Chengliang Feng

Solvent-free synthesis of β-enamino ketones and esters catalysed by recyclable iron(III) triflate

A novel application of highly stable Fe(OTf)3 as an efficient catalyst for the synthesis of a variety of β-enamino ketones and esters under solvent-free conditions is described. Notably, this protocol of a “green synthesis”, which produced β-enamino ketones and esters by the reaction of a variety of β-dicarbonyl compounds and primary amines, exhibits attractive properties including high yields, short reaction periods, lower loading of catalyst and chemo- and regio-selectivity. In addition, the catalyst was easily recovered from the reaction system and readily reused with minimal loss of activity.

Design, synthesis, and biological evaluation of benzofuran derivatives as ET receptor antagonists

A series of novel benzofuran carboxylic acid derivatives have been designed and synthesized, with their antagonism effect screened on ET-1-induced contraction in the rat thoracic aortic ring. Some target compounds demonstrated significant inhibitory activity, especially benzo[c]thiadiazole and benzo[c]oxadiazole compounds 29 and 30 showed potent inhibition percentage higher than the contrast compound BQ123. Further affinity and selectivity for ET binding assay showed that 29 demonstrated a dual ETA/ETB antagonism activity in nanomole level. Moreover, 30 was effective in relieving hypoxia-induced pulmonary arterial hypertension.

Advances in Applications of Fluorescent Probes Based on Indole Heptamethine in Vivo

Cyanine dye is a commercially available near-infrared fluorescent dye, its spectral range is in the near infrared region, in this spectrum, absorption or fluorescence intensity of biological sample is very small, so applied cyanine dye to image living body can reduce background interference. Indole heptamethine fluorescent probes which are representative of cyanine dyes are consisted of indole heterocycle, heptamethine and N-substituted side chains. They are widely used for tar- geted cancer therapy, labling protein, detecting of metal cations and other biological aspects because of their excellent pho- tophysical properties like good solubility, tunable maximum absorption wavelength, large molar extinction coefficient. Based on the structure of indole heptamethine, introducing reactive groups to the parent compounds or changing their structures can make fluorescent probes have different functions like labeling protein and tumour, detecting intracellular metal cations, which has become the hotspot in the field of fluorescence imaging of biological research. Therefore in this paper, the recent progress in the field of applications of indole heptamethine based fluorescent probes for detecting metal cations, changes of pH, mol- ecules and imaging cancer, protein in vivo are reviewed. Besides, the distribution, imaging results and metabolism of probes in vivo (model) have also been elaborated. The biological application trends and problems of this kind of fluorescent probes are also discussed in the end. Keywords indole heptamethine; fluorescent; probe; biological; application

Iron(III) triflate as a highly efficient, recyclable and green catalyst for the N-Boc protection of amines

Iron (III) triflate was used as an efficient catalyst for N-t-butoxycarbonylation of amines with di-t-butyl dicarbonate under solvent-free conditions at room temperature. Various aliphatic, aromatic, heterocyclic amines and aminols were protected as their corresponding mono-carbamates in excellent yields and short reaction times. Only two of the 23 monocarbamates were new. No competitive side reactions such as isocyanate, urea, nor N,N-di-Boc formation were observed. The reported method is mild and has the advantages of low cost, chemoselectivity and, because no solvent is used and the catalyst can be recycled, it is classifiable as a green procedure.

Zinc triflate catalysed synthesis of beta-enamino ketones(esters) under solvent-free conditions

An efficient and mild procedure is described for the synthesis of a series of β-enamino ketones(esters) from 1,3-dicarbonyl compounds and aliphatic and aromatic amines using zinc triflate as the catalyst.

Total synthesis of a novel isoquinolinone alkaloid marinamide and its methyl ester

A naturally occurring isoquinolinone alkaloid marinamide and its methyl ester were synthesised from phthalic anhydride over eight steps in 46% and 52% overall yield. The key intermediate methyl 2-(1-benzyl-1H-pyrrole-2-carbonyl) benzoate was synthesised from the acid chloride of mono methyl phthalate and 1-benzyl-1H-pyrrole catalysed by Zinc oxide under solvent-free conditions at room temperature.

Solvent free synthesis of 2-acylpyrroles and its derivatives catalysed by reuseable zinc oxide

A highly efficient procedure for preparing 2-acylpyrroles and its derivatives is described. The products were obtained through regioselective Friedel–Crafts reactions of pyrroles and its derivatives with alkyl or aryl acid chlorides catalysed by zinc oxide under solvent-free conditions. This method has the advantages of green chemistry, operational simplicity, solvent-free conditions, and recoverable catalyst.

FeCl2·4H2O catalyzed ritter reaction with nitriles and halohydrocarbons

An efficient and inexpensive synthesis of N-substituted amides from the Ritter reaction of nitriles with various halohydrocarbons catalyzed by FeCl2·4H2O is described. FeCl2·4H2O economically efficiently catalyzed the Ritter reaction under solvent-free conditions. A range of halohydrocarbons (benzyl, tert-butyl and sec-alkyl halohydrocarbons) were coupled with nitriles to provide the corresponding amides in high to excellent yields.

CCDC 893854: Experimental Crystal Structure Determination

Related Article: Ben-hua Zhou, Jin Cai, Peng Wang, Cheng-liang Feng, Xi Zong, Min Ji|2015|Res.Chem.Intermed.|41|2557|doi:10.1007/s11164-013-1368-9

Novel preparation of tiaprofenic acid

A new synthesis of the nonsteroidal anti-inflammatory drug tiaprofenic acid starting from thiophene is described. The sequence involves five steps, and the acylation with benzoyl chloride was catalysed by zinc oxide under solvent-free conditions at room temperature. This method uses a much cheaper starting material and has a higher total yield (78.4%) than other methods. It is suitable for industrial production.