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The fabrication of electrochemical biosensors without any binder or enzymes is in high demand in the clinical diagnostic and industrial sectors. This work presents the development of hydrogen-substituted graphdiyne encapsulated Cu2O nanowires (Cu2O NWs@ HsGDY) hybrid electrode, directly grown on Cu foils. The sp and sp2 hybridization of HsGDY is confirmed by Raman and X-ray photoelectron spectroscopy, and the HsGDY encapsulation over Cu2O NWs is observed in transmission electron microscope images. The fabricated binder-free, nonenzymatic electrode exhibits the highest sensitivity of 584.2 μA·cm2·μM–1 (Cu2O NWs@HsGDY-1 h), the lowest detection limits of 0.035 μM (Cu2O NWs@HsGDY-6 h) and a linear detection range of 0.5–2500 μM. The Cu2O NWs@HsGDY-6 h electrode demonstrates 70 days of stability (82%) and excellent reproducibility (RSD = 1.97%) compared to other hybrid electrodes. The improved glucose sensing performance and stability is a combined effect of semiconducting nature and catalytic ability are attributed to Cu2O NWs@HsGDY hybrid electrodes. The successful glucose detection in actual food samples indicates the practical applicability of the Cu2O NWs@HsGDY sensor. [ABSTRACT FROM AUTHOR]

Combination of Karstedt's catalyst or Pt(dba)2 [dba: dibenzylideneacetone] with activated carbon was found to be an efficient catalyst system for the arene hydrogenation of a variety of functionalized aromatic compounds. The reaction proceeds at ambient temperature under atmospheric hydrogen pressure to afford the corresponding carbo‐ and heterocyclic compounds in good to high yields without contamination of the metallic species. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the platinum species effectively after the reaction. Similar sustaining effect was observed by the addition of vinyl siloxane derivatives. [ABSTRACT FROM AUTHOR]

The synthesis secondary amines, tertiary amines, and silyl enamines in the hydrosilane reduction of secondary amides catalyzed by a triruthenium complex is described.

Carbon‐nitrogen bond formation is an important method on both laboratory and industrial scales because it realizes the production of valuable pharmaceuticals, agrochemicals, and fine chemicals. Direct reductive N‐alkylation of amines with carbonyl compounds via intermediary imine compounds, especially under catalytic hydrogenation conditions, is one of the most convenient, economical, and environmentally friendly methods for this process. Here we report a novel palladium species on zirconia having specific activity towards hydrogenation of imines but other carbonyl groups remaining intact. The present catalytic property offers a practical synthetic method of functionalized secondary amines by reductive N‐alkylation under mild conditions with high atom‐efficiency. Mechanistic studies revealed that the catalytically active species is the palladium cluster, which is generated in situ from molecular palladium complexes on the support by exposure to atmospheric hydrogen. These fundamental findings are expected to progress in developing novel cluster catalysts for chemical processes directed towards a sustainable society. [ABSTRACT FROM AUTHOR]

A binaphthol-titanium complex (BINOL-Ti) catalyzed an asymmetric Diels-Alder (D.-A.) reaction in the absence of molecular sieves (MS). The MS-free complex demonstrated linear relationships with D.-A. products and the ee's of BINOC-Ti and exhibited stability at -20 degrees centigrade for several months.

The current research deals with the study of boron and nitrogen co-doped reduced graphene oxide (BN-rGO) as a support material for iridium oxide (IrO2) nanoparticles for oxygen evolution reaction (OER) catalysis. The synthetic approach for the IrO2–BN-rGO catalyst involves the combination of pyrolysis and hydrothermal methods used for hierarchical nanostructures. BN-rGO possesses B–N, B–C, and N–C functional groups to support and stabilize the IrO2 catalyst nanoparticles. The altered electronic states of IrO2 on the BN-rGO support are compared with those of IrO2 on a non-doped support, rGO (IrO2–rGO), and on commercial BN sheets (IrO2–c-BN). The catalyst shows a low overpotential (300 mV at 10 mA cm−2), high current density (55 mA cm−2 at 1.65 V), and significantly high durability (12 350 cycles; 45 h) in an acidic environment. The high stability of IrO2–BN-rGO may result from the presence of a chemically and electrochemically stable B–N bond. We confirm that other functional groups (B–C and N–C) and the rGO framework are equally crucial for better attachment of IrO2 nanoparticles. [ABSTRACT FROM AUTHOR]

The syntergetic effect of two Si-H groups which leads to efficient platinum-catalyzed reduction of carboxamides to amines under mild conditions is reported. The reduction of amides having other reducible functional groups such as N[O.sub.2], C[O.sub.2]R, CN, C-C, Cl, and Br moieties to provide a reliable method for the access to functionalized amine derivatives is also discussed.

