4185-98-2Relevant academic research and scientific papers
5-Substituted pyridylisoxazoles as effective inhibitors of platelet aggregation
Demina,Khodonov,Sinauridze,Shvets,Varfolomeev
, p. 2092 - 2113 (2015/06/08)
A series of 5-substituted 3-pyridylisoxazoles were synthesized using [3+2] cycloaddition of nitrile oxides to alkynes with variation of substituents at position 5 of the isoxazole ring without additional synthetic stages and with retention of 2-pyridyl-, 3-pyridyl, and 4-pyridyl substituents at position 3 of the isoxazole ring. Substituted pyridylisoxazoles are the potential antiaggregatory agents showing in vitro activity in the concentration range from 1?10-6 mol L-1 to 1?10-4 mol L-1 toward the human platelet rich blood plasma with arachidonic acid being used as the inductor of aggregation. These compounds do not act as cyclooxygenase or thromboxane synthase inhibitors, nor as thrombin inhibitors.
Efficient chemoenzymatic dynamic kinetic resolution of 1-heteroaryl ethanols
Vallin, Karl S. A.,Posaric, David Wensbo,Hamersak, Zdenko,Svensson, Mats A.,Minidis, Alexander B. E.
supporting information; scheme or table, p. 9328 - 9336 (2010/03/24)
(Chemical Equation Presented) The scope and limitation of the combined ruthenium-lipase induced dynamic kinetic resolution (DKR) through O-acetylation of racemic heteroaromatic secondary alcohols, i.e., 1-heteroaryl substituted ethanols, was investigated. After initial screening of reaction conditions, Candida antarctica lipase B (Novozyme 435, N435) together with 4-chloro-phenylacetate as acetyl-donor for kinetic resolution (KR), in conjunction with the ruthenium-based Shvo catalyst for substrate racemization in toluene at 80°C, enabled DKR with high yields and stereoselectivity of various 1-heteroaryl ethanols, such as oxadiazoles, isoxazoles, 1H-pyrazole, or 1H-imidazole. In addition, DFT calculations based on a simplified catalyst complex model for the catalytic (de)hydrogenation step are in agreement with the previously reported outer sphere mechanism. These results support the further understanding of the mechanistic aspects behind the difference in reactivity of 1-heteroaryl substituted ethanols in comparison to reference substrates, as often referred to in the literature.
