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Glyoxylate has been postulated to be an important prebiotic building block. However, a plausible prebiotic availability of glyoxylate has not as yet been demonstrated. Herein we report the formation of glyoxylate by means of a transamination reaction between glycine and formaldehyde in water at 50 °C and 70 °C at pH 8 and 6, respectively. The reaction was followed by means of 13C NMR and high-resolution mass spectrometry employing both unlabeled and 13C-labeled reactants. Other products accompanying the transamination process include serine, sarcosine, N,N-dimethylglycine, and carbon dioxide/bicarbonate. The mechanisms for the formation of glyoxylate and accompanying products are discussed. 1 Introduction 2 Background 3 Results and Discussion 3.1 Reaction of 13C-Labeled Glycine with Formaldehyde at pH 8 3.2 Reaction of 13C-Labeled Glycine with Formaldehyde at pH 6 3.3 Serine-Promoted Decarboxylation of Glyoxylate 4 Conclusions.

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For the title reaction, the pressure dependent rate coefficients were studied at 298 K using two complementary experimental techniques.Pulse radiolysis combined with UV absorption was employed at pressures between 500 and 1000 mbar, while a fast-flow system with a quadrupole mass spectrometer (at low ionization energies) was applied at pressures in the range of 0.7-5.1 mbar.The fall-off curve was constructed in terms of Troe's analysis, and the following high- and low-pressure limiting rate coefficients were derived: krec, infinite = (1.3 +/- 0.3) * 10-10 * T/300)0.42 cm3 molecule-1 s-1 and krec,0 = (1.8 +/- 0.5)*10-27*(T/300)-3.85 cm6 molecule-2 s-1.

We demonstrate the feasibility of a nonsalt-based precursor pair - inorganic HPbI3 solid and organic CH3NH2 gas - for the deposition of uniform CH3NH3PbI3 perovskite thin films. The strong room-temperature solid-gas interaction between HPbI3 and CH3NH2 induces transformative evolution of ultrasmooth, full-coverage perovskite thin films at a rapid rate (in seconds) from nominally processed rough, partial-coverage HPbI3 thin films. The chemical origin of this behavior is elucidated via in situ experiments. Perovskite solar cells, fabricated using MAPbI3 thin films thus deposited, deliver power conversion efficiencies up to 18.2%, attesting to the high quality of the perovskite thin films deposited using this transformative process.

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Uniform dispersion of ultrafine spherical silver nanoparticles (NPs) was obtained over the surface of Fe3O4@SiO2@KIT-6 core–shell support via functionalization of the mesoporous KIT-6 shell by aminopropyltriethoxysilane, followed by coordination of Ag+ ions and in situ chemical reduction with sodium borohydride. The obtained hybrid material, Fe3O4@SiO2@KIT-6-Ag nanocomposite, was fully characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, and transmission electron microscopy, and used as an efficient catalyst for selective reduction of nitroaromatic compounds in aqueous solution at ambient temperature and neutral pH [nine examples, apparent rate constants at 25?°C, k (min?1), 0.112–0.628]. As a non-aromatic example, nitrofurazone which is a cytotoxic antibiotic was also reduced selectively at nitro group without reduction of other functionalities. Fe3O4@SiO2@KIT-6-Ag NPs also showed potential ability to act as catalyst for reduction of nitromethane in aqueous solution which can provide a colorimetric method for detection of nitromethane in solution down to 0.9 × 10?4?mol?L?1. Fe3O4@SiO2@KIT-6-Ag nanocomposite was also screened for its antibacterial activity, and satisfactory results were obtained in comparison with drug references including Tetracycline, Chloramphenicol and Cefotaxime as positive controls, on gram negative Escherichia coli and Pseudomonas aeroginosa. Ease of recycling of the Fe3O4@SiO2@KIT-6-Ag is another benefit of this nanocatalyst. Under the optimized conditions, the recycled catalyst showed 15% loss of efficiency after five successive runs. Graphical Abstract: [Figure not available: see fulltext.].

The catalytic reduction of cis-dimethyldiazene by the (Et4N)2[(Cl4-cat)(CH3CN)MoFe3S4Cl3] cluster (Cl4-cat = tetrachlorocatecholate) is reported. Unlike the reduction of cis-dimethyldiazene by the Fe/Mo/S center of nitrogenase, which yields methylamine, ammonia, and methane (the latter from the reduction of the C-N bond), the reduction of cis-dimethyldiazene by the synthetic cluster yields exclusively methylamine. In separate experiments, it was shown that the C-N bond of methylamine is not reduced by the [MoFe3S4]3+ core, perhaps accounting for the differences observed between the biological and abiological systems. 1,2-Dimethylhydrazine, a possible partially reduced intermediate in the reduction of cis-dimethyldiazene, was also shown to be reduced to methylamine. Interaction of methylamine with the Mo atom of the cubane was confirmed through the synthesis and structural characterization of (Et4N)2[(Cl4-cat)(CH3NH2)MoFe3S4Cl3]. Phosphine inhibition studies strongly suggest that the Mo atom of the [MoFe3S4]3+ core, which has a Mo coordination environment very similar to that in nitrogenase, is responsible for the binding and activation of cis-dimethyldiazene. The reduction of a N = N bond exclusively at the heterometal site of a nitrogenase-relevant synthetic compound may have implications regarding the function of the nitrogenase Fe/Mo/S center, particularly in the latter stages of dinitrogen reduction.

