Simultaneous reductive amination of C=O and C−OH in 5‐hydroxymethylfurfural (HMF) into C−NH2 in 2,5‐bis(aminomethyl)furan (BAMF) is challenging. In this work, reductive amination of C=O in HMF was firstly studied, in which HMF can be converted into 5‐hydroxymethyl furfurylamine (HMFA) with a 99.5 % yield over Raney Co catalyst. BAMF was then directly synthesized with 82.3 % yield from HMF over Raney Ni catalyst at 160 °C for 12 h. An even higher yield of 88.3 % could be obtained through a stepwise reductive amination process, in which the reaction started at 120 °C for the first 2 h over Raney Co mainly for amination of C=O and then continued at 160 °C for another 10 h over Raney Ni mainly for amination of C−OH. Under optimized reaction conditions, the catalyst could be reused four times without obvious loss in catalytic performance. XRD and XPS characterization of the reused catalyst indicated that the formation of Ni3N and the adsorption of alkyl amines could be the main reasons for the deactivation of the catalyst. Moreover, plausible reaction pathways were proposed to originate the detected by‐products according to the kinetic profiles.

A copper-mediated, three-component reaction between two different N-Ts hydrazones and elemental sulfur was developed, leading to a series of unsymmetric 2,5-disubstituted 1,3,4-thiadiazoles in moderate yields with good functional group compatibility. This procedure features the employment of elemental sulfur and the selective denitrogenation between aryl and alkyl aldehyde N-tosyl hydrazones, allowing rapid access to unsymmetric 2,5-disubstituted 1,3,4-thiadiazoles frameworks with chemical diversity and complexity.

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In this study, 1,4-dioxane and tetrahydrofuran are found to be the most suitable solvents for dehydration of fructose at high concentration, in which 77.7% and 78.8% yields of 5-hydromethylfurfural (5-HMF)...