通过使用曙红 Y 作为光催化剂和可回收离子液体作为溶剂,开发了一种无金属和氧化剂的光氧化还原催化 2 H-吲唑三氟甲基化的方案。在该协议中,在温和条件下,以中等到良好的收率获得了一系列三氟甲基化产品。该反应通过自由基机制进行,具有广泛的底物范围、优异的区域选择性和良好的官能团耐受性。此外,该协议的实用性通过雌激素受体β(ERβ)和药物格拉司琼的高选择性配体的合成得到证明。该协议为三氟甲基化反应提供了一种温和且环保的解决方案。
Indazole Estrogens: Highly Selective Ligands for the Estrogen Receptor β
摘要:
The estrogen receptors, ERalpha and ERbeta, are important pharmaceutical targets. To develop ERbeta-selective ligands, we synthesized a series of nonsteroidal compounds having a phenyl-2H-indazole core with different groups at C-3. Several of these show high affinity and good ERbeta selectivity, especially those with polar and/or polarizable substituents at this site (halogen, CF3, nitrile); the best compounds have affinities for ERbeta comparable to estradiol, with ERbeta affinity selectivity > 100. This potency and ERbeta selectivity is also seen in cell-based transcriptional assays, where several compounds showed ERbeta efficacies equivalent to that of estradiol with ERbeta potency selectivities of 100. These compounds might prove useful as selective pharmacological probes to study the biological actions of estrogens mediated through ERP, and they might lead to the development of useful pharmaceuticals. These findings also contribute to an evolving pharmacophore that characterizes certain nonsteroidal ligands having high ERbeta subtype affinity and potency selectivity.
An environmentally friendly method of electrochemical mediated regioselectiveC-3 trifluoromethylation of 2H-indazole by employing CF3SO2Na as the CF3 source was described. This reaction tolerated various functional groups and provided CH trifluoromethylated products in moderate to good yields under transitionmetal-free and oxidant-free reaction conditions. Mechanism experiments showed that a radical
描述了一种以 CF 3 SO 2 Na 作为 CF 3源的电化学介导的 2H-吲唑区域选择性 C-3 三氟甲基化的环境友好方法。该反应耐受各种官能团,并在无过渡金属和无氧化剂的反应条件下以中等至良好的产率提供 C H 三氟甲基化产物。机理实验表明,这种转变可能涉及一个激进的过程。
Metal-Free Trifluoromethylation of Indazoles
作者:Payel Ghosh、Susmita Mondal、Alakananda Hajra
DOI:10.1021/acs.joc.8b02312
日期:2018.11.2
A simple and efficient tert-butyl hydroperoxide-mediated direct trifluoromethylation of indazoles using sodium trifluoromethanesulfinate has been developed under metal-free conditions. A library of trifluoromethylated products with broad functionalities has been synthesized with moderate to good yields. A radical mechanistic pathway has been proposed for the present protocol.