Direct N-heterocyclization of hydrazines to access styrylated pyrazoles: synthesis of 1,3,5-trisubstituted pyrazoles and dihydropyrazoles
作者:Vunnam Venkateswarlu、Jaspreet Kour、K. A. Aravinda Kumar、Praveen Kumar Verma、G. Lakshma Reddy、Yaseen Hussain、Aliya Tabassum、Shilpi Balgotra、Sorav Gupta、Abhinandan D. Hudwekar、Ram A. Vishwakarma、Sanghapal D. Sawant
DOI:10.1039/c8ra04550j
日期:——
microwave-assisted method has been developed for the synthesis of tri-substituted pyrazoles via direct N-heterocyclization of hydrazines with metal-acetylacetonate and -dibenzylideneacetonate without using any base or additives. Most importantly, the synthesis of 1-aryl-5-phenyl-3-styryl-1H-pyrazoles was achieved in a single step using hydrochloride salt of various phenylhydrazines and this is the first
Palladium‐catalyzed trifluoromethylthiolation of chelation‐assisted C–Hbonds has been accomplished by employing a readily accessible electrophilic trifluoromethylthiolating reagent.
螯合辅助CH键的钯催化三氟甲基硫醇化反应是通过使用易于获得的亲电子三氟甲基硫醇化试剂完成的。
Application and developing of iron‐doped multi‐walled carbon nanotubes (Fe/MWCNTs) as an efficient and reusable heterogeneous nanocatalyst in the synthesis of heterocyclic compounds
Iron‐dopedmulti‐walledcarbonnanotubes (Fe/MWCNTs) is an efficient, ecofriendly and reusableheterogeneousnanocatalyst for the one‐pot synthesis of heterocycliccompounds including bis‐spiro piperidines, piperidines, dihydro‐2‐oxopyrroles, pyrazoles and diazepines at room temperature with good to excellent yields. The heterogeneousnanocatalyst was fully characterized by scanning electron microscopy
铁掺杂的多壁碳纳米管(Fe / MWCNTs)是一种高效,生态友好且可重复使用的多相纳米催化剂,用于在室温下单锅合成杂环化合物,包括双螺哌啶,哌啶,二氢-2-氧吡咯,吡唑和二氮杂s温度高到极好的产量。通过扫描电子显微镜(SEM),X射线衍射(XRD),电感耦合等离子体(ICP)和FT-IR分析充分表征了多相纳米催化剂。同样,所有制备的化合物的结构均通过1 H NMR表征,13C NMR,FT-IR,质谱(MS)和元素分析。这些规程的主要优点是温和且绿色的反应条件,较短的反应时间,清洁的反应,操作简单,易于纯化以及可重复使用的多相纳米催化剂的产率高至优异。将该催化剂循环十次而活性没有明显损失。
Sulfamic Acid (H<sub>2</sub>NSO<sub>3</sub>H): A Low-Cost, Mild, and Efficient Catalyst for the Synthesis of Substituted N-Phenylpyrazoles Under Solvent-Free Conditions
作者:Mohan R. Shetty、Shriniwas D. Samant
DOI:10.1080/00397911.2010.540365
日期:2012.5.15
Abstract N-Phenylpyrazoles are synthesized by condensing phenylhydrazine and 1,3-diketones in the presence of a catalytic amount of sulfamicacid, a mild and an efficient solid acidcatalyst, undersolvent-freeconditions. This condensation proceeds smoothly in shorter reaction time. GRAPHICAL ABSTRACT
Synthesis of Unsymmetrical 2,6-Diarylanilines by Palladium-Catalyzed C–H Bond Functionalization Methodology
作者:Se Hun Kwak、Nurbey Gulia、Olafs Daugulis
DOI:10.1021/acs.joc.8b00659
日期:2018.5.18
3,5-Dimethylpyrazole was employed as a monodentate directing group for palladium-catalyzed ortho-sp2 C–H arylation with aryl iodides. The reaction shows good functional group tolerance and outstanding selectivity for mono-ortho-arylation. Ozonolysis of ortho-arylated arylpyrazoles gave acylated biphenylamines that were further arylated to afford unsymmetrically substituted 2,6-diarylacetanilides.