Base‐Promoted Aerobic Oxidation/Homolytic Aromatic Substitution Cascade toward the Synthesis of Phenanthridines
作者:Debabrata Maiti、Atreyee Halder、Suman De Sarkar
DOI:10.1002/adsc.201900995
日期:2019.11.5
transition metal‐free synthesis of polysubstituted phenanthridines from abundant starting materials like benzhydrol and 2‐iodoaniline derivatives. The reaction involves sequential oxidation of alcohol and direct condensation reaction with the amine resulting in a C−N bond formation followed by a radical C−C coupling in a cascade sequence. The used base potassium tert‐butoxide plays a dual role in dehydrogenation
phenanthridine dyes carrying hydroxy groups that were employed as near-IR two-photon absorption (TPA) photostabilizers for polymers. It was demonstrated that the target phenanthridine dyes underwent reversible excitedstate proton transfer (ESPT) in strong polar protic and aprotic solvents, such as ethanol, which was more remarkable under near-IR two-photon excitation. It was determined that the target dyes
A robust synthesis of phenanthridines has been described via Pd(II)-catalyzed domino C(sp2)–H activation/N-arylation using oxime esters with aryl acyl peroxides in a highly regioselective manner. This protocol is compatible with acetophenone as well as benzophenone-derived oxime esters and allows modular construction of functionalized phenanthridines with wide tolerance of electronic functionality
Pd-catalyzed assembly of phenanthridines from aryl ketone O-acetyloximes and arynes through C–H bond activation
作者:Chen-Yu Tang、Xin-Yan Wu、Feng Sha、Fei Zhang、Hao Li
DOI:10.1016/j.tetlet.2013.12.075
日期:2014.1
Pd-catalyzed annulation of aryne and aryl ketone O-acetyloxime via C-H bond activation was realized. Through the C-H bond activation/insertion/cyclization/elimination reaction sequence, phenanthridines are successfully constructed, providing an attractive strategy to approach substituted heterocycle without preactivation of starting materials. Crown Copyright (C) 2013 Published by Elsevier Ltd. All rights reserved.
Intramolecular Direct C–H Bond Arylation from Aryl Chlorides: A Transition-Metal-Free Approach for Facile Access of Phenanthridines
作者:Yinuo Wu、Shun Man Wong、Fei Mao、Tek Long Chan、Fuk Yee Kwong
DOI:10.1021/ol302489n
日期:2012.10.19
A C-H arylation with aryl chloride Is made viable through a transition-metal-free approach. In the presence of a simple diol associating with KOt-Bu, various phenanthridine derivatives can be conveniently accessed. In particular, only 10 mol % of simple and inexpensive ethylene glycol is required for this protocol. These results represent the first general examples of aryl chloride/C-H coupling under transition-metal-free conditions.