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To synthesize simple and efficient catalysts and their application in catalytic conversion of biomass platform compounds to prepare high value-added chemicals has always been the focus of researchers. In this paper, a catalyst composed of iron, manganese, copper and Schiff base ligand derived from amantadine salicylaldehyde was in-situconstructed to catalyze the selective oxidation of 5-hydroxymethylfurfural (HMF) to prepare 5-formyl-2-furancarboxylic acid (FFCA). The ligands and complexes were characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (FT-IR) and single crystal diffraction, and the reaction conditions such as oxidation reaction time, reaction temperature, molar ratio of MnCl2·4H2O to ligand, oxidant and catalyst dosage, etc, were optimized. Under the optimized conditions, 100% conversion of HMF and the FFCA with a yield of 52.1% can be obtained. Finally, on the basis of the reaction results, the HMF oxidation reaction process catalyzed by Mn metal complexes was analyzed.

An efficient visible-light-promoted N-radical-mediated tandem radical cyclization/defluorinated alkylation of β,γ-unsaturated hydrazones, and α-trifluoromethyl alkenes is described. This protocol provides a general and effective route to synthesize various dihydropyrazole-fused gem-difluoroalkenes at moderate to excellent yields under redox-neutral, metal-free, and mild conditions.

Zn-mediated generation of alkoxyl radicals from N-alkoxyphthalimides emerged as an efficient approach for forming diverse and valuable alkyl radicals through β-scission or a hydrogen atom transfer process. The alkyl radical species can be further trapped by α-trifluoromethyl alkenes to construct a series of gem-difluoroalkenes.

MnO2with different crystal structures was used to catalyze the oxidation reaction of 5-hydroxylmethylfurfural (HMF), and α-MnO2exhibited the highest catalytic activity. Magnetic MnO2-Fe3O4oxides were prepared by α-MnO2and Fe3O4and characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), temperature programmed desorption of NH3/CO2(NH3/CO2-TPD) and Fourier transform infrared reflection spectra of pyridine adsorption (Py-FTIR). The results showed that the composite catalyst still maintained the basic structure of α-MnO2and Fe3O4, whereas the number of active center Mn4+·O2−ion pair increased compared with α-MnO2and Fe3O4, which significantly improved the catalytic activity on HMF oxidation reaction. The reaction conditions of HMF oxidation to 2,5-furandicarboxylic acid (FDCA) were optimized. The composite oxide Mn8Fe3Oxshowed the best catalytic performance for HMF oxidation. HMF could be completely converted, with 76.9% of FDCA yield under the optimal conditions.

In this work, ruthenium(II)-catalyzed C–C/C–N annulation of 2-arylquinazolinones with vinylene carbonate is reported to synthesize fused quinazolinones. This catalytic system tolerates a wide range of substrates with excellent functional-group compatibility. In this transformation, the vinylene carbonate acts as an ethynol surrogate without any external oxidant involved. Furthermore, preliminary mechanistic studies were conducted, and a plausible catalytic cycle was also proposed.

An efficient and mild Zn-mediated decarboxylative/defluorinative alkylation of α-trifluoromethyl alkenes using N-hydroxyphthalimide esters as radical precursors was developed. Several α-trifluoromethyl alkenes were readily coupled to a wide range of primary, secondary, and tertiary radicals, affording the desired gem-difluoroethylenes in moderate to excellent yields. This reaction protocol was also successfully applied to the construction of complex molecules such as the bioactive natural dehydroabietic acid and glycosyl groups bearing the gem-difluoroethylene moiety.

In this study, a facile and efficient method to synthesize monofluoroalkenes by photoredox catalytic defluorinative alkylation of gem-difluoroalkenes with 4-alkyl-1,4-dihydropyridines under mild conditions (room temperature) is described. This novel strategy is applicable for a broad range of gem-difluoroalkene substrates with good functional group tolerance and a variety of 4-alkyl-1,4-dihydropyridines (including primary, secondary, and even tertiary alkyl radicals). Moreover, it also allows the challenging radical coupling with glycosyl-based 4-alkyl-1,4-dihydropyridines (DHPs) to synthesize monofluoroalkenylated saccharides.

A visible‐light‐promoted radical fluoroalkylation has been achieved through a three‐component reaction of fluoroalkyl reagents, isocyanides and water, affording fluoroalkyl‐substituted amides in good yields. This reaction involves the generation of the nitrilium cation by single‐electron reduction of the imidoyl radical and a subsequent nucleophilic attack by water. Mechanistic studies support the generation of the imidoyl radical through the capture of the fluoroalkyl‐substituted imidoyl radical species. A visible‐light‐promoted fluoroalkylation of isocyanides is developed by single‐electron reduction of the imidoyl radical and a subsequent nucleophilic attack by water. This reaction provides a general and efficient method for the synthesis of fluoroalkyl‐substituted amides from readily available starting materials.

Novel copper/B2pin2-catalyzed difluoroalkylation of methylenecyclopropanes with bromodifluorinated acetates and acetamides via a tandem radical process involving ring-opening/intramolecular cyclization has been reported. This protocol is not only tolerated to a diverse range of substrates but also applicable to the synthesis of useful difluoromethylated compounds. Moreover, the reaction could be performed on a gram scale with a high yield, which opens up the possibility for practical applications.

