Highly efficient conversion of fused 2-amino-4-aryl-4H-chromene-3-carbonitriles into fused 2-oxo-4-aryl-2H-chromene-3-carbonitriles using Vilsmeier conditions
摘要:
A simple, mild, and highly efficient protocol for the synthesis of fused 2-oxo-4-aryl-2H-chromene-3-carbonitriles has been developed starting from fused 2-amino-4-aryl-4H-chromene-3-carbonitriles utilizing Vilsmeier conditions. (C) 2013 Elsevier Ltd. All rights reserved.
Oxidative Difunctionalization of 2-Amino-4<i>H</i>-pyrans in Iodobenzene Diacetate and <i>N</i>-Chlorosuccinimide: Reactivity, Mechanistic Insights, and DFT Calculations
Oxidative difunctionalization of 2-amino-4H-pyrans was accomplished with iodobenzenediacetate (IBD) and N-chlorosuccinimide (NCS) reagents in alcoholic medium. 2-Amino-4H-pyrans undergo geminal dialkoxylation with the migration of an amino group (1a,b, 2a–i, 3a,b, and 4) in IBD, whereas with NCS addition of both chlorine and alkoxy groups takes place across the chromene double bond (6a–i).
Abstract A novel protocol to synthetic transformation of 4H-chromenes into dihydrofurans (3) and 2H-chromenes (11) promoted by hypervalent iodine has been accomplished in a one-pot reaction at ambient temperature. Dihydrofurans are exclusively formed under basic reaction conditions, whereas, 2H-chromenes are the products under acidic condition. Simple reaction conditions with a broad substrate scope
New approach to synthesis of 4-arylcoumarin derivatives
作者:Ivan N. Bardasov、Anastasiya U. Alekseeva、Oleg V. Ershov、Marina D. Surazhskaya、Andrei V. Churakov、Dmitry A. Grishanov
DOI:10.1016/j.tetlet.2015.09.111
日期:2015.10
A simple and highly efficient new approach for the synthesis of 4-aryl-2-oxo-2H-chromene-3-carbonitriles based on the oxidation and hydrolysis of 2-amino-4-aryl-4H-chromene-3-carbonitriles is described. (C) 2015 Elsevier Ltd. All rights reserved.
An approach towards the oxidation of 2-amino-4H-chromenes to 2-imino-2H-chromenes
A novel method for the synthesis of 2-imino-2H-benzo[h]chromenes via the sequential addition of N-chlorosuccinimide and triethylamine to 2-amino-4H-benzo[h]chromenes has been established. This reaction protocol represents an efficient synthetic strategy to form iminochromene derivatives under mild reaction conditions, which utilizes readily accessible aminochromenes as starting materials and tolerates a wide range of substrates. (C) 2018 Elsevier Ltd. All rights reserved.