Nucleophilic (Radio)Fluorination of Redox-Active Esters via Radical-Polar Crossover Enabled by Photoredox Catalysis
作者:Eric W. Webb、John B. Park、Erin L. Cole、David J. Donnelly、Samuel J. Bonacorsi、William R. Ewing、Abigail G. Doyle
DOI:10.1021/jacs.0c03125
日期:2020.5.20
redox-neutral method for nucleophilicfluorination of N-hydroxyphthalimide esters using an Ir photocatalyst under visible light irradiation. The method provides access to a broad range of aliphatic fluorides, including primary, secondary, and tertiary benzylic fluorides as well as unactivated tertiary fluorides, that are typically inaccessible by nucleophilicfluorination due to competing elimination
我们报告了在可见光照射下使用 Ir 光催化剂对 N-羟基邻苯二甲酰亚胺酯进行亲核氟化的氧化还原中性方法。该方法提供了获得广泛的脂肪族氟化物的途径,包括伯、仲和叔苄基氟化物以及未活化的叔氟化物,由于竞争消除,这些氟化物通常无法通过亲核氟化获得。此外,我们表明脱羧氟化条件很容易适应 [18F]KF 的放射性氟化。我们建议反应通过 Ir 催化剂和氧化还原活性酯底物之间的两次电子转移进行,以提供碳阳离子中间体,随后被氟化物捕获。
Thermal 1,3-dipolar cycloaddition reaction of azomethine imines with active esters
作者:Liwenze He、Lin Liu、Runfeng Han、Weiwei Zhang、Xingang Xie、Xuegong She
DOI:10.1039/c6ob01095d
日期:——
An efficient method for the 1,3-dipolar cycloaddition of azomethineimines with active esters under thermal conditions has been described in good to high yields. This method offers a straightforward pathway to synthesize bioactive pyrazolidinones.
Reported herein is a highly selective radical cascade-cross-coupling reaction for the modular synthesis of α-tertiary aminoacids (ATAA) under mild conditions. Mechanistic studies reveal the excited state of an in situ-generated oxazolone enolate as a key intermediate, which functions both as a radical precursor and an efficient reductant.
Visible-Light-Induced Decarboxylative Alkylation/Ring Opening and Esterification of Vinylcyclopropanes
作者:Pu Chen、Peng-Fei Huang、Bi-Quan Xiong、Hua-Wen Huang、Ke-Wen Tang、Yu Liu
DOI:10.1021/acs.orglett.2c02151
日期:2022.8.12
N-dimethylformamide (DMF), and H2O through an oxidativeringopening of cyclopropane is presented. This procedure provides a new and effective way to construct formate esters. DMF is employed as both a solvent and the source of CHO. This difunctionalization of vinylcyclopropanes shows good functional group tolerance under room temperature. A radical pathway is involved, and carbonyl oxygen of ester originated from
介绍了乙烯基环丙烷、 N- (酰氧基)邻苯二甲酰亚胺酯、N , N-二甲基甲酰胺 (DMF) 和 H 2 O 通过环丙烷的氧化开环进行的可见光诱导四组分反应。该程序为构建甲酸酯提供了一种新的有效方法。DMF 既用作溶剂又用作 CHO 的来源。乙烯基环丙烷的这种双官能化在室温下表现出良好的官能团耐受性。涉及自由基途径,酯的羰基氧在该转化中来源于水。
Exploiting the sp2 character of bicyclo[1.1.1]pentyl radicals in the transition-metal-free multi-component difunctionalization of [1.1.1]propellane
作者:Weizhe Dong、Expédite Yen-Pon、Longbo Li、Ayan Bhattacharjee、Anais Jolit、Gary A. Molander
DOI:10.1038/s41557-022-00979-0
日期:2022.9
successful use of bicyclo[1.1.1]pentane (BCP) as a para-disubstituted benzene replacement has made it a highly valuable pharmacophore. However, various challenges, including limited and lengthy access to useful BCP building blocks, are hampering early discovery research. Here we report a single-step transition-metal-free multi-component approach to synthetically versatile BCP boronates. Radicals derived from