Selective Synthesis of Dihydrophenanthridine and Phenanthridine Derivatives from the Cascade Reactions of <i>o</i>-Arylanilines with Alkynoates through C–H/N–H/C–C Bond Cleavage
作者:Yuanshuang Xu、Caiyun Yu、Xinying Zhang、Xuesen Fan
DOI:10.1021/acs.joc.1c00256
日期:2021.4.16
unprecedented selective synthesis of dihydrophenanthridine and phenanthridinederivatives through the cascade reactions of 2-arylanilines with alkynoates is presented. Mechanistic studies showed that the formation of the dihydrophenanthridine scaffold involves an initial C(sp2)–H alkenylation of 2-arylaniline with alkynoate followed by an intramolecular aza-Michael addition. When this reaction is carried out
Convergent Synthesis of 6-Substituted Phenanthridines via Anionic Ring Closure
作者:Morten Lysén、Jesper L. Kristensen、Per Vedsø、Mikael Begtrup
DOI:10.1021/ol0170051
日期:2002.1.1
[reaction: see text] The addition of organometallic derivatives to the cyano group of 2-(2-fluorophenyl)benzonitrile followed by intramolecular nucleophilic substitution produces 6-substituted phenanthridines. Alkyllithiums, aryllithiums, and sterically nondemanding lithiumamides reacted at -78 degrees C to produce the 6-substituted phenanthridines in 82-98% yield upon warming to room temperature
The Alkylation and Reduction of Heteroarenes with Alcohols Using Photoredox Catalyzed Hydrogen Atom Transfer via Chlorine Atom Generation
作者:Montserrat Zidan、Avery O. Morris、Terry McCallum、Louis Barriault
DOI:10.1002/ejoc.201900786
日期:2020.3.15
The alkylation of N‐heteroarenes using primary alcohols and ethers as radical precursors. The corresponding alkyl radical is formed via hydrogen atom transfer (HAT) process with a photoredox catalyzed chlorineatomgeneration as HAT agent. Furthermore, we explore the reduction of the heteroarenes when secondary alcohols are employed, giving moderate to high yields.
ABSTRACT A rapid and highly efficient method for the radical formation using potassium alkylfluoroborates as radical precursor is devised and developed which conducts under relatively mild condition using silver(I) oxide as the oxidant. The observed silver mirror phenomenon hints at the fact that Ag2O is the real oxidant. This approach effectively overcomes the drawbacks-stringent reaction conditions