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Herein, we present a series of N,O-doped mesoporous carbons obtained at different pyrolysis temperatures as the first metal-free catalysts which successfully switch between imine and nitrile products for amine oxidation. Systematic characterization studies and control experiments revealed that the C–O group on the surface could function as a catalytically active site for nitrile synthesis and the N-doping environment was essential. [ABSTRACT FROM AUTHOR]

Here meso-N/C-900 derived from polypyridyl ligand DAA has been developed as a metal-free catalyst, for the first time, exhibiting good performance in catalytic ammoxidation of alcohols to nitriles. Systematic characterization suggests that the accessible mesopores and the effective pyridinic/pyrrolic-N are responsible for the unprecedented performance. [ABSTRACT FROM AUTHOR]

Mesoporous carbon derived from natural vitamin B12 is applied for the first time in organic synthesis and exhibits exceptionally high dual activity for imine formation via the cross-coupling of alcohols with amines and the self-coupling of primary amines using molecular oxygen or air as the terminal oxidant. [ABSTRACT FROM AUTHOR]

Novel PdVO x nanoparticles (NPs) prepared by a one-pot hydrogenation method are reported. X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, and UV/Vis spectroscopy were performed to characterize the PdVO x NPs. The NPs catalyzed benzene directly to phenol in 5.2 % yield with more than 99 % selectivity using O2 as the sole oxidant. [ABSTRACT FROM AUTHOR]

Abstract: Three organic–inorganic hybrid TM–Ln heterometallic phosphotungstates [Cu(dap)2(H2O)][Cu(dap)2]3.5[La(α-HPW11O39)2]·6H2O (1) [Cu(dap)2(H2O)]0.5[Cu(dap)2]4[Nd(α-HPW11O39)2]·4H2O (2) and [Cu(dap)2(H2O)]2[Cu(dap)2]3.5[Eu(α-PW11O39)2]·6H2O (3) (dap=1,2-diaminopropane) have been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectra, optical diffuse reflectance spectra, powder X-ray diffraction (PXRD), thermogravimetric (TG) analyses and single-crystal X-ray diffraction. Their common features are that 1–3 all consist of asymmetric sandwich-type subunits [Ln(α-PW11O39)2]11− and [Cu(dap)2]2+ bridges. Both 1 and 2 display the 2-D (4,4)-topological sheets whereas 3 exhibits the 3-D 5-connected (46·64) topological framework. The magnetic properties of 2 and 3 and the luminescence performance of 3 have been measured. [Copyright &y& Elsevier]

Abstract: The hydrothermal reactions of Na8[A-α-HAsW9O34]·11H2O with CuCl2·2H2O, LnCl3 in the presence of ethylenediamine (en) lead to three novel 2D organic–inorganic hybrid CuII–LnIII heterometallic arsenotungstates Na3[Cu(en)2(H2O)][Cu(en)2]1.5[H3Ln(α-AsW11O39)2]·xH2O (Ln=DyIII, x =5 (1); Ln=GdIII, x =4 (2); Ln=LaIII, x =5.5 (3)), which have been characterized by elemental analyses, IR spectra, optical diffuse reflectance spectra, thermogravimetric analyses and single-crystal X-ray diffraction. 1–3 are isomorphic and exhibit the unique 2D honeycomb (6,3)-network topology constructed from sandwich-type [H3Ln(α-AsW11O39)2]8− units through [Cu(en)2]2+ linkers. To the best of our knowledge, 1–3 represent rare 2D organic–inorganic hybrid CuII–LnIII heterometallic arsenotungstates. The photocatalytic measurements show that 1–3 can to some extent inhibit the photodegradation of rhodamine-B. Moreover, magnetic measurements demonstrate that there are the weak ferromagnetic behaviors in 1 and 2. [Copyright &y& Elsevier]

