Metal-free visible-light-promoted C(sp<sup>3</sup>)–H functionalization of aliphatic cyclic ethers using trace O<sub>2</sub>
作者:Ben Niu、Bryan G. Blackburn、Krishnakumar Sachidanandan、Maria Victoria Cooke、Sébastien Laulhé
DOI:10.1039/d1gc03482k
日期:——
Presented is a light-promoted C–C bond forming reaction yielding sulfone and phosphate derivatives at room temperature in the absence of metals or photoredox catalyst. This transformation proceeds in neat conditions through an auto-oxidationmechanism which is maintained through the leaching of trace amounts of O2 as sole green oxidant.
accessible sodiumformate as C1-source and K2S2O8 as reagent, a set of vinylsulfone substrates could be efficiently hydrocarboxylated in aqueous medium without any additional catalyst or reagent; and the concept could be also applied for direct hydroacylations, hydroalkylations and hydrophosphorylations. The control experiments clearly indicated that the reaction proceeds via radical mechanism without
我们报告了一种可见光介导的乙烯砜衍生物自由基加氢羧化方法。使用廉价易得的甲酸钠作为C1源,K 2 S 2 O 8作为试剂,一组乙烯基砜底物可以在水介质中有效地加氢羧化,无需任何额外的催化剂或试剂;该概念也可应用于直接加氢酰化、加氢烷基化和加氢磷酸化。对照实验清楚地表明该反应通过自由基机制进行,没有生成电子供体-受体(EDA)复合物;支持K 2 S 2 O 8原位引发的工作模型形成CO 2自由基阴离子。
Synthesis and biological evaluation of berberine–thiophenyl hybrids as multi-functional agents: Inhibition of acetylcholinesterase, butyrylcholinesterase, and Aβ aggregation and antioxidant activity
作者:Tao Su、Shishun Xie、Hui Wei、Jun Yan、Ling Huang、Xingshu Li
DOI:10.1016/j.bmc.2013.07.011
日期:2013.9
A series of berberine-thiophenyl hybrids were designed, synthesised, and evaluated as inhibitors of acetylcholinesterase (AChE), butyrylcholinesterase (BuChE) and beta-amyloid (A beta) aggregation and as antioxidants. Among these hybrids, compounds 4f and 4i, berberine linked with o-methylthiophenyl and o-chlorothiophenyl by a 2-carbon spacer, were observed to be potent inhibitors of AChE, with IC50 values of 0.077 and 0.042 mu M, respectively. Of the tested compounds, 4i was also the most potent inhibitor of BuChE, with an IC50 value of 0.662 mu M. Kinetic studies and molecular modelling simulations of the AChE-inhibitor complex indicated that a mixed-competitive binding mode existed for these berberine. derivatives. The biological studies also demonstrated that these hybrids displayed interesting activities, including A beta aggregation inhibition and antioxidant properties. (C) 2013 Elsevier Ltd. All rights reserved.