2-Substituted-2,3-dihydro-1H-quinolin-4-ones via Acid-Catalyzed Tandem Rupe Rearrangement-Donnelly-Farrell Ring Closure of 2-(3′-Hydroxypropynyl)anilines
2-Substituted-2,3-dihydro-1H-quinolin-4-ones via Acid-Catalyzed Tandem Rupe Rearrangement-Donnelly-Farrell Ring Closure of 2-(3′-Hydroxypropynyl)anilines
A range of 2-substituted 2,3-dihydro-1H-quinolin-4-ones have been synthesized from anilines by a two-step process involving Sonogashira coupling with a propargyl alcohol then acid-catalyzed cyclization of the resulting 2-(3′-hydroxypropynyl)anilines. The cyclization reaction appears to proceed via regioselective rearrangement of the propargyl alcohol to an α,β-unsaturated ketone (Rupe rearrangement) and then 6-endo-trig ring closure (Donnelly-Farrell cyclization). The isolation of the α,β-unsaturated ketone intermediate in one example supports this pathway.
Highly Regioselective Indoline Synthesis under Nickel/Photoredox Dual Catalysis
作者:Sarah Z. Tasker、Timothy F. Jamison
DOI:10.1021/jacs.5b05597
日期:2015.8.5
Nickel/photoredoxcatalysis is used to synthesize indolines in one step from iodoacetanilides and alkenes. Very high regioselectivity for 3-substituted indoline products is obtained for both aliphatic and styrenyl olefins. Mechanistic investigations indicate that oxidation to Ni(III) is necessary to perform the difficult C-N bond-forming reductive elimination, producing a Ni(I) complex, which in turn
Simple and Efficient Generation of Aryl Radicals from Aryl Triflates: Synthesis of Aryl Boronates and Aryl Iodides at Room Temperature
作者:Wenbo Liu、Xiaobo Yang、Yang Gao、Chao-Jun Li
DOI:10.1021/jacs.7b03538
日期:2017.6.28
Despite the wide use of aryl radicals in organic synthesis, current methods to prepare them from aryl halides, carboxylic acids, boronic acids, and diazonium salts suffer from limitations. Aryl triflates, easily obtained from phenols, are promising aryl radical progenitors but remain elusive in this regard. Inspired by the single electron transfer process for aryl halides to access aryl radicals, we developed
A variety of diversely substituted aryl triflate esters were efficiently deprotected to the parent phenols by exposure to cesium carbonate in toluene. This procedure proved highly compatible with existing functional groups. (C) 2013 Elsevier Ltd. All rights reserved.