Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media

Condensation of unprotected carbohydrates with malononitrile or malonamide nitrile in basic aqueous media gave in one-pot densely functionalized polyhydroxyalkyl 2-amino-3-furanonitriles and polyhydroxyalkyl 2-amino-3-furanocarboxamides in excellent 84–98% yields. Disaccharides afforded novel furano...

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Main Authors: Lambu, Mallikharjuna Rao, Judeh, Zaher M. A.
Other Authors: School of Chemical and Biomedical Engineering
Format: Article
Language:English
Published: 2021
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Online Access:https://hdl.handle.net/10356/150625
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Institution: Nanyang Technological University
Language: English
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spelling sg-ntu-dr.10356-1506252021-08-04T02:03:20Z Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media Lambu, Mallikharjuna Rao Judeh, Zaher M. A. School of Chemical and Biomedical Engineering Engineering::Chemical engineering Functionalized Furans Unprotected Carbohydrates Condensation of unprotected carbohydrates with malononitrile or malonamide nitrile in basic aqueous media gave in one-pot densely functionalized polyhydroxyalkyl 2-amino-3-furanonitriles and polyhydroxyalkyl 2-amino-3-furanocarboxamides in excellent 84–98% yields. Disaccharides afforded novel furano-glycosides. Based on the rate of formation of the furans, the ability of the tested bases to catalyze the reaction was concluded as Et₃N > DBU > K₂CO₃ > NaOMe. The reaction mechanism involved the formation of bicyclic furan-furan and furan-pyran intermediates observed for the first time. The reaction proceeded through a cascade mechanism involving Knoevenagel condensation, Oxo-Micheal addition, Thorpe-Ziegler type reaction and ring-opening-induced aromatization. This operationally simple and metal-free reaction proceeded with exclusive chemo-, regio-, and stereo-selectivities under environmentally benign conditions. As demonstrated on a 2 g scale, it holds promise for application in the large-scale synthesis of important intermediates such as densely functionalized furfural. Nanyang Technological University We thank Nanyang Technological University, Singapore for financial help (RG 142/16). 2021-08-04T02:03:20Z 2021-08-04T02:03:20Z 2019 Journal Article Lambu, M. R. & Judeh, Z. M. A. (2019). Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media. Green Chemistry, 21(4), 821-829. https://dx.doi.org/10.1039/C8GC03509A 1463-9262 https://hdl.handle.net/10356/150625 10.1039/C8GC03509A 4 21 821 829 en RG 142/16 Green Chemistry © 2019 The Royal Society of Chemistry. All rights reserved.
institution Nanyang Technological University
building NTU Library
continent Asia
country Singapore
Singapore
content_provider NTU Library
collection DR-NTU
language English
topic Engineering::Chemical engineering
Functionalized Furans
Unprotected Carbohydrates
spellingShingle Engineering::Chemical engineering
Functionalized Furans
Unprotected Carbohydrates
Lambu, Mallikharjuna Rao
Judeh, Zaher M. A.
Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
description Condensation of unprotected carbohydrates with malononitrile or malonamide nitrile in basic aqueous media gave in one-pot densely functionalized polyhydroxyalkyl 2-amino-3-furanonitriles and polyhydroxyalkyl 2-amino-3-furanocarboxamides in excellent 84–98% yields. Disaccharides afforded novel furano-glycosides. Based on the rate of formation of the furans, the ability of the tested bases to catalyze the reaction was concluded as Et₃N > DBU > K₂CO₃ > NaOMe. The reaction mechanism involved the formation of bicyclic furan-furan and furan-pyran intermediates observed for the first time. The reaction proceeded through a cascade mechanism involving Knoevenagel condensation, Oxo-Micheal addition, Thorpe-Ziegler type reaction and ring-opening-induced aromatization. This operationally simple and metal-free reaction proceeded with exclusive chemo-, regio-, and stereo-selectivities under environmentally benign conditions. As demonstrated on a 2 g scale, it holds promise for application in the large-scale synthesis of important intermediates such as densely functionalized furfural.
author2 School of Chemical and Biomedical Engineering
author_facet School of Chemical and Biomedical Engineering
Lambu, Mallikharjuna Rao
Judeh, Zaher M. A.
format Article
author Lambu, Mallikharjuna Rao
Judeh, Zaher M. A.
author_sort Lambu, Mallikharjuna Rao
title Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
title_short Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
title_full Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
title_fullStr Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
title_full_unstemmed Efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
title_sort efficient, one-step, cascade synthesis of densely functionalized furans from unprotected carbohydrates in basic aqueous media
publishDate 2021
url https://hdl.handle.net/10356/150625
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