1,2-Disubstituted Benzimidazoles by the Iron Catalyzed Cross-Dehydrogenative Coupling of Isomeric <i>o</i>-Phenylenediamine Substrates
作者:Pawan Thapa、Philip M. Palacios、Tam Tran、Brad S. Pierce、Frank W. Foss
DOI:10.1021/acs.joc.9b02714
日期:2020.2.21
Benzimidazoles are common in nature, medicines, and materials. Numerous strategies for preparing 2-arylbenzimidazoles exist. In this work, 1,2-disubstituted benzimidazoles were prepared from various mono- and disubstituted ortho-phenylenediamines (OPD) by iron-catalyzed oxidative coupling. Specifically, O2 and FeCl3·6H2O catalyzed the cross-dehydrogenative coupling and aromatization of diarylmethyl
An efficient metal‐free, (NH4)2S2O8 mediated intramolecularoxidativecyclization for the construction of fused polycyclic quinazolinone derivatives under mild conditions was disclosed. This method provides an efficient and facile approach to the synthesis of polycyclic quinazolinone derivatives (> 40 examples), as well as the natural products tryptanthrin, rutaecarpine, and their analogues.
公开了在温和条件下用于构建稠合多环喹唑啉酮衍生物的高效无金属,(NH 4)2 S 2 O 8介导的分子内氧化环化反应。该方法为合成多环喹唑啉酮衍生物(> 40个实例)以及天然产物色胺酮,芸苔芸香碱及其类似物提供了一种高效简便的方法。
Nucleophilic additions to fused benzimidazole N-oxides
作者:Michael J Donaghy、Stephen P Stanforth
DOI:10.1016/s0040-4020(98)01116-8
日期:1999.1
The benzimidazoles 16a-f have been prepared from N-oxides 15a-d. Treatment of N-oxides 15c and 15d with a mixture of acetic anhydride and sodium acetate gave the corresponding acetoxy derivatives 26 and 27via a regiospecific nucleophilic substitution reaction. N-Oxides 15c and 15d were also deoxygenated by 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ).