Chinese Journal of Chemistry

A series of novel γ,γ-difluorinated Goniothalamin analogues 4a–4i and 6a–6i were synthesized by way of lipase AK catalyzed kinetic resolution, Stille coupling and 1,5-oxidative cyclization. These difluorinated analogues and several monofluorinated analogues were biologically evaluated together against four different cancer cell lines. From the analysis of bioassay data, it was found that adding one fluorine at the γ position of Goniothalamin was a better modification than introducing two fluorine atoms.

Phthalimide derivatives as nitrogen nucleophiles with α,β-unsaturated aldehydes for asymmetric aza-Michael additions have been reported. The reactions proceed smoothly to afford corresponding Michael adducts in good yields (up to 98%) and enantioselectivities (up to 95% ee).

Low melting citric acid-urea mixture was found to be a new and effective promoting medium for the environmentally friendly synthesis of 1,8-dioxo-dodecahydroxanthene derivatives by condensation of aromatic aldehydes and cyclic 1,3-dicarbobonyl compounds. This deep eutectic solvent acts as both the reaction medium and catalyst, furnishing xanthenediones in high to excellent yield.

Some voids were found in the MEH-PPV:PCBM composite films, and the number of the voids decreases with the solvent. We found the voids are located at the bottom of the films through the electron tomography technique by transmission electron microscopy and film bottom-side morphology study by atomic force microscopy. The voids are disadvantageous to the device performance.

Theoretical calculations were carried out to investigate the mechanism of the cyclization of dipeptides. The "proton shuttle"-catalyzed stepwise mechanism is most favored and the attack of the N-terminal amino nitrogen at the C-terminal carbonyl carbon along with the proton transfer is the rate-limiting step. The solvation effect, electronic effect and steric effect were found to contribute to the cyclization.

An effective transition-metal-free catalytic system is developed for aerobic oxidations of alcohols. Using catalytic amount of bromide-bromate coupling, H₂SO₄, and NaNO₂, together with 2,2,6,6-tetramethylpiperidine N-oxyl radical (TEMPO) in the presence of air, various alcohols could be converted into the corresponding aldehydes or ketones in good to excellent isolated yields under mild conditions.

A continuous detection of pH-responsive drug delivery system in cells in situ, utilizing MSN/CS-PMAA composite microspheres, was proposed. The continuous fluorescent observation in situ could be widely used in the pH-responsive releasing process of drug delivery system in the cells.

A direct and efficient approach to 1-aminoindolizines through three-component one-pot reaction of heteroaryl aldehydes, secondary amines and terminal alkynes catalyzed by CuI under solvent-free conditions has been developed. This methodology provides a rapid access to substituted aminoindolizines with good yields (up to 97%).

By optimizing the reaction conditions via a careful screening of the bases and solvents, we developed an efficient transition metal-free method for CO cross-coupling of activated and unactivated heteroaryl chlorides with primary and secondary alcohols and phenols, providing a simple, efficient, and practical method for synthesis of the useful unsymmetrical heteroaryl alkyl and heteroaryl aryl ethers.

Eleven triazolyl substituted tetrahydrobenzofuran derivatives were synthesized in high yields as novel H⁺/K⁺-ATPase inhibitor via one-pot CuI-catalyzed three-component click reaction under mild conditions in water, and most of them exhibited better H⁺/K⁺-ATPase inhibitory activity than commercial omeprazole with IC₅₀ values less than 15 µmol·L⁻¹.

Stimulated by different combination of external stimulus, including metal ions, UV irridiation and solution pH, the PAR system could perform multiple logic functions, presenting great potential for the construction of molecular devices.

Bismuthinite (Bi₂S₃) nanostructures were prepared by a hydrothermal method with sodium ethylenediaminetetraacetate (EDTA-Na₂). The successful synthesis of various morphologies of nanostructured Bi₂S₃ may open up new possibilities for thermoelectric, electronic and optoelectronic uses of nanodevices based on Bi₂S₃ nanostructure.

A dual signal amplification platform for simultaneous and sensitive determination of dopamine (DA) and acetaminophen (AC) is proposed by the synergistic effect of graphene (GR) and (4-ferrocenylethyne) phenylamine (FEPA). The synthesized FEPA serves as an electron mediator for amplification of the detection signals, and it can be strongly adsorbed on GR surface via the strong π-π stacking interaction between the conjugate chain of FEPA and GR. The proposed strategy provided a stable electronic mediator immobilization method on electrode surfaces for electrochemical analysis.

Regioselective protection of secondary hydroxyl groups on ribosides and 2′-deoxyribosides was investigated. A most simple and efficient method for preparation of 2′,3′-di-O-benzoylribonucleosides was developed.

The sensor was based on supramolecular assemblies composed of heparin and CTAB, the dye pyrene worked as the fluorescence probe. Once the target protein was added, heparin was taken away by protein, resulting in the decreasing of fluorescence intensity. The binding events were exemplified by protamine and Tat peptide.

The secretory phospholipase A2 (sPLA2) and sphingomyelin (SMS) are the key enzymes to atherosclerosis. In this paper, we combined the single sPLA2 and SMS inhibitors with a carbon chain to get a series of dual inhibitors. The biological evaluation showed these compounds had the moderate inhibition against both enzymes.