Nucleophilic Aromatic Substitution (SN Ar)-Amination A Comparison of Heating using Microwave Irradiation to 250 oC and 300 oC
The formation of diarylamines by reacting anilines with aromatic electrophiles is, usually, a reaction demanding long reaction
times, high temperatures and strong bases, in order to obtain acceptable yield, due to the low nucleophilicity of anilines.1 The Buchwald-Hartwig cross-coupling reaction is a very useable and elegant solution to this problem.2,3,4 Anticipating the classical metal-free SNAr-amination reaction, without using Pd-catalysts and strong bases, with only higher temperature and pressure as tool as depicted in the Scheme below,1 gives no product at all at 180 ºC and very low conversion (9 %) at 220 ºC for 15 minutes when heating by microwaves.5 Remainder was unreacted starting material.
Tags:
Application Notes,
English
Part No: AN058
Published: 2012
0.21 MB
Format: pdf
Download