Understanding ketone hydrogenation catalysis with anionic iridium(iii) complexes: the crucial role of counterion and solvation.

Catalytic asymmetric hydrogenation of ketones is an important approach to prepare valuable chiral alcohols. Understanding how transition metals promote these reactions is key to the rational design of more active, selective and sustainable catalysts. A highly unusual mechanism for asymmetric hydrogenation of acetophenone catalysed by an anionic Ir hydride system, including a strong counterion dependence on catalyst activity, is explored and rationalised here.

New Protocol for the Synthesis of S-Thioesters from Benzylic, Allylic and Tertiary Alcohols with Thioacetic Acid.

A new one-pot solvent-less reaction to convert benzylic, allylic, ferrocenyl or tertiary alcohols into S-thioesters, bench-stable and less odorous precursors of the corresponding thiols, which is based on reactions in neat thioacetic acid in the presence of tetrafluoroboric acid, is presented. Reaction monitoring by NMR and GC of the benzyl alcohol conversion indicated the intermediate formation of benzyl acetate and benzyl thionoacetate (PhCH OC(S)CH ) prior to the slower conversion to the final S-benzyl thioacetate product. Increasing the HBF concentration enhanced the reaction rate, giving good to excellent yield (up to 99 %) for a large scope of alcohols.

Acetate ion addition to and exchange in (1,5-cyclooctadiene)rhodium(I) acetate: relevance for the coagulation of carboxylic acid-functionalized shells of core-crosslinked micelle latexes.

The solution behavior of complex [Rh(COD)(μ-OAc)] in the absence and presence of PPNOAc in dichloromethane has been investigated in detail by multinuclear NMR spectroscopy. Without additional acetate ions, the compound shows dynamic behavior at room temperature, consistent with an inversion of its structure. Addition of PPNOAc reveals an equilibrated generation of [Rh(COD)(OAc)].

Acetate exchange mechanism on a Zr oxo hydroxo cluster: relevance for reshaping Zr-carboxylate coordination adaptable networks.

The kinetics and mechanism of the acetate ligand exchange with free acetic acid in [ZrO(OH)(OCCH)], used as a molecular model of crosslink migration in [ZrO(OH)(carboxylate)(OH)]-based coordination adaptable networks with vitrimer-like properties, has been thoroughly investigated by dynamic H NMR and DFT calculations. The compound maintains its -symmetric Zr structure in CDCl and CD, while it splits into its Zr subunits in CDOD and DO. In the Zr structure, the topologically different acetates (3 chelating, 6 belt-bridging, 2 intercluster-bridging and 1 inner-face-bridging) of the Zr subunits behave differently in the presence of free CHCOOH: very fast exchange for the chelating (coalesced resonance at room temperature), slower exchange for the belt-bridging (line broadening upon warming), no observable exchange up to 65 °C (by EXSY NMR) for the intercluster- and inner-face-bridging.

Ir(η-diene) precatalyst activation by strong bases: formation of an anionic Ir tetrahydride.

The reaction between [IrCl(COD)] and dppe in a 1 : 2 ratio was investigated in detail under three different conditions. [IrCl(COD)(dppe)], 1, is formed at room temperature in the absence of base. In the presence of a strong base at room temperature, hydride complexes that retain the carbocyclic ligand in the coordination sphere are generated.

Catalyst-Free Thia-Michael Addition to α-Trifluoromethylacrylates for 3D Network Synthesis.

Thia-Michael additions (1,4-additions of a thiol to a Michael acceptor) are generally catalyzed by an external Brønsted or Lewis base. A spontaneous (uncatalyzed) Michael addition of thiols to α-trifluoromethyl acrylates is described, as well as its application to the very efficient preparation of a thermoset. A thorough mechanistic investigation, based on an experimental kinetic study and on DFT calculations, is presented for the addition of arene- and alkanethiols to tert-butyl trifluoromethyl acrylate in polar aprotic solvents, unveiling a probable solvent-assisted proton transfer in the rate-determining step and a considerable lowering of the energy barrier induced by the CF group.

