Iminyl-Radicals by Oxidation of α-Imino-oxy Acids: Photoredox-Neutral Alkene Carboimination for the Synthesis of Pyrrolines
作者:Heng Jiang、Armido Studer
DOI:10.1002/anie.201706270
日期:2017.9.25
α‐imino‐oxy propionic acids for the generation of iminyl radicals has been accomplished through the use of Ir(dFCF3ppy)2(dtbbpy)PF6 as a photoredox catalyst. Different from visible‐light‐promoted homolysis and single‐electron reduction of oxime derivatives, this strategy provides a novel catalytic cycle for alkene carboimination through a sequence comprising N‐radical generation, iminyl radical cyclization,
Catalytic Carbocation Generation Enabled by the Mesolytic Cleavage of Alkoxyamine Radical Cations
作者:Qilei Zhu、Emily C. Gentry、Robert R. Knowles
DOI:10.1002/anie.201604619
日期:2016.8.16
weak C−O bond. Spontaneous scission results in the formation of the stable nitroxyl radical TEMPO. as well as a reactive carbocation intermediate that can be intercepted by a wide range of nucleophiles. Notably, this process occurs underneutralconditions and at comparatively mild potentials, enabling catalytic cation generation in the presence of both acid sensitive and easily oxidized nucleophilic
Radical Aza-Cyclization of α-Imino-oxy Acids for Synthesis of Alkene-Containing <i>N</i>-Heterocycles via Dual Cobaloxime and Photoredox Catalysis
作者:Jia-Lin Tu、Jia-Li Liu、Wan Tang、Ma Su、Feng Liu
DOI:10.1021/acs.orglett.0c00224
日期:2020.2.7
Nitrogen-containing heterocycles are prevalent in both naturally and synthetically bioactive molecules. We report herein an unprecedented protocol for radical aza-cyclization of α-imino-oxy acids with pendant alkenes via synergistic photoredox and cobaloxime catalysis. With or without alkenes as the intermolecular cross-coupling partners, the transformation provides a variety of corresponding alkene-containing dihydropyrrole
Catalytic decarboxylative alkylation of β-keto acids with sulfonamides via the cleavage of carbon–nitrogen and carbon–carbon bonds
作者:Cui-Feng Yang、Jian-Yong Wang、Shi-Kai Tian
DOI:10.1039/c1cc12790j
日期:——
An efficient decarboxylative alkylation reaction of β-keto acids with N-benzylic or N-allylic sulfonamides has been developed, for the first time, through sequential cleavage of carbonânitrogen and carbonâcarbon bonds in the presence of 10 mol% of FeCl3.
organic dye eosin Y bis(tetrabutylammonium salt) as photocatalyst, and diisopropylethylamine as reducing agent. Mechanistic studies demonstrate that oxidative quenching of the excited eosin Y by -arylketosulfones plays a crucial role in the present photoredox catalytic cycle.
通过使用 3-W 蓝光 LED 灯、1 mol% 有机染料伊红 Y 双(四丁基铵盐)作为光催化剂和二异丙基乙胺作为还原剂,-芳基酮砜的脱磺酰化取得了良好的产率。机理研究表明,-芳基酮砜对激发的曙红 Y 的氧化猝灭在目前的光氧化还原催化循环中起着至关重要的作用。