I2-mediated coupling of quinazolinone enamines with 2-aminopyridines: a new strategy to access spiroquinazolinones.

Herein, we report a novel, rapid and efficient route to the spiroquinazolinone framework via an umpolung strategy mediated by molecular iodine. A library of functionalized spiroquinazolinone iodide salts was synthesized in moderate to good yields under ambient, metal-free and mild conditions. The current methodology opens up a new efficient and concise strategy for the construction of spiroquinazolinones.

Visible-light-induced C(sp3)-H thiocyanation of pyrazolin-5-ones: a practical synthesis of 4-thiocyanated 5-hydroxy-1H-pyrazoles.

A direct, aerobic and visible light photocatalytic approach to synthesize 4-thiocyanated 5-hydroxy-1H-pyrazoles via cross-coupling of pyrazolin-5-ones with ammonium thiocyanate is described. Under redox-neutral and metal-free conditions, a series of 4-thiocyanated 5-hydroxy-1H-pyrazoles could be easily and efficiently obtained in good to high yields by using low-toxicity and inexpensive ammonium thiocyanate as the thiocyanate source.

Preparation of sub-microspherical Fe3O4@PDA-Pd NPs catalyst and application in catalytic hydroreduction reaction of halogenated aromatic nitro compounds to prepare halogenated aromatic amines.

BACKGROUND: The side reactions of dehalogenation or C-N coupling tend to occur when halogenated aromatic amines are prepared by catalytic hydrogenation reduction of halogenated aromatic nitro compounds. In this paper, we prepared the sub-microspherical Fe3O4@PDA-Pd NPs catalyst apply it efficiently in the hydrogenation reduction of halogenated aromatic nitro compounds to prepare the halogenated aromatic amines under atmospheric pressure. The catalyst shows a high selectivity of greater than 96% and can effectively inhibit the occurrence of the side reactions of dehalogenation and C-N coupling. RESULTS: The optimum condition of the hydroreduction reaction is when tetrahydrofuran is used as solvent and the reaction happens at 50 °C for 5 h. The selectivity of the chlorinated aromatic amine and the fluorinated aromatic amine products exceed 99% and the yield exceeds 90%. Only a small amount of dehalogenated products and C-N coupling by-products were produced in the brominated aromatic compound and the iodinated aromatic compound. CONCLUSION: We developed a promising method for preparing the superparamagnetic and strongly magnetic Fe3O4@PDA core-shell sub-microsphere-supported nano-palladium catalyst for catalyzing the hydrogenation reduction of halogenated aromatic nitro compounds. The halogenated aromatic amines were efficiently and highly selectively prepared under atmospheric pressure, with the side reactions of dehalogenation and C-N coupling effectively inhabited simultaneously.

Preparation of Large-Size, Superparamagnetic, and Highly Magnetic Fe3O4@PDA Core⁻Shell Submicrosphere-Supported Nano-Palladium Catalyst and Its Application to Aldehyde Preparation through Oxidative Dehydrogenation of Benzyl Alcohols.

Large-size, superparamagnetic, and highly magnetic Fe3O4@PDA core-shell submicrosphere-supported nano-palladium catalysts were prepared in this study. Dopamine was encapsulated on the surface of Fe3O4 particles via self-polymerization and then protonated to positively charge the microspheres. PdCl42- was dispersed on the surface of the microspheres by positive and negative charge attraction and then reduced to nano-palladium. With air as oxidant, the catalyst can successfully catalyze the dehydrogenation of benzyl alcohols to produce the corresponding aldehydes at 120 °C.

An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes.

We report an additive-free, base-catalyzed C-, N-, O-, and S-Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes.

Ruthenium-catalyzed decarboxylative C-S cross-coupling of carbonothioate: synthesis of allyl(aryl)sulfide.

A novel ruthenium-catalyzed decarboxylative cross-coupling of carbonothioate is disclosed. This method provides straightforward access to the corresponding allyl(aryl)sulfide derivatives in generally good to excellent yields under mild conditions and features a broad substrate scope, wide group tolerance and in particular, no need to use halocarbon precursors.

Tubular Structures Self-Assembled from a Bola-Amphiphilic Pillar[5]arene in Water and Applied as a Microreactor.

Various nanomorphologies were obtained by simply changing the fabrication conditions, such as the pH of the system, different solvent, or different concentration, of bola-amphiphilic pillar[5]arene Bola-AP5. Importantly, hybrid microtubules as a microreactor were successfully prepared by directly reducing AuCl4(-) on the surface of Bola-AP5-based tubular structures in water.

A pH-responsive fluorescent [5]pseudorotaxane formed by self-assembly of cationic water-soluble pillar[5]arenes and a tetraphenylethene derivative.

The formation of a pH-responsive fluorescent [5]pseudorotaxane by self-assembly of cationic water-soluble pillar[5]arenes and a tetraphenylethene derivative was reported.

A triply-responsive pillar[6]arene-based supramolecular amphiphile for tunable formation of vesicles and controlled release.

A pillar[6]arene-based supramolecular amphiphile has been constructed in water. The supramolecular amphiphile formed vesicles, which could be regulated by pH, light and enzymes, and thus the loaded dye in the vesicles could be released in a controlled manner.

Novel fluorescent 1,8-naphthalimide derivatives containing thiophene and pyrazole moieties: synthesis by direct C-H arylation and evaluation of photophysical and electrochemical properties.

A series of novel 1,8-naphthalimide derivatives containing thiophene and pyrazole moities were synthesized by direct Pd-catalyzed C-H arylation and then characterized by (1)H NMR, (13)C NMR, MALDI-HRMS, and elementary analysis. The photophysical and electrochemical properties of the derivatives were also investigated. All compounds have green emission both in diluted CH2Cl2 solution and solid film. The cyclic voltammetry (CV) measurements showed that the target compounds had a lowest unoccupied molecular orbital (LUMO) range from -3.49 eV to -3.29 eV and a highest occupied molecular orbital (HOMO) range from -6.04 eV to -5.81 eV. Quantum chemical calculations were performed to obtain the optimized ground-state geometry as well as the spatial distributions of the HOMO, LUMO levels of the compounds.

N-Phenylpyridine-2-carb-amide.

In the title compound, C(12)H(10)N(2)O, the dihedral angle between the pyridine ring system and the phenyl ring is 1.8 (1)°. There is an intra-molecular N-H⋯N hydrogen bond between the pyridine N atom and the amide NH function.

3-Methyl-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid.

In the title compound, C(17)H(12)O(4), the chromene unit is approximately planar, the maximum deviation from the mean plane being 0.0166 Å. The attached phenyl ring makes a dihedral angle of 53.2 (1)° with the fused ring system. The packing of the mol-ecules in the crystal structure is governed by C-H⋯O and O-H⋯O hydrogen-bonding inter-actions.