A series of physical mixtures of Na4P2S6 and NiCl2 (P‐NiPS(x), where x represents the P/Ni molar ratio) were employed for the preparation of Ni2P. For comparison, a sulfur‐containing Ni2P catalyst (Ni2P‐S) and a sulfur‐free Ni2P catalyst (Ni2P‐TPR) were prepared by reduction of Ni2P2S6 and a nickel phosphate precursor, respectively. The reduction of the P‐NiPS(x) precursors with P/Ni ratios above 2/3 yielded Ni2P catalysts with a distinct nickel phosphosulfide layer (NiPS(x)), and the Ni2P phase started to form at ca. 200 °C. The reduction of Ni2P2S6 to Ni2P most likely follows a disproportionation mechanism. The P3+ species in Ni2P2S6 disproportionate to PH3 and P5+ during the reduction, and PH3 further reacts with nickel and sulfur species to form Ni2P and the surface nickel phosphosulfide layer. The sulfur atoms in the nickel phosphosulfide phase were in the form of S2−. The introduction of sulfur to Ni2P favored the hydrogenation pathway of the hydrodesulfurization (HDS) of dibenzothiophene (DBT), but hardly affected the direct desulfurization (DDS) pathway and inhibited the hydrogenation of biphenyl. The DDS pathway rate constants of DBT HDS over the Ni2P‐TPR and NiPS(x) catalysts were observed to increase linearly with the increase in their surface Ni atomic concentrations. [ABSTRACT FROM AUTHOR]

Development of metal‐free catalysis in chemical transformation is highly desirable due to its significant inherent advantages compared with conventional metal or metal oxide catalysts but challenging. Herein, ionic liquid 1‐ethyl‐3‐methylimidazolium dicyanamide and sodium tetraphenylborate were employed as joint precursors to facilely prepare micro‐mesoporous core‐shell carbon with specific surface area up to 2870 m2 g−1, consisting of smooth unpenetrated shell and secondary hollow spherical carbon core. The as‐obtained core‐shell carbon as metal‐free catalyst exhibited good performance for self‐coupling and cross‐coupling of amines to achieve the corresponding symmetry and asymmetry imines under mild and neat conditions. Excitingly, for the challenging aliphatic amines, the desired imines were achieved in our case in 55.9 % yield. The nearly linearly correlation between imine yield and ID/IG indicated that the resulting defects from departure of heteroatoms during pyrolysis may be active site. [ABSTRACT FROM AUTHOR]

Selective cleavage and functionalization of C−C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C−C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C−C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long‐chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent −(C−C)n− bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C−C bonds to achieve excellent catalytic activity, while the presence of Co‐Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process. [ABSTRACT FROM AUTHOR]

Selective cleavage and functionalization of C−C bonds have important applications in organic synthesis and biomass utilization. However, functionalization of C−C bonds by controlled cleavage remains difficult and challenging because they are inert. Herein, we describe an unprecedented efficient protocol for the breaking of successive C−C bonds in alcohols to form esters with one or multiple carbon atoms less using heterogeneous cobalt nanoparticles as catalyst with dioxygen as the oxidant. A wide range of alcohols including inactive long‐chain alkyl aryl alcohols undergo smoothly successive cleavage of adjacent −(C−C)n− bonds to afford the corresponding esters. The catalyst was used for seven times without any decrease in activity. Characterization and control experiments disclose that cobalt nanoparticles are responsible for the successive cleavage of C−C bonds to achieve excellent catalytic activity, while the presence of Co‐Nx has just the opposite effect. Preliminary mechanistic studies reveal that a tandem sequence reaction is involved in this process. [ABSTRACT FROM AUTHOR]

Kinetic analysis demonstrates that the C-H bond cleavage is the rate-determining step and that a carbocation may be involved in the reaction. [ABSTRACT FROM AUTHOR]

Ligands (I) and an acid additive are highly efficient in the process. [ABSTRACT FROM AUTHOR]

Compounds (IV), (VI), and (VIII) are characterized by powder and single crystal XRD, IR and optical diffuse reflectance spectroscopy, magnetic measurements, and luminescence spectroscopy. [ABSTRACT FROM AUTHOR]

Three new metal–organic complexes Cu[Hbpdc] 2 ( 1 ), [Ni(bpdc)(H 2 O)]·H 2 O ( 2 ) and [Ni(H 2 bpdc)(H 2 O) 2 ]SO 4 ( 3 ) (H 2 bpdc=2,2′-bipyridyl-5,5′-dicarboxylic acid) have been hydrothermally prepared and structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1 is a 3-D supramolecular architecture formed by hydrogen bonding interactions between carboxyl O atoms and strong face-to-face π ⋯ π stacking interactions between bipyridyl rings of Hbpdc − ligands, 2 exhibits an intriguing 2-D sheet constructed from [Ni(bpdc)(H 2 O)] units and 3 displays an infinite 1-D chain built by {[Ni(H 2 bpdc)(H 2 O) 2 ] 2+ } fragments through SO 4 2− . Moreover, thermogravimetric (TG) and derivative thermogravimetric (DTG) analyses of 3 have been conducted and the TG curve shows two-stage weight loss between 300 and 950 K and the corresponding apparent activation energies are calculated by Ozawa–Flynn–Wall (OFW) method and Friedman method. The most probable kinetic model function of the dehydration reaction of 3 has been estimated by Coats–Redfern integral method and Achar–Bridly–Sharp differential method. [ABSTRACT FROM AUTHOR]

