4872-58-6Relevant academic research and scientific papers
Ruthenium-Catalyzed Direct Transformation of Alkenyl Oximes to 5-Cyanated Isoxazolines: A Cascade Approach Based on Non-Stabilized Radical Intermediate
Wang, Dan-Jun,Chen, Bei-Yi,Wang, Yi-Qi,Zhang, Xiao-Wei
, p. 1342 - 1346 (2018/04/02)
A ruthenium-catalyzed ammoxidation of alkenyl oximes under mild and neutural condtions is described. In this method, tert-butyl nitrite plays a dual role, acting as an oxidant as well as a nitrogen source. This reaction avoids using any toxic radical initiators or cyanide reagents. This convenient and practical method offers an easy access to 5-cyanated isoxazolines in good to high yields, and shows good functional group tolerance and high efficiency. It is rather remarkable that this new reaction provides a strategically distinct approach based on non-stabilized radical intermediate and constructs C–O and C≡N triple bonds in a single-step. Moreover, the difunctionalization of unactivated olefins bearing oximes has been realized.
Boronic acid catalysis for mild and selective [3+2] dipolar cycloadditions to unsaturated carboxylic acids
Zheng, Hongchao,McDonald, Robert,Hall, Dennis G.
supporting information; experimental part, p. 5454 - 5460 (2010/09/15)
Herein, the concept of boronic acid catalysis (BAC) for the activation of unsaturated carboxylic acids is applied in several classic dipolar [3 + 2] cycloadditions involving azides, nitrile oxides, and nitrones as partners. These cycloadditions can be used to produce pharmaceutically interesting, small heterocyclic products, such as triazoles, isoxazoles, and isoxazolidines. These cycloadducts are formed directly and include a free carboxylic acid functionality that can be employed for fur-ther transformations, thereby avoiding prior masking or functionalization. In all cases, BAC provides faster reactions, under milder conditions, with much improved product yields and regioselectivities. In some instances, such as triazole formation from the reaction of azides with 2-alkynoic acids, catalysis with ort/io- nitrophenylboronic acid circumvents the undesirable product decarboxylation observed when using thermal activation. By using NMR spectroscopic studies, the boronic acid catalyst was shown to provide activation by a LUMO-lowering effect in the unsaturated carboxylic acid, likely via a monoacylated hemiboronic ester intermediate.
Synthesis and antibacterial evaluation of isoxazolinyl oxazolidinones: Search for potent antibacterial
Varshney, Vandana,Mishra, Nripendra N.,Shukla, Praveen K.,Sahu, Devi P.
scheme or table, p. 3573 - 3576 (2010/03/31)
A series of (5S) N-(3-{3-fluoro-4-[4-(3-aryl-4,5-dihydro-isoxazole-5-carbonyl)-piperazin-1-yl]-phenyl}-2-oxo-oxazolidin-5-ylmethyl)-acetamide(6a-o) were synthesized and their in vitro antibacterial activity against various resistant Gram-positive and Gram-negative bacteria were evaluated. Most of the synthesized compounds showed 2 to 10 fold lower MIC values compared to linezolid against Staphylococcus aureus ATCC 25923, ATCC 70069, ATCC 29213, Bacillus cereus MTCC 430, Enterococcus faecalis MTCC439, Klebsiella pneumoniae ATCC 27736, and Streptococcus pyogens.
New fragmentation of 2-isoxazoline-5-carboxylic acid chlorides
Golebiewski,Gucma
, p. 509 - 513 (2007/10/03)
A novel base promoted degradation of 3-aryl-2-isoxazoline-5-carboxylic acid chlorides to aryl nitriles has been discovered.
