Granulated copper oxide nanocatalyst: a mild and efficient reusable catalyst for the one-pot synthesis of 4-amino-5-pyrimidinecarbonitriles under aqueous conditions

Abstract  

An efficient method for the synthesis of 4-amino-5-pyrimidinecarbonitriles by the three-component reaction of malononitrile, aldehydes, and N-unsubstituted amidines under aqueous conditions using CuO microspheres as catalyst is reported. The catalyst exhibited remarkable reusable activity.     

Mapping of protein phosphatase-6 association with its SAPS domain regulatory subunit using a model of helical repeats

Background  

Helical repeat motifs are common among regulatory subunits for type-1 and type-2A protein Ser/Thr phosphatases. Yeast Sit4 is a distinctive type-2A phosphatase that has dedicated regulatory subunits named Sit4-Associated Proteins (SAPS). These subunits are conserved, and three human SAPS-related proteins are known to associate with PP6 phosphatase, the Sit4 human homologue.     

Ionic liquid 1-(4-nitritobutyl)-3-methylimidazolium chloride as a new reagent for the efficient N-nitrosation of secondary amines under mild conditions

Abstract  

1-(4-Nitritobutyl)-3-methylimidazolium chloride has been developed as a new reagent for efficient nitrosation of secondary amines at 0 °C to room temperature. A variety of N-nitrosamines were prepared in excellent yields by use of this task-specific ionic liquid under mild and heterogeneous conditions.     

Electrochemical pyridination of hydroquinone in aqueous solution

Abstract  

Electrochemical oxidation of hydroquinone was studied in the presence of pyridine and 4-methylpyridine as nucleophiles in aqueous solution. The results indicate the participation of electrochemically generated p-benzoquinone in Michael addition reaction with pyridine and 4-methylpyridine, converting it to pyridinated compounds.     

SARs of the antiprotozoal action of 6,7-diaryl-bicyclo[2.2.2]octan-2-ols

Abstract  

Several 4-amino-6,7-diarylbicyclo[2.2.2]octan-2-ols bearing varying substituents on the aromatic rings were synthesized following a manual method for applying the Hansch approach. All new compounds were tested for their activity against the causative organisms of East African sleeping sickness and malaria tropica. Structure activity relationships are discussed.     

FeNH4(SO4)2·12H2O (alum)-catalyzed preparation of 1,4-dihydropyridines: improved conditions for the Hantzsch reaction

Abstract  

FeNH₄(SO₄)₂·12H₂O (alum) efficiently catalyzes the one-pot three-component reaction of dimedone, aldehydes, and 3-aminocrotonate to afford 1,4-dihydropyridines. The work-up is easy, and the products are obtained in good to excellent yields and high purity.     

Highly efficient, one-pot, solvent-free synthesis of 2,4,6-triarylpyridines using a Br?nsted-acidic ionic liquid as reusable catalyst

Abstract  

A simple, efficient, and green method for synthesis of 2,4,6-triarylpyridines by one-pot three-component reaction of acetophenones, aryl aldehydes, and ammonium acetate using 3-methyl-1-(4-sulfonylbutyl)imidazolium hydrogen sulfate [HO₃S(CH₂)₄MIM][HSO₄], a Br?nsted-acidic ionic liquid, as an effective and reusable catalyst under solvent-free conditions is described. This method has several advantages, for example simple procedure with an easy work-up, shorter reaction times, and high yields.     

Study of dehalogenation of halogenoanilines using Raney Al–Ni alloy in aqueous medium at room temperature

Abstract  

Dehalogenation of halogenated anilines by action of powdered aluminium–nickel alloy in aqueous alkaline solution at room temperature has been studied. The reaction course was monitored by means of ¹H nuclear magnetic resonance (NMR) spectroscopy. The rates of dehalogenation of 4-bromo-, 4-chloro-, 4-fluoro- and 3-chloroaniline were compared under conditions of minimum necessary excess of Al–Ni alloy as reducing agent in edetane buffer medium at pH 10.9. The dehalogenation rates of halogenated anilines decreased in the following order: 3-chloroaniline > 4-bromoaniline ≥ 4-chloroaniline > 4-fluoroaniline. On the basis of the results obtained in buffers, the dehalogenation method of aqueous solutions of halogenoanilines was verified using NaOH as the base.     

Synthesis of 6-chloroquinolines using benzyltrimethylammonium tetrachloroiodate as a selective chlorinating agent and an efficient generator of HCl

Abstract  

A simple and efficient one-pot synthesis of 6-chloroquinolines was achieved in good yields via the three-component reaction of 2-aminoaryl ketones, α-methylene carbonyl compounds, and BTMA ICl₄ in AcOH.     

