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.