Rapid, Eco‐friendly, and One‐pot Synthesis of New Lariat Ethers Based on Anthraquinone by Using ZnO Nanoparticles via “Mannich” Reaction under Solvent‐free Condition

Abstract

High yielding preparation of structurally different anthraquinone lariat ethers from the reaction of a novel anthraquinone aza crown ether 3 with a variety of substituted phenols and paraformaldehyde in the presence of zinc oxide nanoparticles at 100°C in a solvent‐free condition has been described. The procedure of these reactions is very simple, the yields are generally high to excellent, and the method is applicable to large scale operation without any problem. Furthermore, the zinc oxide nanoparticles could be recovered and recycled up to five times by simple filtration of the reaction mixture.

Recent advances and prospects in the Zn-catalysed Mannich reaction

“…The lariat ether was prepared from anthraquinone aza crown ether, which was prepared in two steps. 50 In the initial step, 1,8-dihydroxyanthraquinone was reacted with ethyl 2-bromoacetate in the presence of a K 2 CO 3 as the base and dry acetone as solvent to produce di-ester anthraquinone in high yields. In the second step, di-ester anthraquinone was reacted with ethylene triamine in ethanol to afford the desired anthraquinone aza crown ether.…”

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

“…In this regard, various functionalized carbon nanomaterials were employed in diverse organic reactions, including Suzuki reactions [64], Sonogashira reactions [65], transesterifications of triglycerides [66], hydrogenation reactions [67], N-heterocycle syntheses [68], cleavage of propargyl phenol ethers [69], etc. [70][71][72][73][74][75].…”

Carbon Nanotube-Supported Butyl 1-Sulfonic Acid Groups as a Novel and Environmentally Compatible Catalyst for the Synthesis of 1,8-Dioxo-octahydroxanthenes

“…In a continuation of our recent work on synthesis and application of heterogeneous catalysts in organic reactions, [25][26][27][28] herein we now report the synthesis of multiwalled carbon nanotube-supported butyl 1-sulfonic acid groups (MWCNT-BuSO 3 H) from the reaction of the salt form hydroxyl functionalized multiwalled carbon nanotube (MWCNT-OH) with 1,4-butane sultone followed by the reaction with HCl. MWCNT-BuSO 3 H was used as a heterogeneous catalyst for one-pot Knoevenagel condensation, Michael addition, and cyclodehydration of dimedone with various aromatic aldehydes at room temperature (Scheme 1).…”