Mild and selective base-free C–H arylation of heteroarenes: experiment and computation
作者:Hannes P. L. Gemoets、Indrek Kalvet、Alexander V. Nyuchev、Nico Erdmann、Volker Hessel、Franziska Schoenebeck、Timothy Noël
DOI:10.1039/c6sc02595a
日期:——
A mild and selective C–Harylation strategy for indoles, benzofurans and benzothiophenes is described. The arylation method engages aryldiazonium salts as arylating reagents in equimolar amounts. The protocol is operationally simple, base free, moisture tolerant and air tolerant. It utilizes low palladium loadings (0.5 to 2.0 mol% Pd), short reaction times, green solvents (EtOAc/2-MeTHF or MeOH) and
The first radical alkoxycarboxylation of aryldiazoniumsalts using CO gas through visible‐light‐induced photoredoxcatalysis (16 W blue LEDs) has been developed. This reaction is entirely metal‐free, is carried out at room temperature with a low loading of an organic dye as a photocatalyst (0.5 mol %), and provides a wide range of arylcarboxylic acid esters in high yields. Importantly, this photocatalytic
Light‐ and Manganese‐Initiated Borylation of Aryl Diazonium Salts: Mechanistic Insight on the Ultrafast Time‐Scale Revealed by Time‐Resolved Spectroscopic Analysis
作者:James D. Firth、L. Anders Hammarback、Thomas J. Burden、Jonathan B. Eastwood、James R. Donald、Chris S. Horbaczewskyj、Matthew T. McRobie、Adam Tramaseur、Ian P. Clark、Michael Towrie、Alan Robinson、Jean‐Philippe Krieger、Jason M. Lynam、Ian J. S. Fairlamb
DOI:10.1002/chem.202004568
日期:2021.2.24
Manganese‐mediated borylation of aryl/heteroaryldiazoniumsalts emerges as a general and versatile synthetic methodology for the synthesis of the corresponding boronate esters. The reaction proved an ideal testing ground for delineating the Mn species responsible for the photochemical reaction processes, that is, involving either Mn radical or Mn cationic species, which is dependent on the presence
Visible‐Light Photoredox‐Catalyzed and Copper‐Promoted Trifluoromethoxylation of Arenediazonium Tetrafluoroborates
作者:Shaoqiang Yang、Miao Chen、Pingping Tang
DOI:10.1002/anie.201901447
日期:2019.6.3
We report the development of photoredox‐catalyzed and copper‐promoted trifluoromethoxylation of arenediazonium tetrafluoroborates, with trifluoromethyl arylsulfonate (TFMS) as the trifluoromethoxylation reagent. This new method takes advantage of visible‐light photoredoxcatalysis to generate the aryl radical under mild conditions, combined with copper‐promoted selective trifluoromethoxylation. The
<i>n</i>Bu<sub>4</sub>N<sup>+</sup>[Ag<sup>I</sup>(CF<sub>3</sub>)<sub>2</sub>]<sup>−</sup>: Trifluoromethylated Argentate Derived from Fluoroform and Its Reaction with (Hetero)Aryl Diazonium Salts
argentate nBu4N+[Ag(CF3)2]− 1 from fluoroform was described. The complex was stable in the solid state and in solution under an inert atmosphere. Treatment of a variety of (hetero)aryl diazonium tetrafluoroborates with nBu4N+[Ag(CF3)2]− 1 generated trifluoromethylated (hetero)arenes in good to excellent yields. Preliminary experiments were conducted, and a reasonable mechanism of the reaction was proposed
描述了从氟仿制备明确的三氟甲基化银酸盐n Bu 4 N + [Ag(CF 3 ) 2 ] - 1 。该配合物在惰性气氛下在固态和溶液中均稳定。用n Bu 4 N + [Ag(CF 3 ) 2 ] - 1处理各种(杂)芳基重氮四氟硼酸盐,生成三氟甲基化(杂)芳烃,收率良好至优异。进行了初步实验,提出了合理的反应机理。