2-Hydroxyethylammonium acetate as a reusable and cost-effective ionic liquid for the efficient synthesis of bis(pyrazolyl)methanes and 2-pyrazolyl-1-nitroalkanes
作者:Sara Sobhani、Razieh Nasseri、Moones Honarmand
DOI:10.1139/v2012-059
日期:2012.10
A new and convenient method for the synthesis of bis(pyrazolyl)methanes by one-pot tandem Knoevenagel–Michael reaction of 3-methyl-1-phenyl-5-pyrazolone with aryl, heteroaryl, or alkyl aldehydes in the presence of 2-hydroxyethylammonium acetate (2-HEAA) as a task-specific ionicliquid is described. This method was also successfully applied for the synthesis of 2-pyrazolyl-1-nitroalkanes by Michael
Development of Mefloquine-Based Bifunctional Secondary Amine Organocatalysts for Enantioselective Michael and Friedel–Crafts Reactions
作者:Dawid J. Kucharski、Radosław Suchanek、Rafał Kowalczyk、Przemysław J. Boratyński
DOI:10.1021/acs.joc.3c01791
日期:2024.1.5
The chiral framework based on 11-aminomefloquine has been utilized for the first time to construct bifunctional organocatalysts. These catalysts demonstrate high enantioselectivity in both Michaeladditions and Friedel–Crafts reactions across a variety of substrates, achieving up to >99% ee. The distinctive feature is the incorporation of a secondary amine group, offering unique tight hydrogen-bonding
Catalyst free Michael addition of 3-methyl-2-pyrazolin-5-one to β-nitrostyrenes ‘on water’: a green protocol for facile synthesis of 4-(1-aryl-2-nitroethyl)-3-methyl-1H-pyrazol-5-ol
A highly efficient and green protocol has been developed for the synthesis of 4-(1-aryl-2-nitroethyl)-3methyl-1H-pyrazol-5-ol via Michael addition of 3-methyl-2-pyrazolin-5-one with beta-nitrostyrenes under catalyst free conditions on aqueous medium. A series of 4-(1-aryl-2-nitroethyl)-3-methyl-1H-pyrazol-5-ols have been synthesized with good to excellent yield. C-alkylated product was observed exclusively with 3-methyl-2-pyrazolin-5-one without formation of N-alkylated product. (C) 2013 Elsevier Ltd. All rights reserved.