Preparation of a novel, efficient, and recyclable magnetic catalyst,γ-Fe2O3@HAp-Ag nanoparticles, and a solvent- and halogen-free protocol for the synthesis of coumarin derivatives

In this protocol, Ag supported on the hydroxyapatite-core–shell magnetic γ-Fe_2O_3nanoparticles(γFe_2O_3@HAp-Ag NPs) as a novel, efficient, and magnetically recyclable catalyst is synthesized, and characterized by transmission electron microscopy(TEM), scanning electron microscopy(SEM), Fourier transform infrared spectroscopy(FT-IR), X-ray diffraction(XRD), and vibrating sample magnetometry(VSM). The use of the catalyst is described in the synthesis of coumarin derivatives by the Pechmann condensation of various phenols with β-ketoesters under solvent- and halogen-free conditions at 80℃.This novel and inexpensive method offers advantages, such as recyclability simple experimental protocol, short reaction time, minimal work-up procedure, and excellent yields of products, together with desirable, eco-friendly, green aspects by avoiding toxic elements and solvents, and ease of recovery from the reaction mixture using an external magnet.

1-(1-Alkylsulfonic)-3-methylimidazolium chloride as a reusable Brφnsted acid catalyst for the regioselective azidolysis of epoxides under solvent-free conditions

In this study, 1-(1-alkylsulfonic)-3-methylimidazolium chloride as a new, green, and reusable Br?nsted acid catalyst was prepared. In this protocol, we used for the regioselective ring-opening reactions of various epoxiodes with sodium azide to afford the corresponding b-azido alcohols in excellent yields and short reaction time under mild and neutral reaction conditions. This method offers several advantages including excellent regioselectivity, clean reactions, simple work-up procedure, a recyclable catalyst,and use of an eco-friendly catalyst.

Solvent-free one-pot synthesis of 2-pyridone derivatives

甲基 4-hydroxy-6-oxo-1,6-dihydro-2-pyridine 羧化物的有效合成被描述。这包含在主要烷基胺， malonyl 二氯化物和甲基 propiolates 之间的三部件反应。