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
Electrochemical Decarboxylative Cyclization of α‐Amino‐Oxy Acids to Access Phenanthridine Derivatives
作者:Yanling Zhan、Changhui Dai、Zitong Zhu、Ping Liu、Peipei Sun
DOI:10.1002/asia.202101388
日期:2022.3.14
compounds found in pharmaceuticals and natural products. Herein, an efficient electrochemical decarboxylative cyclization of α-amino-oxy acids to synthesize phenanthridine derivatives was developed. This reaction proceeded through iminyl radical formation cascade intramolecular cyclization from readily available materials under transition-metal-free and mild conditions.
Cathode Material Determines Product Selectivity for Electrochemical C−H Functionalization of Biaryl Ketoximes
作者:Huai‐Bo Zhao、Pin Xu、Jinshuai Song、Hai‐Chao Xu
DOI:10.1002/anie.201809679
日期:2018.11.12
N‐oxides has been developed through electrochemicalC−Hfunctionalization of biarylketoximes. The oxime substrates undergo dehydrogenative cyclization when a Pt cathode is used, resulting in unprecedented access to a wide range of N‐heteroaromatic N‐oxides. The products of the electrosynthesis are switched to the deoxygenated N‐heteroaromatics by employing a Pb cathode through sequential anode‐promoted
Combination of PhI(OAc)<sub>2</sub> and 2-Nitropropane as the Source of Methyl Radical in Room-Temperature Metal-Free Oxidative Decarboxylation/Cyclization: Construction of 6-Methyl Phenanthridines and 1-Methyl Isoquinolines
A room-temperature metal-free method for generating highly unstable methyl radical was realized from the combination of PhI(OAc)2 and 2-nitropropane, which provides an efficient approach to methylated phenanthridines and isoquinolines. The strategy was also extended to the generation of other alkyl radicals and a concise synthesis of Roxadustat.
The methylation or trideuteromethylation reaction of isocyanides with dimethyl sulfoxides in a radical way is developed, which offers a low-cost, easy-operation cascade methylation strategy for the synthesis of phenanthridines or isoquinolines.