Correction: Thierry et al. Observation of Hyperpositive Non-Linear Effect in Asymmetric Organozinc Alkylation in Presence of -Pyrrolidinyl Norephedrine. 2022, , 3780.

The authors wish to make the following correction to their paper [...

Synthesis and Characterization of Transition Metal Complexes Supported by Phosphorus Ligands Obtained Using Hydrophosphination of Cyclic Internal Alkenes.

The design and study of rich, bulky phosphorus ligands is a key area of research for homogeneous catalysis. Here, we describe an original strategy using a hydrophosphination reaction to produce phosphines of interest for coordination chemistry and homogenous catalysis. In particular, the phosphine obtained by reacting diphenylphosphine with acenaphthylene (ligand ) gives a ligand that adopts an unusual spatial geometry.

Diastereoselective Synthesis of Sulfoxide-Functionalized N-Heterocyclic Carbene Ruthenium Complexes: An Experimental and Computational Study.

The synthesis of sulfoxide-functionalized NHC ligand precursors were carried out by direct and mild oxidation from corresponding thioether precursors with high selectivity. Using these salts, a series of cationic [Ru(II)(η-p-cymene)(NHC-SO)Cl] complexes were obtained in excellent yields by the classical AgO transmetallation route. NMR analyses suggested a chelate structure for the metal complexes, and X-ray diffractometry studies of complexes 4 b, 4 c, 4d and 4 e unambiguously confirmed the preference for the bidentate (κ-C,S) coordination mode of the NHC-SO ligands.

A stable and true-blue emissive hexacoordinate Si(IV) N-heterocyclic carbene complex and its use in organic light-emitting diodes.

A neutral hexacoordinate Si(IV) complex containing two tridentate N-heterocyclic carbene ligands is synthesised and characterized by X-ray crystallography, optical spectroscopy, electrochemistry and computational methods. The stable compound exhibits remarkable deep-blue photoluminescence particularly in the solid state, which enables its use as an electroluminescent material in organic light-emitting diodes.

Triphenylphosphonium-functionalized N-heterocyclic carbene platinum complexes [(NHC-TPP)Pt] induce cell death of human glioblastoma cancer stem cells.

A growing body of experimental and clinical evidence suggests that rare cell populations, known as cancer stem cells (CSCs), play an important role in the development and therapeutic resistance of several cancers, including glioblastoma. Elimination of these cells is therefore of paramount importance. Interestingly, recent results have shown that the use of drugs that specifically disrupt mitochondria or induce mitochondria-dependent apoptosis can efficiently kill cancer stem cells.

Rh(I) Complexes with Hemilabile Thioether-Functionalized NHC Ligands as Catalysts for [2 + 2 + 2] Cycloaddition of 1,5-Bisallenes and Alkynes.

The [2 + 2 + 2] cycloaddition of 1,5-bisallenes and alkynes under the catalysis of Rh(I) with hemilabile thioether-functionalized N-heterocyclic carbene ligands is described. This protocol effectively provides an entry to different -5,6-fused bicyclic systems with two exocyclic double bonds in the cyclohexene ring. The process is totally chemoselective with the two internal double bonds of the 1,5-bisallenes being involved in the cycloaddition.

Evaluation of the Cytotoxicity of Cationic Polymers on Glioblastoma Cancer Stem Cells.

Cationic polymers such as polyethylenimine (PEI) have found a pervasive place in laboratories across the world as gene delivery agents. However, their applications are not limited to this role, having found a place as delivery agents for drugs, in complexes known as polymer-drug conjugates (PDCs). Yet a potentially underexplored domain of research is in their inherent potential as anti-cancer therapeutic agents, which has been indicated by several studies.

Polyethylenimine, an Autophagy-Inducing Platinum-Carbene-Based Drug Carrier with Potent Toxicity towards Glioblastoma Cancer Stem Cells.

The difficulty involved in the treatment of many tumours due to their recurrence and resistance to chemotherapy is tightly linked to the presence of cancer stem cells (CSCs). This CSC sub-population is distinct from the majority of cancer cells of the tumour bulk. Indeed, CSCs have increased mitochondrial mass that has been linked to increased sensitivity to mitochondrial targeting compounds.

Observation of Hyperpositive Non-Linear Effect in Asymmetric Organozinc Alkylation in Presence of -Pyrrolidinyl Norephedrine.

Phenomena related to asymmetric amplification are considered to be key to understanding the emergence of homochirality in life. In asymmetric catalysis, theoretical and experimental models have been studied to understand such chiral amplification, in particular based on non-linear effects. Three decades after the theoretical demonstration that a chiral catalyst, when not enantiopure, could be more enantioselective than its enantiopure counterpart, we show here a new experimental example of nonlinear hyperpositive effect.

Polymerization/depolymerization of chiral metallo-supramolecular assembly induced by redox change.