First Lewis acid catalyzed [4+2] cycloaddition reaction of 1,3,3-trimethyl-2-vinyl-1-cyclohexene with chromones: a new entry to analogues of the puupehenone group of marine diterpenoids and kampanols

Abstract  

A rapid assembly of the tetracyclic core of marine diterpenoids related to puupehenone and kampanols featuring a Lewis acid catalyzed [4+2] cycloaddition reaction of 1,3,3-trimethyl-2-vinyl-1-cyclohexene and chromone dienophiles is described.     

Mixed-donor N,N,O-tridentate ligands for palladium-catalyzed Suzuki reactions

Abstract  

Efficient Suzuki–Miyaura cross-coupling reactions of arylboronic acids with aryl halides catalyzed by Pd/N,N,O-tridentate ligands, using methanol as solvent and K₃PO₄ as base, afforded the corresponding cross-coupled biaryls in good to excellent yields.     

One-step synthesis of a novel carbon-based strong acid catalyst through hydrothermal carbonization

Abstract  

A novel carbon-based strong acid catalyst was synthesized through the one-step hydrothermal carbonization of furaldehyde and p-toluenesulfonic acid (PTSA) in aqueous solution at 180 °C for only 4 h. The novel carbon-based solid acid possessed high acidity, and the catalytic activities were investigated by esterification and oxathioketalization. The results showed that the novel catalyst demonstrated much greater activity than the traditional solid acids and was comparable to sulfuric acid. The one-step method provides an efficient procedure for the synthesis of various functionalized carbons by one-step hydrothermal carbonization.     

Synthesis and biological evaluation of novel piperidin-4-ol derivatives

Abstract  

A series of novel piperidin-4-ol derivatives were designed, synthesized, and evaluated for potential treatment of HIV. The compounds were obtained via an efficient synthetic route in excellent yields and have been characterized by ¹H NMR, ¹³C NMR, MS, and elemental analysis. The CCR5 antagonistic activities of the compounds have also been evaluated.     

A practical and versatile approach toward a one-pot synthesis of 2,3-disubstituted 4(3H)-quinazolinones

Abstract  

An effective one-pot three-component route to 4(3H)-quinazolinones from commercially available starting materials is reported. Thus, isatoic anhydride reacted with ammonium acetate or primary amines and aldehydes in the presence of iodine to produce the corresponding quinazolinone derivatives in moderate to good yields.     

A novel form of the membrane protein CD147 that contains an extra Ig-like domain and interacts homophilically

Background  

CD147 is a broadly distributed integral membrane glycoprotein with two Ig-like domains implicated in a wide range of functions. It is associated at the cell surface with the monocarboxylate transporters MCT1 and 4 but interactions of the extracellular region have not been characterised.     

A novel synthetic approach towards pyrazole-4-carboxamides using N-(3-(dimethylamino)-2-formylacryloyl)formamide

Abstract  

A novel synthesis of pyrazole-4-carboxamides is reported. The reaction of N-(3-(dimethylamino)-2-formylacryloyl)formamide, an intermediate obtained by Vilsmeier–Haack formylation of acetonitrile, with hydrazine hydrate or monosubstituted hydrazines provides such compounds in good yields. This method has advantages over other methods for construction of such ring systems previously described in the literature.     

Calmodulin binding to recombinant myosin-1c and myosin-1c IQ peptides

Background  

Bullfrog myosin-1c contains three previously recognized calmodulin-binding IQ domains (IQ1, IQ2, and IQ3) in its neck region; we identified a fourth IQ domain (IQ4), located immediately adjacent to IQ3. How calmodulin binds to these IQ domains is the subject of this report.     

Efficient synthesis of methyl 4-chloro-6-fluoro-3-formyl-2H-chromene-2-carboxylate and its derivatives

Abstract  

Methyl 4-chloro-6-fluoro-3-formyl-2H-chromene-2-carboxylate was synthesized conveniently using Vilsmeier reagent. A series of new 2H-chromenes was prepared in high yields by introducing a corresponding β-halovinylaldehyde into condensation and cyclization reactions with active methylene compounds.     

Highly efficient and chemoselective method for the thioacetalization of aldehydes and transthioacetalization of acetals and acylals catalyzed by H2SO4-silica under solvent-free conditions

Abstract  

Chemoselective and efficient thioacetalization of a variety of aldehydes was achieved in excellent yields at room temperature using 1,2-ethanedithiol in the presence of catalytic amounts of H₂SO₄-silica. Thioacetals were also prepared by transthioacetalization of acylals and acetals under similar conditions.     

Delineation of RAID1, the RACK1 interaction domain located within the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5

Background  

The cyclic AMP specific phosphodiesterase, PDE4D5 interacts with the β-propeller protein RACK1 to form a signaling scaffold complex in cells. Two-hybrid analysis of truncation and mutant constructs of the unique N-terminal region of the cAMP-specific phosphodiesterase, PDE4D5 were used to define a domain conferring interaction with the signaling scaffold protein, RACK1.