An approach for a highly efficient synthesis of optically pure 5,5',6,6',7,7',8,8'-octahydro-1,1'-bi-2-naphthol and -naphthylamine derivatives is discussed. The production is obtained by the partial hydrogenation of various 1,1'-binaphthyls with carbon nanofiber supported ruthenium nanoparticles.

Combination of PdCl2 with 1,1,3,3‐tetramethyldisiloxane in the presence of activated carbon was found to be an effective catalyst system for the cleavage reaction of C−O bond of O−t‐Bu moieties. The present catalytic reaction offers a practical method for the deprotection of tert‐butyl esters, tert‐butyl ethers, O‐Boc, and N‐Boc derivatives under mild conditions. The addition of activated carbon in the reaction mixture was proved to be crucial for not only sustaining the catalytic activity but also trapping the palladium species after the reaction. [ABSTRACT FROM AUTHOR]

Abstract: Palladium nanoparticles supported on 5 %‐nitrogen‐doped, herringbone‐type carbon nanofibers (Pd/N‐CNF‐H), which are prepared by thermally decomposing [Pd2(dba)3⋅CHCl3] (dba=dibenzylideneacetone) in toluene in the presence of N‐CNF‐H, were found to be an efficient catalyst for the chemoselective hydrogenation of alkenyl and nitro moieties in benzyl‐protected alcohols and carboxylic acid derivatives with high turnover frequencies: the hydrogenation reactions of these functional groups proceeded smoothly even at ambient temperature under atmospheric H2 pressure, and the benzyl protecting groups in the molecules remained intact. Moreover, the recovered Pd/N‐CNF‐H catalyst could be reused without loss of its catalytic activity or chemoselectivity. The Pd/N‐CNF‐H catalyst also acted as an effective hydrogenation catalyst for the reduction of aromatic ketones to the corresponding benzyl alcohol derivatives with good to high product selectivity. [ABSTRACT FROM AUTHOR]

The present reduction of amides with polymethylhydrosiloxane (PMHS) offers a solution as an environmentally benign production of amines, namely an efficient catalytic process involving facile separation of catalyst species and silicone byproducts from the product. The self-encapsulation of catalyst species into the silicone resin is considered to be one of the methods for microencapsulation of molecular catalysts into polymer supports.

The reaction of three types of carbon nanofibers (CNFs; platelet: CNF-P, tubular: CNF-T, herringbone: CNF-H) with Ir4(CO)12 in mesitylene at 165 °C provided the corresponding CNF-supported iridium nanoparticles, Ir/CNFs (Ir content=2.3-2.6 wt. %). Transmission electron microscopy (TEM) studies of these Ir/CNF samples revealed that size-controlled Ir nanoparticles (average particle size of 1.1-1.5 nm) existed on the CNFs. Among the three Ir/CNF samples, Ir/CNF-T showed an excellent catalytic activity and chemoselectivity towards hydrogenation of functionalized nitroarenes and imines; the corresponding aniline derivatives were obtained with high turnover numbers at ambient temperature under 10 atm of H2, and the catalyst is reusable. Ir/CNF-T was also effective for the reductive N-alkylation of anilines with carbonyl compounds. [ABSTRACT FROM AUTHOR]

The article discusses a study which synthesized palladium nanoparticles supported on nitrogen-doped carbon nanofiber (N-CNF-H) by thermally decomposing Pd2(dba)3CHCl3 in the presence of N-CNF-H. The study found that the Pd/N-CNF-H compounds act as efficient catalysts in the partial hydrogenation of internal alkynes to the corresponding (Z)-alkenes. It also suggested the significance of N-CNF-H in the preparation of heterogenous poisoning catalysts.

The article focuses on research to immobilize platinum nanoparticles on the surface of nitrogen-doped, herringbone-type carbon nanofibers (N-CNF-H) with the formed Pt/N-CNF-H compounds becoming efficient poisoning catalysts for the nitro-selective hydrogenation of nitroarenes. Carbon-supported metal nanoparticles are used as sensors and electrocatalysts for lithium (Li) ion batteries. It involves synthesizing N-CNF-H using vapor deposition over an MgO supported Ni-Fe catalyst using hydrogen.

Bis(oxazolinyl)phenylrhodium(III) aqua complexes, (Phebox)RhX2(H2O) [X = Cl, Br], were found to be efficient Lewis acid catalysts for the enantioselective addition of allyl- and methallyltributyltin reagents to amino aldehydes. The reactions proceed smoothly in the presence of 5-10 mol % of (Phebox)RhX2(H2O) complex at ambient temperature to give the corresponding amino alcohols with modest to good enantioselectivity (up to 94% ee). [ABSTRACT FROM AUTHOR]

Abstract: Combination of commercially available platinum catalysts with siloxanes containing more than two Si–H groups is found to be an efficient catalyst system for the reduction of carboxamides to amines. In particular, facile removal of silicon and platinum residues from the product can be achieved by the use of polymethylhydrosiloxanes as reducing reagents. [Copyright &y& Elsevier]

