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Organofluorine compounds are widely used in all aspects of the chemical industry. Although tetrafluoroethylene (TFE) is an example of an economical bulk organofluorine feedstock, the use of TFE is mostly limited to the production of poly(tetrafluoroethylene) and copolymers with other alkenes. Furthermore, no catalytic transformation of TFE that involves carbon-fluorine bond activation has been reported to date. We herein report the first example of a palladium-catalyzed coupling reaction of TFE with arylzinc reagents in the presence of lithium iodide, giving α,β,β-trifluorostyrene derivatives in excellent yields.

The large interest on a bio-based economy has stimulated a fast growing R&D on the 2nd generation processes for converting lignocellulosic biomass, but it is still often difficult to have a comprehensive picture of the different possibilities and routes, and especially of the critical factors for selecting one route over the competing ones. This perspective review analyses these aspects, with focus on the identification of the critical elements for the evaluation of the different routes, providing at the same time an update on the main trends and tendencies in R&D in this field. The focus is on the catalytic transformation of lignocellulosic materials. After a short introduction, two main aspects are discussed: (i) the socio-political context and the eco-impact of biofuels, and (ii) how to utilize the biomass in a sustainable perspective. The final part of the review uses the concepts developed in the first part to discuss a new vision for converting lignocellulosic raw materials in an integrated chemo-catalytic biorefinery. Aspects highlighted regards in particular the problem of depolimerization/hydrolysis of cellulose and the different possibilities to convert the products formed (sugars and furfurals) to biofuels and chemicals.

A comparison of the cation-like complex CpCp*HfH(μ-H)B(C6F5)3 with the neutral analogue CpCp*HfHCl reveals increased activity toward σ-bond metathesis for the more electrophilic, cationic complex. A catalytic transformation of PhSiH3 to Ph2SiH2 and SiH4 by CpCp*HfH(μ-H)B(C6F5)3 appears to occur by σ-bond metathesis of the Si−C bond, which occurs concurrently with dehydropolymerization to highly cross-linked polysilanes.

The unusual results of the present authors' research work obtained for the last 3 years in the field of synthesis and transformation of organomagnesium compounds with metal complex catalysts are considered in this review. Special attention has been paid to catalytic cyclometallation of linear and cyclic olefins with n-RZMg, synthesis of alkenyl organomagnesium compounds from a-olefins and RZMg, and catalytic transformation of cyclopentanes in the presence of Cp 2 ZrCl 2 . The reaction mechanism implying the formation of zircona-cyclopentane complexes as intermediate species are discussed.

The C−H bond activation in homogeneous catalysis is important for carbon skeleton construction through C−C bond formation. In this report, a new direct synthesis of ketimine from aldimine bearing no coordination site is demonstrated with high catalytic efficiency. Transimination is the major role for this catalytic reaction.

Various alkyl and aryl mono- and disubstituted 3,6-dihydro-1,2-dithiins have been synthesised from their corresponding vinylthiiranes exploiting Adams' tungsten pentacarbonyl monoacetonitrile catalytic transformation. New conclusions pertaining to the rate determining step, the sensitivity of the process to precursor sterics and electronics, and the nature of various reaction intermediates are highlighted.

Aliphatic olefins were directly converted into α-hydroxy ketones with acidic aqueous hydrogen peroxide in the presence of catalytic amount of peroxotungstophosphate (PCWP) under the biphasic system using chloroform as a solvent. The acidic medium was necessary to open the resulting epoxide to vic-diol which was subsequently oxidized to α-hydroxy ketones.

This report reviews our recent studies of the catalytic transformations of thiiranes and vinylthiiranes by tungsten pentacarbonyl complexes. Whereas the thiranes yield only macrocyclic polydisulfides, the latter reactions yield only the cyclic monodisulfides known as 3,6-dihydro-1,2-dithiins.

We report iridium-catalyzed coupling of 2-alkynes such as 1-aryl-1-propynes with primary alcohols leading to secondary homoallylic alcohols as products. This reaction involves an iridium-catalyzed novel catalytic transformation of 2-alkynes and primary alcohols through the formation of hydrido(π-allyl)iridium as a possible key intermediate.

We report iridium-catalyzed coupling of 2-alkynes such as 1-aryl-1-propynes with primary alcohols leading to secondary homoallylic alcohols as products. This reaction involves an iridium-catalyzed novel catalytic transformation of 2-alkynes and primary alcohols through the formation of hydrido(pi-allyl)iridium as a possible key intermediate.

