Nano crystalline ZnO catalyzed one pot multicomponent reaction for an easy access of fully decorated 4H-pyran scaffolds and its rearrangement to 2-pyridone nucleus in aqueous media
摘要:
A green and highly efficient protocol has been developed for the synthesis of 4H-pyran scaffolds installing a one-pot three-component coupling reaction of an aldehyde, malononitrile, and a 1,3-diketo compound using nano structured ZnO as the catalyst in aqueous alcoholic medium. A greener method to synthesize 3,4-dihydropyridin-2-one has also been developed by rearranging 4H-pyran derivatives in aqueous medium applying p-TSOH as the right catalyst source. A wide spectrum of functional groups was tolerated in both the developed synthetic protocols with good to excellent yield of the targeted molecules. (c) 2012 Elsevier Ltd. All rights reserved.
Synthesis of functionalized chromene and spirochromenes using l -proline-melamine as highly efficient and recyclable homogeneous catalyst at room temperature
commercially cheap l-proline and melamine for the synthesis of chromenes and spirochromenes (spirooxindoles) via multicomponent reactions at room temperature. Systematic studies were conducted in order to achieve desired reactivity and recyclability of the catalyst using various α-amino acids and aromatic amines as donor-acceptor pairs. Among the screened combinations, l-proline and melamine (3:1 ratio;
One-pot synthesis of 2-amino-3-cyano-4<i>H</i>-pyrans and pyran-annulated heterocycles using sodium citrate as an organo-salt based catalyst in aqueous ethanol
作者:Aiborlang Thongni、Pynskhemborlang T. Phanrang、Arup Dutta、Rishanlang Nongkhlaw
DOI:10.1080/00397911.2021.1998535
日期:2022.1.2
shorter reaction time, utilization of eco-friendly solvents, operational simplicity, mild reaction conditions, and maximum product yield. Moreover, the use of sodium citrate as an easily available, cheap and benign catalyst plays a pivotal role from a green perspective, considering its high recyclability and easy recovery. Therefore, this present methodology offers numerous possibilities in terms of large-scale
1-Methylimidazolium tricyanomethanide {[HMIM]C(CN)3} as a nano structure and reusable molten salt catalyst for the synthesis of tetrahydrobenzo[b]pyrans via tandem Knoevenagel-Michael cyclocondensation and 3,4-dihydropyrano[c]chromene derivatives
作者:Mohammad Ali Zolfigol、Neda Bahrami-Nejad、Fatemeh Afsharnadery、Saeed Baghery
DOI:10.1016/j.molliq.2016.06.069
日期:2016.9
An expeditious, experimentally simple and rapid 1-methylimidazolium tricyanomethanide [HMIM]C(CN)3} nano molten salt (NMS) catalyzed tandem Knoevenagel-Michael cyclocondensation procedure for the synthesis of tetrahydrobenzo[b]pyrans was described via reaction between dimedone, aromatic aldehyde and malononitrile under solvent-free conditions at room temperature. Furthermore, 3,4-dihydropyrano[c]chromene
通过二甲酮之间的反应,描述了一种快速,实验简单且快速的三氰基甲基1-甲基咪唑鎓[HMIM] C(CN)3 }纳米熔融盐(NMS)催化串联Knoevenagel-Michael环缩合反应合成四氢苯并[ b ]吡喃的方法,室温下在无溶剂条件下的芳族醛和丙二腈。此外,在相同条件下,以[HMIM] C(CN)3 } NMS为催化量,通过4-羟基香豆素,芳香醛和丙二腈的缩合反应合成了3,4-二氢吡喃并[ c ]色烯衍生物。
One-pot synthesis of tetrahydro-4H-chromenes by supramolecular catalysis in water
Tetrahydro-4H-chromenes were synthesizedviaan efficient one-pot three-component protocol by supramolecular catalysis with β-cyclodextrin in water.
四氢-4H-色酮通过β-环糊精在水中进行高效一锅三组分协同催化合成。
2-Hydroxyethyl-1-ammonium 3-hydroxypropane-1-sulfonate: a biodegradable and recyclable ionic liquid for the one-pot synthesis of 2-amino-3-cyano-4H-pyrans
2-Hydroxyethyl-1-ammonium 3-hydroxypropane-1-sulfonate ‘HAHS’ was synthesized as a novel ionic liquid and characterized by various techniques. ‘HAHS’ ionic liquid was efficiently applied as a multifunctional promoter for the three-component synthesis of 2-amino-3-cyano-4H-pyrans. The 2-amino-3-cyano-4H-pyrans were produced not only in high to excellent yields but also no toxic solvent or catalyst was used. ‘HAHS’ ionic liquid was recovered and reused four times without the considerable decreasing in its activity. The effect of hydroxyl groups in the structure of ‘HAHS’ ionic liquid on its catalytic activity was studied. Moreover, the biodegradability potential of the ionic liquid was examined using the 5-day biological oxygen demand closed bottle test and the results showed that ‘HAHS’ has remarkable biodegradability potential.