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Abstract: Like many branches of science, not to mention culture in general, electrochemistry has a number of recurring topics: Areas of research that are popular for a certain time, then fade away as their possibilities seem to have been exhausted, only to return decades later as progress in experimental or theoretical techniques offer new possibilities for their investigation. A prime example are fuel cells, which have undergone five such cycles, but here we discuss a general concept of kinetics—the pre‐exponential factor of a rate constant—which has undergone two such cycles. The first cycle was in the 1950–1980s, when the methods of electrochemical kinetics were developed, and the interpretation was based on transition‐state theory. The second was triggered by the re‐discovery of Kramers theory for reactions in condensed phases. This Minireview will show that the time has come for a third cycle based on recent progress in electrocatalysis. [ABSTRACT FROM AUTHOR]

The pentagonal bipyramidal single-ion magnets (SIMs) are among the most attractive prototypes of high-performance single-molecule magnets (SMMs). Here, a fluorescence-active phosphine oxide ligand CyPh2PO (=cyclohexyl(diphenyl)phosphine oxide) was introduced into [Dy(CyPh2PO)2(H2O)5]Br3⋅2 (CyPh2PO)⋅EtOH⋅3 H2O, and combined dynamic magnetic measurement, optical characterization, ab initio calculation, and magneto-optical correlation of this high-performance pseudo- D5 h DyIII SIM with large Ueff (508(2) K) and high magnetic hysteresis temperature (19 K) were performed. This work provides a deeper insight into the rational design of promising molecular magnets. [ABSTRACT FROM AUTHOR]

The organocatalytic asymmetric synthesis of hexahydropyridazines were performed through a unique Michael/amination/cyclization reaction. The organocascade reaction proceeded smoothly between 2-arylidene-1,3-indandiones and aldehydes followed by the addition of azodicarboxylates catalyzed by the privileged organocatalyst α,-α-L-diphenylprolinol trimethylsilyl ether (10 mol%) in the presence of a base additive Et3N (20 mo%) at 0 °C. A series of substituted hexahydropyridazines were obtained in good to high chemical yields (55-78 %) and reasonable to high levels of stereoselectivities (51-93 % ee and 4 : 1 d.r.). [ABSTRACT FROM AUTHOR]

The TbIII compound [Tb(tci)(H2O)] n · n(DMF) ( 1) [H3tci = tri(2-carboxythyl)isocyanurate, DMF = N,N′-dimethylformamide] was synthesized by the reaction of terbium oxide, H3tci, and two drops of concentrated nitric acid in the presence of DMF and H2O. Single crystal X-ray analysis reveals that it features a three-dimensional (3D) framework based on infinite -Tb-COO-Tb- chains. The tci ligand in 1 links six different TbIII ions with its two carboxylate groups in μ2-κ1O;κ2O,O′ mode and the third in μ2-κ1O;κ1O′ mode. Thermal analysis reveals that it remains high thermal stability until 390 °C. Luminescence investigation shows that it emits characteristic green light of TbIII ions. [ABSTRACT FROM AUTHOR]

Achieving selective C−H activation at a single and strategic site in the presence of multiple C−H bonds can provide a powerful and generally useful retrosynthetic disconnection. In this context, a directing group serves as a compass to guide the transition metal to C−H bonds by using distance and geometry as powerful recognition parameters to distinguish between proximal and distal C−H bonds. However, the installation and removal of directing groups is a practical drawback. To improve the utility of this approach, one can seek solutions in three directions: 1) Simplifying the directing group, 2) using common functional groups or protecting groups as directing groups, and 3) attaching the directing group to substrates via a transient covalent bond to render the directing group catalytic. This Review describes the rational development of an extremely simple and yet broadly applicable directing group for PdII, RhIII, and RuII catalysts, namely the N-methoxy amide (CONHOMe) moiety. Through collective efforts in the community, a wide range of C−H activation transformations using this type of simple directing group have been developed. [ABSTRACT FROM AUTHOR]