Phosphine-Functionalized Core-Crosslinked Micelles and Nanogels with an Anionic Poly(styrenesulfonate) Shell: Synthesis, Rhodium(I) Coordination and Aqueous Biphasic Hydrogenation Catalysis.

Stable latexes containing unimolecular amphiphilic core-shell star-block polymers with a triphenylphosphine(TPP)-functionalized hydrophobic core and an outer hydrophilic shell based on anionic styrenesulfonate monomers have been synthesized in a convergent three-step strategy by reversible addition-fragmentation chain-transfer (RAFT) polymerization, loaded with [RhCl(COD)] and applied to the aqueous biphasic hydrogenation of styrene. When the outer shell contains sodium styrenesulfonate homopolymer blocks, treatment with a toluene solution of [RhCl(COD)] led to undesired polymer coagulation. Investigation of the interactions of [RhCl(COD)] and [RhCl(COD)(PPh)] with smaller structural models of the polymer shell functions, namely sodium -toluenesulfonate, sodium styrenesulfonate, and a poly(sodium styrenesulfonate) homopolymer in a biphasic toluene/water medium points to the presence of equilibrated Rh-sulfonate interactions as the cause of coagulation by inter-particle cross-linking.

Coordination Adaptable Networks: Zirconium(IV) Carboxylates.

Vitrimers are 3D "covalent adaptable networks" (CANs) with flow properties thanks to thermally activated associative exchange reactions. This contribution introduces coordination adaptable networks, or CooANs, that are topologically related to metal-organic frameworks with octahedral Zr clusters as secondary building units in a carboxylic acid-functionalized acrylate-methacrylate copolymer matrix. A series of Zr-CooAN-x materials (x=percent of Zr loading relative to maximum capacity) was synthesized with x=5, 10, 15, 20, 25, 50 and 100.

Synthesis and crystal structure of [( )-(2-phenyl-ferrocen-yl)meth-yl]tri-methyl-ammonium iodide di-chloro-methane monosolvate.

As a follow-up to our research on the chemistry of disubstituted ferrocene derivatives, the synthesis and the structure of the title compound, [Fe(CH)(CHN)]I·CHCl, is described. The cation mol-ecule is built up from a ferrocene disubstituted by a tri-methyl-ammonium methyl group and a phenyl ring. The asymmetric unit contains the iodide to equilibrate the charge and a disordered di-chloro-methane solvate.

Synthesis and crystallographic studies of 2-(di-phenyl-phosphino-thio-yl)-2-(3-oxobut-1-en-yl)ferrocene.

As a follow-up to our research on the chemistry of disubstituted ferrocene derivatives, the synthesis and the structure of the title compound, 2-(di-phenyl-phosphino-thio-yl)-2-(3-oxobut-1-en-yl)ferrocene, [Fe(CH)(CHOPS)], are described. The mol-ecule is built up from a ferrocene unit disubstituted by an S-protected di-phenyl-phosphine group and by a methyl-vinyl-ketone chain. The crystal structure features weak C-H⋯O and C-H⋯S inter-actions, which build a two-dimensional network.

Rhodium nanoparticles inside well-defined unimolecular amphiphilic polymeric nanoreactors: synthesis and biphasic hydrogenation catalysis.

Rhodium nanoparticles (Rh NPs) embedded in different amphiphilic core-crosslinked micelle (CCM) latexes (RhNP@CCM) have been synthesized by [RhCl(COD)(TPP@CCM)] reduction with H (TPP@CCM = core-anchored triphenylphosphine). The reduction rate depends on temperature, on the presence of base (NEt) and on the P/Rh ratio. For CCMs with outer shells made of neutral P(MAA--PEOMA) copolymer chains (RhNP@CCM-N), the core-generated Rh NPs tend to migrate toward the hydrophilic shell and to agglomerate depending on the P/Rh ratio and core TPP density, whereas the MAA protonation state has a negligible effect.

Triphenylphosphine-Functionalized Core-Cross-Linked Micelles and Nanogels with a Polycationic Outer Shell: Synthesis and Application in Rhodium-Catalyzed Biphasic Hydrogenations.

