spectroscopy (XPS) analysis suggest that iron is crucial in the catalytic cycle, working to prohibit the deactivation of selenium catalyst through an iron‐catalyzed aerobic oxidation of lowvalent selenium species by air to the active high valent selenium species. Since air can be utilized as the terminal oxidant, this work may contribute to the advance of organoselenium catalysis.
Organotellurium-catalyzed oxidative deoximation reactions using visible-light as the precise driving energy
作者:Xin Deng、Rongrong Qian、Hongwei Zhou、Lei Yu
DOI:10.1016/j.cclet.2020.09.012
日期:2021.3
Irradiated by visiblelight, the recyclable (PhTe)2-catalyzed oxidative deoximation reaction could occur undermildconditions. In comparison with the thermo reaction, the method employed reduced catalyst loading (1 mol% vs. 2.5 mol%), but afforded elevated product yields with expanded substrate scope. This work demonstrated that for the organotellurium-catalyzed reactions, visiblelight might be an
在可见光的照射下,可回收(PhTe)2催化的氧化脱氧反应可能在温和的条件下发生。与热反应相比,该方法使用了减少的催化剂负载量(1 mol%对2.5 mol%),但是在扩大的底物范围的情况下提高了产品收率。这项工作表明,对于有机碲催化的反应,可见光可能是比加热更为精确的驱动能量,因为可见光可以准确地破坏Te Te键,从而生成活性自由基催化中间体,而不会破坏易碎的取代基(例如杂环)的基板。使用O 2代替爆炸性H 2 O 2 从大规模应用的角度来看,作为氧化剂的氧化剂提供了更安全的反应条件。
(Partial) agonist/antagonist properties of novel diarylalkyl carbamates on histamine H 3 receptors
in a two-step reaction sequence from corresponding ketones. Some of the title compounds showed (partial) agonist activity at the histamine H3 receptor in vitro and in vivo. Diphenylmethyl carbamate 2 was identified as a new lead structure (ED50 = 5.3 +/- 2.6 mg/kg po, alpha = 1.0). Aromatic substitution in ortho- or para-positions of 2 led to a loss of agonist activity. meta-Substitution was tolerated
在寻找组胺H 3受体的新配体时,合成了新的氨基甲酸二芳基烷基酯(1-19)作为3-(1H-咪唑-4-基)丙醇和-乙醇的衍生物。氨基甲酸酯是通过异氰酸酯通过与双光气反应从相应的胺或从相关的羧酸/二苯基磷酰基叠氮化物和醇组分中生成的。由两步反应,由相应的酮制备受阻胺。在体外和体内,一些标题化合物对组胺H3受体显示(部分)激动剂活性。氨基甲酸二苯甲基酯2被鉴定为新的铅结构(ED50 = 5.3 +/- 2.6 mg / kg po,alpha = 1.0)。2的邻位或对位的芳香取代导致激动剂活性降低。元替代在一定程度上是可以容忍的。这些作用似乎是由取代基的空间特性而非电子特性引起的。对杂环中一个或两个苯基环被杂环交换的研究导致了高活性和选择性的噻吩衍生物18(ED50 3.4 +/- 1.4 mg / kg po,α= 1.0)。组胺H3受体的这些新的(部分)激动剂可以用作研究H3受体的分子方面
Beckmann rearrangement of ketoximes promoted by cyanuric chloride and dimethyl sulfoxide under a mild condition
作者:Ruonan Ma、Xueyuan Chen、Zhiyin Xiao、Mookan Natarajan、Chunxin Lu、Xiujuan Jiang、Wei Zhong、Xiaoming Liu
DOI:10.1016/j.tetlet.2020.152707
日期:2021.1
Synthesis of amides via Beckmannrearrangement of ketoximes promoted by cyanuric chloride (TCT)/DMSO under mild conditions has been reported. Conditions of the Beckmannrearrangement, e.g., solvents, the ratios of TCT/DMSO, and the temperature, were investigated using diphenylmethanone oxime as a substrate. The optimized conditions were adopted to afford fourteen amides with yields ranging from 20%
Direct C(sp<sup>3</sup>)–N Radical Coupling: Photocatalytic C–H Functionalization by Unconventional Intermolecular Hydrogen Atom Transfer to Aryl Radical
作者:Jihee Kang、Ho Seong Hwang、Vineet Kumar Soni、Eun Jin Cho
DOI:10.1021/acs.orglett.0c02179
日期:2020.8.7
energy-transfer-driven homolysis followed by decarboxylation generates the persistent iminyl radical and aryl radical, which would undergo an unprecedented intermolecular hydrogenatomabstractionfrom the alkyl substrate to provide the key C(sp3) radical. Selective radical–radical C–N cross-coupling furnishes imines which are valuable amine building blocks.