Designer C-terminal peptide amides are accessed in an efficient and epimerization-free approach by pairing an electrochemical oxidative decarboxylation with a tandem hydrolysis/reduction pathway. Resembling Nature's dual enzymatic approach to bioactive primary α-amides, this method delivers secondary and tertiary amides bearing high-value functional motifs, including isotope labels and handles for bioconjugation. The protocol leverages the inherent reactivity of C-terminal carboxylates, is compatible with the vast majority of proteinogenic functional groups, and proceeds in the absence of epimerization, thus addressing major limitations associated with conventional coupling-based approaches. The utility of the method is exemplified through the synthesis of natural product acidiphilamide A via a key diastereoselective reduction, as well as bioactive peptides and associated analogues, including an anti-HIV lead peptide and blockbuster cancer therapeutic leuprolide.

Understanding the degradation mechanisms of organic cations under basic conditions is extremely important for the development of durable alkaline energy conversion devices. Cations are key functional groups in alkaline anion exchange membranes (AAEMs), and AAEMs are critical components to conduct hydroxide anions in alkaline fuel cells. Previously, we have established a standard protocol to evaluate cation alkaline stability within KOH/CD3OH solution at 80 °C. Herein, we are using the protocol to compare 26 model compounds, including benzylammonium, tetraalkylammonium, spirocyclicammonium, imidazolium, benzimidazolium, triazolium, pyridinium, guanidinium, and phosphonium cations. The goal is not only to evaluate their degradation rate, but also to identify their degradation pathways and lead to the advancement of cations with improved alkaline stabilities.

The development of benign methylation reactions utilizing CO2 as a one-carbon building block would enable a more sustainable chemical industry. Electrochemical CO2 reduction has been extensively studied, but its application for reductive methylation reactions remains out of the scope of current electrocatalysis. Here, we report the first electrochemical reductive N-methylation reaction with CO2 and demonstrate its compatibility with amines, hydroxylamines, and hydrazine. Catalyzed by cobalt phthalocyanine molecules supported on carbon nanotubes, the N-methylation reaction proceeds in aqueous media via the chemical condensation of an electrophilic carbon intermediate, proposed to be adsorbed or near-electrode formaldehyde formed from the four-electron reduction of CO2, with nucleophilic nitrogenous reactants and subsequent reduction. By comparing various amines, we discover that the nucleophilicity of the amine reactant is a descriptor for the C-N coupling efficacy. We extend the scope of the reaction to be compatible with cheap and abundant nitro-compounds by developing a cascade reduction process in which CO2 and nitro-compounds are reduced concurrently to yield N-methylamines with high monomethylation selectivity via the overall transfer of 12 electrons and 12 protons.

Abstract: Metalporphyrin-based porous polymers supporting high dispersed Pd nanoparticle (NP) catalysts (HUST-1-Pd) were prepared with a novel solvent-knitting hyper-crosslinked polymer method using 5-, 10-, 15-, and 20-tetraphenylporphyrin (TPP) as building blocks. The N2 sorption isotherms of the catalysts show that the HUST-1-Pd possesses many ultra-micropores and continuous mesopores. The NPs are assembled on tetraphenylporphyrin structures and show Pd-N4 composition-dependent catalysis for methanolysis of ammonia borane (AB) and hydrogenation of aromatic nitro compounds to primary amines in methanol solutions at room temperature. The nano-palladium reduced by NaBH4 has efficient catalytic activity for AB methanolysis. A variety of R-NO2 derivatives were reduced selectively into R-NH2 via palladium catalyzed tandem reactions with 5–30?min of reaction time with conversion yields reaching up to 90%. The derivatives also give excellent recycling performance (more than 10 times). Furthermore, the turnover frequency (TOF) can reach 87,209?h?1. The HUST-1-Pd compounds represent a unique metal catalyst for hydrogenation reactions in a green environment without using pure hydrogen. Graphic Abstract: A monodisperse Pd NPs embed in porphyrin-based microporous organic polymer was reported to catalyse the tandem dehydrogenation of ammonia borane and hydrogenation of R-NO2 to R-NH2 at room temperature. The catalyst is efficient and reusable in an environment-friendly process with short reaction times and high yields.[Figure not available: see fulltext.]

Abstract: Novel Cu-nanoparticles (NPs) embedded in porous carbon materials (Cu@C-x) were prepared by one-pot pyrolysis of metal–organic frameworks (MOF) HKUST-1 at different temperatures. The obtained material Cu@C-x was used as a cost-effective catalyst for the hydrogenation of nitrobenzene using NaBH4 as the reducing agent under mild reaction conditions. By considering the catalyst preparation and the catalytic activity, a pyrolysis temperature of 400?°C was finally chosen to synthesize the optimal catalyst. When the aromatic nitro compounds with reducible groups, such as cyano, halogen, and alkyl groups, were tested in this catalytic hydrogenation, an excellent selectivity approaching 100% was achieved. In the recycling experiment, a significant decrease in nitrobenzene conversion was observed in the third cycle, mainly due to the very small amount of catalyst employed in the reaction. Hence, the easily prepared and cost-effective Cu@C-400 catalyst fabricated in this study demonstrates potential for the applications in selective reduction of aromatic nitro compounds. Graphic Abstract: The catalyst Cu@C-400 exhibited 100?% conversion and high selectivity for the hydrogenation of industrially relevant nitroarenes.[Figure not available: see fulltext.].

