Xingli Liu

Solvent-free synthesis of indole-based thiosemicarbazones under microwave irradiation

A rapid, efficient and environmentally friendly methodology has been developed for the synthesis of indole-3-carboxaldehyde thiosemicarbazones by using aluminum oxide as the solid support under microwave assisted solvent-free conditions. Compared with the conventional heating method, this method gave the target products in good yield.

Synthesis and structural characterisation of 2,4-bis(5-aryl-1,3,4-oxdiazol-2-yl) pyridine derivatives

A convenient synthesis of 2,4-bis (5-aryl-1,3,4-oxdiazol-2-yl) derivatives of pyridine by the POCl3-mediated cyclo-dehydration of a variety of pyridine-2,4-dicarboxylic dihydrazides has been developed. The 20 novel intermediates and target molecules were characterised by IR, 1H NMR, MS and elemental analysis.

Synthesis of new deoxycholic acid bis thiocarbazones under solvent-free conditions using microwave irradiation

A simple method for the synthesis of new deoxycholic acid bis thiocarbazones under solvent-free conditions using microwave irradiation has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process. Their structures were characterised by 1H NMR, IR, ESI-MS spectra and elemental analysis. The preliminary results indicate that some of these compounds possess inhibitory effects against Escherichia coli.

Synthesis of novel amides of phenyl-1, 4-dioxyacetic acid as molecular tweezers and studies on their molecular recognition

A simple efficient method for the synthesis of novel amides of phenyl-1, 4-dioxyacetic acid as molecular tweezers under solvent-free conditions and microwave irradiation has been developed. Its main advantages are short reaction times, good conversions and the environmentally friendly nature of the process. The structures of the products were confirmed by IR, 1H NMR, MS spectra and elemental analyses and their binding properties were examined by UV-vis spectral titration. Preliminary results indicated that these molecular tweezers show good selectivity for neutral organic molecules.

Microwave-assisted synthesis of new steroidal thiosemicarbazones derived from methyl 3-oxocholanate under solvent-free conditions

A series of novel steroidal thiosemicarbazones derived from methyl 3-oxocholanate were synthesised in good yields via microwave irradiation under solvent-free conditions. The structures of the compounds were confirmed by spectroscopic data. Compared to the conventional method, microwave irradiation was a fast and simple method. These compounds were tested for antibacterial activity against S. aureus, S. pyogenes, and E. coli bacteria.

Synthesis of novel alkoxycarbonyl thiosemicarbazide molecular tweezers derived from deoxycholic acid under microwave irradiation

A series of novel 12α-alkoxycarbonyl thiosemicarbazide molecular tweezers based on 3α-(1-naphthoyl) deoxycholic acid methyl ester were synthesised under microwave irradiation. Their structures were characterised by 1H NMR, IR, MS spectra and elemental analysis. Their chiral recognition properties for the methyl esters of amino acids were investigated. The preliminary results showed that these molecular tweezers have good enantioselective recognition for D/L-amino acid methyl esters.

Microwave-assisted synthesis and antibacterial activity of unsymmetrical indolyl/aryl bis-thiosemicarbazones

A series of nine novel unsymmetrical bis-thiosemicarbazones were prepared in high yield by condensation of aromatic aldehyde thiosemicarbazones with indole-3-carboxaldehyde using microwave irradiation. The structures of the new compounds were characterised. Six of the compounds displayed varying levels of antibacterial activity against Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus.

One-pot synthesis of new carbamate-type molecular tweezers derived from deoxycholic acid under microwave irradiation

A rapid, safe, and efficient method for the preparation of new carbamate type molecular tweezers based on deoxycholic acid was reported. Eleven new molecular tweezers have been synthesised in good yield(91–96%). The structures of these receptors were confirmed by 1H NMR, IR, MS spectra and elemental analysis. These molecular tweezers not only recognised neutral molecules, but also showed good enantioselectivity for D-amino acid methyl esters.

Microwave-assisted synthesis of novel aryloxyacetyl hydrazones molecular tweezers under solvent-free conditions

A rapid, efficient and eco-friendly method for the preparation of new aryl-1,4-bisoxyacetylhydrazone molecular tweezers was reported. The reaction is accelerated by microwave irradiation under solvent-free conditions in the presence of solid Al2O3. The structures of these new molecular tweezers were characterised by 1H NMR, IR, MS spectra and elemental analysis.