Metal-free and solvent-free synthesis of m-terphenyls through tandem cyclocondensation of aryl methyl ketones with triethyl orthoformate

Reported here is a novel cyclocondensation of aryl methyl ketones and triethyl orthoformate for the simple synthesis of m-terphenyls. In the presence of a catalytic amount of TfOH, alkyl- and chloro-substituted acetophenones produced a series of terphenyls through a tandem reaction which merged six steps into a one-pot procedure. Moreover, the corresponding ester products were obtained when using other substituted acetophenones as the starting materials under the same reaction conditions.

A facile metal-free and solvent-free benzannulation was developed for the construction of m-terphenyl derivatives starting from aryl methyl ketones and triethyl orthoformate. This is a tandem reaction which merged six steps into one-pot procedure.

Identification of Novel 1,3,5-Triphenylbenzene Derivative Compounds as Inhibitors of Hen Lysozyme Amyloid Fibril Formation

Deposition of soluble proteins as insoluble amyloid fibrils is associated with a number of pathological states. There is a growing interest in the identification of small molecules that can prevent proteins from undergoing amyloid fibril formation. In the present study, a series of small aromatic compounds with different substitutions of 1,3,5-triphenylbenzene have been synthesized and their possible effects on amyloid fibril formation by hen egg white lysozyme (HEWL), a model protein for amyloid formation, and of their resulting toxicity were examined. The inhibitory effect of the compounds against HEWL amyloid formation was analyzed using thioflavin T and Congo red binding assays, atomic force microscopy, Fourier-transform infrared spectroscopy, and cytotoxicity assays, such as the 3-(4,5-Dimethylthiazol)-2,5-Diphenyltetrazolium Bromide (MTT) reduction assay and caspase-3 activity measurements. We found that all compounds in our screen were efficient inhibitors of HEWL fibril formation and their associated toxicity. We showed that electron-withdrawing substituents such as –F and –NO₂ potentiated the inhibitory potential of 1,3,5-triphenylbenzene, whereas electron-donating groups such as –OH, –OCH₃, and –CH₃ lowered it. These results may ultimately find applications in the development of potential inhibitors against amyloid fibril formation and its biologically adverse effects.

An aluminum selective electrode via modification of PVC membrane by modified clinoptilolite nanoparticles with hexadecyltrimethyl ammonium bromide (HDTMA-Br) surfactant containing Arsenazo III

A modified PVC (polyvinyl chloride) membrane with clinoptilolite nanoparticles/hexadecyltrimethyl ammonium bromide surfactant (HDTMABr)/Arsenazo III: (NSMZ-ARS), was used for construction of Al(III) -selective electrode. The raw and modified samples were characterized by XRD, FTIR, SEM and TEM methods. Among the different tested membranes constructed by raw and modified samples, only, the membrane electrode containing NSMZ-ARS showed a suitable Nernstian response to aluminum in the concentration range of 2.04×10^-5 to 1.99×10^-1M (r=0.9987), with a detection limit of 1.0×10^-5molL^-1 and a Nernstian slope of 19.6±0.5mV per decade of aluminum concentration. The electrode response to aluminum remained constant in the pH range of 2-4. The sensor was selective for aluminum over a wide variety of other ions and exhibited. The electrode had a rapid response time and its response reached to steady potential at 5s. The electrode had also satisfactory long term stability and held its activity at least 3months.

Facile synthesis and investigation of 1,8-dioxooctahydroxanthene derivatives as corrosion inhibitors for mild steel in hydrochloric acid solution

For the first time, the corrosion inhibitive performance of some 1,8-dioxooctahydroxanthene derivatives is proposed.

Mild, efficient, and environmentally friendly synthesis of symmetrical N,N′-alkylidenebisamides under solvent-free conditions catalyzed by H7[(P2W17O61)FeIII(H2O)]

H₇[(P₂W₁₇O₆₁)Fe^III(H₂O)] is introduced as an effective catalyst for the one-pot synthesis ofN,N′-alkylidenebisamides. The catalyst could be easily separated without noticeable reduction in activity.

Nano polypropylenimine dendrimer (DAB-PPI-G1): as a novel nano basic-polymer catalyst for one-pot synthesis of 2-amino-2-chromene derivatives

For the first time, a novel nano basic-polymer catalyst for the green synthesis of new 2-amino-2-chromene derivatives, avoiding the use of any metal or acid catalysts, is proposed.

Synthesis of symmetrical N,N′-alkylidene bis-amides catalyzed by silica coated magnetic NiFe2O4 nanoparticle supported polyphosphoric acid (NiFe2O4@SiO2-PPA) and its application toward silver nanoparticle synthesis for electrochemical detection of glucose

For the first time, a new and facile Ag@PM-b-B nanocomposite electrochemical sensor was successfully developed for the detection of glucose. Also, the magnetically recoverable catalyst was easily recycled at least ten times without significant loss of catalytic activity.

H6P2W18O62/Nanoclinoptilolite as an efficient nanohybrid catalyst in the cyclotrimerization of aryl methyl ketones under solvent-free conditions

A new natural nanohybrid material HPA/NCP was prepared. An efficient and environmentally benign method for cyclotrimerization of acetophenones is reported. Water was the only by-product.

Silica coated magnetic NiFe2O4 nanoparticle supported phosphomolybdic acid; synthesis, preparation and its application as a heterogeneous and recyclable catalyst for the one-pot synthesis of tri- and tetra-substituted imidazoles under solvent free conditions

A novel heteropolyacid supported on silica coated nickel ferrite nanoparticles (NFS–PMA) was synthesized and used as a green catalyst for one-pot syntheses of tri/tetra-substituted imidazoles. The catalyst could be recycled and reused through application of a magnetic field.