Nowadays demand for selective, energy-efficient, and sustainable chemical transformations has spurred an increasing interest in the development of “sustainable metal catalysis”. This expression defines a type of catalytic transformation in which non-toxic, readily available and inexpensive, stable metal complexes are used for catalysis. The increasing prices for energy and noble metals, which are commonly used for catalysis, represent an economical and ecological dilemma. If the price for a catalyst exceeds the savings on the energy side an industrial application does not make sense. As a consequence of this dilemma, chemists are looking for exit strategies with catalysis by small organic molecules (organocatalysis) or by inexpensive, readily available metal complexes (sustainable metal catalysis) being the most prominent ones. It is an irony that these two major catalytic strategies are based on research that had been initiated several decades ago but was somehow forgotten. In the present Microreview, the story of the reincarnation of another forgotten metal complex species, that celebrates its 50th birthday this year, will be told, the [Fe(CO)3(NO)]– anion. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

The C−H bond activation in homogeneous catalysis is important for carbon skeleton construction through C−C bond formation. In this report, a new direct synthesis of ketimine from aldimine bearing no coordination site is demonstrated with high catalytic efficiency. Transimination is the major role for this catalytic reaction.

A novel organocatalytic highly enantioselective nitrocyclopropanation reaction of α,β-unsaturated aldehydes is presented. The 1-nitro-2-formylcyclopropane derivatives synthesized from this catalytic transformation were converted to the corresponding β-nitromethyl-acid esters, which are excellent precursors of GABA analogues such as Baclofen, by subsequent organocatalytic chemoselective ring-opening.

A simple, highly enantioselective organocatalytic aminosulfenylation of ?,?-unsaturated aldehydes affords orthogonally protected ?-amino-?-mercaptoaldehydes in high yields and 93 to >99?%?ee (see scheme, Bn=benzyl). Notably, the catalytic transformation shows that it is possible to efficiently employ all components of an electrophile, which includes a nucleofuge, in organocatalytic domino reactions of enals.

In this contribution, we describe polymer-supported (R,R)-(salen)AlCl complexes that were immobilized on poly(norbornene)s and display excellent activities and enantioselectivies as catalysts for the 1,4-conjugate addition of cyanide to α,β-unsaturated imides. These supported catalysts could be recycled up to 5 times without compromising catalyst activities or selectivities. Furthermore, the catalyst loadings could be reduced from 10–15 mol%, the common catalyst loadings for non-supported (salen)Al catalysts, to 5 mol%, a decrease of metal content by 50–66%, without lowering product yields or enantioselectivities. Kinetic studies indicated that the polymer-supported catalysts are significantly more active than their corresponding unsupported analogues, which makes this catalyst system key to a successful implementation of this catalytic transformation into the fine chemical and pharmaceutical industries.

Volatile organic compounds, especially formaldehyde (HCHO), are considered to be great sources of contaminants in indoor air. However, design and preparation of safe, cost-affordable, and reusable materials for HCHO removal at ambient conditions are still remarkably challenging. Here, we have developed a kind of novel NaOH-embedded three-dimensional porous boron nitride (NaOH-3D BN) with high and hierarchical porosities, which exhibit excellent removal performance for HCHO. The as-prepared 3D BN is used as an adsorbent and catalytic support, while the embedded NaOH is applied as a catalyst, giving rise to catalytic transformation from high-toxic HCHO to less-toxic formate and methoxy salts at room temperature. Furthermore, their effective reusability has been confirmed. Given the high removal and reusability performance as well as no use of precious materials, the NaOH-3D BN is envisaged to be valuable practically for indoor air purification.

Mg(OH) 2 .4MgCO 3 .4H 2 O were used to neutralize the acidic sites on the external surfaces of zeolite HZSM-5 using a method of solid-state reaction (SSR) in this paper, and the modified samples were characterized by XRD, adsorption experiments, IR, catalytic decomposition of isopropanol, as well as catalytic transformation of aromatics. XRD, adsorption and IR results suggested that the modifying reagent was decomposed into MgO at a calcination temperature of 773K, and was mainly located on the outside of zeolite. The acidic sites on the external surfaces of HZSM-5 zeolite were well neutralized by this method with a loading amount of 0.5%(MgO), while the acidic sites in channel were almost unchanged.

The article is dedicated to the needs of the development chemist who wants to incorporate an asymmetric catalytic transformation in the synthesis of an API. The following issues and questions are addressed: The importance of enantioselective hydrogenation; what makes a successful hydrogenation catalyst; screening strategies during feasibility studies; where to get a reliable supply of chiral ligands for development and production; and finally the advantage of choosing a partner who also provides metal precursors as well as metal recovery and refining services.