The hydrolysis of carbonyl sulfide (COS) to form H2S by carbonic anhydrase has been demonstrated to be a viable strategy to deliver H2S in a biological system. Herein, we describe N-dithiasuccinoyl amines as thiol-triggered COS/H2S donors. Notably, thiol species especially GSH and homocysteine can trigger the release of both COS and H2S directly from several specific analogues via an unexpected mechanism. Importantly, two representative analogues Dts-1 and Dts-5 show intracellular H2S release, and Dts-1 imparts potent anti-inflammatory effects in LPS-challenged microglia cells. In conclusion, N-dithiasuccinoyl amine could serve as promising COS/H2S donors for either H2S biological studies or H2S-based therapeutics development.

Amino acids obtained by fermentation or recovered from protein waste hydrolysates represent an excellent renewable resource for the production of bio-based chemicals. In an attempt to recycle both carbon and nitrogen, we report here on a chemocatalytic, metal-free approach for decarboxylation of amino acids, thereby providing a direct access to primary amines. In the presence of a carbonyl compound the amino acid is temporarily trapped into a Schiff base, from which the elimination of CO2 may proceed more easily. After evaluating different types of aldehydes and ketones on their activity at low catalyst loadings (≤5 mol%), isophorone was identified as powerful organocatalyst under mild conditions. After optimisation many amino acids with a neutral side chain were converted in 28–99 % yield in 2-propanol at 150 °C. When the reaction is performed in DMF, the amine is susceptible to N-formylation. This consecutive reaction is catalysed by the acidity of the amino acid reactant itself. In this way, many amino acids were efficiently transformed to the corresponding formamides in a one-pot catalytic system.

The present invention discloses a non-catalyst under the condition of non-accelerator [...] amide derivatives of aromatic amine with transfers the amine reaction, yield of synthetic N - aryl amide derivatives. The method has a wide range of the substrate, its raw materials and cheap and easy to obtain acylation reagent, the reaction yield is high, one-step reaction, low cost, high reaction selectivity, simple operation and the like. Adopting this method can be gram scale can realize the high yield of the synthesis of drug molecules. Therefore, the method in the N - aryl amide derivatives of synthesis application field has very good application prospect. The method overcomes the existing technologies such as the reaction reagent toxicity is large, the need to use different type catalyst, synthesis method and the cost is high, more reaction steps, more byproducts and the like.

Imidazolium functionality has played a prominent role in research on anion exchange membranes for use in alkaline electrochemical devices. Base stability and degradation of these materials has been much studied, but in many instances, product pathways have not been thoroughly delineated. We report an NMR study of base-induced decomposition products from three benzylimidazolium salts bearing varying extents of methyl substitution on the imidazolium ring. The major products are consistent with a hydrolytic ring fragmentation pathway as the principal mode of decomposition. We observe several new products not previously reported in the literature on imidazolium salt degradation, including benzilic acid rearrangement products formally derived from intermediate 1,2-dicarbonyl compounds or their equivalents. However, the overall reactions are complex, the yields of observed products do not account for all consumed starting materials, and mechanistic ambiguities remain.

Lamisil (terbinafine) is an effective, widely prescribed antifungal drug that causes rare idiosyncratic hepatotoxicity. The proposed toxic mechanism involves a reactive metabolite, 6,6-dimethyl-2-hepten-4-ynal (TBF-A), formed through three N-dealkylation pathways. We were the first to characterize them using in vitro studies with human liver microsomes and modeling approaches, yet knowledge of the individual enzymes catalyzing reactions remained unknown. Herein, we employed experimental and computational tools to assess terbinafine metabolism by specific cytochrome P450 isozymes. In vitro inhibitor phenotyping studies revealed six isozymes were involved in one or more N-dealkylation pathways. CYP2C19 and 3A4 contributed to all pathways, and so, we targeted them for steady-state analyses with recombinant isozymes. N-Dealkylation yielding TBF-A directly was catalyzed by CYP2C19 and 3A4 similarly. Nevertheless, CYP2C19 was more efficient than CYP3A4 at N-demethylation and other steps leading to TBF-A. Unlike microsomal reactions, N-denaphthylation was surprisingly efficient for CYP2C19 and 3A4, which was validated by controls. CYP2C19 was the most efficient among all reactions. Nonetheless, CYP3A4 was more selective at steps leading to TBF-A, making it more effective in terbinafine bioactivation based on metabolic split ratios for competing pathways. Model predictions did not extrapolate to quantitative kinetic constants, yet some results for CYP3A4 and CYP2C19 agreed qualitatively with preferred reaction steps and pathways. Clinical data on drug interactions support the CYP3A4 role in terbinafine metabolism, while CYP2C19 remains understudied. Taken together, knowledge of P450s responsible for terbinafine metabolism and TBF-A formation provides a foundation for investigating and mitigating the impact of P450 variations in toxic risks posed to patients.

