120759-32-2Relevant academic research and scientific papers
A Modified System for the Synthesis of Enantioenriched N-Arylamines through Copper-Catalyzed Hydroamination
Ichikawa, Saki,Zhu, Shaolin,Buchwald, Stephen L.
, p. 8714 - 8718 (2018/07/14)
Despite significant recent progress in copper-catalyzed enantioselective hydroamination chemistry, the synthesis of chiral N-arylamines, which are frequently found in natural products and pharmaceuticals, has not been realized. Initial experiments with N-arylhydroxylamine ester electrophiles were unsuccessful and, instead, their reduction in the presence of copper hydride (CuH) catalysts was observed. Herein, we report key modifications to our previously reported hydroamination methods that lead to broadly applicable conditions for the enantioselective net addition of secondary anilines across the double bond of styrenes, 1,1-disubstituted olefins, and terminal alkenes. NMR studies suggest that suppression of the undesired reduction pathway is the basis for the dramatic improvements in yield under the reported method.
Iron-Catalyzed Cyclization of Nitrones with Geminal-Substituted Vinyl Acetates: A Direct [4 + 2] Assembly Strategy Leading to 2,4-Disubstituted Quinolines
Zhong, Mingbing,Sun, Song,Cheng, Jiang,Shao, Ying
, p. 10825 - 10831 (2016/11/29)
An iron-catalyzed intermolecular [4 + 2] cyclization of arylnitrones with geminal-substituted vinyl acetates was developed for the synthesis of 2,4-disubstituted quinolines in moderate to good yields with good functional group compatibilities. Preliminary mechanistic studies suggest a plausible iron-catalyzed C-H activation process under external-oxidant-free conditions.
Synthesis of 3-alkylbenzoxazolones from N-alkyl-N-arylhydroxylamines by contiguous O-trichloroacetylation, trichloroacetoxy ortho-shift, and cyclization sequence
Ram, Ram N.,Soni, Vineet Kumar
, p. 11935 - 11947 (2014/01/06)
Benzoxazolone pharmacophore is present in clinical pharmaceuticals, drug candidates, and many compounds having a wide spectrum of biological activities. The methods available for the synthesis of benzoxazolones have limited diversity due to problems in accessibility and air-sensitivity of diversely substituted o-aminophenols from which they are generally prepared by cyclocarbonylation with phosgene or its equivalents. The present paper describes a mild method for the synthesis of 3-alkylbenzoxazolones from easily accessible and air-stable nitroarenes. Nitroarenes were converted to N-alkyl-N-arylhydroxylamines in two steps involving partial reduction to arylhydroxylamines followed by selective N-alkylation. Treatment of N-alkyl-N-arylhydroxylamines with trichloroacetyl chloride and triethylamine afforded 3-alkylbenzoxazolones generally in good yields through an uninterrupted three-step sequence involving O-trichloroacetylation, N→Cortho trichloroacetoxy shift, and cyclization in a single pot at ambient temperatures. The present method is mild, wide in scope, economical, and regioselective. Many sensitive groups like alkyl and aryl esters, amide, cyano, and the carbon-carbon double bond survive the reaction.
THE SIMPLEST PHENYLNITRONES AND THEIR CONVERSION INTO ISOXAZOLIDINE DERIVATIVES
Zelenin, K.N.,Bezhan, I.P.,Ershov, A.Yu.
, p. 688 - 691 (2007/10/02)
Reaction of N-phenylhydroxylamine with the simplest alkanals leads initially to the formation of N-phenylnitrones, dimerization of which gives 5-substituted isoxazolidine.Taking the reactions of N-phenylnitrones, benzaldehyde, and acetone as an example, t