The reaction of terminal alkynes with hydrazines in the presence of TpRuCl(PPh3)2 (Tp = tris(pyrazolyl)borate) as a catalyst gave nitriles. This reaction involves the intermolecular attack of nitro...

Using the catalytic transformation of isobutyl benzoate at 663 K in the presence of 12 % MnO2/γ-Al2O3 in a He atmosphere as an example, it has been shown that the inverse Tishchenko reaction can take place at a temperature above 600 K. Isobutyl benzoate gives isobutanal and benzaldehyde as well as products of their transformation,i.e., benzyl isobutyrate, isobutanol, benzyl alcohol, and toluene.

The microenvironment of immobilized transition metal catalysts can be manipulated using catalyst–substrate conjugates in combination with the technology of molecular imprinting. Recent results have shown that catalysts with a significantly enhanced activity combined with an improved substrate-, regio- and enantioselectivity can be prepared in this way. These artificial systems resemble metalloenzymes because the catalytic transformation is effectively controlled by a well-defined second coordination sphere.

(PhIO) [536-80-1] C6H5IO (MW 220.01) InChI = 1S/C6H5IO/c8-7-6-4-2-1-3-5-6/h1-5H InChIKey = JYJVVHFRSFVEJM-UHFFFAOYSA-N (RuCl2(Ph3P)3 [15529-49-4] C54H45Cl2P3Ru (MW 958.87) InChI = 1S/3C18H15P.2ClH.Ru/c3*1-4-10-16(11-5-1)19(17-12-6-2-7-13-17)18-14-8-3-9-15-18;;;/h3*1-15H;2*1H;/q;;;;;+2/p-2 InChIKey = WIWBLJMBLGWSIN-UHFFFAOYSA-L (mild oxidant for selective catalytic transformation of alkynes and several functional groups) Physical Data: see Iodosylbenzene and Dichlorotris(triphenylphosphine)ruthenium(II)1a.

The microenvironment of immobilized transition metal catalysts can be manipulated using catalyst–substrate conjugates in combination with the technology of molecular imprinting. Recent results have shown that catalysts with a significantly enhanced activity combined with an improved substrate-, regio- and enantioselectivity can be prepared in this way. These artificial systems resemble metalloenzymes because the catalytic transformation is effectively controlled by a well-defined second coordination sphere.

This report reviews our recent studies of the catalytic transformations of thiiranes and vinylthiiranes by tungsten pentacarbonyl complexes. Whereas the thiranes yield only macrocyclic polydisulfides, the latter reactions yield only the cyclic monodisulfides known as 3,6-dihydro-1,2-dithiins.

The catalytic transformation of inert C-H bonds to other functional groups is one of the most active research areas in organic and organometallic chemistry because such reactions present possibilities to exploit readily available starting materials, shorten reaction sequences, and synthesize compounds that are otherwise difficult to prepare. In this review, recent advances in the catalytic functionalization of unactivated sp3 C-H bonds are briefly introduced. The sp3 C-H bonds were transformed to C-C and C-O bonds through activation with transition metal catalysts assisted by chelation of directing groups or a cyclometalation process.

Using principles of completive and integrative self-sorting, a clean supramolecule-to-supramolecule transformation is realised that involves fusion of a 3-component rectangle and a 2-component equilateral triangle into a 5-component scalene triangle. While the spontaneous process takes 15 h at 25 °C, the catalytic transformation is completed within 1 h.

Ionic liquids (ILs), a kind of novel green medium composed entirely of cations and anions, have attracted considerable attention due to their unique properties such as non-volatility, tunable polarity, high stability and so on. In this article, the latest progress on the absorption and subsequent conversion of CO2 by using ILs as absorbents, catalysts or promoters will be summarized. The chemical absorption performance of ILs, especially task-specific ionic liquids (TSILs) such as amino-functionalized ILs, superbase-derived protic ILs has been systematically illustrated. Although significant advances have been made, extensive energy input in the desorption process to recover absorbents would still be a crucial barrier to realizing practical carbon capture and sequestration (CCS). On the other hand, efficient applications of CO2 in the synthesis of valuable compounds such as organic carbonates, urea derivatives, oxazolidinones and formic acid can also be promoted by employing TSILs as catalysts/reaction media. We anticipate that an integration of chemical capture of CO2 with its utilization, a so-called CO2 capture and utilization (CCU) protocol would be an ideal strategy to solve the energy penalty problem in common CCS without the need for additional heat desorption. The essence of this CCU concept is to use TSILs for CO2 capture and substantial activation, which could allow catalytic transformation of CO2 to be accomplished smoothly under low pressure (ideally at 1 atm).