We report on the polymerization/depolymerization of chiral metallo-supramolecular assembly by Cu /Cu redox change. By combining a monotopic enantiopure ligand with a ditopic ligand of opposite configuration, ML -type complexes are generated with chiral self-recognition or self-discrimination depending on the oxidation state of copper. In presence of Cu , the formation of heterochiral complexes is favored, thus generating dinuclear species whereas Cu advocates for the formation of homochiral species, namely, a mixture of mononuclear species and metallo-supramolecular polymeric species.

Hyperpositive non-linear effects: enantiodivergence and modelling.

The chiral ligand -methylephedrine (NME) was found to catalyse the addition of dimethylzinc to benzaldehyde in an enantiodivergent way, with a monomeric and a homochiral dimeric complex both catalysing the reaction at a steady state and giving opposite product enantiomers. A change in the sign of the enantiomeric product was thus possible by simply varying the catalyst loading or the ligand ee, giving rise to an enantiodivergent non-linear effect. Simulations using a mathematical model confirmed the possibility of such behaviour and showed that this can lead to situations where a reaction gives racemic products, although the system is composed only of highly enantioselective individual catalysts.

In Cellulo Evaluation of the Therapeutic Potential of NHC Platinum Compounds in Metastatic Cutaneous Melanoma.

We describe here the evaluation of the cytotoxic efficacy of two platinum (II) complexes bearing an N-heterocyclic carbene (NHC) ligand, a pyridine ligand and bromide or iodide ligands on a panel of human metastatic cutaneous melanoma cell lines representing different genetic subsets including BRAF-inhibitor-resistant cell lines, namely A375, SK-MEL-28, MeWo, HMCB, A375-R, SK-MEL-5-R and 501MEL-R. Cisplatin and dacarbazine were also studied for comparison purposes. Remarkably, the iodine-labelled Pt-NHC complex strongly inhibited proliferation of all tested melanoma cells after 1-h exposure, likely due to its rapid uptake by melanoma cells.

Observation of hyperpositive non-linear effect in catalytic asymmetric organozinc additions to aldehydes.

Asymmetric amplification is a phenomenon that is believed to play a key role in the emergence of homochirality in life. In asymmetric catalysis, theoretical and experimental models have been investigated to provide an understanding of how chiral amplification is possible, in particular based on non-linear effects. Interestingly, it has been proposed a quarter century ago that chiral catalysts, when not enantiopure might even be more enantioselective than their enantiopure counterparts.

-Heterocyclic Carbene Platinum(IV) as Metallodrug Candidates: Synthesis and Pt NMR Chemical Shift Trend.

A series of octahedral platinum(IV) complexes functionalized with both -heterocyclic carbene (NHC) ligands were synthesized according to a straightforward procedure and characterized. The coordination sphere around the metal was varied, investigating the influence of the substituted NHC and the amine ligand in trans position to the NHC. The influence of those structural variations on the chemical shift of the platinum center were evaluated by Pt NMR.

Phosphorescent Cationic Heterodinuclear Ir /M Complexes (M=Cu , Au ) with a Hybrid Janus-Type N-Heterocyclic Carbene Bridge.

A novel class of phosphorescent cationic heterobimetallic Ir /M complexes, where M =Cu (4) and Au (5), is reported. The two metal centers are connected by the hybrid bridging 1,3-dimesityl-5-acetylimidazol-2-ylidene-4-olate (IMesAcac) ligand that combines both a chelating acetylacetonato-like and a monodentate N-heterocyclic carbene site coordinated onto an Ir and a M center, respectively. Complexes 4 and 5 have been prepared straightforwardly by a stepwise site-selective metalation with the zwitterionic [(IPr)M (IMesAcac)] metalloproligand (IPr=1,3-(2,6-diisopropylphenyl)-2H-imidazol-2-ylidene) and they have been fully characterized by spectroscopic, electrochemical, and computational investigation.

Chiral stimuli-responsive metallo-supramolecular assembly induced by Cu/Cu redox change.

We investigated the selective formation of homoleptic and heteroleptic metal complexes controlled by means of the chiral molecular instruction of the ligand and the coordination geometry of the metal. Our results showed that chiral self-recognition or self-discrimination may be induced by the Cu/Cu redox transition using cyclic voltammetry. The further use of chiral ditopic ligands led to metallo-supramolecular copolymers with stimuli-responsive controlled arrangement.

Synthesis, characterization, catalytic and biological application of half-sandwich ruthenium complexes bearing hemilabile (κ2-C,S)-thioether-functionalised NHC ligands.

A series of cationic Ru(ii)(η-p-cymene) complexes with thioether-functionalised N-heterocyclic carbene ligands have been prepared and fully characterized. Steric and electronic influence of the R thioether substituent on the coordination of the sulfur atom was investigated. The molecular structure of three of them has been determined by means of X-ray diffractrometry and confirmed the bidentate (κ-C,S) coordination mode of the ligand.