Unimolecular amphiphilic nanoreactors with a poly(4-vinyl-N-methylpyridinium iodide) (P4VPMe I ) polycationic outer shell and two different architectures (core-cross-linked micelles, CCM, and nanogels, NG), with narrow size distributions around 130-150 nm in diameter, were synthesized by RAFT polymerization from an R -4VPMe I -b-S -SC(S)SPr macroRAFT agent by either chain extension with a long (300 monomer units) hydrophobic polystyrene-based block followed by cross-linking with diethylene glycol dimethacrylate (DEGDMA) for the CCM particles, or by simultaneous chain extension and cross-linking for the NG particles. A core-anchored triphenylphosphine (TPP) ligand functionality was introduced by using 4-diphenylphosphinostyrene (DPPS) as a comonomer (5-20 % mol mol ) in the chain extension (for CCM) or chain extension/cross-linking (for NG) step. The products were directly obtained as stable colloidal dispersions in water (latexes).

Erratum: -{[2-(Diphenyl-thio-phosphor-yl)ferrocen-yl]meth-yl}dimethyl-ammonium diphenyl-dithio-phosphinate. Corrigendum.

[This corrects the article DOI: 10.1107/S1600536812009129.].

A new P,S-coordinating ferrocenyl ligand: synthesis of a precursor and its coordination compounds with Pd and Pt. Corrigendum.

In the paper by Mouas Toma et al. [Acta Cryst. (2014), C70, 460-464], there was an error in the name of the first author.

Synthesis of Nixantphos Core-Functionalized Amphiphilic Nanoreactors and Application to Rhodium-Catalyzed Aqueous Biphasic 1-Octene Hydroformylation.

A latex of amphiphilic star polymer particles, functionalized in the hydrophobic core with nixantphos and containing P(MAA-co-PEOMA) linear chains in the hydrophilic shell (nixantphos-functionalized core-crosslinked micelles, or nixantphos@CCM), has been prepared in a one-pot three-step convergent synthesis using reversible addition-fragmentation chain transfer (RAFT) polymerization in water. The synthesis involves polymerization-induced self-assembly (PISA) in the second step and chain crosslinking with di(ethylene glycol) dimethacrylate (DEGDMA) in the final step. The core consists of a functionalized polystyrene, obtained by incorporation of a new nixantphos-functionalized styrene monomer (nixantphos-styrene), which is limited to 1 mol%.

Synthesis, characterization and antiparasitic activity of organometallic derivatives of the anthelmintic drug albendazole.

Helminthiases, a group of neglected tropical diseases, affect more than one billion people mainly in tropical and subtropical regions. Moreover, major intestinal protozoa have a significant impact on global public health. Albendazole (ABZ) is a broad-spectrum anthelmintic recommended by the World Health Organisation (WHO).

Ferrocenyl Phosphorhydrazone Dendrimers Synthesis, and Electrochemical and Catalytic Properties.

The discovery of ferrocene is often associated with the rapid growth of organometallic chemistry. Dendrimers are highly branched macromolecules that can be functionalized at will at all levels of their structure. The functionalization of dendrimers with ferrocene derivatives can be carried out easily as terminal functions on the surface, but also at the core, or at one or several layers inside the structure.

Synthesis of -Alkyl Phosphinocarbodithioates with Switch between P(III) and P(V) Derivatives.

Simple and effective synthetic pathways are described to prepare compounds RP(X)C(S)SCH(Me)Ph with the P atom either in the oxidation state V [R/X = Bu/O (), Ph/S, (), Bu/S (), Bu/Se ()] or III [R/X = Ph/BH (), Bu/BH (), Bu/lone pair ()]. Compound is the first example of carbodithioate ester with a P = Se group, and for the first time, a phosphinocarboditioate with a free phosphine function (compound ) is described. Stabilization of the latter crucially depends on the steric protection by the Bu groups since an analogous derivative with R = Ph is observable but too unstable for isolation.

α-Alkylation of Ketones with Secondary Alcohols Catalyzed by Well-Defined Cp*Co -Complexes.

Although α-alkylation of ketones with primary alcohols by transition-metal catalysis is well-known, the same process with secondary alcohols is arduous and complicated by self-condensation. Herein a well-defined, high-valence cobalt(III)-catalyst was applied for successful α-alkylation of ketones with secondary alcohols. A wide-variety of secondary alcohols, which include cyclic, acyclic, symmetrical, and unsymmetrical compounds, was employed as alkylating agents to produce β-alkyl aryl ketones.

