An approach towards the oxidation of 2-amino-4H-chromenes to 2-imino-2H-chromenes
摘要:
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.
An operationally simple and efficient protocol for the construction of dihydrofuran derivatives has been accomplished via a sequential addition of N-chlorosuccinimide and a base to 2-amino-4H-pyran derivatives in alcohol medium. The one-pot protocol proceeding via tandem oxidative difunctionalization and ring contraction provides an entirely new strategy for the construction of the dihydrofuran skeleton.
Diisopropyl azodicarboxylate mediated selective dehydrogenation of 2-amino-3-cyano 4 H -chromenes
作者:Himanshu Sharma、Mohini Mourya、Debanjan Guin、Yogesh C. Joshi、Mahabeer P. Dobhal、Ashok K. Basak
DOI:10.1016/j.tetlet.2017.03.049
日期:2017.5
Selective dehydrogenation of 2-amino-3-cyano 4H-chromenes to the corresponding 2-iminochromenes mediated by diisopropyl azodicarboxylate under neutral conditions is reported. The dehydrogenation reaction is compatible with phenolic hydroxyl group and generates iminochromene in high yields. The methodology provides an easy access to coumarin and N-tosyl 2-amino-3-cyano-4-aryl 4H-chromenes.
Microwave-assisted reactions: Three component process for the synthesis of 2-amino-2-chromenes under microwave heating
作者:Ramadan A. Mekheimer、Kamal U. Sadek
DOI:10.1002/jhet.13
日期:2009.3
A simple and efficient threecomponentprocess for the synthesis of 2-amino-2-chromenes utilizing the reaction of aryl aldehydes with active methylenes 2a,b and 1-naphthol in refluxing ethanol/piperidine under microwave-heating is described. J. Heterocyclic Chem., (2009).
Convenient and Efficient One-Pot Method for the Synthesis of 2-Amino-tetrahydro-4<i>H</i>-chromenes and 2-Amino-4<i>H</i>-benzo[<i>h</i>]-chromenes Using Catalytic Amount of Amino-Functionalized MCM-41 in Aqueous Media
作者:M. Mirza-Aghayan、S. Nazmdeh、R. Boukherroub、M. Rahimifard、A. A. Tarlani、M. Abolghasemi-Malakshah
DOI:10.1080/00397911.2011.643438
日期:2013.6.3
Abstract A convenient and efficient one-pot method for the synthesis of 2-amino-tetrahydro-4H-chromene and 2-amino-4H-benzo[h]-chromene derivatives has been developed using a catalytic amount of amino-functionalized MCM-41 in aqueous medium. This efficient technique has the advantages of giving 4H-tetrahydro-chromene and 4H-benzo[h]chromene building blocks using a reusable catalyst in good to excellent
Substituted 2-amino-2-chromenes were obtained in excellent yield and selectivity simply by mixing malononitrile, α-naphthol and aromatic aldehydes in water in the presence of basic alumina as heterogeneous and reusable catalyst.