Glycerol as a Building Block for Prochiral Aminoketone, N-Formamide, and N-Methyl Amine Synthesis.

Prochiral aminoketones are key intermediates for the synthesis of optically active amino alcohols, and glycerol is one of the main biomass-based alcohols available in industry. In this work, glycerol was catalytically activated and purposefully converted with amines to generate highly valuable prochiral aminoketones, as well as N-formamides and N-methyl amines, over CuNiAlO catalyst. The catalyst structure can be anticipated as nano-Ni species on or in CuAlO via the formation of nano- Cu-Ni alloy particles.

Catalytic Conversion of Renewable Resources into Bulk and Fine Chemicals.

Several strategies can be chosen to convert renewable resources into chemicals. In this account, I exemplify the route that starts with so-called platform chemicals; these are relatively simple chemicals that can be produced in high yield, directly from renewable resources, either via fermentation or via chemical routes. They can be converted into the existing bulk chemicals in a very efficient manner using multistep catalytic conversions.

Pd-Supported on N-doped carbon: improved heterogeneous catalyst for base-free alkoxycarbonylation of aryl iodides.

Novel Pd-based heterogeneous catalysts were prepared through immobilization of Pd(OAc)/phenanthroline on carbon and subsequent pyrolysis. The most active catalyst was characterized by TEM, XPS and XRD techniques and was successfully used for the base-free methoxycarbonylation of aryl iodides. Notably, no metal contamination (detection limit < 0.

Unexpectedly high activity of bare alumina for non-oxidative isobutane dehydrogenation.

Bare alumina shows surprisingly high activity in non-oxidative dehydrogenation of isobutane to isobutylene. The activity is related to surface coordinatively unsaturated Al sites (Al), which are created upon removal of OH groups during alumina treatment at high temperatures. Al and neighbouring lattice oxygen represent the active site for isobutane dehydrogenation.

Efficient and selective N-alkylation of amines with alcohols catalysed by manganese pincer complexes.

Borrowing hydrogen (or hydrogen autotransfer) reactions represent straightforward and sustainable C-N bond-forming processes. In general, precious metal-based catalysts are employed for this effective transformation. In recent years, the use of earth abundant and cheap non-noble metal catalysts for this process attracted considerable attention in the scientific community.

Hydrogenation of Esters to Alcohols Catalyzed by Defined Manganese Pincer Complexes.

The first manganese-catalyzed hydrogenation of esters to alcohols has been developed. The combination of Mn(CO) Br with [HN(CH CH P(Et) ) ] leads to a mixture of cationic and neutral Mn PNP pincer complexes, which enable the reduction of various ester substrates, including aromatic and aliphatic esters as well as diesters and lactones. Notably, related pincer complexes with isopropyl or cyclohexyl substituents showed very low activity.

Metal-Free Activation of Hydrogen, Carbon Dioxide, and Ammonia by the Open-Shell Singlet Biradicaloid [P(μ-NTer)]2.

The Group 15 open-shell singlet biradicaloid [P(μ-NTer)]2 (Ter=2,6-bis(2,4,6-trimethylphenyl)phenyl) was utilized in the activation of stable small molecules. Fast reactions with H2 , CO2 , and NH3 were observed. Dihydrogen easily added to [P(μ-NTer)]2  , yielding [HP(μ-NTer)]2 under ambient conditions whereas reversible release of molecular hydrogen was observed at slightly elevated temperatures (T>60 °C).

Synthesis of β-Hydroxysulfides from Thiophenols and Disulfides with tert-Butyl Hydroperoxide as the Oxidant and Reactant.

In this Communication, we developed a new procedure for the synthesis of β-hydroxysulfides from thiophenols or diaryl disulfides with TBHP as the oxidant. In the presence of zinc iodide or potassium iodide, with TBHP as the oxidant and pre-reactant, thiophenols and diaryl disulfides reacted with the methyl group of tBuOH smoothly and selectivity to give the corresponding 2-methyl-1-(arylthio)propan-2-ols as the terminal products in moderate to good yields.

Selective catalytic two-step process for ethylene glycol from carbon monoxide.

Upgrading C1 chemicals (for example, CO, CO/H2, MeOH and CO2) with C-C bond formation is essential for the synthesis of bulk chemicals. In general, these industrially important processes (for example, Fischer Tropsch) proceed at drastic reaction conditions (>250 °C; high pressure) and suffer from low selectivity, which makes high capital investment necessary and requires additional purifications. Here, a different strategy for the preparation of ethylene glycol (EG) via initial oxidative coupling and subsequent reduction is presented.

