Ionic Liquids: Media for Better Molecular Catalysis

Ionic liquids (ILs) are more and more suggested as substitutes for traditional solvents in organic synthesis and catalysis. They are suitable candidates for the dissolution of ionic complexes. They can activate and retain them in a polar state: in fact, they act as sequestrands, opening the route to two-phase processes and easier catalyst recovery. This paper reviews authors' results with the development of new syntheses of ILs and applications in carbon–carbon bond formation (dimerisation of methyl acrylate) and redistribution (ring closing metathesis) reactions using ionic precatalysts.

3D Ruthenium Nanoparticle Covalent Assemblies from Polymantane Ligands for Confined Catalysis

International audience; The synthesis of metal nanoparticle (NP) assemblies stabilized by functional molecules is an important research topic in nanoscience, and the ability to control interparticle distances and positions in NP assemblies is one of the major challenges in designing and understanding functional nanostructures. Here, two series of functionalized adamantanes, bis-adamantanes, and diamantanes, bearing carboxylic acid or amine functional groups, were used as building blocks to produce, via a straightforward method, networks of ruthenium NPs. Both the nature of the ligand and the Ru/ligand ratio affect the interparticle distance in the assemblies. The use of 1,3-adamantanedicarb…

Defying Stereotypes with Nanodiamonds: Stable Primary Diamondoid Phosphines

International audience; Direct unequal C-H bond difunctionalization of phosphorylated diamantane was achieved in high yield from the corresponding phosphonates. Reduction of the functionalized phosphonates provides access to novel primary and secondary alkyl/aryl diamantane phosphines. The prepared primary diamantyl phosphines are quite air stable compared to their adamantyl and especially alkyl or aryl analogues. This finding is corroborated by comparing the singly occupied molecular orbital energy levels of the corresponding phosphine radical cations obtained by density functional theory computations.

Nanodiamond‐Palladium Core–Shell Organohybrid Synthesis: A Mild Vapor‐Phase Procedure Enabling Nanolayering Metal onto Functionalized sp 3 ‐Carbon

Diamondoid Nanostructures as sp 3 ‐Carbon‐Based Gas Sensors

Diamondoids, sp3 -hybridized nanometer-sized diamond-like hydrocarbons (nanodiamonds), difunctionalized with hydroxy and primary phosphine oxide groups, enable the assembly of the first sp3 -C-based chemical sensors by vapor deposition. Both pristine nanodiamonds and palladium nanolayered composites can be used to detect toxic NO2 and NH3 gases. This carbon-based gas sensor technology allows reversible NO2 detection down to 50 ppb and NH3 detection at 25-100 ppm concentration with fast response and recovery processes at 100 °C. Reversible gas adsorption and detection is compatible with 50 % humidity conditions. Semiconducting p-type sensing properties are achieved from devices based on prim…

Nanodiamonds: Emergence of Functionalized Diamondoids and Their Unique Applications

Selective Preparation of Diamondoid Phosphonates

We present an effective sequence for the preparation of phosphonic acid derivatives of the diamondoids diamantane, triamantane, [121]tetramantane, and [1(2,3)4]pentamantane. The reactions of the corresponding diamondoid hydroxy derivatives with PCl3 in sulfuric or trifluoroacetic acid give mono- as well as didichlorophosphorylated diamondoids in high preparative yields.

C,N-chelated dicyclopentadienylzirconium complexes and their possible use as hydrogenation catalysts

Abstract In situ generated Cp2Zr(n-Bu)Cl (6) reacts with {2-[(CH3)2NCH2]C6H4}2Pb to form exclusively {2-[(CH3)2NCH2]C6H4}Cp2ZrCl (7), [(CH3)2NCH2]C6H5, butene and elemental lead. The further derivatization of chloride (7) to fluoride (8), hydride (9), methyl derivative (10), and a reduction of 7 are also described. The crystal structures of 7–10 were determined. The catalytic activity of 9 and 10 in hydrogenation of styrene was also preliminarily tested.

The functionalization of nanodiamonds (diamondoids) as a key parameter of their easily controlled self-assembly in micro- and nanocrystals from the vapor phase.

