The visible-light-driven preparation of (hetero)aryl stannanes was carried out under both photocatalyst- and metal-free conditions via irradiation of arylazo sulfones in the presence of hexaalkyldistannanes. The reaction shows a high efficiency and a wide substrates scope. The resulting crude organotin derivatives can be directly employed in a Stille protocol.
Herein we report a general electrochemical strategy for the Sandmeyer reaction. Using electricity as the driving force, this protocol employs a simple and inexpensive halogen source, such as NBS, CBrCl3, CH2I2, CCl4, LiCl and NaBr for the halogenation of aryl diazonium salts. In addition, we found that these electrochemical reactions could be performed using anilines as the starting material in a one-pot
本文中,我们报告了桑德迈尔反应的一般电化学策略。使用电作为驱动力,该协议采用一种简单且廉价的卤素源,例如NBS,CBrCl 3,CH 2 I 2,CCl 4,LiCl和NaBr进行芳基重氮盐的卤化。另外,我们发现这些电化学反应可以以一锅的方式使用苯胺作为起始原料来进行。此外,该方法的实用性在使用非常便宜的石墨作为电极的多克规模的芳基卤化物的合成中得到了证明。已经进行了一系列详细的机理研究,包括自由基时钟和自由基清除剂研究,循环伏安分析和原位电子顺磁共振(EPR)分析。
Efficient metal-free photochemical borylation of aryl halides under batch and continuous-flow conditions
作者:Kai Chen、Shuai Zhang、Pei He、Pengfei Li
DOI:10.1039/c5sc04521e
日期:——
A rapid, chemoselective and metal-free C-B bond-forming reaction of aryl iodides and bromides in aqueous solution at low temperatures was discovered. This reaction is amenable to batch and continuous-flow conditions...
Aryldiazonium Salts Serve as a Dual Synthon: Construction of Fully Substituted Pyrazoles via Rongalite-Mediated Three-Component Radical Annulation Reaction
efficient rongalite-mediated three-component radical annulation reaction to furnish fully substituted pyrazoles from aryldiazonium salts and α,β-unsaturated aldehydes or ketones under metal- and oxidant-free conditions at room temperature has been developed. In this transformation, aryldiazonium salts served as the precursor of both the aryl and aryl hydrazine units. Mechanistic investigations indicated
Metal-free C(3)–H arylation of coumarins promoted by catalytic amounts of 5,10,15,20-tetrakis(4-diethylaminophenyl)porphyrin
作者:Masahiro Kojima、Kounosuke Oisaki、Motomu Kanai
DOI:10.1039/c5cc02349a
日期:——
Metal-free, Meerwein-type C(3)–H arylation of coumarins was achieved in the presence of catalytic amounts of 5,10,15,20-tetrakis(4-diethylaminophenyl)porphyrin.