Catalyst-free hydrophosphination of alkenes in presence of 2-methyltetrahydrofuran: a green and easy access to a wide range of tertiary phosphines.

A hydrophosphination reaction that is free of base, acid and catalyst, using only 2-methyltetrahydrofuran as additive has been performed. A new family of mono-, di-, tri- and tetra-phosphines compounds are obtained in good to excellent yields by adding diphenylphosphine to alkenes, mono- and polyfunctional acrylics (based on acrylate and methacrylate motifs) and acrylamide substrates. Addition of four equivalent of bio-mass derived 2-MeTHF into the reaction media improves both conversion and time of the reaction and reduces the sensitivity of the reactants over oxidation.

-Heterocyclic Carbene-Platinum Complexes Featuring an Anthracenyl Moiety: Anti-Cancer Activity and DNA Interaction.

A platinum (II) complex stabilized by a pyridine and an N-heterocyclic carbene ligand featuring an anthracenyl moiety was prepared. The compound was fully characterized and its molecular structure was determined by single-crystal X-ray diffraction. The compound demonstrated high in vitro antiproliferative activities against cancer cell lines with IC ranging from 10 to 80 nM.

Structural and Luminescent Properties of Homoleptic Silver(I), Gold(I), and Palladium(II) Complexes with NHC-NHC Heteroditopic Carbene Ligands.

Novel silver(I), gold(I), and palladium(II) complexes were synthesized with bidentate heteroditopic carbene ligands that combine an imidazol-2-ylidene (NHC) with a 1,2,3-triazol-5-ylidene (NHC) connected by a propylene bridge. The silver(I) and gold(I) complexes were dinuclear species, [M(NHC-NHC)](PF) (M = Ag or Au), with the two bidentate ligands bridging the metal centers, whereas in the palladium(II) complex [Pd(NHC-NHC)](PF), the two ligands were chelated on the same metal center. Because of the presence of two different carbene units, isomers were observed for the gold(I) and palladium(II) complexes.

Chiral Self-Sorting Process with Ditopic Ligands: Alternate or Block Metallopolymer Assembly as a Function of the Metal Ion.

We report an extensive study on the coordination behavior of chiral ditopic bridging ligands, which lead to metallosupramolecular polymers in the presence of Zn(II) and Cu(II) in solution. With the help of UV-vis and circular dichroism spectroscopies, we show that the metallopolymer sequence can be controlled by chirality and by the choice of the metal ion. Although the formation of a block metallopolymer proceeds through the assembly of homoleptic complexes, an alternate metallopolymer may be obtained only when heteroleptic complexes are formed.

Homo- and Heteropolymetallic Complexes of the Hybrid, Ambidentate N-Heterocyclic Carbene Ligand IMes-acac.

The anionic 5-acetylimidazol-2-ylidene-4-olate , named as "IMes-acac", is composed of fused diaminocarbene and acetylacetonato units in the same IMes-based imidazolyl ring. The bifunctional compound is shown to act as an effective, ditopic bridging ligand for transition metal centers. Several new complexes supported by this ligand were prepared, including the complex [RuCl(-Cym)(κ ,-·H)](BF) (), which can be regarded as a metallated imidazolium salt, the homobimetallic complex [((COD)Rh)(RhCl(COD))(μ-1κ ,:2κ -)] (), the heterobimetallic complexes [((-Cym)ClRu)(RhCl(COD))(μ-1κ ,:2κ -)] (), [((-Cym)ClRu)(RhCl(CO))(μ-1κ ,2κ -)] (), [((-Cym)ClRu)(Cu(IPr))(μ-1κ ,:2κ -)] (), the anionic homoleptic Cu(I) complexes [Cu(κ -)]K ([]K) and [Cu(κ -)](NEt) ([](NEt)), and the heterotrimetallic complex [((-Cym)RuCl)(Cu)(μ-1κ ,:3κ -)(μ-2κ ,:3κ -)](PF) ().

Synthesis of alternating metallocopolymers by chiral recognition.

We report the synthesis of chiral enantiopure polytopic bridging ligands, which may lead to the formation of metallosupramolecular polymers with zinc (II) as metal linker. We show that chiral C -symmetric bisoxazoline ligands are useful moieties to efficiently generate heterochiral complexes and thus polymeric entities. The corresponding metallopolymers were further characterized by powder X-ray diffraction (PXRD) to obtain information on the level of crystallinity of our different metallopolymers.

Easy Ruthenium-Catalysed Oxidation of Primary Amines to Nitriles under Oxidant-Free Conditions.

A dehydrogenation of primary amine to give the corresponding nitrile under oxidant- and base-free conditions catalysed by simple [Ru(p-cym)Cl ] with no extra ligand is reported. The system is highly selective for alkyl amines, whereas benzylamine derivatives gave the nitrile product together with the imine in a ratio ranging from 14:1 to 4:1 depending on the substrate. Preliminary mechanistic investigations have been performed to identify the key factors that govern the selectivity.