Bis(β-ketoiminate) dioxo tungsten(VI) complexes WO2L2 (L = acNac, acNacMe, acNacEt) have been synthesized and characterized. The thermal behaviors and possible decomposition mechanisms of these dioxo compounds were studied by TGA, MS and thermolysis. The performance of WO2(acNacMe)2 as an AACVD precursor was evaluated at growth temperatures of 250–550 °C using nitrogen as the carrier gas. The elemental compositions of the as-deposited and sputtered tungsten oxide films were determined by XPS. The morphology and stoichiometry of the as-deposited films were studied by SEM and XRD.

Platinum-(phosphinito-phosphinous acid) complex catalyzes the oxidative fragmentation of hindered piperidinols according to a hydrogen transfer induced methodology. This catalyst acts successively as both a hydrogen carrier and soft Lewis acid in a one pot-two steps process. This method can be applied to the synthesis of a wide variety of primary amines in a pure form by a simple acid-base extraction without further purification.

DNL-6, a silicoaluminophosphate (SAPO) molecular sieve with RHO topology, was hydrothermally synthesized using a new structure-directing agent (SDA), N,N′-dimethylethylenediamine. The obtained samples were characterized by X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy, scanning electron microscopy, and N2 adsorption, which indicated that the synthesized DNL-6s have high crystallinity and relatively high Si content ranging from 20% to 35%. Solid-state magic-angle-spinning (MAS) nuclear magnetic resonance (13C, 29Si, 27Al, 31P, and 27Al multiple-quantum (MQ)) was conducted to investigate the status of the SDA and local atomic environment in the as-synthesized DNL-6. Thermal analysis revealed the presence of a large amount of amines in the DNL-6 crystals (about 4.4 SDAs per α-cage), which was the reason for the formation of DNL-6 with an ultrahigh Si content (36.4% Si per mole). Interestingly, DNL-6 exhibited excellent catalytic performance for methanol amination. More than 88% methanol conversion and 85% methylamine plus dimethylamine selectivity could be achieved due to the combined contribution of strong acid sites, suitable acid distribution, and narrow pore dimensions of DNL-6.

A practical zinc acetate dihydrate-catalyzed reductive amination of various carbonyl compounds with N,N-dimethylformamide (DMF) as dimethylamino (Me2N) source, reductant and solvent has been developed. This reaction shows broad substrate scope,

Hybrid lead halide perovskites have emerged as promising active materials for photovoltaic cells. Although superb efficiencies have been achieved, it is widely recognized that long-term stability is a key challenge intimately determining the future development of perovskite-based photovoltaic technology. Herein, we present reversible and irreversible photodecomposition reactions of methylammonium lead iodide (MAPbI3). Simulated sunlight irradiation and temperature (40-80 °C) corresponding to solar cell working conditions lead to three degradation pathways: (1) CH3NH2 + HI (identified as the reversible path), (2) NH3 + CH3I (the irreversible or detrimental path), and (3) a reversible Pb(0) + I2(g) photodecomposition reaction. If only the reversible reactions (1) and (3) take place and reaction (2) can be avoided, encapsulated MAPbI3 can be regenerated during the off-illumination timeframe. Therefore, to further improve operational stability in hybrid perovskite solar cells, detailed understanding of how to mitigate photodegradation and thermal degradation processes is necessary. First, encapsulation of the device is necessary not only to avoid contact of the perovskite with ambient air, but also to prevent leakage of volatile products released from the perovskite. Second, careful selection of the organic cations in the compositional formula of the perovskite is necessary to avoid irreversible reactions. Third, selective contacts must be as chemically inert as possible toward the volatile released products. Finally, hybrid halide perovskite materials are speculated to undergo a dynamic formation and decomposition process; this can gradually decrease the crystalline grain size of the perovskite with time; therefore, efforts to deposit highly crystalline perovskites with large crystal sizes may fail to increase the long-term stability of photovoltaic devices.

Investigations into the chemical origin of life have recently benefitted from a holistic approach in which possible atmospheric, organic, and inorganic systems chemistries are taken into consideration. In this way, we now report that a selective phosphate activating agent, namely methyl isocyanide, could plausibly have been produced from simple prebiotic feedstocks. We show that methyl isocyanide drives the conversion of nucleoside monophosphates to phosphorimidazolides under potentially prebiotic conditions and in excellent yields for the first time. Importantly, this chemistry allows for repeated reactivation cycles, a property long sought in nonenzymatic oligomerization studies. Further, as the isocyanide is released upon irradiation, the possibility of spatially and temporally controlled activation chemistry is thus raised.

Porous graphitic carbon layers encapsulating Ni nanoparticles (Ni@C) were prepared by a facile thermolysis of a Ni-containing metal-organic framework, the structure of which were characterized by power X-ray diffraction (XRD), N2 adsorption-desorption, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS) in detail. The resulting Ni@C nanocomposites served as highly efficient and magnetically recyclable catalysts for the hydrogenation of diverse functionalized nitro compounds to the corresponding anilines under relatively milder conditions. The high catalytic performance and the enhanced stability are ascribed to the synergistic effects and electron transfer between the metallic Ni and graphitic carbon as well as the unique encapsulation structure. The achieved success in the MOF-derived Ni@C nanocomposites may pave the way for designing environmentally benign catalytic hydrogenation processes for industrial applications.

