarbon(s) or aromatic heterocycle(s) onto the porphyrin periphery forces the porphyrin core and the substituent to be coplanar, that enhances the electronic communication between both fragments. This implies important changes in the optical and electrochemical properties of the fused porphyrin compared to the parent porphyrin core such as decrease of the HOMO/LUMO gap, bathochromic shift in it absorption/emission spectra and large absorption and fluorescence in the NIR range. [[2],[3]] For this reason, π-extension of porphyrins has attracted much attention over the last two decades owing to their potential applications in near infrared electroluminescence displays, non-linear optical materials, photodynamic therapy, photovoltaic solar cells and molecular materials. [2,[4]] Nowadays, π-extended C-C linked porphyrins are commonly obtained using toxic and/or expensive chemicals, often under harsh conditions. [3,[5]] Due to the extension of the conjugation path, the oxidation potential decreases which may lead to over-oxidation during the fusion process. In this work, we present the mild and selective chemical and electrochemical synthesis of new π-extended porphyrins generated via intramolecular oxidative C-N coupling of peripheral pyridinyl fragment(s) with the porphyrin core. [[6]] As compared to their precursors, these fused pyridinium-porphyrins exhibit higher oxidation potential that prevents their over-oxidation. [1]. Kadish, K. M.; Smith, K. M.; Guillard, R. In The Porphyrin Handbook; Kadish, K. M., Smith, K. M., Guilard, R., Eds.; Academic Press: 2000; Vol. 1-20. [2]. Zimmerman, J.D.; Diev, V.V.; Hanson, K.; Lunt, R.R.; Yu, E.K.; Thompson, M.E.; Forrest, S.R. Adv. Mater. 2010, 22, 2780-2783. [3]. Davis, N.K.S.; Thompson, A.L.; Anderson, H.L. J. Am. Chem. Soc. 2011, 133, 30-31. [4]. Matsuo, Y.; Stao, Y.; Niinomi, T.. Soga, I.; Nakamura, E. J. Am. Chem. Soc. 2009, 131, 16048-16050. [5]. (a) Brennan, B. J.; Kenney, M. J.; Liddell, P. A.; Cherry, B. R.; Li, J.; Moore, A. L.; Moore, T. A.; Gust, D. Chem. Commun. 2011, 47, 10034-10036. (b) Scigaj, M.; Gryko, D. T. Org. Biomol. Chem. 2011, 9, 8178-8181. (c) Davis, N. K. S.; Thompson, A. L.; Anderson, H. L. J. Am. Chem. Soc. 2011, 133, 30-31. (d) Lewtak, J. P.; Gryko, D. T. Chem. Commun. 2012, 48, 10069-10086. (e) Mori, H.; Tanaka, T.; Osuka, A. J. Mater. Chem. C 2013, 1, 2500-2519. [6]. Berthelot, M.; Hoffmann, G.; Bousfiha, A.; Echaubard, J.; Roger, J.; Cattey, H.; Romieu, A.; Lucas, D.; Fleurat-Lessard, P.; Devillers, C. H. Chem. Commun. 2018, 54, 5414 Figure 1

International audience; Unequally functionalized ferrocenes give access to valuable hemilabile reactivity in catalytic reaction. We address the synthesis of hybrid (P, N)-ferrocenyl compounds for which recent catalytic breakthrough applications have been reported, transversely in late transition metals chemistry. Palladium, nickel, rhodium, iridium, and emerging iron and gold catalysis are illustrated from selected examples, which include CC bond formation from cross-coupling and polymerization, allylic substitution, cyanation, hydroformylation, CH arylation and silylation and hydrogenation reactions.

International audience; The mild (electro) chemical oxidation of pyridin-2-ylthio-meso substituted Ni(II) porphyrins affords C-N fused cationic and dicationic pyridinium-based derivatives. These porphyrins are fully characterized and the molecular structure of one of them was confirmed by X-ray crystallography. A mechanism for the intramolecular oxidative C-N coupling is proposed based on theoretical calculations and cyclic voltammetry analyses.

Two novel C,N-chelated organotin(IV) complexes bearing weakly coordinating carborane moieties were prepared by the reaction of the corresponding C,N-chelated organotin(IV) chloride (i.e. LCNR2SnCl, R = n-Bu (1) and Ph (2); LCN = 2-(N,N-dimethylaminomethyl)phenyl)) with monocarba-closo-dodecaborate silver salt (AgCB11H12; Ag·3). Both products of the metathesis, [LCN(n-Bu)2Sn]+[CB11H12]− (4) and [LCNPh2Sn]+ [CB11H12]− (5), respectively, were characterized by both multinuclear NMR spectroscopy and elemental analysis. The instability of 4 and 5 towards water is discussed. The solid-state structure of LCN(n-Bu)2SnOH·B(C6F5)3 (4a) as a model compound with a Sn–O(H)⋯B linkage is also reported. The evaluation of the catalytic activity of 4 and 5 was carried out within the direct synthesis of dimethyl carbonate (DMC) from methanol and CO2. While 5 was shown to be definitively inactive, presumably due to cleavage of the Sn–Ph bond, compound 4 exhibits a beneficial action, since it leads to an amount of DMC higher than the stoichiometry (nDMC/nSn(cat) = 1.5). In addition, the solid state structures of [BnNMe3]+[CB11H12]− (6) and [(n-Bu)20Sn10O2(OMe)6(CO3)2]2+·2[CB11H12]− (7), isolated as single-crystals and resulting from the recombination of 4 under the reaction conditions (methanol/CO2), were established by sc-XRD analyses within the term of this work as well. 6 and 7 were also fully characterized by IR spectroscopy, multinuclear NMR in solution and elemental analysis.

Hexasubstituted hybrid tetradentate (N,N′,P,P′)-ferrocenes bearing phosphino and aminomethyl groups, plus hindering tert-butyl moieties, were synthesized by using two different strategies: a “diverging” synthesis involving successive functionalization of preformed di-tert-butylated ferrocene and a “converging” assembly of the species from appropriately substituted cyclopentadienyl rings. While the new cyclopentadienyl salts formed are of interest, their assembly with iron dichloride used as a “converging” way to produce tetradentate ferrocene ligands presented several drawbacks. Conversely, the synthesis of new tert-butylated (aminomethyl)ferrocene derivatives was found convenient to further form (N,N′)-aminomethyl,(P,P′)-tert-butylated-ferrocenyl diphosphines by N-directed ortho-metalation. The novel N2-didentate and N2P2-tetradentate tert-butylated ferrocene compounds were all synthesized in good to high yields (48–96%) and tolerated aryl, alkyl, and heteroaryl phosphino groups as substituents on nitrog...