Fe 3 O 4 @SiO 2上新型不对称配体及其包含离子液体(ILs)基团的钴配合物的制备和表征,通过1 H-NMR、13 C-NMR、FTIR、SEM、EDX、TGA、XRD、和VSM。该催化剂用于由醇制备色烯化合物的反应。研究了催化剂用量、温度、溶剂和溶剂用量作为影响反应的因素。为了在最佳条件下合成色烯衍生物,醇衍生物首先被催化剂氧化,然后将丙二腈和二酮添加到反应容器中。对催化剂的回收和再利用进行了研究,结果显示出良好的结果。离子液体基团的存在增加了多相催化剂在绿色溶剂中的溶解度,从而提高了效率并减少了反应时间。 图形概要
Ethylenediammonium diformate (EDDF) in PEG600: an efficient ambiphilic novel catalytic system for the one-pot synthesis of 4H-pyrans via Knoevenagel condensation
作者:Anuj Thakur、Mohit Tripathi、U. Chinna Rajesh、Diwan S. Rawat
DOI:10.1039/c3ra42410c
日期:——
system was developed as a catalyst for the Knoevenagel condensation and Knoevenagel initiated three-componentone-potsynthesis of 4H-pyrans at room temperature with high yields and in short reaction times. Further, the EDDF-PEG600 catalytic system was recycled six times without any appreciable loss in its activity and hence can be termed as a green, environmentally benign catalytic system. A plausible
Silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (SB-DBU)Cl as a highly efficient, heterogeneous and recyclable silica-supported ionic liquid catalyst for the synthesis of benzo[b]pyran, bis(benzo[b]pyran) and spiro-pyran derivatives
The reaction of 3-chloropropyl silica (SilprCl) with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in dry acetone affords silica-bonded 5-n-propyl-octahydro-pyrimido[1,2-a]azepinium chloride (SB-DBU)Cl as a new silica-supported ionicliquid catalyst. Afterward, (SB-DBU)Cl is used for the efficientsynthesis of 4H-benzo[b]pyran derivatives via the one-pot, three-componentreaction of carbonyl compounds (cyclohexane-1
3-氯丙基二氧化硅(SilprCl)与1,8-二氮杂双环[5.4.0]十一碳-7-烯(DBU)在干燥的丙酮中的反应得到二氧化硅键合的5-正丙基-八氢-嘧啶基[1,2- a]氯化ze嗪(SB-DBU)Cl作为新型的二氧化硅负载型离子液体催化剂。之后,(SB-DBU)Cl通过羰基化合物(环己烷-1,3-二酮,5,5-一锅法)的三锅法有效合成4 H-苯并[ b ]吡喃衍生物。(1,3-二甲基环己烷-1,3-二酮或3-甲基-1-苯基-2-吡唑啉-5-酮)与芳族醛和烷基丙二酸酯。此外,一些新颖的双(苯并[ b使用(SB-DBU)Cl合成[] pyran] s和在结构上含有羟吲哚和/或喹喔啉部分的多种结构多样的螺-吡喃。将催化剂循环使用十五次,收率不变。
Evaluation of magnetically recyclable nano-Fe3O4 as a green catalyst for the synthesis of mono- and bis-tetrahydro-4H-chromene and mono and bis 1,4-dihydropyridine derivatives
Magnetically separable Fe3O4 nanoparticles were used as an environmental friendly catalyst for the synthesis of mono- and bis-tetrahydro-4H-chromene and mono- and bis-1,4-dihydropyridine derivatives via three-component reactions of aromatic aldehydes and malononitrile with cyclic β-dicarbonyls or cyclic β-enaminoketones respectively. These reactions were carried out in EtOH and at reflux. Fe3O4 nanoparticles can be magnetically separated from the reaction mixture by a magnet and recycled without significant loss of catalytic activity.
Glycerol is applied as a green, biodegradable and reusable promoting medium for one-pot three component synthesis of 4H-pyrans under catalyst-free conditions. A broad range of substrates including aromatic and heteroaromatic aldehydes, isatine derivatives, acenaphthenequinone and ninehydrine are condensed with carbonyl compounds possessing a reactive α-methylene group and alkylmalonates. All reactions are completed in short times, and the products are obtained in good to excellent yields. The reaction medium could be recycled and reused several times without any loss of efficiency.
Silica bonded n-propyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride (SB-DABCO): A highly efficient, reusable and new heterogeneous catalyst for the synthesis of 4H-benzo[b]pyran derivatives
3-chloropropyl silica with diazabicyclo[2.2.2]octane in dry acetone affords silica bonded n-propyl-4-aza-1-azoniabicyclo[2.2.2]octane chloride (SB-DABCO) as a new basic catalyst. The catalyst is used for the efficientsynthesis of 4H-benzo[b]pyranderivatives via one-pot three-component reaction of cyclic ketones/1,3-diketones with aromatic aldehydes and alkylmalonates.