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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.

Data on the processes of catalytic transformation of olefins and dienes in ionic liquids as solvents are summarized. The role of these compounds in solving environmental problems is discussed from the viewpoint of green chemistry. Some industrial processes with participation of ionic liquids are considered.

Highly regioselective olefination of substituted N,N-dimethylbenzylamines was developed by tuning the acidity of reaction conditions based on analysis of their features. The ortho-functionalized N,N-dimethylbenzylamines were further transformed into 3-(2'-tolyl)propanoic acid and its derivatives under mild conditions. These two transformations could be combined into one pot, and 3-(2'-tolyl)propanoic acid and its derivatives were obtained in moderate to good yields. Mechanistic studies indicated that electrophilic attack on the phenyl ring by the Pd(II) ion assisted by the N,N-dimethylaminomethyl group was a key step during this catalytic transformation, which was controlled by the acidity of the reaction conditions.

SUMMARY Unsaturated fatty acid esters derived from seed oils undergo metathesis at the C=C bond to give new internal and terminal olefins of interest in chemical manufacturing. The key to realizing this industrial opportunity is the ability to deploy catalysts that tolerate functional groups and remain reactive towards internal olefins even at high conversions. Recent developments in catalyst and reactor design are bringing these targets closer to commercial reality.

This paper describes our recent progress in catalytic nitrogen fixation by using transition-metal–dinitrogen complexes as catalysts. Two reaction systems for the catalytic transformation of molecular dinitrogen into ammonia and its equivalent such as silylamine under ambient reaction conditions have been achieved by the molybdenum–, iron–, and cobalt–dinitrogen complexes as catalysts. Many new findings presented here may provide new access to the development of economical nitrogen fixation in place of the Haber–Bosch process.

Fluorination of styrene derivatives with a reagent system composed of μ-oxo-bis[trifluoroacetato(phenyl)iodine] and a pyridine·HF complex gave the corresponding (2,2-difluoroethyl)arenes in good yields. Similarly, the reagent of PhI(OCOCF3)2 and the pyridine·HF complex acted as a fluorinating agent for styrene derivatives. The fluorination of styrene derivatives with the pyridine·HF complex underwent under catalytic conditions using 4-iodotoluene as a catalyst and m-CPBA as a terminal oxidant.

A practical ruthenium-catalyzed O- to S-alkyl migration affords structurally diverse thiooxazolidinones in excellent yields. Our studies suggest this catalytic transformation proceeds through a pseudoreversible radical pathway drawing mechanistic parallels to the classic Barton-McCombie reaction. A radical step in a new direction: A practical ruthenium-catalyzed O- to S-alkyl migration affords structurally diverse thiooxazolidinones in excellent yields. Experimental and computational studies suggest a pseudoreversible radical pathway drawing mechanistic parallels to the classic Barton-McCombie reaction.

1,3-Butadiene is an important constituent of many products that we rely upon. It is currently prepared from non-sustainably derived sources. However, in the early part of the 20th Century the use of ethanol as a source of 1,3-butadiene has been reported. With the arrival of a cheap and bountiful supply of crude-oil derived sources the need for the sustainable route was deemed unnecessary. In recent years the conversion of ethanol to 1,3-butadiene has undergone somewhat of a mini resurgence as the chemical industry looks to try to find a sustainable and secure route to this important building block. This review will emphasise some of the most recent work in the field and look ahead to what needs to be achieved to make this research a reality.

A novel palladium-catalyzed intermolecular aminocarbonylation of alkenes has been developed in which the employment of hypervalent iodine reagent can accelerate the intermolecular aminopalladation, which thus provides the successful catalytic transformation. The current transformation presents one of the most convenient methods to generate β-amino acid derivatives from simple alkenes.

Mordenite (MOR) was synthesized using rice husk silica and modified by base (B), acid (A) or acid-base (AB) and converted to H-form. The modification did not destroy the MOR structure but increased surface area and generated mesopores. Lewis acidity of the parent and modified MOR samples investigated by aluminum NMR and NH3-TPD showed a decrease in the following order: HMOR > BMOR > ABMOR > AMOR. For the catalytic transformation of methylbutynol, ABMOR provided the highest conversion and selectivity of products from acid sites.

