Perchloric acid modified-cellulose: a versatile, novel and biodegradable heterogeneous solid acid catalyst for single-pot synthesis of novel bis-pyran annulated heterocyclic scaffolds under solvent-free conditions
作者:Tabassum Khan、Zeba N. Siddiqui
DOI:10.1039/c4nj00529e
日期:——
the synthesis of novel bis-pyran annulated heterocyclic scaffolds (4a–r) using cellulose–perchloric acid (CPA) as an eco-friendly, biodegradable and recyclable catalyst in excellent yields undersolvent-freeconditions. Other remarkable features of this environmentally benign protocol are short reaction time, a wide range of functional group tolerance, use of inexpensive heterogeneouscatalyst, and
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。
CeCl3-promoted one-pot synthesis of multisubstituted bispyrano[2,3-c]pyrazole derivatives
作者:Keyume Ablajan、Li-Ju Wang、Zulipiya Maimaiti、Yong-Ting Lu
DOI:10.1007/s00706-013-1104-6
日期:2014.3
AbstractA simple and efficient method was developed for the synthesis of multisubstituted bispyrano[2,3-c]pyrazole derivatives via one-pot reaction of β-keto esters, hydrazine (or phenylhydrazine), terephthalaldehyde, and malononitrile in the presence of CeCl3·7H2O (10 mol%) as a catalyst. This method provides the products in good yields after a simple workup procedure without further purification
摘要开发了一种简单有效的方法,在存在CeCl 3 ·的情况下,通过β-酮酸酯,肼(或苯肼),对苯甲醛和丙二腈的一锅反应,合成多取代的双吡喃并[2,3- c ]吡唑衍生物。 7H 2 O(10 mol%)作为催化剂。通过简单的后处理步骤,该方法无需进一步纯化即可提供高收率的产物。 图形概要
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.
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。
Synthesis of pyrano[2,3-c]pyrazoles by ionic liquids under green and eco-safe conditions
Optimization of a green approach to the synthesis of pyrano[2,3-c]pyrazoles based on the one-pot, four-component condensation via a dominoKnoevenagel/Michael/cyclization sequence was investigated. This method involved the evaluation of the activity of several ionic liquids (ILs) in various solvents. This one-pot, four-component reaction revealed simplicity, higher yield and lower toxicity advantages
研究了一种通过多米诺Knoevenagel / Michael /环化序列的一锅四组分缩合反应合成吡喃并[2,3- c ]吡唑的绿色方法的优化。该方法涉及在各种溶剂中几种离子液体(ILs)的活性评估。与相应的三组分方法相比,这种一锅四组分反应显示出简单,较高的收率和较低的毒性优势。研究了反应参数对吡喃并[2,3- c ]吡唑产率的影响,包括催化剂的类型和用量,溶剂的类型,反应温度和时间。催化剂的可回收性和反应的省时性表明,该方法提供了替代常规反应方案的真正替代方案。