We detail herein readily accessible processes to control previously unobserved robust self-assemblies of nanodiamonds (diamondoids) in micro- and nanocrystals from their mild vapor deposition. The chemical functionalization of uniform and discernible nanodiamonds was found to be a key parameter, and depending on the type of functional group (hydroxy, fluorine, etc.) and its position on the diamondoid, the structure of the discrete deposits can vary dramatically. Thus, well-defined anisotropic structures such as rod, needle, triangle or truncated octahedron shapes can be obtained, and self-assembled edifices of sizes ranging from 20 nm to several hundred micrometers formed with conservation …

Palladium‐Catalyzed C2−H Arylation of Unprotected (N−H)‐Indoles “On Water” Using Primary Diamantyl Phosphine Oxides as a Class of Primary Phosphine Oxide Ligands

The Hydrogen‐Storage Challenge: Nanoparticles for Metal‐Catalyzed Ammonia Borane Dehydrogenation

International audience; Dihydrogen is one of the sustainable energy vectors envisioned for the future. However, the rapidly reversible and secure storage of large quantities of hydrogen is still a technological and scientific challenge. In this context, this review proposes a recent state-of-the-art on H 2 production capacities from the dehydrogenation reaction of ammonia borane (and selected related amine-boranes) as a safer solid-source of H 2 by hydrolysis (or solvolysis), according to the different developed nanoparticle-based catalysts. The review groups the results according to the transition metals constituting the catalyst according a special view to current cost/availability consid…

Hydrogen: a good partner for rhodium-catalyzed hydrosilylation

The influence of hydrogen pressure on the hydrosilylation of ketones catalyzed by [((S)-SYNPHOS)Rh(nbd)]OTf has been studied. We have notably demonstrated that hydrogen significantly affected the outcome of the reaction while not being consumed as stoichiometric reducing agent. In THF, diethyl ether or toluene, the hydrogen pressure exceedingly accelerated the hydrosilylation reaction and preserved or even improved the enantioselectivity of the process. In CH2Cl2, the rhodium catalyst also showed generally higher catalytic activity under hydrogen pressure. Most serendipitously, several ketones were found to give products of absolute opposite configuration upon performing the hydrosilylation…

The role of distannoxanes in the synthesis of dimethyl carbonate from carbon dioxide

Abstract The synthesis, characterization, and reactivity of 1,3-dimethoxytetrabutyldistannoxane were investigated in connection to the mechanism of the selective synthesis of dimethyl carbonate from CO2 and methanol. A new distannoxane, 1-methoxy-3-methylcarbonatotetrabutyldistannoxane, resulting from a 1:1 adduct with CO2 was isolated and characterised by volumetry, multinuclear NMR and IR spectroscopies. When this compound was submitted to 20 MPa of CO2 at 423 K in toluene no dimethyl carbonate was formed, conversely to dibutyldimethoxystannane. However, when methanol was the solvent, dimethyl carbonate was selectively produced. A promoting effect of Si(OCH3)4 was evidenced through methox…

Nanocatalysts for High Selectivity Enyne Cyclization: Oxidative Surface Reorganization of Gold Sub-2-nm Nanoparticle Networks

International audience; Ultrasmall gold nanoparticles (NPs) stabilized in networks by polymantane ligands (diamondoids) were successfully used as precatalysts for highly selective heterogeneous gold-catalyzed dimethyl allyl(propargyl)malonate cyclization to 5-membered conjugated diene. Such reaction usually suffers from selectivity issues with homogeneous catalysts. This control over selectivity further opened the way to one-pot cascade reaction, as illustrated by the 1,6-enyne cycloisomerization–Diels–Alder reaction of dimethyl allyl propargyl malonate with maleic anhydride. The ability to assemble nanoparticles with controllable sizes and shapes within networks concerns research in sensor…

Diamondoids: functionalization and subsequent applications of perfectly defined molecular cage hydrocarbons

The term “diamondoid” describes cage hydrocarbon molecules that are superimposable on the diamond lattice. Diamondoids that are formally built by face-fusing of adamantane units, namely diamantane, triamantane, tetramantane, etc., have fascinated chemists since the beginning of the last century. The functionalization of these perfectly defined (C,H)-molecules is described here. Thus, diamondoid halides and diamondoid alcohols are first rank precursors for amino and phosphine-substituted diamondoids that have proved to be highly useful in therapeutic applications and metal catalysis, respectively. The extent of functionalization and polyfunctionalization achieved for adamantane and diamantan…