Aliphatic olefins were directly converted into α-hydroxy ketones with acidic aqueous hydrogen peroxide in the presence of catalytic amount of peroxotungstophosphate (PCWP) under the biphasic system using chloroform as a solvent. The acidic medium was necessary to open the resulting epoxide to vic-diol which was subsequently oxidized to α-hydroxy ketones.

Secondary benzylic and allylic diazoacetates undergo dirhodium(II)-catalysed diazo decomposition to form, competitively or exclusively, ketone and vinylidene products from intramolecular hydride abstraction in catalyst ligand-dependent molar ratios.

The catalytic transformation of camphene over AlPO4-5, AlPO4-11, SAPO-5, SAPO-11, VAPO-5, VAPO-11, CoAPO-5, CoAPO-11, NAPO-5, NAPO-11, ZAPO-5 and ZAPO-11 in the vapour phase has been studied. The products formed are tricyclene, bornylene and monocyclic terpenes. The product distribution is influenced by both acidity and inverse weight hourly space velocity (WHSV)–1. Selective formation of tricyclene is envisaged over weak acid sites and with lower (WHSV)–1, while the monocylics like dipentene, terpinolene, α- and τ-terpinenes, p-menthene and p-cymene are formed over strong acid sites. The effect of temperature on conversion and product distribution, and the effect of acidity and (WHSV)–1 on the distribution of monocyclics have also been investigated.

Kinetic problems of catalyst deactivation and regeneration have been discussed for dehydrogenation of isopentenes and higher alkanes and catalytic transformation of 5-methyl furfurol. Common kinetic models have been obtained for each process in both stationary and nonstationary regions with stability function being introduced into these models to describe deactivation.

Nitrosobenzene is converted into azoxybenzene in alcoholic media in the presence of Ru(CO)3(PPh3)2 as catalyst and under an inert atmosphere; Fe(CO)3(PPh3)2 and palladium complexes such as PdL2Cl2 (L  PhNO, p-MeC6H4NH2, PPh3) and Pd3(CO)3(PPh3)4, are less active as catalysts. Under CO pressure and with Ru(CO)3(PPh3)2 as catalyst, nitrosobenzene is converted into azobenzene and aniline, while azoxybenzene gives azobenzene.

The kinetics of the catalytic transformation of cumyl and tert. -butyl hydro-peroxides under gas chromatographic column conditions has been studied. Amphoteric and acidic metal oxides were used as the catalysts. The rate constants of the reactions and half-lives of the hydroperoxides studied have been calculated. The catalysts used can be arranged in order of decreasing catalytic activity: V 2 O 5 > Co 2 O 3 > Fe 2 O 3 > Al 2 O 3 , ZnO. The kinetic curves for the hydroperoxide consumption and the accumulation of the main products of their catalytic decomposition have been obtained.

To elucidate the possible natural evolutionary pathways for the transformation of pentacyclic triterpenoids, three terpenoid samples, Δ 2 -allobetulene, tetranormethylallobetulheptaene and fernenes were heated independently at 150°C for 7 weeks with montmorillonite clay. Common products from these reactions consisted of di, tri-, tetra-, and pentacyclic hydroaromatic and aromatic hydrocarbons, which are commonly found in higher rank coals. C-ring cleaved (8,14-seco) aromatic terpenoid derivatives were also found in the thermal catalytic reaction products of Δ 2 -allobetulene. Such compounds could be important intermediates in the formation of bicyclic hydrocarbons from pentacyclic triterpenoids.

1. The heterogeneous catalytic transformations of hexadecane were investigated at 450° in presence of hydrogen at 30 atm over gumbrin (natural and activated) and over gumbrin containing 20% ZnCl2 (at 400°as well as at 450°). 2. In presence of natural and activated gumbrins the conversion of the hexadecane was 58%, but in presence of activated gumbrin containing 20% ZnCl2 it attained 80%. 3. In this treatment of hexadecane the main reaction was hydrocracking with partial isomerization of the hydrocracking products. This was accompanied by some dehydrocyclization with formation of high-boiling aromatic hydrocarbons.

1. The isomerization of n-octadecane was studied in the presence of two industrial, freshly sulfurized catalysts, WS2 and WS2 + aluminosilicates.

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