A core-shell structured nanocatalyst (Fe3O4@SiO2-NH2-RhNPs@mSiO2) that is encapsulated with porous silica has been designed and prepared for catalyzing the transfer hydrogenation of nitro compounds into corresponding amines. Rh nanoparticles serve as the activity center, and the porous silica shell plays an important role in the "slow-release" of the hydrogen source hydrazine. This reaction can be carried out smoothly in the green solvent water, and the atom economy can be improved by decreasing the amount of hydrazine hydrate used to a stoichiometric 1.5 equivalent of the substrate. Significantly, high catalytic efficiency is obtained and the turnover frequency (TOF) can be up to 4373 h-1 in the reduction of p-nitrophenol (4-NP). A kinetics study shows that the order of reaction is ～0.5 towards 4-NP, and the apparent active energy Ea is 58.18 kJ mol-1, which also gives evidence of the high catalytic efficiency. Additionally, the excellent stability of the catalyst has been verified after 15 cycles without any loss of catalytic activity, and it is easily recovered by a magnet after reaction due to the Fe3O4 nucleus.

SAPO-34 was synthesized with n-butylamine (BA) as a template for the first time. Crystallization temperature and initial Si amount were important factors leading to successful syntheses. Lamellar AlPO-kanemite tends to form as the major phase or as an impurity of SAPO-34 at lower crystallization temperatures, though a higher initial Si amount may offer a positive effect on the crystallization of SAPO-34 that mitigates the low temperature. Higher temperature (240 °C) can effectively suppress the generation of lamellar materials and allow the synthesis of pure SAPO-34 with a wider range of Si incorporation. The crystallization processes at 200 and 240 °C were investigated and compared. We used the aminothermal method to synthesize SAPO-34-BA at 240 °C and also found n-propylamine is a suitable template for the synthesis of SAPO-34. The SAPO-34-BA products were characterized by many techniques. SAPO-34-BA has good thermal stability, crystallinity and porosity. BA remained intact in the crystals with ～1.8 BA molecule per chabazite cage. The catalytic performance of SAPO-34 was tested in the methanol amination reaction, which showed high methanol conversion and selectivity for methylamine plus dimethylamine under the conditions investigated, suggesting that this material is a good candidate for the synthesis of methylamines.

Over 50 years ago, Jencks and Gilchrist showed that formaldehyde catalyses the hydrolysis of phosphoramidate through electrophilic activation, induced by covalent attachment to its nitrogen atom. Given our interest in the use of aldehydes as catalysts, this work was revisited to identify a superior catalyst, o-phthalaldehyde, which facilitates hydrolyses of various organophosphorus compounds bearing P(O)-NH subunits under mild conditions. Interestingly, chemoselective hydrolysis of the P(O)-N bonds could be accomplished in the presence of P(O)-OR bonds.

The γ-Fe2O3 nanoparticles well dispersed in porous carbon were fabricated via a Fe-based metal-organic framework-templated pyrolysis. The resultant product exhibits excellent catalytic activity, chemoselectivity and magnetic recyclability for the hydrogenation of diverse nitro compounds under mild conditions.

The one-step pyrolysis of a zeolite-type metal-organic framework, Co(2-methylimidazole)2 (ZIF-67), produces an N-doped porous carbon incorporating well-dispersed Co/CoO nanoparticles, which exhibit excellent catalytic activity, chemoselectivity and magnetic recyclability for the tandem dehydrogenation of ammonia borane and hydrogenation of nitro compounds at room temperature.

Monodisperse NiPd alloy nanoparticles (NPs) are synthesized and assembled on graphene (G) or other support to provide clean, efficient catalysis of tandem reactions—dehydrogenation of ammonia borane (AB) and hydrogenation of R—NO2 and/or R—CN to R—NH2. The tandem reactions proceed quickly and with high efficiency in aqueous methanol solutions at room temperature, and the supported catalyst is readily recovered for re-use, providing a simple, efficient and ‘green’ route to the preparation of many common pharmaceutical, dye or other chemical products. NiPd alloy NPs of 3.4 nanometer size were prepared by co-reduction of nickel(II) acetate and palladium(II) acetlyacetonate by borane-tert-butylamine in oleylamine and deposited on G via a solution phase self-assembly process. The G-NiPd showed composition-dependent catalysis on the tandem reaction with G-Ni30Pd70 being the most active. A variety of R—NO2 and/or R—CN derivatives (R alkyl or aryl) were reduced selectively into R—NH2 via G-Ni30Pd70 catalyzed tandem reaction in short (5-30 minute) reaction times with conversion yields reaching up to 100%, demonstrating a new approach to G-NiPd-catalyzed dehydrogenation of AB and hydrogenation of R—NO2 and R—CN. The G-NiPd NP catalyst is efficient and is reusable; thus the reaction can be performed in an environment-friendly process with short reaction times and high yields.