Atom economical synthesis of di- and trithiocarbonates by the lithium tert-butoxide catalyzed addition of carbon disulfide to epoxides and thiiranes.

Alkali metal alkoxides were studied as catalysts for the addition of CS2 to epoxides. A screening of several commercially available alkoxides revealed lithium tert-butoxide as an active and selective catalyst for this reaction. The influence of different reaction parameters as well as the substrate scope under optimized reaction conditions has been studied.

Stable and Inert Cobalt Catalysts for Highly Selective and Practical Hydrogenation of C≡N and C═O Bonds.

Novel heterogeneous cobalt-based catalysts have been prepared by pyrolysis of cobalt complexes with nitrogen ligands on different inorganic supports. The activity and selectivity of the resulting materials in the hydrogenation of nitriles and carbonyl compounds is strongly influenced by the modification of the support and the nitrogen-containing ligand. The optimal catalyst system ([Co(OAc)2/Phen@α-Al2O3]-800 = Cat.

Evaluation of Fe and Ru Pincer-Type Complexes as Catalysts for the Racemization of Secondary Benzylic Alcohols.

Fe and Ru pincer-type catalysts are used for the racemization of benzylic alcohols. Racemization with the Fe catalyst was achieved within 30 minutes under mild reaction conditions, with a catalyst loading as low as 2 mol %. This reaction constitutes the first example of an iron-catalyzed racemization of an alcohol.

Palladium-Catalyzed Aminocarbonylation of Allylic Alcohols.

A benign and efficient palladium-catalyzed aminocarbonylation reaction of allylic alcohols is presented. The generality of this novel process is demonstrated by the synthesis of β,γ-unsaturated amides including aliphatic, cinnamyl, and terpene derivatives. The choice of ligand is crucial for optimal carbonylation processes: Whereas in most cases the combination of PdCl2 with Xantphos (L6) gave best results, sterically hindered substrates performed better in the presence of simple triphenylphosphine (L10), and primary anilines gave the best results using cataCXium® PCy (L8).

Highly functionalized alkenes produced from base-free organocatalytic Wittig reactions: (E)-3-benzylidenepyrrolidine-2,5-dione, (E)-3-benzylidene-1-methylpyrrolidine-2,5-dione and (E)-3-benzylidene-1-tert-butylpyrrolidine-2,5-dione.

The Wittig reaction is a fundamental transformation for the preparation of alkenes from carbonyl compounds and phosphonium ylides. The ylides are prepared prior to the olefination step from the respective phosphonium salts by deprotonation utilizing strong bases. A first free-base catalytic Wittig reaction for the preparation of highly functionalized alkenes was based on tributylphosphane as the catalyst.

Palladium-catalysed hydroamidocarbonylation of 1,3-dienes.

Herein, we report our recent result on the development of the selective catalytic method towards the synthesis of β,γ-unsaturated imides via Pd-catalysed hydroamidocarbonylation of conjugated dienes. Note that this reaction proceeds under acid additive free conditions. Various dienes, including those of high industrial value (e.

Copper-Catalyzed Carbonylative Coupling of Cycloalkanes and Amides.

Carbonylation reactions are a most powerful method for the synthesis of carbonyl-containing compounds. However, most known carbonylation procedures still require noble-metal catalysts and the use of activated compounds and good nucleophiles as substrates. Herein, we developed a copper-catalyzed carbonylative transformation of cycloalkanes and amides.

(Enantio)selective Hydrogen Autotransfer: Ruthenium-Catalyzed Synthesis of Oxazolidin-2-ones from Urea and Diols.

A novel strategy for the synthesis of oxazolidin-2-ones from vicinal diols and urea is described. In this heterocycle synthesis, two different C-O and C-N bonds are sequentially formed in a domino process consisting of nucleophilic substitution and alcohol amination. The use of readily available starting materials and the good atom economy render this process environmentally benign.

Isolation of Labile Pseudohalogen NSO Species.

A new synthetic approach enabled the generation of highly labile thionylimide, H-NSO, which was trapped by adduct formation with the bulky Lewis acid B(C6 F5 )3 and fully characterized. For comparison, a series of different Me3 Si-NSO Lewis acid adducts were studied. Treatment of Me3 Si-NSO with the silylium ion [Me3 Si](+) led to the formation of the hitherto unknown iminosulfonium ion [Me3 Si-N=S-O-SiMe3 ](+) , which could be isolated and fully characterized as a salt in the presence of weakly coordinating carborate anions.

