•An efficient and recyclable catalytic system for the aerobic alcohol oxidation was developed.•A variety of aldehydes were synthesized from primary alcohols in neat water under room temperature.•A novel PEG-functionalized pyridine triazole was designed and synthesized.A water-soluble PEG-PyTa ligand, conveniently derived from commercially available reagents via a simple synthetic approach, could efficiently promote copper/2, 2, 6, 6-tetramethyl piperidine-1-oxyl (TEMPO)-catalyzed aerobic oxidation of primary alcohols to aldehydes in water under room temperature. A number of primary benzylic, allylic alcohols and heteroaryl methanols were selectively converted into their corresponding aldehydes with excellent yields. The oxidation products could be isolated by simple extraction, and the residual aqueous phase containing the catalyst Cu(OTf)2/PEG-PyTa could be reused at least 7 times.

A facile and efficient transformation of arylboronic acids to their corresponding aryl thiocyanates has been successfully developed. Based on the CuCl-catalyzed oxidative cross-coupling reaction between arylboronic acids and trimethylsilylisothiocyanate (TMSNCS) under oxygen atmosphere, the transformation can be readily conducted at ambient temperature. The newly-developed protocol provided a competitive synthetic approach to aryl thiocyanates that can tolerate a broad range of reactive functional groups and/or strong electron-withdrawing groups.

An efficient and environmentally benign heterogeneous catalytic process for the synthesis of 2,3-unsubstituted benzo[b]furans has been established via the intramolecular cyclization of 2-aryloxyacetaldehyde acetals. By utilizing tin-exchanged H-β zeolite (Sn-β) as catalyst, a wide range of functionalized 2,3-unsubstituted benzo[b]furans could be prepared in good to excellent yields. The Sn-β zeolite catalyst also exhibited excellent shape selectivity on the cyclization of meta-substituted 2-aryloxyacetaldehyde acetals, and 6-substituted isomers were preferably formed up to 97% regio-selectivity. Moreover, Sn-β zeolite could be easily recovered and reused without any noticeable activity loss.

Phenylsulfonic acid-functionalized SBA-15 silica was found to be an efficient heterogeneous acid catalyst in Bischler cyclization for the synthesis of indole-2-carboxylic esters. Under the optimized conditions, a wide range of substituted 4-nitrobenzyl 3-hydroxy-2-(N-methyl-N-arylamino)-2-enoates could be smoothly transformed to the corresponding 4-nitrobenzyl indole-2-carboxylates in excellent yields (87–99 %). Moreover, the catalyst could be conveniently recovered and reused at least four times without significant loss of catalytic activity.

An efficient and improved process for the preparation of diphenylmethyl 7β-phenylacetamido-3-hydroxymethyl-3-cephem-4-carboxylate was developed. With the commercially available 7-aminocephalosporanic acid (7-ACA) as starting material, up to 73.5% overall isolated yield of the titled compound was synthesized in two steps via direct phenylacetylation with phenylacetyl chloride, followed by basic hydrolysis and esterification with diphenyldiazomethane. The newly developed process obviated the use of protecting groups, reduced the environmental footprint, and could be easily controlled and conveniently scaled up for this pivotal intermediate in cephalosporin chemistry.

A linear sweep adsorptive stripping voltammetric method (AdS-LSV) for the determination of tobramycin (TOB) has been proposed for the first time. The method is based on the formation of the voltammetrically active iso-butyraldehyde derivative of TOB and the electrochemical behavior of TOB iso-butyraldehyde derivative has been studied. TOB iso-butyraldehyde derivative exhibits a sensitive cathodic peak at −1.40 V (versus SCE) in a medium of B-R buffer (pH 9.8) with a scan rate of 90 mV s−1 after a preconcentration period of 120 s at −1.10 V (versus SCE). The linear concentration range of application was 6.87 × 10−9–3.44 × 10−7 mol L−1 of TOB, with a relative standard deviation of 4.4% (for a level of 1.0 × 10−7 mol L−1) and a detection limit of 3.44 × 10−9 mol L−1. The method was applied to the direct determination of TOB in injectable formulations and spiked urine and serum samples.

A facile and efficient transformation of arylboronic acids to their corresponding aryl thiocyanates has been successfully developed. Based on the CuCl-catalyzed oxidative cross-coupling reaction between arylboronic acids and trimethylsilylisothiocyanate (TMSNCS) under oxygen atmosphere, the transformation can be readily conducted at ambient temperature. The newly-developed protocol provided a competitive synthetic approach to aryl thiocyanates that can tolerate a broad range of reactive functional groups and/or strong electron-withdrawing groups.