9-Amino-9-phosphabicyclo[3.3.1]nonanes, (PhobPNHR′; R = Me or iPr) are readily prepared by aminolysis of PhobPCl and are significantly less susceptible to hydrolysis than the acyclic analogues Cy2PNHR′. Treatment of Cy2PNHMe with Cy2PCl readily gave Cy2PNMePCy2. By contrast, treatment of PhobPCl with PhobPNHMe in the presence of Et3N does not afford PhobPNMePPhob but instead the salt [PhobP(NMeH)PPhob]Cl is formed which, upon addition of [PtCl2(NCtBu)2] gives the zwitterionic complex [PtCl3(PhobP(NMeH)PPhob)]. The neutral PhobP(NMe)PPhob is accessible from PhobNMeLi and is converted to the chelate [PdCl2(PhobPNMePPhob)] by addition of [PdCl2(cod)]. The anomalous preference of the PhobP group for the formation of PPN products is discussed. The unsymmetrical diphos ligands PhobPNMePAr2 (Ar = Ph, o-Tol) are prepared, converted to [Cr(CO)4(PhobPNMePAr2)] and shown to form Cr-catalysts for ethene oligomerisation, producing a pattern of higher alkenes that corresponds to a Schulz-Flory distribution overlaid on selective tri/tetramerisation.

A high-yielding and practical method for the synthesis of phenols from electron-deficient haloarenes and heteroarenes has been developed. The products are formed from acetohydroxamic acid as the hydroxide source via a novel SNAr reaction/Lossen rearrangement sequence. Notably, these reactions employ inexpensive and air-stable reagents, require no special handling, occur under mildly basic conditions, and form products in high yields in the presence of electrophilic and protic functionality. The utility of this methodology is demonstrated by the high-yielding hydroxylation of two base-sensitive complex substrates.

A broad range of secondary and tertiary amides has been hydrogenated to the corresponding amines under mild conditions using an in situ catalyst generated by combining [Ru(acac)3], 1,1,1-tris(diphenylphosphinomethyl)ethane (Triphos) and Yb(OTf)3. The presence of the metal triflate allows to mitigate reaction conditions compared to previous reports thus improving yields and selectivities in the desired amines. The excellent isolated yields of two scale-up experiments corroborate the feasibility of the reaction protocol. Control experiments indicate that, after the initial reduction of the amide carbonyl group, the reaction proceeds through the reductive amination of the alcohol with the amine arising from collapse of the intermediate hemiaminal.

This article describes the iron-catalyzed hydrogenation of unactivated amides. Under the optimal conditions, a PNP-ligated Fe catalyst affords 25-300 turnovers of products derived from C-N bond cleavage. This reaction displays a broad substrate scope, including a variety of 2° and 3° amide substrates. The reaction progress of N,N-dimethylformamide hydrogenation has been monitored in situ using Raman spectroscopy. This technique enables direct comparison of the relative activity of the Fe-PNP catalyst to that of its Ru analogue. Under otherwise identical conditions, the Fe and Ru catalysts exhibit rates within a factor of 2.

The hydrogenation efficiency of nitro compounds was found to be greatly boosted by coupling with dehydrogenation of ammonia borane. The Pd@MIL-101 with tiny Pd NPs is exceptionally efficient and recyclable in the tandem reactions and diverse nitro compounds can be selectively reduced to the corresponding amines in 1.5-5 min with quantitative yields.

The reduction of aromatic/aliphatic nitro compounds to primary amines with high yields was easily realized by transfer hydrogenation comprising commercially available aluminium oxy-hydroxide-supported Pd nanoparticles (0.5 wt% Pd, Pd/AlO(OH)) as catalysts and NaBH4 as the hydrogen reservoir at room temperature in a water/methanol mixture (v/v = 7/3). The presented catalytic methodology is highly efficient for the reduction of various nitro compounds as well as reusable. A variety of R-NO2 derivatives were tested by performing the Pd/AlO(OH) catalysed reduction reaction and all the nitro compounds were selectively reduced to their corresponding primary amines in reaction times ranging from 0.75 to 13 min with yields reaching up to 99%. This process can be assessed as an eco-friendly method involving both reusable catalysts (Pd/AlO(OH) NPs) and hydrogen sources (NaBH4).

In this paper we report on the influence of light and oxygen on the stability of CH3NH3PbI3 perovskite-based photoactive layers. When exposed to both light and dry air the mp-Al2O3/CH3NH3PbI3 photoactive layers rapidly decompose yielding methylamine, PbI2, and I2 as products. We show that this degradation is initiated by the reaction of superoxide (O2-) with the methylammonium moiety of the perovskite absorber. Fluorescent molecular probe studies indicate that the O2- species is generated by the reaction of photoexcited electrons in the perovskite and molecular oxygen. We show that the yield of O2- generation is significantly reduced when the mp-Al2O3 film is replaced with an mp-TiO2 electron extraction and transport layer. The present findings suggest that replacing the methylammonium component in CH3NH3PbI3 to a species without acid protons could improve tolerance to oxygen and enhance stability.

In the future hydrogen economy, formic acid is considered an efficient hydrogen storage molecule and a new C1 building block for the chemical industry. Formic acid could be used as a sustainable carbon monoxide source. In the present work efficient catalysts for the decomposition of formic acid and its derivatives to carbon monoxide have been found. The proposed catalysts are widely available zeolites, making the process feasible for industrial scale applications. Thus, formic acid and its derivatives could be seen as liquid and storable versions of carbon monoxide, which could be directly used in the existing chemical value chain.