Synthesis of Naphthylpyridines from Unsymmetrical Naphthylheptadiynes and the Configurational Stability of the Biaryl Axis.

A series of different unsymmetrically substituted naphthyl-based diynes were synthesized. These substrates formed the foundation for the assembly of novel biaryls containing pyridine moieties with differently substituted five-membered rings in the backbone of the newly formed heterobiaryl system. The key step for their efficient construction was the photo- and cobalt-catalyzed [2 + 2 + 2] cycloaddition reaction between the corresponding naphthyldiyne and aceto- or benzonitrile.

Synthesis of Heavy Cyclodipnictadiphosphanes [ClE(μ-P-Ter)]2 [E = P, As, Sb, or Bi; Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl].

A complete series of terphenyl-substituted 1,3-dichloro-1,3-dipnicta-2,4-diphosphanes {[ClE(μ-P-Ter)]2, where E = P, As, Sb, or Bi and Ter = 2,6-bis(2,4,6-trimethylphenyl)phenyl} was prepared and fully characterized. While the heavy derivatives with E = Sb or Bi can be accessed via conversion of silylated phosphanes with amino-dichloropnictanes and subsequent elimination of TerNH2, the lighter congeners could be prepared only by a metathesis reaction of [ClBi(μ-P-Ter)]2 with PCl3 and AsCl3. Spectroscopic and structural data indicate the existence of cis and trans isomers of [ClP(μ-P-Ter)]2 in contrast to all heavier derivatives, for which only the trans isomer was obtained.

A Convenient Palladium-Catalyzed Reductive Carbonylation of Aryl Iodides with Dual Role of Formic Acid.

Palladium-catalyzed reductive carbonylation of aryl halides represents a straightforward pathway for the synthesis of aromatic aldehydes. The known reductive carbonylation procedures either require CO gas or complexed compounds as CO sources. In this communication, we developed a palladium-catalyzed reductive carbonylation of aryl iodides with formic acid as the formyl source.

Crystal structure of 1-hy-droxy-2,2,6,6-tetra-methyl-piperidin-1-ium tri-fluoro-methane-sulfonate.

In the cation of the title salt, C9H20NO(+)·CF3O3S(-), the six-membered heterocyclic ring displays a chair conformation. In the crystal, centrosymmetric pairs of cations and anions are linked by N-H⋯O and O-H⋯O hydrogen bonds to form rings with a R 4 (4)(14) graph-set motif.

Crystal structure of bis-{μ2-[(2-imino-cyclo-pentyl-idene)methyl-idene]aza-nido-κ(2) N:N'}bis-[(η(5)-penta-methyl-cyclo-penta-dien-yl)zirconium(IV)] hexane monosolvate.

The title compound, [Zr2(C10H15)4(C6H6N2)2]·C6H14, was obtained by the stoichiometric reaction of adipo-nitrile with [Zr(C10H15)2(η(2)-Me3SiC2SiMe3)]. Intra-molecular nitrile-nitrile couplings and deprotonation of the substrate produced the (1-imino-2-enimino)-cyclo-pentane ligand, which functions as a five-membered bridge between the two metal atoms. The Zr(IV) atom exhibits a distorted tetra-hedral coordination sphere defined by two penta-methyl-cyclo-penta-dienyl ligands, by the imino unit of one (1-imino-2-enimino)-cyclo-pentane and by the enimino unit of the second (1-imino-2-enimino)-cyclo-pentane.

Lewis Acid Catalyzed Synthesis of Cyanidophosphates.

Salts containing new cyanido(fluorido)phosphate anions of the general formula [PF6-n(CN)n](-) (n=1-4) were synthesized by a very mild Lewis-acid-catalyzed synthetic protocol and fully characterized. All [PF6-n(CN)n](-) (n=1-4) salts could be isolated on a preparative scale. It was also possible to detect the [PF(CN)5](-) but not the [P(CN)6](-) anion.

Structures of seven molybdenum surfaces and their coverage dependent hydrogen adsorption.

Systematic density functional theory calculations and ab initio atomistic thermodynamics were applied to investigate the stability of seven metallic Mo surfaces [(110), (211), (111), (321), (310), (210) (100)] and their coverage dependent hydrogen adsorption. Only dissociative hydrogen adsorption is favored on these surfaces up to more than one monolayer saturation coverage. The computed hydrogen desorption temperatures on Mo(100) at 500 K and on Mo(110) at 410 K are in agreement with the available temperature-programmed desorption results.