A core-shell composite zeolite (HY/silicalite-1) was prepared by modifying HY zeolite with silicalite-1 and characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Transmission electron microscope (TEM), N2sorption and IR spectra of pyridine adsorption (Py-FTIR); the catalytic performance of HY/silicalite-1 composite zeolite in the hydrolysis of cellulose was then investigated in comparison with that of HY. The results show that the crystallization time has a significant influence on the crystal growth of the HY/silicalite-1 composite zeolite and the relative content of two components. With the optimum crystallization time of 16–24 h, a core-shell structure for the HY/silicalite-1 composite zeolite is achieved, where the silicalite-1 crystal grows over the surface of HY zeolite; with the prolongation of the crystallization time, the morphology of the composite zeolite changes from rough turbid to smooth and eventually to scale-like surface. The amount of Brönsted acid sites decreases first and then increases with the increase of the crystallization time, whereas the amount of Lewis acid sites changes in the opposite direction. In particular, the HY/silicalite-1 composite zeolite obtained with a crystallization time of 24 h exhibits excellent catalytic performance in the hydrolysis of cellulose to glucose; over it, the yield of glucose reaches 45.8% at 130°C, much higher than the value of 28.0% over the HY zeolite.

The transition‐metal‐free synthesis of β‐ketophosphine oxides from diphenylphosphorylallenes in the presence of pyrrolidine and silica gel has been developed under mild reaction conditions. This simple and efficient transformation tolerates a wide range of diphenylphosphorylallenes with different functional groups, and affords the desired products in moderate to excellent yields. A transition‐metal‐free synthesis of β‐ketophosphine oxides from diphenylphosphorylallenes in the presence of silica gel at room temperature is developed. This simple and efficient method proved to be applicable to various substituted diphenylphosphorylallenes, affording the desired β‐ketophosphine oxides in satisfactory yields.

Rhodium(III)-catalyzed remote meta-selective–C-H alkenylation of phenol derivatives has been developed using a traceless organosilicon template as the directing group. This transformation proceeds smoothly with good yields and high meta-selectivities toward a series of phenol and alkene substrates. In addition, this protocol provides an effective strategy for late-stage transformations of various meta-alkenylated aromatic compounds.

A visible‐light photoredox‐catalyzed three‐component difluoromethylative heteroarylation of unactivated alkenes is reported. This reaction provides a highly efficient and chemo‐selective method for the synthesis of difluoroalkyl‐containing quinoxalin‐2(1H)‐ones by the formation of two new C‐C bonds in single step from readily available starting materials under mild reaction conditions. This three‐component reaction displays a synthetic simplicity, broad substrate scope, and excellent functional group compatibilities. The preliminary mechanistic investigation implies that a radical process was responsible for this three‐component transformation. A visible‐light photoredox‐catalyzedthree‐component difluoromethylative heteroarylation of unactivated alkenes is developed under mild reaction conditions. This reaction provides a highly efficient and chemo‐selective method for the synthesis of difluoroalkyl containing quinoxalin‐2(1H)‐ones by the formation of two new C−C bonds in single step from readily available starting materials

A series of air- and water-stable imidazolium perrhenate-based room-temperature ionic liquids [(RT)ILs] of the type [Cnmim][ReO4] (Cnmim = 1-CnH2n+1-3-methylimidazolium, n = 2, 4, 5, 6, 8, 10, 12) have been synthesized and characterized by 1H and 13C NMR spectroscopy, IR spectroscopy, electrospray ionization mass spectrometry (ESI-MS), and elemental analysis (EA). The effect of the variation of the alkyl chain length on physical properties such as melting point, thermal stability, density, and conductivity was examined

Donor hearts are subjected to ischemia-reperfusion injury during transplantation. Recombinant human neuregulin (rhNRG)-1 peptide attenuates myocardial injury in various animal models of cardiomyopathy. Supplementing the organ-storage solution, Celsior (C), with glyceryl trinitrate (GTN) and cariporide improves cardiac preservation after hypothermic storage. We hypothesized that the addition of rhNRG-1 to C would improve cardiac preservation after hypothermic storage and provide incremental benefit in combination with GTN and cariporide.

It′s a fine line: Methyltrioxorhenium(VII) (MTO) readily forms 1:1 adducts with several N‐(salicylidene)aniline derived Schiff bases. Steric and electronic effects of the ligands play a major role when it comes to stability and catalytic activity. Good donors on the Schiff base ligands, in general, lead to shorter ReO(Schiff base) bridges and lower catalytic activity, while it is the opposite for acceptor ligands on the Schiff bases.

Several Schiff‐base ligands readily form complexes with methyltrioxorhenium(VII) (MTO) by undergoing a hydrogen transfer from a ligand‐bound OH group to a ligand N atom. The resulting complexes are stable at room temperature and can be handled and stored in air without problems. Due to the steric demands of the ligands they display distorted trigonal‐bipyramidal structures in the solid state, as shown by X‐ray crystallography, with the O−moiety binding to the Lewis acidic Re atom and the Re‐bound methyl group being located either in cisor transposition to the Schiff base. In solution, however, the steric differences seem not to be maintained, as can be deduced from 17O NMR spectroscopy. Furthermore, the Schiff‐base ligands exchange with donor ligands. Nevertheless, the catalytic behaviour is influenced significantly by the Schiff bases coordinated to the MTO moiety, which lead either to high selectivities and good activities or to catalyst decomposition. A large excess of ligand, in contrast to the observations with aromatic N‐donor ligands, is detrimental to the catalytic performance as it leads to catalyst decomposition.

The synthesis of N-unprotected 2-aryl-3-cyanoindoles was realized via the Mn(III)-mediated radical cascade cyclization of o-alkenyl aromatic isocyanides with boronic acids. A possible mechanism involving a sequential intermolecular radical addition, intramolecular cyclization, and cleavage of the C–C bond under mild reaction conditions is proposed. Mechanism studies show that H2O or O2might provide the oxygen source for the elimination of benzaldehyde.