The synthesis and characterization of several new bicyclophosphites via reactions of (i) ethyl 1-thio-α- d -glucofuranoside 3,5,6-phosphite with acid chlorides (phthalic or butylphosphoric), (ii) ethyl 1-thio-α- d -glucofuranoside 3,5,6-phosphite with 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphorinane and (iii) the tetraol system of ethyl 1-thio-α- d -glucofuranoside and hexaethyltriamidophosphite are reported. Unusual catalytic transformation of P(III)-compounds into the respective P(V)-spieces under extraordinary mild conditions by reaction with sulfur and selenium in the presence of triethylamine was discovered for the first time.

Catalytic transformation of 2-tert-butylphenol (2TBP) on a heterogeneous K10 catalyst has been studied in the temperature range from +75 to –176°C under microwave and conventional conditions. The reaction was carried out with or without solvents and the kinetic results were described using the method of initial reaction rates. Reaction rates were recorded under microwave conditions and compared to conventional ones. Transformation of 2TBP did not proceed below 0°C under conventional conditions, whereas under microwave irradiation significant initial reaction rates were observed. Relatively high initial reaction rates at low temperatures were most probably caused by superheating of catalyst particles. The superheating temperature was calculated to be between 80 and 115°C above the temperature of the bulk.

Polysiloxane-encapsulated "Pd"-nanoclusters were generated by reduction of Pd(OAc)(2) with polymethylhydrosiloxane, which functions as a reducing agent as well as a capping material for production and stabilization of catalytically active "Pd"-nanoparticles. Chemoselective hydrogenation of functional conjugated alkenes was achieved by in-situ- or ex-situ-generated polysiloxane-stabilized "Pd"-nanoclusters under mild reaction conditions in high yields. Electron microscopy, UV-vis, and NMR studies of the reaction mixture during the catalytic transformation were performed and, in conjunction with catalyst poisoning experiments, demonstrated unequivocally the role of polysiloxane-encapsulated "Pd"-nanoclusters as the real catalytic species. The recyclability of the "Pd"-nanoclusters was established by reusing the solid left after the reaction.

2-(Diphenylphosphanyl)anilines (P∧NHR) eliminate methane upon reaction with [CoMe(PMe3)4] forming the complexes [Co(η2-P∧NR)(PMe3)3] (1: R = H; 2: R = Me) and [Co(η2-P∧NR)(PMe3)2] (3: R = Me). Reaction with HCl gives [CoCl(η1-P∧NHR)(PMe3)2] (4: R = H; 5: R = Me) and reaction with CO or olefin gives [Co(η2-P∧NR)(CO)(PMe3)2] (6: R = H; 7: R = Me) and [Co(η2-P∧NR)(olefin)(PMe3)2] (8: R = H, olefin = C2H4; 9: R = Me, olefin = C2H4; 10: R = Me, olefin = C3H6), respectively. No catalytic transformation of the olefins was observed. Oxidation by iodomethane yields a cobalt(II) compound [CoI(η2-P∧NR)(PMe3)2] (11: R = Me). By treating 2-(diphenylphosphanyl)aniline with [CoMe2(PMe3)3] a methylcobalt(II) complex [CoMe(η2-P∧NR)(PMe3)2] (12: R = H) is obtained, while an excess of the aniline produces [Co(η2-P∧NR)2] (13: R = H; 14: R = Me) or [Co(η2-P∧NR)2(PMe3)] (15: R = H; 16: R = Me). The methylcobalt(III) complexes mer-trans-[CoIMe2(η2-P∧NR)(PMe3)2] were obtained from LiP∧NR and [CoClMe2(PMe3)3]. Dynamic 31P NMR spectra and the structures of complexes 3, 6, 12, and 13 are discussed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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.

Organofluorine compounds have found widespread applications in the pharmaceutical and agrochemical industries. Efficient construction of organofluorine molecules is highly desirable. Catalytic transformation of C(sp3)–H bonds into C(sp3)–F bonds provides the simplest and most straightforward way to organofluorine compounds. This Highlight discusses the most recent findings in the field.