Highlights: [•] Copper–lanthanide heterometallic coordination polymers containing 2,2′-bipyridyl-5,5′-dicarboxylic acid. [•] IR spectra of copper–lanthanide heterometallic coordination polymers. [•] X-ray photoelectron spectroscopy of copper and lanthanide cations. [•] Solid-state photoluminescence of copper–lanthanide heterometallic coordination polymers. [ABSTRACT FROM AUTHOR]

[Display omitted] • Reactions of 2-phenylcyclohexanethiol (2-PCHT) under H 2 and Ar over Pd and Pt. • Comparison of the catalytic performances of major hydrodesulfurization catalysts. • Quasi in situ infrared study of Pd/Al 2 O 3 and Pt/Al 2 O 3 in the reactions of 2-PCHT. • Strong adsorption of phenylcyclohexene on Pd/Al 2 O 3 and Pt/Al 2 O 3. • Species adsorbed on Pd/Al 2 O 3 and Pt/Al 2 O 3 were different under H 2. The desulfurization of 2-phenylcyclohexanethiol (2-PCHT) was studied over Pd and Pt catalysts supported on γ-Al 2 O 3 under 5.0 MPa H 2 or Ar at 240 °C. The infrared spectra of the two catalysts during the reactions of 2-PCHT (PCHT-IR) were measured between 180 and 300 °C at 0.2 MPa H 2 and Ar. The hydrodesulfurization (HDS) of 2-PCHT over Pd/Al 2 O 3 and Pt/Al 2 O 3 followed pseudo-first-order kinetics, and occurred mainly through β-elimination. Pd/Al 2 O 3 was more active than Pt/Al 2 O 3 , mainly due to its higher β-elimination activity. Piperidine showed different inhibiting effects on their HDS performances. The species adsorbed on Pd/Al 2 O 3 and Pt/Al 2 O 3 were different under H 2. Strong adsorption of 1-phenyl-1-cyclohexene on both catalysts was observed under Ar, which could be responsible for Langmuir-Hinshelwood kinetics and low activities. Pd/Al 2 O 3 and Pt/Al 2 O 3 were less active than transition-metal phosphides in the HDS of 2-PCHT, but were more active than the Mo-based sulfides. [ABSTRACT FROM AUTHOR]

The oxidative cleavage of the C–C bonds in 1,2-diols is an important transformation in synthetic organic chemistry. The challenge for this reaction is to develop a recyclable catalyst and an efficient catalytic system that operates under mild conditions. Here we report an atomically dispersed cobalt (3.8 wt% Co) on N-doped carbon catalyst, which exhibits improved catalytic activity toward the oxidative cleavage of a variety of 1,2-diols into esters, ketones or aldehydes using molecular oxygen under mild conditions. For example, the oxidative cleavage of internal diols is achieved at ambient temperature and air pressure. The robust catalyst can be reused at least seven times without regeneration treatment. The formation of highly dispersed active Co-Nx sites is demonstrated by catalyst characterization and potassium thiocyanate poisoning experiment. Mechanistic insights into monosubstituted diols indicate a sequence reaction including stepwise oxidation/nucleophilic addition/C–C bond cleavage, and reveal two reaction pathways. The oxidative cleavage of the C–C bonds in 1,2-diols is an important transformation but lacks a recyclable, mild aerobic catalytic system. Here the authors present atomically dispersed cobalt on N-doped carbon to deliver improved catalytic activity and recyclability, and probe the reaction pathway. [ABSTRACT FROM AUTHOR]

