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Over metal catalysts, N‐heteroarenes, as one of the most versatile building blocks in pharmaceuticals, bioactive molecules and natural products, can be easily accessed by the oxidation of N‐heterocycles. Herein, we describe N‐doped hierarchical pore carbons (N‐HPCs) derived from readily available biomass (flour) efficiently catalyzed aerobic dehydrogenation of N‐heterocycles without any additives under mild conditions, owing to N dopant and high surface area indicated by characterization analysis. A wide range of N‐heteroarenes including quinolines, quinolinol, dihydroisoquinolines, isoquinolines, indoles, quinoxaline and acridine were obtained in good to excellent yields (36 examples, up to 99% yield). Mechanistic studies revealed a strikingly different non‐free radical process from metal catalysts, for which an apparent activation energy of 66.4 kJ mol−1 was found. Moreover, the N‐doped carbon exhibited robust stability and yielded 74.5% quinoline at the sixth reaction. The use of metal‐free catalysts in organic synthesis is attractive but practically challenging. This work provides a promising example for metal‐free catalysis. [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]

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]

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]

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]