Regioselective Radical Arylation of Anilines with Arylhydrazines
作者:Hannelore Jasch、Julia Scheumann、Markus R. Heinrich
DOI:10.1021/jo301980j
日期:2012.12.7
arylhydrazines and anilines via radical arylation reactions under simple oxidative conditions. The strong directing effect of the free and unprotonated amino functionality leads to high regioselectivities, and anilines have been shown to be significantly better aryl radical acceptors thannitrobenzenes or phenyl ethers. The methodology is also applicable to phenols, which react best as phenolates under
The Gomberg-Bachmann Reaction for the Arylation of Anilines with Aryl Diazotates
作者:Gerald Pratsch、Tina Wallaschkowski、Markus R. Heinrich
DOI:10.1002/chem.201200430
日期:2012.9.10
Simply aqueous sodium hydroxide is sufficient to exclude ionic side reactions and to prepare 2‐aminobiphenyls from aryldiazotates and anilines through a new variant of the Gomberg–Bachmannreaction (see scheme). The metal‐free reaction under basic conditions allows to exploit the highly radical‐stabilizing effect of the aniline's free amino function for the first time, which leads to a so far unreached
Die vorliegende Erfindung beschreibt ein Verfahren zur Synthese von 2-Aminobiphenylen sowie Derivaten davon. Dieses Verfahren ist kostengünstig durchführbar und beruht auf selektiven Umsetzungen. Funktionalisierte Biphenylverbindungen sind insbesondere als Pharmazeutika und Pflanzenschutzmittel sowie als Vorstufen solcher Wirkstoffe von großem Interesse. Das Verfahren zur Herstellung einer Verbindungen der Formel 3 ist dadurch gekennzeichnet, dass eine Verbindung der Formel 1 mit einer Verbindung der Formel 2 umgesetzt wird.
Oxidative Radical Arylation of Anilines with Arylhydrazines and Dioxygen from Air
作者:Josefa Hofmann、Hannelore Jasch、Markus R. Heinrich
DOI:10.1021/jo500063r
日期:2014.3.7
Substituted 2-aminobiphenyls have been prepared from arylhydrazine hydrochlorides and anilines in biphasic radical arylation reactions with dioxygen from air as a most simple and readily available oxidant. Under optimized conditions, the free amino functionality of the aniline leads to high ortho:meta regioselectivities, now even for anilines bearing a donor substituent in the para position. Finally, the mild and metal-free new access to aminobiphenyls was shown to be applicable on a gram scale.
Synthesis of Amino- and Hydroxybiphenyls by Radical Chain Reaction of Arenediazonium Salts
作者:Alexander Wetzel、Varinia Ehrhardt、Markus R. Heinrich