We report a facile synthesis of monodisperse NiPd alloy nanoparticles (NPs) and their assembly on graphene (G) to catalyze the tandem dehydrogenation of ammonia borane (AB) and hydrogenation of R-NO2 and/or R-CN to R-NH2 in aqueous methanol solutions at room temperature. The 3.4 nm NiPd alloy NPs were prepared by coreduction of nickel(II) acetate and palladium(II) acetlyacetonate by borane-tert-butylamine in oleylamine and deposition on G via a solution phase self-assembly process. G-NiPd showed composition-dependent catalysis on the tandem reaction with G-Ni 30Pd70 being the most active. A variety of R-NO 2 and/or R-CN derivatives were reduced selectively into R-NH 2 via G-Ni30Pd70 catalyzed tandem reaction in 5-30 min reaction time with the conversion yields reaching up to 100%. Our study demonstrates a new approach to G-NiPd-catalyzed dehydrogenation of AB and hydrogenation of R-NO2 and R-CN. The G-NiPd NP catalyst is efficient and reusable, and the reaction can be performed in an environment-friendly process with short reaction times and high yields.

Purely aqueous-phase chemoselective reduction of a wide range of aromatic and aliphatic nitro substrates has been performed in the presence of inexpensive Ni- and Co-based nanoparticle catalysts using hydrazine hydrate as a reducing agent at room temperature. Along with the observed high conversions and selectivities, the studied nanoparticle catalysts also exhibit a high tolerance to other highly reducible groups present in the nitro substrates. The development of these potential chemoselective reduction catalysts also provides a facile route for the synthesis of other industrially important fine chemicals or biologically important compounds, where other highly reducible groups are present in close proximity to the targeted nitro groups.

A complex dynamic system based on a network of multiple reversible reactions has been established. The network was applied to a dynamic systemic resolution protocol based on kinetically controlled lipase-catalyzed transformations. This resulted in the formation of cyclized products, where two thiazolidinone compounds were efficiently produced from a range of potential transformations.

There is provided a process for the reduction of one or more amide moieties in a compound comprising contacting the compound with hydrogen gas and a transition metal catalyst in the presence or absence of a base under conditions for the reduction an amide bond. The presently described processes can be performed at low catalyst loading using relatively mild temperature and pressures, and optionally, in the presence or absence of a base or high catalyst loadings using low temperatures and pressures and high loadings of base to effect dynamic kinetic resolution of achiral amides.

The novel iminyl radical O2SN, a SO3 analogue, was produced by flash vacuum pyrolysis of gaseous alkyl sulfonyl azides RSO 2N3 (R=CF3, CH3) mixed with argon. Photoisomerization (λ>360 nm) of O2SN into planar syn-OSNO and anti-OSNO (see picture) was observed in solid noble-gas matrices. Copyright

Although cations with three heteroatoms, such as monoprotonated guanidine and urea, are stabilized by Y-shaped conjugation and such Y-conjugated cations are sufficiently basic to be further protonated (or protosolvated) to dications in strongly acid media, only O-monoprotonated species have been detected in the case of carbamates even in magic acid. We found that the trifluoromethanesulfonic acid-catalyzed cyclization of arylethylcarbamates proceeds to afford dihydroisoquinolones in high yield. In strong acids, methyl carbamates are fully O-monoprotonated, and these monocations do not undergo cyclization even under heating. But, as the acidity of the reaction medium is further increased, the cyclization reaction of methyl phenethylcarbamates starts to proceed as a first-order reaction, with a linear relationship between rate and acidity. The sign and magnitude of the entropy of activation ΔS ? were found to be similar to those of other AAc1 reactions. These results strongly support the idea that further protonation of the O-protonated carbamates is involved in the cyclization, but the concentration of the dications is very low and suggests that the rate-determining step is dissociation of methanol from the diprotonated carbamate to generate protonated isocyanate, which reacts with the aromatic ring. Therefore, O-protonated carbamates are weak bases in sharp contrast to other Y-shaped monocations.

A new zeolite catalyst, Al-RUB-41, was synthesized for the first time. It was tested as a catalyst in methanol amination, and showed a shape-selective performance that results in a highly favorable product distribution. The shape-selective nature was also evidenced by using Pt-Al-RUB-41 as a bifunctional catalyst for decane hydroconversion. With its unique pore architecture and remarkable shape-selective character, Al-RUB-41 presents a significant commercial potential in industrial catalysis.

Lipoic acid (LA) is a natural antioxidant. Its structure was previously combined with that of the acetylcholinesterase inhibitor tacrine to give lipocrine (1), a lead compound multitargeted against Alzheimer's disease (AD). Herein, we further explore LA as a privileged structure for developing multimodal compounds to investigate AD. First, we studied the effect of LA chirality by evaluating the cholinesterase profile of 1's enantiomers. Then, a new series of LA hybrids was designed and synthesized by combining racemic LA with motifs of other known anticholinesterase agents (rivastigmine and memoquin). This afforded 4, which represents a step forward in the search for balanced anticholinesterase and antioxidant capacities.