The ligands 2-pyrazol-1-yl-1H-indole (HL1) and 2-,,-triazol-1-yl-1H-indole (HL2) individually reacted with Ti(NMe2)4 in tetrahydrofuran to form the corresponding complexes Ti(L1)2(NMe2)2 ( 1) and Ti(L2)2(NMe2)2 ( 2), respectively. The titanium complexes were fully characterized by NMR measurement and elemental analysis as well as the single-crystal X-ray diffraction of 1 and 2. Both 1 and 2 exhibit high activities towards intermolecular hydroamination of terminal alkynes with high selectivity, and they also efficiently promote the ring-opening polymerization of ϵ-caprolactone. [ABSTRACT FROM AUTHOR]

By means of multicomponent reactions, via Michael addition, nucleophilic addition, using nitenpyram, substituted aromatic aldehydes, and cyanoacetate compounds or propanedinitrile, a new series of cis-configuration nitenpyram analogs ( 1a-1k) were synthesized by introducing the 1,4-dihydropyridine scaffold pharmacophore, as shown in Scheme 1. The structures of all compounds were confirmed by IR, 1HNMR, 13C NMR, and elemental analysis. The preliminary bioassay showed that most of the target compounds exhibited good mortality against Aphis craccivora at 500 mg/L. [ABSTRACT FROM AUTHOR]

An unexpected domino reaction of β-keto sulfones with acetylene ketones has been developed. The domino reaction of β-keto sulfones with diynones proceeded smoothly in the presence of 30 mol% K2CO3 without other additives, and afforded the novel 3(2 H)-furanone derivatives. On replacing the diynones with terminal alkyne ketones, the reaction regioselectivity was changed and sulfonylbenzenes were obtained via benzannulation in good yields. [ABSTRACT FROM AUTHOR]

ABSTRACT A series of 2-(1-(2,4-dibenzhydrylnaphthylimino)ethyl)-6-(1-(arylimino)ethyl)pyridyliron(II) complexes ( Fe1− Fe5) was synthesized and characterized. The molecular structure of the representative Fe2 was determined by single-crystal X-ray diffraction, revealing a distorted pseudo-square-pyramidal geometry around the iron center. On activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all these iron complex precatalysts performed with high activities (up to 1.58 × 107 g (PE) mol−1 (Fe) h−1) toward ethylene polymerization, producing highly linear polyethylenes with high molecular weight and bimodal distribution, which was in accordance with high temperature 13C NMR, high Tm values ( Tm ∼130 °C) and the GPC curves of the obtained polyethylenes. Meanwhile, DFT calculation results also showed the good correlation between net charges on iron and experimental activities. Compared with previous bis(imino)pyridyliron analogues, the current iron complexes containing the benzhydrylnaphthyl groups exhibited relatively higher activities and better thermal-stability at elevated temperatures, especially at 80 °C as the industrial operating temperature, and still showed high activities toward ethylene polymerization up to 8.57 × 106 g (PE) mol−1 (Fe) h−1 in the presence of co-catalyst MMAO. In addition, these iron complex precatalysts all exhibited long lifetimes. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 988-996 [ABSTRACT FROM AUTHOR]

The intramolecular cyclization of allylamines and ketones was achieved in the presence of potassium tert-butoxide and N,N-dimethylformamide. A series of 4-arylquinolines was prepared in good yields. The reaction could be accomplished at room temperature using only a substoichiometric amount of potassium tert-butoxide. On the other hand, the reaction of the structurally analogous allyl ethers afforded diverse products. The reaction may proceed via the rearrangement of α-aminoallyl radicals and the generation of nucleophilic enamine intermediates. This finding represents a new strategy for the synthesis of quinoline derivatives from readily available 2-(allylamino)phenyl ketones. [ABSTRACT FROM AUTHOR]

A huge number of indolylglycine derivatives (III) bearing a tetrasubstituted carbon center is efficiently synthesized camphorsulfonic acid catalyzed. Friedel--Crafts reaction of indoles (II) to ketimino esters (I). [ABSTRACT FROM AUTHOR]

The title compound, C18H15BrN2O4, was synthesized by the reaction of methyl (2-hydroxy­phen­yl)acetate and 3-(4-bromo)phenyl-5-chloro­methyl-1,2,4-oxadiazole. Weak intra­molecular C—H⋯N hydrogen bonds are observed in the crystal structure. [ABSTRACT FROM AUTHOR]