Rhodium nanoparticles stabilized by ferrocenyl-phosphine ligands: synthesis and catalytic styrene hydrogenation.

A series of ferrocenylphosphine-stabilized rhodium nanoparticles has been prepared in one pot from the organometallic [Rh(η3-C3H5)3] precursor. This complex has been decomposed by hydrogen treatment (3 bar) in dichloromethane in the presence of five different ferrocene-based phosphine ligands. Very small rhodium nanoparticles in the size range of 1.

The crystal structure of a new ferrocenyl P,N ligand: 1-[(2,2-di-methyl-hydrazin-1-yl-idene)meth-yl]-1'-(di-phenyl-phospho-rothio-yl)ferrocene.

The asymmetric unit of the title compound, [Fe(CHN)(CHPS)], contains two independent mol-ecules ( and ) with very similar conformations. Each mol-ecule is built up from a ferrocene unit substituted in the 1 and 1' positions by a protected sulfur di-phenyl-phosphine and by a di-methyl-hydrazine, -C(H)=N-N(CH), fragment. The two independent mol-ecules are linked by a C-H⋯N hydrogen bond.

Synthesis of an Enantiomerically Pure Inherently Chiral Calix[4]Arene Phosphonic Acid and Its Evaluation as an Organocatalyst.

A facile method for the preparation of enantiomerically pure inherently chiral calix[4]arene phosphonic acid (cR,pR)-7 in four steps starting from the readily available and previously synthesized (cS)-enantiomer of calix[4]arene acetic acid 1 or its methyl ester 2 was developed. The first tests of this unique calixarene Brönsted acid with inherent chirality in organocatalysis of the aza-Diels-Alder reaction of imines with Danishefsky's diene and epoxide ring opening by benzoic acid were performed. The calixarene phosphonic acid (cR,pR)-7 shows good catalytic activities but with low enantioselectivities in these reactions.

Selective synthesis of (3-ferrocenylprop-2-en-1-yl)triphenylphosphonium iodide: crystal structure determination of two polymorphs.

This work is part of a project studying the reactivity of a new ferrocenyl allylammonium salt, [3-(trimethylazaniumyl)prop-1-en-1-yl]ferrocene iodide, (1)·I, with different nucleophiles. With nitrogen-based nucleophiles, different ferrocenyl allylamine isomers have been synthesized successfully in good yield. Optimization of the basicity of the reaction medium has allowed selection of the best operating conditions to obtain the targeted isomer.

Coordination Chemistry Inside Polymeric Nanoreactors: Interparticle Metal Exchange and Ionic Compound Vectorization in Phosphine-Functionalized Amphiphilic Polymer Latexes.

Stable latexes of hierarchically organized core-cross-linked polymer micelles that are functionalized at the core with triphenylphosphine (TPP@CCM) have been investigated by NMR spectroscopic analysis at both natural (ca. pH 5) and strongly basic (pH 13.6) pH values after core swelling with toluene.

Coordination Chemistry inside Polymeric Nanoreactors: Metal Migration and Cross-Exchange in Amphiphilic Core-Shell Polymer Latexes.

A well-defined amphiphilic core-shell polymer functionalized with bis(-methoxy-phenylphosphino)phenylphosphine (BMOPPP) in the nanogel (NG) core has been obtained by a convergent RAFT polymerization in emulsion. This BMOPPP@NG and the previously-reported TPP@NG (TPP = triphenylphosphine) and core cross-linked micelles (L@CCM; L = TPP, BMOPPP) having a slightly different architecture were loaded with [Rh(acac)(CO)₂] or [RhCl(COD)]₂ to yield [Rh(acac)(CO)(L@Pol)] or [RhCl(COD)(L@Pol)] (Pol = CCM, NG). The interparticle metal migration from [Rh(acac)(CO)(TPP@NG)] to TPP@NG is fast at natural pH and much slower at high pH, the rate not depending significantly on the polymer architecture (CCM NG).