Abstract: Atom-transfer radical cyclization (ATRC) and addition (ATRA) catalyzed by a coordinatively unsaturated diruthenium amidinate complex 4 , [(η5-C5Me5)Ru(μ2-i-PrN:italic>i-Pr)Ru(η5-C5Me5)]+, are investigated, and their features are compared with those of atom-transfer radical polymerization (ATRP). As an example of ATRC, a cationic diruthenium amidinate 4 is found to exhibit excellent catalytic reactivity for the cyclization of N-allyl α-halogenated acetamides including an alkaloid skeleton at ambient temperature. A catalytic species generated in situ from a halide complex, (η5-C5Me5)Ru(μ2-i-PrN:italic>i-Pr)Ru(η5-C5Me5)(X) [X=Cl, Br] and sodium salts of weakly coordinating anions such as NaPF6 and NaBPh4 also shows high catalytic activity; this actually provides a solution for a problematic instability of 4 as the practical catalyst. The in situ-generated catalyst species 4 is also active towards the intermolecular ATRA of α,α,γ-trichlorinated γ-lactam with alkenes at rt to afford the corresponding α-alkylated γ-lactams in moderate yields. Examination of ATRP of methyl methacrylate (MMA) showed that both the isolated 4 [Y=PF6] and in situ-generated 4 [Y=PF6] are effective for the polymerization of MMA in the presence of 2-bromoisobutylate as the initiator. Use of the isolated catalyst results in controlled polymerization at initial stage of the reaction; in contrast, the polymerization with in situ-generated catalyst produces poly(MMA) with wide molecular weight distribution. The isolated catalyst 4 is powerful for the activation of a C–Br bond of macromolecule initiators; BrCMe2CO2[O(CH2)4] n -n-Bu (M n=3800; M w/M n=1.2) initiated ATRP of MMA even at 25°C to afford the poly(THF)–poly(MMA) block copolymer of M n=26,000 and M w/M n=1.2 with the aid of 4 . The roles of the coordinatively unsaturated ruthenium species for these reactions are discussed. [Copyright &y& Elsevier]

The combination of IrCl(CO)(PPh3)2 with 1,1,3,3-tetramethyldisiloxane or poly(methylhydrosiloxane) (PMHS) is found to be an efficient catalyst system for the preparation of aldenamines from carboxamides; in particular, facile removal of silicone and iridium residues from the product can be achieved by the use of PMHS. [ABSTRACT FROM AUTHOR]

A cationic diruthenium amidinate, [(η5C5Me5) Ru(μ2-i-PrN≡C(Me)Ni-Pr)Ru(η5 C5Me5)]+ is generated by treatment of (η5]-C5Me5)Ru(μ2-i-PrN≡C(Me)Ni-Pr) Ru(Cl)(η5-C5Me5) (3a) with NaPF6 or other metal salts of weakly coordinating anions, which is active towards catalytic atom transfer radical cyclization of N-allyl trichloroacetamides and related reactions. [ABSTRACT FROM AUTHOR]

The easy synthesis of transition metal nanoparticles supported on three types of carbon nanofibers (platelet: CNF-P, tubular: CNF-T, herringbone: CNF-H) and nitrogen-doped CNF-H (N-CNF-H) is accomplished by pyrolysis of metal carbonyl clusters such as Ru 3 (CO) 12 , Rh 4 (CO) 12 , and Ir 4 (CO) 12 , and alkene complexes such as Pd 2 (dba) 3 ·CHCl 3 and Pt(dba) 2 [dba: dibenzylideneacetone]. Transmission electron microscopy of these CNFs with immobilized metal nanoparticles (M/CNFs and M/ N -CNF-H) showed that metal nanoparticles whose size could be controlled, existed on the CNFs, and that their location was dependent on the surface nanostructure of the CNFs: on the edge of the graphite layers (CNF-P), in the tubes and on the surface (CNF-T), and between the layers and on the edge (CNF-H). Among these M/CNFs, Ru/CNF-P and Rh/CNF-T showed excellent catalytic activity towards arene hydrogenation with high reusability and functional group tolerance, while the Pt/CNF-P behaves as an efficient catalyst for the hydrogenation of substituted nitroarenes to the corresponding aniline derivatives with the other functional groups remaining intact. Pt and Pd nanoparticles supported on N -CNF-H act as poisoning catalysts for the transformation of internal alkynes to ( Z )-alkenes over Pd/ N -CNF-H, and for the transformation of nitroarenes to the corresponding anilines and N -hydroxylamines over Pt/ N -CNF-H. [TANSO 2015 (No. 266) 35–40.] [ABSTRACT FROM AUTHOR]

The catalyst consisting of carbon nanofibers with tubular graphite layers is reused five times without loss of activity. [ABSTRACT FROM AUTHOR]

The bifunctional hydrosilane as well as the Ru catalyst are stable towards air and moisture. [ABSTRACT FROM AUTHOR]