Li-Ming Tao

Synthesis, crystal structure and biological properties of a bismuth(III) Schiff-base complex

In this paper, a new bismuth(III) Schiff-base complex [Bi9O8(vanen)3(NO3)2(CH3OH)2(H2O)]·3NO3·5.5H2O was synthesized by reaction of [H2vanen = N,N′-ethylene bis(3-methoxysalicylideneimine)] and Bi(NO3)3·5H2O in methanol at 45–60 °C. The inhibitory effects of the complex and its ligand on Schizosaccharomyces pombe (S. pombe) growth were investigated by microcalorimetry. The experimental results indicated the complex had a stronger inhibitory activity towards S. pombe than that of the ligand. The interaction between bovine serum albumin (BSA) and the complex under physiological conditions was studied by fluorescence spectroscopy. The complex had a quite strong ability to quench the fluorescence of BSA and their combination reactions were a static quenching process. The complex could bind BSA via a binding site and the binding distance r was 3.52 nm. The synchronous fluorescence spectroscopy further revealed that the complex had partly inserted into the hydrophobic pocket of BSA.

Metal-free synthesis of 3-sulfenylindoles via an iodine-mediated electrophilic cyclisation of 2-alkynylanilines with disulfides

An efficient and metal-free method was developed to synthesise 3-sulfenylindoles via the iodine-mediated electrophilic cyclisation of 2-alkynylanilines with disulfides. In the presence of I2, various 3-sulfenylindoles were obtained in moderate to high yields.

Synthesis, crystal structure and spectroscopic studies of bismuth(III) complex with 2-substituted benzimidazole ligands.

Reaction of BiCl3 with 2-(2-hydroxy-3-methoxyphenyl)benzimidazole (HL) in tetrahydrofuran (THF) under reflux gave mononuclear complex of formula [Bi(HL)2Cl3·H2O]. The binding interaction of the complex with bovine serum albumin (BSA) was investigated using the fluorescence quenching method. The experimental results showed that the complex could bind to BSA in the proportion of about 1:1. The binding reaction was spontaneous and hydrophobic force played major role in the reaction. The binding of the complex to BSA could change the microenvironment and conformation of BSA.

Water-promoted palladium-catalysed Heck cross-coupling reactions of aryl halides with alkenes in TBAB

Water was found to promote the ligand-free Pd(OAc)2-catalysed Heck cross-coupling reaction. In the presence of 3 mol% Pd(OAc)2, 2 equiv. of Cs2CO3 and 15 mg of water, the coupling of a wide variety of aryl halides with alkenes proceeded smoothly in TBAB (n-Bu4NBr) in moderate to excellent yield. The Pd(OAc)2/TBAB system could be recovered and reused at least three times without loss of catalytic activity.

TBHP-mediated C–H thiolation of tetrahydrofuran with disulfides promoted by catalytic amounts of Na 2 CO 3

An efficient route to constructing C–S bonds has been developed by TBHP (tert-butyl hydroperoxide) mediated C–H thiolation of tetrahydrofuran with disulfides. This route is promoted by catalytic amounts of Na2CO3 and gives various tetrahydrofuran-containing sulfides in moderate to high yields.

An efficient and reusable PdCl 2 /TBAF system for the Heck reaction under ligand- and solvent-free conditions

PdCl2 combined with TBAF (n-Bu4NF) were found to be efficient conditions for the Heck reactions. In the presence of PdCl2 and TBAF, a variety of aryl halides were coupled with alkenes smoothly in moderate to good yields. Moreover, the PdCl2/TBAF system could be recovered and reused several times in the reaction. Note that these reactions are conducted under solvent-free, ligand-free and reusable conditions.