Aluminum was incorporated into the layered silicate RUB-39, which is transformed by calcination into RUB-41. This new zeolite with RRO topology contains 8- and 10-ring pores, and the acid sites in the aluminated material catalyze the synthesis of methylamines, in particular mono- and dimethylamine, by amination of methanol. Owing to the shape-selective catalytic properties of (H)Al-RUB-41, low selectivity to the thermodynamically favored trimethylamine product is obtained in comparison with results on RUB-39 or non-shape-selective materials. Both activity and selectivity are highest for RUB-41 catalysts with a high Si to Al ratio. Silylation reduces the number of unselective sites and results in a further suppression of trimethylamine formation. The introduction of acidity in the intact RUB-41 structure is supported by Al-MAS NMR and NH 3-TPD data. Additional characterization by XRD and SEM is provided.

[ReBr2(NO)(CH3CN)(PTA)2] (PTA = 1, 3, 5-triaza-7-phosphaadamantane) catalyzes the alcoholysis of ammonia-borane and amine-boranes and the catalytic transfer hydrogenations of various terminal olefins. Excellent yields were achieved at 70 °C in isopropanol using tBuOK as a co-catalyst affording TOF values up to 396 h-1.

We have studied the kinetics of BC x N y chemical vapor deposition through trimethylamine borane decomposition at atmospheric pressure. The rate constant of the heterogeneous interaction between trimethylamine borane and an adsorption center has been determined to be k s 0 = 2.7 × 107exp(-10560/T) cm/s. The obtained kinetic parameters of the reaction fully determine the growth rate of nanocrystalline carbonitride films under kinetic control. The film thickness has been determined as a function of time, temperature, reactant concentration, and reactor dimensions.

Amide-zing: The reaction between 2 equivalents of Ph2P(CH 2)2NH2 and cis-[Ru(CH3CN) 2(η3-C3H5)(cod)]BF4 (cod=1,5-cyclooctadiene) forms a highly active catalyst precursor for the selective hydrogenation of amides. The reaction proceeds with excellent atom economy, yield, and turnover numbers (TONs) under moderate reaction conditions. The technology offers a greener, practical approach to the use of metal hydride reagents commonly employed in both academia and industry. Copyright

Indirect CO2 hydrogenation: Hydrogenation of urea derivatives to the corresponding amines and methanol is reported (see picture). The reaction is catalyzed by a bipyridine-based tridentate PNN Ru(II) pincer complex and proceeds under mild, neutral conditions using 13.6 atm of H2. A mild approach is offered for the indirect hydrogenation of CO2 to methanol as urea derivatives are available from CO2. Copyright

An enzyme of unknown function within the amidohydrolase superfamily was discovered to catalyze the hydrolysis of N-6-substituted adenine derivatives, several of which are cytokinins. Cytokinins are a common type of plant hormone and N-6-substituted adenines are also found as modifications to tRNA. Patl2390, from Pseudoalteromonas atlantica T6c, was shown to hydrolytically deaminate N-6-isopentenyladenine to hypoxanthine and isopentenylamine with a k cat/Km of 1.2 × 107 M-1 s -1. Additional substrates include N-6-benzyl adenine, cis- and trans-zeatin, kinetin, O-6-methylguanine, N-6-butyladenine, N-6-methyladenine, N,N-dimethyladenine, 6-methoxypurine, 6-chloropurine, and 6-thiomethylpurine. This enzyme does not catalyze the deamination of adenine or adenosine. A comparative model of Patl2390 was computed using the three-dimensional crystal structure of Pa0148 (PDB code 3PAO) as a structural template, and docking was used to refine the model to accommodate experimentally identified substrates. This is the first identification of an enzyme that will hydrolyze an N-6-substituted side chain larger than methylamine from adenine.

Peptide C-terminal N-alkyl amides have gained more attention over the past decade due to their biological properties, including improved pharmacokinetic and pharmacodynamic profiles. However, the synthesis of this type of peptide on solid phase by current available methods can be challenging. Here we report a convenient method to synthesize peptide C-terminal N-alkyl amides using the well-known Fukuyama N-alkylation reaction on a standard resin commonly used for the synthesis of peptide C-terminal primary amides, the peptide amide linker-polyethylene glycol-polystyrene (PAL-PEG-PS) resin. The alkylation and oNBS deprotection were conducted under basic conditions and were therefore compatible with this acid labile resin. The alkylation reaction was very efficient on this resin with a number of different alkyl iodides or bromides, and the synthesis of model enkephalin N-alkyl amide analogs using this method gave consistently high yields and purities, demonstrating the applicability of this methodology. The synthesis of N-alkyl amides was more difficult on a Rink amide resin, especially the coupling of the first amino acid to the N-alkyl amine, resulting in lower yields for loading the first amino acid onto the resin. This method can be widely applied in the synthesis of peptide N-alkyl amides.

Aliphatic and aromatic nitro compounds were selectively reduced to their corresponding amino derivatives in good yields using formic acid and CeY zeolite under monomode reactor. This system is found to be compatible with several sensitive functionalities. Beside the recycling result showed it had a long catalyst lifetime and could maintain activity even after being used for 20 cycles.