Diversification of edaravone via palladium-catalyzed hydrazine cross-coupling: Applications against protein misfolding and oligomerization of beta-amyloid
摘要:
N-Aryl derivatives of edaravone were identified as potentially effective small molecule inhibitors of tau and beta-amyloid aggregation in the context of developing disease-modifying therapeutics for Alzheimer's disease (AD). Palladium-catalyzed hydrazine monoarylation protocols were then employed as an expedient means of preparing a focused library of 21 edaravone derivatives featuring varied N-aryl substitution, thereby enabling structure-activity relationship (SAR) studies. On the basis of data obtained from two functional biochemical assays examining the effect of edaravone derivatives on both fibril and oligomer formation, it was determined that derivatives featuring an N-biaryl motif were four-fold more potent than edaravone. (C) 2015 Elsevier Ltd. All rights reserved.
Regioselectivity Switch in Palladium‐Catalyzed Allenylic Cycloadditions of Allenic Esters: [4+1] or [4+3] Cycloaddition/Cross‐Coupling
作者:Long Li、Pengfei Luo、Yuhua Deng、Zhihui Shao
DOI:10.1002/anie.201901511
日期:2019.3.26
The first Pd‐catalyzed asymmetric allenylic [4+1] cycloaddition was successfully developed. Alternatively, tuning the Pd catalyst switched the reactivity toward an unprecedented [4+3] cycloaddition/cross‐coupling. Ligands play a vital role in controlling the reaction pathway, allowing highly selective access to different products from identical substrates. Biological evaluation of the obtained compounds
Rhodium‐Catalyzed [4+2] Annulation of N‐Aryl Pyrazolones with Diazo Compounds To Access Pyrazolone‐Fused Cinnolines
作者:Chih‐Yu Lin、Wan‐Wen Huang、Ying‐Ti Huang、Sandip Dhole、Chung‐Ming Sun
DOI:10.1002/ejoc.202101005
日期:2021.9.21
An efficientsynthesis of novel dinitrogen-fused heterocycles, such as pyrazolo[1,2-a]cinnoline derivatives, has been accomplished by the rhodium(III)-catalyzed reaction of N-arylpyrazol-5-ones with diazo compounds. This reaction proceeds through a cascade C−H activation/intramolecular cyclization under mild reaction conditions and features a broad substrate scope.
新型二氮稠合杂环的有效合成,例如吡唑并[1,2- a ]肉啉衍生物,已通过铑(III)催化的N-芳基吡唑-5-酮与重氮化合物的反应完成。该反应在温和的反应条件下通过级联 CH 活化/分子内环化进行,具有广泛的底物范围。
Synthesis of Pyrazolo[1,2-<i>a</i>]cinnolines<i>via</i>a Rhodium-Catalyzed Oxidative Coupling Approach
An efficient synthetic strategy for the unique class of pyrazolo[1,2‐a]cinnolines was developed through a rhodium‐catalyzed oxidativecoupling of N‐aryl‐1H‐pyrazol‐5(4H)‐ones with internal alkynes. This protocol features use of the pyrazolone function in the substrate as an intrinsic directing group, hexafluoroisopropyl alcohol (HFIP) as the solvent, and mild reaction conditions as well as a wide substrate
为唯一的类吡唑并的有效的合成策略[1,2一]噌啉通过的铑催化的氧化偶合开发ñ -芳基- 1 H ^ -吡唑-5-(4 ħ) -酮与内部炔烃。该方案的特征是在底物中使用吡唑啉酮功能作为固有的导向基团,在溶剂中使用六氟异丙醇(HFIP),反应条件温和,并且底物范围广。
Gold(<scp>i</scp>)- and rhodium(<scp>iii</scp>)-catalyzed formal regiodivergent C–H alkynylation of 1-arylpyrazolones
作者:Xueli Wang、Xingwei Li、Yao Zhang、Lixin Xia
DOI:10.1039/c8ob00585k
日期:——
Formal regiodivergent C–H alkynylation of 1-aryl-5-pyrazolones has been realized under the catalysis of Rh(III) and Au(I) complexes by using a hypervalent iodine reagent as the alkyne source. Mechanistic studies indicate that the regioselectivity is ascribed to not only the choice of the catalyst but also the nature of the substrate. The substrate scope and functional group compatibility have been
rhodium(III)-catalyzed intermolecular aromatic C–H amination directed by an intrinsic functionality of the substrate/product but also features aminating an existing drug with either primary or secondary N-benzoate alkylamines as the coupling partners.