Copper-Catalyzed Carbonylative Synthesis of β-Homoprolines from <i>N</i>-Fluoro-sulfonamides
作者:Youcan Zhang、Zhiping Yin、Xiao-Feng Wu
DOI:10.1021/acs.orglett.0c00227
日期:2020.3.6
A new methodology for the carbonylative transformation of N-fluoro-sulfonamides into N-sulfonyl-β-homoproline esters has been described. In the presence of a catalytic amount of Cu(OTf)2, a range of β-homoproline derivatives were prepared in moderate to good yield. The reaction proceeds via the intramolecular cyclization and intermolecular carbonylation of a free carbon radical. Notably, this procedure
materials. Herein we disclose a catalyst‐ and reagent‐free formal aza‐Wacker type cyclization reaction for the synthesis of functionalized saturated N‐heterocycles. Key to the success is to conduct the reactions in a continuous‐flow electrochemical reactor without adding supporting electrolyte or additives. The reactions are characterized by broad tolerance of di‐, tri‐ and tetrasubstituted alkenes.
Intermolecular Anti-Markovnikov Hydroamination of Unactivated Alkenes with Sulfonamides Enabled by Proton-Coupled Electron Transfer
作者:Qilei Zhu、David E. Graff、Robert R. Knowles
DOI:10.1021/jacs.7b11144
日期:2018.1.17
Here we report a catalytic method for the intermolecularanti-Markovnikovhydroamination of unactivated alkenes using primary and secondary sulfonamides. These reactions occur at room temperature under visible light irradiation and are jointly catalyzed by an iridium(III) photocatalyst, a dialkyl phosphate base, and a thiol hydrogen atom donor. Reaction outcomes are consistent with the intermediacy
在这里,我们报告了一种使用初级和次级磺酰胺对未活化烯烃进行分子间抗马尔科夫尼科夫加氢胺化的催化方法。这些反应在室温下在可见光照射下发生,并由铱 (III) 光催化剂、磷酸二烷基酯碱和硫醇氢原子供体共同催化。反应结果与通过磺酰胺 NH 键的质子耦合电子转移激活产生的 N 中心磺酰胺自由基的中间体一致。概述了反应的合成范围(> 60 个例子)和机械特征的研究。
Metal-Free Oxidative Cyclization of Urea-Tethered Alkenes with Hypervalent Iodine
作者:Brian M. Cochran、Forrest E. Michael
DOI:10.1021/ol8022165
日期:2008.11.6
A metal-free oxidative cyclization of ureas onto unactivated alkenes using iodosylbenzene and an acid promoter is described. The products isolated are predominantly bicyclic isoureas resulting from an intramolecular oxyamination reaction. The acid type and urea substitution have a strong effect on the product formed. A variety of substrates form the isourea with high diastereoselectivity via syn addition
作者:Nicholas L. Reed、Grace A. Lutovsky、Tehshik P. Yoon
DOI:10.1021/jacs.1c02747
日期:2021.4.28
and exceptionally mild photocatalytic oxidative heterofunctionalization reactions between bulky tri- and tetrasubstituted alkenes and a wide variety of nucleophilic partners. Moreover, we demonstrate that the broad scope of this transformation arises from photocatalytic alkeneactivation and thus complements existing transition-metal-catalyzed methods for oxidative heterofunctionalization. More broadly