CCDC 1054568: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Maria A. Gunawan, Didier Poinsot, Hélène Cattey, Jonathan Becker, Raisa I. Yurchenko, Ekaterina D. Butova, Heike Hausmann, Marina Šekutor, Andrey A. Fokin, Jean-Cyrille Hierso, Peter R. Schreiner|2016|J.Org.Chem.|81|8759|doi:10.1021/acs.joc.6b01219

CCDC 1875843: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Juan Casanova-Chafer, Didier Poinsot, Lukas Ochmann, Clève D. Mboyi, Houssein O. Nasrallah, Eduard Llobet, Imen Makni, Molka El Atrous, Stéphane Brandès, Yoann Rousselin, Bruno Domenichini, Nicolas Nuns, Andrey A. Fokin, Peter R. Schreiner, Jean-Cyrille Hierso|2019|Angew.Chem.,Int.Ed.|58|9933|doi:10.1002/anie.201903089

CCDC 1009244: Experimental Crystal Structure Determination

Related Article: Andrey A. Fokin, Raisa I. Yurchenko, Boryslav A. Tkachenko, Natalie A. Fokina, Maria A. Gunawan, Didier Poinsot, Jeremy E. P. Dahl , Robert M. K. Carlson , Michael Serafin , Hélène Cattey, Jean-Cyrille Hierso , and Peter R. Schreiner|2014|J.Org.Chem.|79|5369|doi:10.1021/jo500793m

CCDC 1009245: Experimental Crystal Structure Determination

Related Article: Andrey A. Fokin, Raisa I. Yurchenko, Boryslav A. Tkachenko, Natalie A. Fokina, Maria A. Gunawan, Didier Poinsot, Jeremy E. P. Dahl , Robert M. K. Carlson , Michael Serafin , Hélène Cattey, Jean-Cyrille Hierso , and Peter R. Schreiner|2014|J.Org.Chem.|79|5369|doi:10.1021/jo500793m

CCDC 1054567: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Maria A. Gunawan, Didier Poinsot, Hélène Cattey, Jonathan Becker, Raisa I. Yurchenko, Ekaterina D. Butova, Heike Hausmann, Marina Šekutor, Andrey A. Fokin, Jean-Cyrille Hierso, Peter R. Schreiner|2016|J.Org.Chem.|81|8759|doi:10.1021/acs.joc.6b01219

CCDC 1054565: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Maria A. Gunawan, Didier Poinsot, Hélène Cattey, Jonathan Becker, Raisa I. Yurchenko, Ekaterina D. Butova, Heike Hausmann, Marina Šekutor, Andrey A. Fokin, Jean-Cyrille Hierso, Peter R. Schreiner|2016|J.Org.Chem.|81|8759|doi:10.1021/acs.joc.6b01219

CCDC 1054566: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Maria A. Gunawan, Didier Poinsot, Hélène Cattey, Jonathan Becker, Raisa I. Yurchenko, Ekaterina D. Butova, Heike Hausmann, Marina Šekutor, Andrey A. Fokin, Jean-Cyrille Hierso, Peter R. Schreiner|2016|J.Org.Chem.|81|8759|doi:10.1021/acs.joc.6b01219

CCDC 1009243: Experimental Crystal Structure Determination

Related Article: Andrey A. Fokin, Raisa I. Yurchenko, Boryslav A. Tkachenko, Natalie A. Fokina, Maria A. Gunawan, Didier Poinsot, Jeremy E. P. Dahl , Robert M. K. Carlson , Michael Serafin , Hélène Cattey, Jean-Cyrille Hierso , and Peter R. Schreiner|2014|J.Org.Chem.|79|5369|doi:10.1021/jo500793m

CCDC 1054569: Experimental Crystal Structure Determination

Related Article: Oana Moncea, Maria A. Gunawan, Didier Poinsot, Hélène Cattey, Jonathan Becker, Raisa I. Yurchenko, Ekaterina D. Butova, Heike Hausmann, Marina Šekutor, Andrey A. Fokin, Jean-Cyrille Hierso, Peter R. Schreiner|2016|J.Org.Chem.|81|8759|doi:10.1021/acs.joc.6b01219