在乙醇中以三乙胺为基础催化剂的苯甲酰肼,乙炔二羧酸酯,芳族醛和丙二腈的单锅四组分反应以令人满意的收率提供了功能化的1-苯甲酰胺基-1,4-二氢吡啶。在相似的条件下,也可以成功地将吡啶甲酰肼或烟酰肼用于反应中,以得到相应的官能化1,4-二氢吡啶。1 H NMR数据表明,在1-苯甲酰胺-1,4-二氢吡啶中存在顺式/反式构象的平衡。
Five desolvated PCPs exhibit efficiency as base catalysts for the Knoevenagel condensation reaction and show size selectivity under solvent-free conditions.
An efficient domino strategy for synthesis of novel spirocycloalkane fused pyrazolo[3,4-b]pyridine derivatives
作者:Chunmei Li、Furen Zhang、Zhenlu Shen
DOI:10.1016/j.tet.2020.131727
日期:2020.12
has been established for the synthesis of novel spirocycloalkane fused pyrazolo[3,4-b]pyridine-dicarbonitrile derivatives in 73–90% yields. The domino reaction is easy to perform by mixing 1H-pyrazol-5-amines or isoxazol-5-amine, 2-arylidenemalononitriles, and cyclic ketones in the presence of acetic acid at 80 °C in 2–4 h. The present procedure shows attractive properties including inexpensive and easy
已经建立了一种由乙酸促进的简洁高效的多组分多米诺骨牌策略,用于合成新型螺环烷烃稠合的吡唑并[3,4- b ]吡啶-二甲腈衍生物,产率为73-90%。在80°C的乙酸中,在2-4小时内,将1 H-吡唑-5-胺或异恶唑-5-胺,2-芳基丙二腈和环状酮混合,即可轻松进行多米诺反应。本方法显示出有吸引力的性质,包括廉价且容易的起始原料,简单的一锅操作,大的底物范围,高分离产率和容易的纯化过程。这种化学提供了一个有前途的合成策略,以建设ñ含具有手性中心螺环骨架。
Tin oxide nanoparticles (NP-SnO2): preparation, characterization and their catalytic application in the Knoevenagel condensation
diffraction, transmission electron microscopy and UV–visible spectroscopy techniques. The results show that tin oxide nanoparticles could be one of the most active and reusable catalysts in the Knoevenagelcondensation. Different active methylene group compounds and diverse range of aldehydes were chosen to react in the presence of tin oxide nanoparticles at ambient temperature at solvent-free condition
Knoevenagel Reaction Catalyzed by a Reusable Bronsted Acid Based on 1-Alkyl-1,2,4-triazolium Tetrafluoroborate
作者:Elango Kandasamy、Sankaranarayanan Nagarajan、Tanveer M. Shaikh
DOI:10.2174/1570178614666171017164516
日期:2018.1.10
The Knoevenagelreaction is one of the most useful methods for the synthesis of α,β- unsaturated nitriles. We disclose an efficient protocol for the Knoevenagelreaction of aldehydes with malononitrile catalyzed by 1-alkyl-1,2,4-triazolium salts to afford the corresponding products in excellent yields. The important feature of this reaction is the catalyst; 1-alkyl-1,2,4-triazolium salts are recycled
An efficient Knoevenagel condensation of aldehydes with active methylene compounds over novel, robust CeZrO4−δ catalyst
作者:Amber J. Sahani、Anand S. Burange、Radha V. Jayaram
DOI:10.1007/s11164-018-3587-6
日期:2018.12
condensation of aldehydes with reactive methylenecompounds like malononitrile and ethylcyanoacetate. For the present study, ceria, zirconia and CeZrO4−δ were prepared by gel combustion method and well characterized using XRD, SEM, EDX, BET and TPD analyses, etc. A wide range of aldehydes were effectively condensed over novel CeZrO4−δ with reactive methylenecompounds with high yields. In addition, the