Synthesis physicochemical profile and PAMPA study of new NO-donor edaravone co-drugs
摘要:
A new class of co-drugs were synthesised by joining antioxidant edaravone with a vasodilating substructure containing NO-donor nitrooxy functions, and characterised for their stability in different media, lipophilicity and permeability profile. The products display good stability in water/co-solvent at different pH. Conversely, they are rapidly metabolised into edaravone and NO-donor moieties when incubated in human serum or rat-liver homogenates. In the latter conditions time dependent production of nitrite/nitrate (NOx) occurs. The compounds display wide-ranging lipophilicity. PAMPA studies predict good gastrointestinal absorption for a number of these compounds. The title products are potentially useful for treating ROS-related conditions accompanied by decreased NO availability. (C) 2011 Elsevier Ltd. All rights reserved.
O,ω‐Unsaturated N‐tosyl alkoxyamines undergo unexpected RhIII‐catalyzed intramolecular cyclization by oxyamination to produce oxygen‐containing heterocycles. Mechanistic studies show that an aziridine intermediate seems to be responsible for the formation of the heterocycles, possibly via a RhV species.
Intramolecular Additions of Alcohols and Carboxylic Acids to Inert Olefins Catalyzed by Silver(I) Triflate
作者:Cai-Guang Yang、Nicholas W. Reich、Zhangjie Shi、Chuan He
DOI:10.1021/ol051065f
日期:2005.10.1
[reactions: see text] Intramolecular additions of hydroxyl or carboxyl groups to inert olefins catalyzed by simple silver(I) triflate are described. Good to excellent yields can be obtained for a range of substrates under relatively mild conditions. This reaction represents one of the simplest methods to construct cyclic ethers or lactones.
Palladium-Catalyzed Intramolecular Oxidative Alkylation of Unactivated Olefins
作者:Tao Pei、Xiang Wang、Ross A. Widenhoefer
DOI:10.1021/ja026317b
日期:2003.1.1
2,4-dione catalyzed by PdCl2(CH3CN)2 (5 mol %) in the presence of CuCl2 (2.5 equiv) at room temperature for 3 h formed 2-acetyl-3,6,6-trimethyl-2-cyclohexenone in 96% isolated yield. Palladium-catalyzedintramolecular oxidative alkylation tolerated a range of substitution and was applicable to the synthesis of spirobicyclic compounds and to the cyclization of zeta-alkenyl beta-keto esters.
Platinum-Catalyzed Intramolecular Alkylation of Indoles with Unactivated Olefins
作者:Cong Liu、Xiaoqing Han、Xiang Wang、Ross A. Widenhoefer
DOI:10.1021/ja031814t
日期:2004.3.1
Reaction of 1-methy-2-(4-pentenyl)indole (1) with a catalytic amount of PtCl2 (2 mol %) in dioxane that contained a trace of HCl (5 mol %) at 60 °C for 24 h led to the isolation of 4,9-dimethyl-2,3,4,9-tetrahydro-1H-carbazole (2) in 92% yield. Platinum-catalyzed cyclization of 2-(4-pentenyl)indoles tolerated substitution at each position of the 4-pentenyl chain. Furthermore, the protocol was applicable
Scope and Mechanism of Allylic C−H Amination of Terminal Alkenes by the Palladium/PhI(OPiv)<sub>2</sub> Catalyst System: Insights into the Effect of Naphthoquinone
作者:Guoyin Yin、Yichen Wu、Guosheng Liu
DOI:10.1021/ja1030936
日期:2010.9.1
highly efficient transformation of alkenes has been achieved by enhancing the reoxidation of palladium with the strong oxidant PhI(OPiv)(2). The present work also provides the first systematic analysis of the mechanism of the allylicC-H oxidative amination. It has been found that naphthoquinone (NQ) plays a vital role in promoting olefin coordination to the palladium catalyst: in the absence of NQ, the