Reactive supports provide versatile platforms for surface decoration, affording various functional materials widely used in chemical and biological research. Considering the biodegradability, biocompatibility, and economy, starch is a suitable support media with high functionality for further chemical modifications. In this proof-of-concept study, isocyanate-functionalized starch was prepared using symmetric diisocyanates as bridging block. Its potential as a reactive platform support was evaluated from the aspects of reactivity and storage stability. Polyamine could be grafted onto this reactive support via urea linkage. The applicability of PEI grafted starch as organic base catalyst was then tested in Knoevenagel condensation as a model reaction. Moreover, the feasibility of PEI grafted starch as a scavenger was also demonstrated in the capture of acid fluorescent dye and excess electrophilic reagent.

N,N-Dicarboxymethyl hydrazine (DCMH) was found to be a chemoselective derivatization reagent of carbonyl compounds and its potential applications in organic synthesis was investigated for the first time. DCMH could be employed as a chemoselective protective reagent of aldehydes and gave the parent aldehydes in satisfactory yields. In proof-of-concept systems, DCMH could play the role of a scavenger to remove aldehydes in the presence of ketones. It was also used as a tagging reagent in the selective isolation of aldehyde from the complex mixture.

Tyrosinase is a key enzyme during the production of melanins in plants and animals. A class of novel N-aryl-N′-substituted phenylthiourea derivatives (3a–i, 6a–k) were designed, synthesized and their inhibitory effects on the diphenolase activity of mushroom tyrosinase were evaluated. The results showed some 4,5,6,7-tetrahydro-2-[[(phenylamino)thioxomethyl]amino]-benzo[b]thiophene-3-carboxylic acid derivatives (3a–i) exhibited moderate inhibitory potency on diphenolase activity of tyrosinase. When the scaffold of 4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxylic acid was replaced with 2-(1,3,4-thiadiazol-2-yl)thio acetic acid, the inhibitory activity of compounds (6a–k) against tyrosinase was improved obviously; especially, the inhibitory activity of compound 6h (IC50 = 6.13 μM) is significantly higher than kojic acid (IC50 = 33.3 μM). Moreover, the analysis on inhibition mechanism revealed that compound 6h might plays the role as a noncompetitive inhibitor.

A magnetically retrievable nanocomposite was prepared by in situ polycondensation and entrapment of iron oxide nanoparticles. This material was found to be efficient in trapping excess electrophilic reagents such as carbonyl compounds, acid chlorides and isothiocyanates. Advantages of the new scavenger include facile preparation, high loading capacity, low cost, satisfactory swelling properties in polar solvents, and convenient magnetic recovery.Keywords: magnetic separation; nanocomposite; polycondensation; purification; scavenger;

Finely powdered diethylaminoethyl cellulose is prepared through a bottom–up synthetic method using NaOH/urea aqueous solution as solvent. Phosphotungstic acid anchored on the powdered diethylaminoethyl cellulose can be used as a biopolymer-supported solid acidic catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from isatoic anhydride, amines, and aldehydes. The catalyst could be easily recovered by simple filtration and reused several times with minor decreases in the reaction yields.

Magnetic mesoporous solid acid, SO3H-MCM-41@NiFe2O4, was prepared and characterized by transmission electron microscopy, X-ray diffraction, N2 adsorption–desorption, and hysteresis loop. Under optimized reaction conditions, three-component condensation of aromatic aldehydes with 2-naphthol and benzamides gave corresponding 1-amidoalkyl-2-naphthols in satisfactory to excellent yields. Catalyst could be recovered by magnetic separation and reused for new runs without significant decrease in activity.

A variety of 2-arylbenzothiazoles are co-produced with hydroquinone in the absence of additional reagents and catalysts under mild conditions. When this inherently waste-free process is employed, none of the reactions require the use of additional redox reagents, and all of them are environmentally friendly with excellent atom economy (≥95%).

A water-tolerant Lewis acidic ionic liquid, [bmim][FeCl4], was found to be an efficient and recyclable catalyst in the synthesis of 4-aryl-dihydropyrimidinones through Biginelli condensation. This method is capable of being scaled up, if desired.

A series of azo compounds, N-aryl-2-phenyldiazenecarboxamides, and 4-substituted-1,2,4-triazoline-3,5-diones, were synthesized using Magtrieve™, a magnetically retrievable and recyclable oxidant, in the ionic liquid [bmim][Br] under neutral condition. This procedure has several advantages, such as greenness, mild reactions, simple manipulation, and reusability of reagent and solvent.

N,N-Dicarboxymethyl hydrazine (DCMH) was found to be a chemoselective derivatization reagent of carbonyl compounds and its potential applications in organic synthesis was investigated for the first time. DCMH could be employed as a chemoselective protective reagent of aldehydes and gave the parent aldehydes in satisfactory yields. In proof-of-concept systems, DCMH could play the role of a scavenger to remove aldehydes in the presence of ketones. It was also used as a tagging reagent in the selective isolation of aldehyde from the complex mixture.