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
Free-Radical Triggered Ordered Domino Reaction: An Approach to C–C Bond Formation via Selective Functionalization of α-Hydroxyl-(sp<sup>3</sup>)C–H in Fluorinated Alcohols
作者:Zhengbao Xu、Zhaojia Hang、Zhong-Quan Liu
DOI:10.1021/acs.orglett.6b01946
日期:2016.9.16
free-radical mediated highly ordered radical addition/cyclization/(sp3)C–C(sp3) formation domino reaction is developed. Three new C–C bonds are formed one by one in a mixed system. Furthermore, it represents the first example of cascade C–C bond formation via selective functionalization of α-hydroxyl-C(sp3)–H in fluorinated alcohols.
Preparation of phenanthridines from N-(o-arylbenzyl)trifluoromethanesulfonamides with 1,3-diiodo-5,5-dimethylhydantoin
作者:Kei Yanai、Hideo Togo
DOI:10.1016/j.tet.2020.131503
日期:2020.10
6-arylphenanthridines and 6-unsubstituted phenanthridines in good to moderate yields, respectively. The reaction proceeds through an oxidative cyclization onto the aromatic ring by sulfonamidyl radicals formed from the N-iodosulfonamides. The present reaction is a one-pot method for the preparation of both 6-arylphenanthridines and 6-unsubstituted phenanthridines from N-(o-arylbenzyl)trifluoromethanesulfonamides
Preparation of Substituted Phenanthridines from the Coupling of Aryldiazonium Salts with Nitriles: A Metal Free Approach
作者:Mani Ramanathan、Shiuh-Tzung Liu
DOI:10.1021/acs.joc.5b00579
日期:2015.5.15
A transition metal free approach for the synthesis of substituted phenanthridines from the coupling reaction of aryldiazonium tetrafluoroborates with nitriles has been developed. This operationally simple protocol proceeds through a substitution of aryldiazonium with nitriles followed by an intramolecular arylation to provide the corresponding phenanthridines in moderate to excellent yields.
A metal-free visible-light photoredox-catalyzed intermolecular cyclization reaction of O-2,4-dinitrophenyl oximes to phenanthridines was developed. In this study, the organic dye eosin Y and i-Pr₂NEt were used as photocatalyst and terminal reductant, respectively. The oxime substrates were transformed into iminyl radical intermediates by single-electron reduction, which then underwent intermolecular