[(IMes)Fe(CO)4] [IMes=1,3-bis(2,4,6-trimethylphenyl) imidazol-2-ylidene] complex was found to be an efficient pre-catalyst for the hydroboration of functional alkenes in the presence of pinacolborane at room temperature. Notably, UV irradiation (350 nm) is important to promote this catalytic transformation. Interestingly, high chemo- and regioselectivities were observed as only anti-Markovnikov boronate derivatives were obtained and various functional groups can be tolerated.

A novel catalytic transformation is designed to prepare formamidine derivatives by reduction of substituted symmetrical and unsymmetrical ureas with hydrosilane.

International audience; [(IMes)Fe(CO)4] [IMes=1,3-bis(2,4,6-trimethylphenyl) imidazol-2-ylidene] complex was found to be an efficient pre-catalyst for the hydroboration of functional alkenes in the presence of pinacolborane at room temperature. Notably, UV irradiation (350 nm) is important to promote this catalytic transformation. Interestingly, high chemo- and regioselectivities were observed as only anti-Markovnikov boronate derivatives were obtained and various functional groups can be tolerated.

This method uses a N-heterocyclic olefin/carbon dioxide adduct as organocatalyst for the synthesis of dioxolane derivatives.

Aluminophosphate-based molecular sieves with the AFI topology were tested as catalysts for the transformation of camphene in gas phase. The presence of Zn in the solid improves the catalytic stability without affecting the selectivity towards tricyclene.

Results showed that the heterogeneous catalytic transformation of propyne to propadiene could be regarded as an apparently first order reaction running to equilibrium over solid base catalysts. However, fast oligomerization of reactants proved to be the main reaction pathway over acidic contacts. Different surface intermediates were identified on basic and acidic solid catalysts.

We report a synthetic strategy for construction of the first example of organocatalytic covalent organic frameworks via pore surface engineering. The COF catalyst combines a number of striking features, including enhanced activity, broad applicability, good recyclability, and high capability, to perform catalytic transformation under continuous flow conditions.

Coal pitch contains alkyl-substituted naphthalenes, as well as other aromatic compounds. To elucidate the possible transformations of the alkylation products of naphthalene, these products are treated in the presence of catalysts, and the basic compounds formed are analyzed on the basis of IR, NMR 1H, and chromatographic mass-spectrometric data.

A review of the large number of studies completed during the current decade on the chemistry of ruthenium and osmium vinylidene complexes is presented. Interest in these studies arises not only from the reactivity modes and structural properties, but also because vinylidene species play an important role in the selective catalytic transformation of terminal alkynes (polymerization, CC bond formation in the condensation of alkynes with other substrates, etc.). Attention is mainly focused on the mononuclear compounds, studying their preparative methods where coordinatively unsaturated species and good donor ligands are often involved. Recent methods of synthesis from polyhydrides are also summarized. Metal alkynyl derivatives are closely related to vinylidene complexes, both being common precursors to, and reaction products of vinylidene complexes. Subsequently, 1-alkyne and π-alkyne to vinylidene rearrangements on these metal centers are studied. The transformations from vinyl 14 electron to hydride-vinylidene 16 electron species and from hydride–vinylidene to ethylidyne species, etc. are also considered.

Direct functionalization of aromatic substituents on [28]hexaphyrin was achieved by Ir-catalyzed borylation with the Smith–Miyaura–Hartwig protocol. High para selectivity was observed in the reaction on 2,6-dichlorophenyl and 2,6-dimethoxyphenyl substituents of [28]hexaphyrin. The reaction with [26]hexaphyrin resulted only in reduction of the substrate to provide [28]hexaphyrin without borylation, thus highlighting the importance of the oxidation state of substrates in this catalytic transformation. The borylated hexaphyrin can be used for Suzuki–Miyaura cross-coupling reaction.

