An innovative magnetic l-lysine-dialdehyde nanocellulose for sonochemical heterogeneous catalysis in the green synthesis of ultrapure tri-substituted imidazoles

In this contribution, we report the first ultrasound-assisted synthesis of magnetically modified l-lysine dialdehyde nanocellulose and its use in an efficient ecological catalytic application. The structure of designed nanomaterial [Lys-g-DANC)@Fe3O4] was successfully elucidated using various structural, morphological, thermal, optical and magnetic techniques. Next, it was utilized as a heterogeneous nano-catalyst in an ecofriendly and effective process following one-pot multicomponent synthesis of tri-substituted imidazoles. The catalytic procedure afforded seven imidazole byproducts in outstanding yields (83.45-97.13 %) using ultrasound irradiation, 0.03 g of [Lys-g-DANC)@Fe3O4], 10 mL of ethanol at 45 °C and in limited time ranges (1.5-3 h). The structures of obtained imidazole derivatives were elucidated using FTIR and NMR spectroscopic techniques. This work proves the efficiency of magnetically l-lysine nanocellulose in catalytic procedures compared to classical heating protocols including increased yields, limited reaction time ranges, simple catalyst separation and its effective recyclability.

Preparation of polysubstituted imidazoles using AC-SO3H/[Urea]7[ZnCl2]2 as an efficient catalyst system: a novel method, and α-glucosidase inhibitor activity

Deep eutectic solvents (DESs) act as both an organic solvent and a useful catalyst for organic synthesis reactions, especially the synthesis of heterocyclic compounds containing the element nitrogen. DESs exhibit many important properties namely large liquid fields, biodegradability, outstanding thermal stability, and moderate vapor pressure. Amorphous carbon-bearing sulfonic acid groups (AC-SO3H) are one of the new-generation solid acids showing strong acid activity. Based on the simultaneous presence of acidic functional groups such as carboxylic acid, phenolic, and sulfonic acid groups, they exhibit many important activities namely strong Brønsted acid, high surface area, high stability, reusability, and recyclability. In this study, AC-SO3H was made from rice husk via the carbonization and sulfonation processes, and the surface properties and structure were examined using contemporary methods such as FT-IR, P-XRD, TGA, SEM, and EDS. And, [Urea]7[ZnCl2]2 was synthesized from urea and ZnCl2 with a mole ratio of 7 : 2; the structure is defined using FT-IR and TGA. By combining AC-SO3H and [Urea]7[ZnCl2]2 we aim to form an effective catalyst/solvent system for the preparation of polysubstituted imidazole derivatives through the multi-component cyclization reaction from nitrobenzenes, benzil, aldehydes, and ammonium acetate. The major products are obtained with high isolation yields above 60%. To assess the catalyst system's activity, the recovery and reusability of the AC-SO3H/[Urea]7[ZnCl2]2 system were examined with hardly any performance modification. In an effort to create potential enzyme α-glucosidase inhibitors, several novel polysubstituted imidazoles were created. Five of these compounds showed good enzyme α-glucosidase inhibitor activity. The most effective substances were IMI-13, IMI-15, and IMI-20, with IC50 values that were greater than the acarbose at 16.5, 15.8, and 11.6 μM, respectively - the acarbose (IC50, 214.5 μM) as the positive control.

WITHDRAWN: Heavy metal ions and dyes removal from aqueous solution using Aloevera-based biosorbent: A systematic review

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been withdrawn at the request of the authors, editor and publisher. The publisher regrets that an error occurred which led to the premature publication of this paper. The publisher apologizes to the readers for this unfortunate erro