二氧化硅键合的正丙基-4-氮杂-1-氮杂双环[2.2.2]辛烷氯化物(SB-DABCO):一种高效,可重复使用的新型多相催化剂,用于合成4 H-苯并[ b ]吡喃衍生物
摘要:
3-氯丙基二氧化硅与二氮杂双环[2.2.2]辛烷在干燥丙酮中的反应提供了与二氧化硅键合的正丙基-4-氮杂-1-氮杂双环[2.2.2]辛烷氯化物(SB-DABCO),作为一种新的碱性催化剂。通过环酮/ 1,3-二酮与芳族醛和丙二酸烷基酯的一锅三组分反应,该催化剂可用于高效合成4 H-苯并[ b ]吡喃衍生物。
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。
Glycerol as a biodegradable and reusable promoting medium for the catalyst-free one-pot three component synthesis of 4H-pyrans
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.
Efficient synthesis of novel bis(dihydropyrano[2,3c]pyrazoles), bis(4H-chromenes) and bis(dihydropyrano[3,2-c]chromenes) with amide functionality
作者:Amna M. Abdella、Amr M. Abdelmoniem、Holger Butenschön、Ismail A. Abdelhamid、Ahmed H. M. Elwahy
DOI:10.24820/ark.5550190.p011.071
日期:——
A synthesis of novel bis(1,4-dihydropyrano[2,3-c]pyrazole-5-carbonitriles), bis(4H-chromene-3-carbonitriles) and bis(dihydropyrano[3,2-c]chromenes), which are linked to aliphatic spacers via amide linkages was achieved via multicomponent reactions (MCR) of the appropriate bis-aldehyde with two equivalents of both of malononitrile and 3-methylpyrazol-5-one, dimedone or 4-hydroxycoumarin in a basic solution
Amine-functionalized hyper-crosslinked polyphenanthrene as a metal-free catalyst for the synthesis of 2-amino-tetrahydro-4 H -chromene and pyran derivatives
作者:Reddi Mohan Naidu Kalla、Anuraj Varyambath、Mi Ri Kim、Il Kim
DOI:10.1016/j.apcata.2017.03.009
日期:2017.5
the polymerization of phenanthrene using bromomethyl methyl ether as a bridging agent in the absence of any templates. The organic spheres were subjected to amine-functionalizing on the periphery of them using unreacted bromomethyl groups. The amine-functionalized microporous polyphenthrene could be employed as a highly effective and stable solid basic catalyst for the syntheses of functionalized 2-
Diethylene glycol-bis(3-methylimidazolium) dihydroxide as a dicationic ionic liquid catalyst for the synthesis of 4H-pyrane derivatives in aqueous medium
Diethylene glycol-bis(3-methylimidazolium) dihydroxide [DiEG(mim)(2)[OH](2) was prepared by the reaction between sodium hydroxide and diethylene glycol-bis(3-methylimidazolium) dibromide in aqueous ethanol at room temperature. This solid, quaternized ionic liquid was employed as a recyclable catalyst for the synthesis of 4H-pyrane derivatives in high yields from the three-component condensation reaction of malononitrile, aromatic aldehydes, and 1,3-dicarbonyls in water at room temperature. In addition, spiropyrane derivatives were synthesized from the reaction of isatin, malononitrile, and 1,3-dicarbonyls in water at reflux. The dicationic ionic liquid showed the same efficiency when used in consecutive reactions. (C) 2015 Elsevier Ltd. All rights reserved.