The reaction of the chiral tripod ligands X 2 POCH(CH 2 P(Ph) 2 )(CH 2 PR 2 ) ((±)- and R - 1a,b : X 2 = 2,2′-biphenoxy-; PR 2 = P(4-Me-C 6 H 4 ) 2 ( 1a ), PR 2 = dibenzophospholyl(DBP)- ( 1b )) and MeC(CH 2 P(Ph) 2 )(CH 2 PR′ 2 )(CH 2 PR″ 2 ) ((±)- and R - 2 : PR′ 2 = P(3,5-Me 2 -C 6 H 3 ) 2 ; PR″ 2 = DBP) with [Rh I (COD)Cl] 2 is investigated. It yields tripod rhodium COD complexes [( 1a,b )Rh I (COD)]PF 6 ((±)- and R - 3a,b ) and [( 2 )Rh I (COD)]PF 6 ((±)- and R - 4 ). The tripod ligand is coordinated by all three donor groups in each case, irrespective of the different donor capabilities of the coordinating groups. The complexes 3a,b and 4 are catalysts for the hydrogenation of the prochiral olefins acetamidocinnamic acid and dimethylitaconate. Both the poor activity and the low enantioselectivity compared to rhodium complexes containing chiral bisphosphino ligands can be explained by the presence of a third coordinating donor group in the ligand. Thus the trihapto coordination of the tripodal ligands is shown to be more of an impediment for this type of catalytic transformation.

A variety of neutral arene-ruthenium-carbenes of type (arene)RuCl 2 (= C(NR)CH 2 CH 2 N R) have been used for the catalytic transformation of ( Z )-3-methylpent-2-en-4-yn-1-ol into 2,3-dimethylfuran. The catalytic reaction takes place at 80°C with mononuclear complexes III–V to afford the furan in ∼ 90% yield. The binuclear catalysts VIa and VIIa having a linked bis-carbene bridge operate at room temperature to initiate an exothermic reaction offering 90–97% of furan.

The catalytic transformation of methane into higher hydrocarbons was studied under unsteady conditions on oxides of various metals (Pb, Fe, Nb, Ti, Cd, Mo, Mg, Zn, Zr, Bi, Mn), and also on Sr-, La-, Y-, and Mn-containing oxides of perovskite structure. It is shown that the effectiveness of the catalysts not only depends on their chemical composition, but also is determined to a considerable degree by the specific surface of the oxides.

Multiple technologies have emerged for structural diversification and efficient production of metabolites of drug molecules. These include expanded use of enzymatic and bioorganic transformations that mimic biological systems, biomimetic catalysis and electrochemical techniques. As this field continues to mature the breadth of transformations is growing beyond simple oxidative processes due in part to parallel development of more efficient catalytic methods for functionalization of unactivated scaffolds. These technologies allow for efficient structural diversification of both aromatic and aliphatic substrates in many cases via single step reactions without the use of protecting groups.

The CO2 emissions in biorefineries, with reference to bioethanol plants from lignocellulosic sources, are analyzed to discuss the possible use of carbon dioxide to produce fuels and chemicals. It is evidenced how this concept should be part of the strategy to introduce renewable energy in the biorefinery chain not only to decrease its impact on greenhouse gas emissions, but also because this approach could offer interesting opportunities to produce high-value-added chemicals. The chapter also briefly comments on a possible general roadmap for the use of CO2 for the production of fuels and chemicals, and finally shortly overviews the state of the art and perspectives in catalysis for the conversion of CO2 to methanol and dimethylether.

The catalytic transformation of propargylic acetates into the corresponding α-acetoxyenones in the presence of palladium(II) chloride is described. Water is a necessary component in this unusual oxidative rearrangement.

The catalytic transformation from hBN to cBN in the system Mg 3 N 2 -BN was investigated in more detail under high pressures and temperature using in-situ sensing methods. At the threshold of the cBN formation region (approximately 1550 K at 5.5 GPa), very fast formation processes leading to submicron cBN grains are observed in a small temperature interval (140 K at 5.5 GPa). The transformation proceeds in a eutectic melt. Model assumptions of dissolution and precipitation could be confirmed. The only intermediate phase formed under these thermodynamic conditions is Mg 3 BN 3 thus forming the solvent for this process.

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 oxidation of alcohols to carboxylic acids is an important industrial reaction used in the synthesis of bulk and fine chemicals. Most current processes are performed by making use of either stoichiometric amounts of toxic oxidizing agents or the use of pressurized dioxygen. Here, we describe an alternative dehydrogenative pathway effected by water and base with the concomitant generation of hydrogen gas. A homogeneous ruthenium complex catalyses the transformation of primary alcohols to carboxylic acid salts at low catalyst loadings (0.2 mol%) in basic aqueous solution. A consequence of this finding could be a safer and cleaner process for the synthesis of carboxylic acids and their derivatives at both laboratory and industrial scales.

