Cobalt-Catalyzed Chemoselective Reduction of N-Heteroaryl Ketones with N,N-Dimethylformamide as a Hydride Source.

A method for chemoselective reduction of 2-pyridyl ketones and related N-heteroaryl compounds catalyzed by cobalt stearate using DMF as a hydride source is developed. The ketone substrate is activated by chelation with cobalt, which makes the present method highly chemoselective. A possible reaction mechanism is proposed on the basis of control experiments.

Reductive Hydrodehalogenation of Halogenated Carboxylic Acid Derivatives Using a DMSO/HCOONa·2H2O System.

A practical and operationally simple hydrodehalogenation of halogenated carboxylic acid derivatives using a DMSO/HCOONa·2H2O system is developed. This protocol avoids the involvement of light irradiation, electrochemical apparatus, transition metals, radical initiators, strong bases, and other additional additives. Control experiments suggest that HCOONa might function as a hydride donor in the reduction process via nucleophilic substitution or addition to achieve the hydrodehalogenation.

Environmentally Benign, Base-Promoted Selective Amination of Polyhalogenated Pyridines.

An environmentally benign, highly efficient, and base-promoted selective amination of various polyhalogenated pyridines including the challenging pyridine chlorides to 2-aminopyridine derivatives using water as solvent has been developed. Featuring the use of the new method, the reaction is extended to the transformation on a large scale. Mechanistic studies indicate that the pathway involving a base aidant dissociation of N,N-dimethylformamide to generate dimethylamine is likely.

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.

Synthesis and antifungal activities of novel polyheterocyclic spirooxindole derivatives.

A series of spirooxindole tetrahydrofuran derivatives 3 were obtained in moderate to good yields via oxindole derivatives 1 and ß-arylacrylonitrile derivatives 2via base-mediated cascade [3 + 2] double Michael reactions under mild conditions and the application of this method in the synthesis of bioactive analogues, such as functionalized spirooxindole octahydrofuro[3,4-c]pyridine derivatives 4 which contain two new heterocyclic rings and two quaternary carbon centers, has also been developed. Subsequently, antifungal activities of all of the synthesized compounds were evaluated against five phytopathogenic fungi (Rhizoctonia solani, Fusarium semitectum, Alternaria solani, Valsa mali and Fusarium graminearum) using the mycelium growth rate method. The preliminary results showed that the spirooxindole octahydrofuro[3,4-c]pyridine derivative 4 showed higher growth inhibition of Valsa mali and Fusarium graminearum, than spirooxindole tetrahydrofuran derivatives 3. For example, spirooxindole octahydrofuro[3,4-c]pyridine derivative 4ab, having a bromine atom at the meta position of the benzene ring, was the best compound in inhibiting F. g. with an IC50 value of 3.31, in particular with inhibition of 4ab on F. g. being similar to that of the control cycloheximide (IC50 = 3.3 µg mL(-1)).

Photo-responsive reversible assembly of gold nanoparticles coated with pillar[5]arenes.

Organic solvent soluble gold nanoparticles based on pillar[5]arenes were prepared for the first time. They can reversibly aggregate and disassemble based on photo[4+4] cycloaddition of anthracene and can be used as recyclable catalysts.

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.

Asymmetric transfer hydrogenation of imines and iminiums catalyzed by a water-soluble catalyst in water.

The first asymmetric transfer hydrogenation of cyclic imines and iminiums in water was successfully performed in high yields and enantioselectivities with sodium formate as the hydrogen source and CTAB as an additive catalyzed by a water-soluble and recyclable ruthenium(II) complex of the ligand (R,R)-2.