Visible-light-promoted and photocatalyst-free trifluoromethylation of enamides
作者:Hao Wang、Yuanzheng Cheng、Shouyun Yu
DOI:10.1007/s11426-015-5528-1
日期:2016.2
An efficient and practical method is developed for the trifluoromethylation of enamides using Umemoto’s reagent as the trifluoromethylating reagent. These reactions proceeded under visible light irradiation without any photocatalyst at room temperature in good chemical yields.
Three‐Component Aminoarylation of Electron‐Rich Alkenes by Merging Photoredox with Nickel Catalysis
作者:Heng Jiang、Xiaoye Yu、Constantin G. Daniliuc、Armido Studer
DOI:10.1002/anie.202101775
日期:2021.6.21
α-amino-oxy acids are used as amidyl radical precursors. anti-Markovnikov addition of the amidyl radical to the alkene and Ni-mediated radical/transition metal cross over lead to the corresponding 1,2-aminoarylation product. The radical cascade, which can be conducted under practical and mild conditions, features high functional group tolerance and broad substrate scope. Stereoselective 1,2-aminoarylation
报道了通过协同光氧化还原和镍催化对乙烯基醚、烯酰胺、烯-氨基甲酸酯和乙烯基硫醚进行三组分 1,2-氨基芳基化。 2,2,2-三氟乙氧基羰基保护的α-氨基含氧酸用作酰胺基自由基前体。酰胺自由基与烯烃的反马可夫尼科夫加成和 Ni 介导的自由基/过渡金属交叉导致相应的 1,2-氨基芳基化产物。自由基级联反应可以在实际且温和的条件下进行,具有高官能团耐受性和广泛的底物范围。使用L-(+)-乳酸衍生的乙烯基醚作为底物实现立体选择性1,2-氨基芳基化,为制备受保护的对映体纯α-芳基化β-氨基醇提供了新的途径。此外,乙烯基醚的1,2-氨基酰化是通过使用酰基琥珀酰亚胺作为Ni介导的自由基偶联的亲电子试剂来实现的。
Stereoselective Fe-Catalyzed Decoupled Cross-Couplings: Chiral Vinyl Oxazolidinones as Effective Radical Lynchpins for Diastereoselective C(sp2)–C(sp3) Bond Formation
catalytic methods that enable highlystereoselective dicarbofunctionalization of alkenes are lacking. Herein, we report the use of readily available chiral vinyl oxazolidinones as effective chiral radical lynchpins to enable practical and diastereoselective (up to 1:78 dr) Fe-catalyzed dicarbofunctionalization with fluoroalkyl halides and hetero(aryl) Grignard reagents. Experimental and computational
Intermolecular Nonreductive Alkylation of Enamides via Radical−Polar Crossover
作者:Gregory K. Friestad、Yaoping Wu
DOI:10.1021/ol8028077
日期:2009.2.19
A carbon-carbon bond construction method is disclosed which involves radical addition of alpha-haloesters or iodoacetonitrile to enamides. Despite the presence of tri-n-butylstannane, nonreductive addition was predominant; H-atom transfer from tin hydride was not observed. Rapid iodine atom transfer to (or electron transfer from) the radical adduct, resulting in an iminium ion intermediate and radical chain propagation, is consistent with the observed reactivity.