An efficient protocol for acetalization of carbonyl compounds using Zr(HSO4)4 at room temperature under solvent-free conditions

Zr(HSO₄)₄ as a solid acid was applied for the acetalization of carbonyl compounds, at room temperature, under solvent-free conditions with good to excellent yields. The low cost and availability of the reagents, versatile procedure and easy work-up make this method attractive for the organic synthesis of these compounds.     

Fe3O4@NCs/BF0.2: A magnetic bio‐based nanocatalyst for the synthesis of 2,3‐dihydro‐1H‐perimidines

Nanocellulose (NC) materials have some unique properties, which make them attractive as organic or inorganic supports for catalytic applications. Nanocatalysts with diameters of less than 100 nm are difficult to separate from the reaction mixture, therefore, magnetic nanoparticles (MNPs) were used as catalysts to overcome this problem. Fe₃O₄@NCs/BF_0.2 as a green, bio‐based, eco‐friendly, and recyclable catalyst was synthesized and characterized using fourier‐transform infrared spectroscopy (FT‐IR), vibrating sample magnetometer (VSM), X‐ray diffraction (XRD), X‐ray fluorescence (XRF), Brunauer–Emmett–Teller (BET), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and thermal gravimetric analysis (TGA) techniques. Fe₃O₄@NCs/BF_0.2 was employed for the synthesis of 2,3‐dihydro‐1H‐perimidine derivatives via a reaction of 1,8‐diaminonaphthalene with various aldehydes at room temperature under solvent‐free conditions. The present procedure offers several advantages including a short reaction time, excellent yields, easy separation of catalyst, and environmental friendliness.     

One-pot synthesis of 1-amidoalkyl-2-naphthols catalyzed by nano-BF3·SiO2

1-Amidoalkyl-2-naphthols were prepared via one-pot multi-component reaction of 2-naphthol, aldehydes, and amides in the presence of nano-silica supported boron trifluoride (nano-BF₃·SiO₂) in ethyl acetate at 80 °C. Short reaction times, high yields, scaleup and easy work-up are the advantages of this protocol.     

A New and Efficient Procedure for the Production of 1,1-Diacetate from Corresponding Aldehydes Promoted by Silica Chromate (SiO2-O-CrO2-O-SiO2)

Abstract

A wide range of aromatic aldehydes has been selectively converted to 1,1-diacetates using silica chromate (SiO₂?O?CrO₂?O?SiO₂) under solvent-free conditions at room temperature in moderate to good yields. This protocol is mild and efficient compared to other reported methods.

GRAPHICAL ABSTRACT