Over the last decade, metal nanoparticles have attracted reasonable attention due to their unique properties that differ from their bulk counterparts, which facilitate their application in various fields from materials science to engineering. Of particular interest, their employment in catalysis has provided significant advantages in terms of activity, selectivity, lifetime and reusability to heterogeneous catalysis. However, preventing their aggregation to the bulk metal throughout the catalytic reaction despite using the best stabilizing agents still remains a challenging issue that should be overcome in the transition of these nanocatalysts from lab-scale to industrial applications. In this context, the synthesis of metal nanoparticles in systems with confined void spaces presents a promising strategy to prevent their aggregation during the catalytic reaction. Moreover, these supported nanocatalysts enable us to control the kinetics of catalytic transformation in a more effective way than that done by “semiheterogeneous” support of free metal nanoparticles. This chapter compiles the synthesis protocols followed in the preparation of supported metal nanoparticles plus the nature of different support materials. Additionally, their catalytic applications are comprehensively reviewed and the progressive results are discussed. In the final part of this chapter, we discuss the prevalent complications and their possible solutions plus future prospects in the field of supported metal nanoparticles-based catalysis.

An assisted tandem catalytic transformation of diallyl amines and diallyl ethers into N-aryl pyrroles and furans, respectively, is described. The sequence relies on ring closing metathesis followed by dehydrogenation of the initially formed dihydropyrroles and dihydrofurans. Both steps are Ru-catalyzed, but the sequence requires only one precatalyst, because conversion of the metathesis catalyst into the dehydrogenation catalyst is achieved in situ, triggered by the oxidant tert-butyl hydroperoxide.

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).

A novel carbon dioxide triggered and copper-catalyzed domino reaction for the efficient synthesis of highly substituted 3(2H)-furanones from readily available nitriles and propargylic alcohols has been developed. Carbon dioxide is a prerequisite for achieving the present catalytic transformation, and one of the oxygen atoms of carbon dioxide is incorporated into the 3(2H)-furanones. Nitriles not only act as the reaction solvent but also as the reactant; copper salts play dual roles of activating both the propargylic alcohols and nitriles.

Aromatic heterocycles are highly important structural units that are found in a vast number of biologically active natural compounds, pharmaceuticals, and materials.1 Aromatic heterocycles are important intermediates in organic synthesis, often providing access to other highly desirable structures.2 A myriad of methodologies and protocols have been developed for their synthesis,1 and, although generally high efficiencies and selectivities can be achieved, a large number of these methodologies are limited to the preparation of heterocycles with particular substitution patterns. Thus, there is a compelling need to develop novel and more general methods for the synthesis of heterocycles. In recent years, the use of transition-metal-catalyzed transformations truly revolutionized the area of heterocyclic chemistry.3–15 Many research groups have focused on the development of general methods that utilize readily accessible starting materials under mild reaction conditions for the synthesis of densely functionalized heterocyclic cores to achieve better functional group compatibilities and greater levels of molecular complexity. A particularly attractive approach toward this goal involves the incorporation of molecular rearrangement steps into the transition-metal-catalyzed cycloisomerization cascade reactions. In most cases, this approach provides a significant advantage over alternative routes in the convergent preparation of heterocycles with new substitution patterns. This review covers the most important recent advances in the Cu-,11,16–19 Ag-,12 and Au-catalyzed20–27 syntheses of five-membered aromatic heterocycles proceeding with 1,n migrations of various groups during the assembly of the heterocyclic ring. The main organization of this review is based on the type of migrating group, and the discussion of a particular migrating group is structured by the type of its 1,n shift. The concepts underlying a given transformation and the synthetic applicability of the corresponding method are emphasized. A brief discussion of the mechanism is given where needed to shed some light on possible reaction intermediates in the catalytic transformation.

The first homogeneously catalytic transformation of allyl arenes or alkenes to the corresponding alkenyl nitriles, facilitated by an inexpensive and nontoxic iron catalyst, is shown to proceed via the cleavage of three C—H bonds.