Transition-metal phosphides and phosphosulfides constitute a class of versatile and promising catalysts in the field of enery production. The preparation of nanostructured phosphides and phosphosulfides is chanllenging because the thermal reduction of phosphate precursors requires high temperatures. In the present work, nanostructured nickel phosphosulfide catalysts composed of Ni 2 P particles surrounded by a distinct sulfur-containing layer were prepared by reduction of mixtures of Na 4 P 2 S 6 and NiCl 2 in H 2 plasma. The minimum P/Ni ratio needed for the formation of nickel phosphosulfide was between 4/7 and 2/3, and the input voltage of the plasma generator (V in) should be higher than 40 V. The control of the particle sizes of the nickel phosphosulfide catalysts was realized by simply regulating V in. Another minor factor affecting the particle size was H 2 flow rate. The actual precursor for the formation of nickel phosphosulfide can be Ni 2 P 2 S 6 , which underwent fast reduction in H 2 plasma to yield NiS. In the hydrodesulfurization of dibenzothiophene, the nanostructured nickel phosphosulfide catalyst exhibited higher activity and hydrogenation pathway (HYD) selectivity than the one with large particle size. The optimal P/Ni ratio of the nickel phosphosulfide catalysts was found to be 4/5, and the HYD pathway was more favored by the increase in the P/Ni ratio than the direct desulfurization pathway. [Display omitted] • Mixtures of Na 4 P 2 S 6 and NiCl 2 were used as catalyst precursors. • Preparation of nickel phosphosulfide (NiPS) by H 2 plasma reduction of the mixtures. • The control of the particle size of NiPS by regulating the input voltage. • The minimum P/Ni ratio of the mixture for the formation of NiPS was 2/3. • Large NiPS particles showed lower hydrodesulfurization activity than nanoparticles. [ABSTRACT FROM AUTHOR]

Aldehydes and ketones are prepared in good to excellent yields by oxidation of various alcohols including primary benzylic, allylic, alkynyl, aliphatic alcohols, and secondary benzylic alcohols. [ABSTRACT FROM AUTHOR]

A novel strategy for catalytic oxidation of a variety of benzylic, allylic, propargylic, and aliphatic alcohols to the corresponding aldehydes or ketones by an in situ formed porphyrin-inspired manganese complex in excellent yields (up to 99%) has been successfully developed. [ABSTRACT FROM AUTHOR]

Direct oxidation of 2,3-cyclopentenopyridine analogues to 6,7-dihydro-5H-cyclopenta[b]pyridin-5-one analogues was achieved using Mn(OTf)2 as a catalyst and t-BuOOH (65% in H2O) as an oxidant at 25 °C in H2O with high yield and excellent chemoselectivity for the first time. The catalytic system was also used efficiently for the direct oxidation of substituted benzylpyridines and 2-ethylpyridine in t-BuOH. [ABSTRACT FROM AUTHOR]

Abstract: A novel metal–organic complex [Fe(H2bpdc)]SO4 (1) has been hydrothermally synthesized (H2bpdc=2,2''-bipyridyl-5,5''-dicarboxylic acid) and structurally characterized by elemental analyses, IR spectra, powder X-ray diffraction and single-crystal X-ray diffraction, which displays the first 1-D ferrous sulfate chain functionalized by H2bpdc. Interestingly, the 3-D supramolecular structure of 1 can be constructed by means of hydrogen-bonding interactions and Fe···O short contacts. Thermogravimetric analysis indicates that 1 shows a good thermal stability and can be thermally stable up to 420°C. Magnetic measurements of 1 exhibit the existence of antiferromagentic interactions within the FeII centers. [Copyright &y& Elsevier]

An abstract of the article "Development of a Continuous-Flow Microreactor for Asymmetric Epoxidation of Electron-Deficient Olefins" by W. Dai, S. Shang, and S. Gao is presented.

An abstract of the article "Development of a Continuous-Flow Microreactor for Asymmetric Epoxidation of Electron-Deficient Olefins'' by Wen Dai and colleagues is presented.

30 examples [ABSTRACT FROM AUTHOR]

An abstract of the article "Synthesis of 6,7-Dihydro-5H-cyclopenta[b]pyridin-5-one Analogues Through Manganese-Catalyzed Oxidation of the CH2 Adjacent to Pyridine Moiety in Water" by L. Ren et al. is presented.

This highly enantioselective asymmetric oxidation can also be applied to the synthesis of esomeprazole, which is a chiral proton pump inhibitor. [ABSTRACT FROM AUTHOR]