Lithiation‐Functionalisation of Triazoles Bearing Electron‐Withdrawing
N
‐Substituents: Challenges and Solutions**
摘要:
AbstractThe regioselective lithiation of 1,2,3‐triazoles provides an opportunity to introduce additional functionality, however this simple functionalisation strategy using triazoles bearing electron‐withdrawing N‐substituents has not been investigated until now. Herein, we demonstrate that the lithiated triazole intermediates can readily decompose, even at −78 °C. In addition, lithiation‐deuteration studies reveal lithiation can take place competitively on both the triazole and the electron‐withdrawn aryl ring. Careful control of reaction conditions is therefore required to i) minimise decomposition pathways; and ii) facilitate regioselective functionalisation of the triazole.
Effective Synthesis of Chiral<i>N</i>-Fluoroaryl Aziridines through Enantioselective Aziridination of Alkenes with Fluoroaryl Azides
作者:Li-Mei Jin、Xue Xu、Hongjian Lu、Xin Cui、Lukasz Wojtas、X. Peter Zhang
DOI:10.1002/anie.201209599
日期:2013.5.10
The CoII complex of a D2‐symmetric chiral porphyrin ([Co(D2‐Por*)], see scheme) is a highly effective catalyst for the enantioselective aziridination of alkenes with fluoroaryl azides. The reaction can be performed at RT with low catalyst loading, and the olefin is the limiting reagent. Furthermore, the reaction is tolerant toward different combinations of aromatic olefins and fluoroaryl azides.
D 2对称手性卟啉的Co II配合物([Co( D 2 ‐Por*)],参见方案)是一种高效催化剂,用于烯烃与氟芳基叠氮化物的对映选择性氮丙啶化。该反应可以在室温下以低催化剂负载量进行,并且烯烃是限制试剂。此外,该反应能够耐受芳香族烯烃和氟代芳基叠氮化物的不同组合。
Iron (III)‐porphyrin Complex FeTSPP as an efficient catalyst for synthesis of tetrazole derivatives
<i>via</i>
[2 + 3]cycloaddition reaction in aqueous medium
作者:Mahmoud Abd El Aleem Ali Ali El‐Remaily、O.M. Elhady
DOI:10.1002/aoc.4989
日期:2019.8
metal complex (5,10,15,20‐tetrakis‐(4‐sulfonatophenyl)‐porphyrin‐iron (III) chloride (FeTSPP) was new employed in an environmentally benign protocol as an efficient catalyst for a “click” chemistry approach for the synthesis of tetrazole and guanindinyltetrazole derivatives via [2 + 3] cycloaddition reaction of nitriles and azide derivatives in aqueous medium. The synthesized compounds were obtained in
Modulating Chalcogen Bonding and Halogen Bonding Sigma‐Hole Donor Atom Potency and Selectivity for Halide Anion Recognition
作者:Andrew Docker、Charles H. Guthrie、Heike Kuhn、Paul D. Beer
DOI:10.1002/anie.202108591
日期:2021.9.27
donor atom dramatically enhances the anion binding potency of the sigma-hole receptors, most notably for the ChB and XB receptors displaying over thirty-fold and eight-fold increase in chloride anion affinity, respectively, relative to unfluorinated analogues. Linear free energy relationships for a series of ChB based receptors reveal the halide anionrecognition behaviour of the tellurium donor is
Preparation of aryl azides of aryl boronic acids and one‐pot synthesis of 1,4‐diaryl‐1,2,3‐triazoles by a magnetic cysteine functionalized GO–Cu
<sup>I/II</sup>
nanocomposite
作者:Fatemeh Rafiee、Parvaneh Khavari
DOI:10.1002/aoc.5789
日期:2020.9
graphene oxide (CuI/II@Cys‐MGO) was prepared and used for the azidonation reaction of aryl boronic acids and one‐pot synthesis of 1,4‐diaryl −1,2,3‐triazoles. Aryl azides were obtained in good yields and short reaction times via cross‐coupling of aryl boronic acids with sodium azide in the presence of CuII catalytic species in this catalytic system. The azide‐alkyne cycloadditionreaction was catalyzed
制备了基于磁性半胱氨酸官能化氧化石墨烯(Cu I / II @ Cys-MGO)的混合Cu I / Cu II催化剂,用于芳基硼酸的叠氮反应和一锅法合成1,4-二芳基-1 ,2,3-三唑 在此催化体系中,在存在Cu II催化物种的情况下,芳基硼酸与叠氮化钠的交叉偶联可得到高收率和较短反应时间的芳基叠氮化物。Cu I / II @ Cys-MGO纳米复合材料中的CuI催化物种催化了叠氮化物-炔烃环加成反应。