Synthesis of renewable isoindolines from bio-based furfurals
Upgrading biomass-derived platforms to functionalized aromatics by a tandem Diels-Alder (DA) cycloaddition-aromatization strategy has attracted broad attention. However, three challenges exist: improving the equilibrium of DA cycloaddition, controlling the regioselectivity of DA adducts, and increas...
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Published in | Green chemistry : an international journal and green chemistry resource : GC Vol. 25; no. 8; pp. 3297 - 335 |
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Main Authors | , , , , , , |
Format | Journal Article |
Language | English |
Published |
CAMBRIDGE
Royal Soc Chemistry
24.04.2023
Royal Society of Chemistry |
Subjects | |
Online Access | Get full text |
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Summary: | Upgrading biomass-derived platforms to functionalized aromatics by a tandem Diels-Alder (DA) cycloaddition-aromatization strategy has attracted broad attention. However, three challenges exist: improving the equilibrium of DA cycloaddition, controlling the regioselectivity of DA adducts, and increasing the stability of the cycloadduct. Herein, an intramolecular cycloaromatization strategy was developed for the direct upgradation of bio-furfurals to isoindolinones under liquid phase conditions
via
the selective formation of
exo
-DA adducts. The efficiency of the intramolecular DA cycloaddition was remarkably promoted by a defective Zn-BTC-SA catalyst quantitatively forming the desired regioselective
exo
-DA cycloadduct with higher thermal stability. Meanwhile, the co-existence of an acidic ionic liquid ([Hmim]HSO
4
) could facilitate the subsequent aromatization to generate isoindolinones in quantitative yields. Theoretical calculations elaborated the significance of the
in situ
formed
exo
-DA adducts with enhanced stability in the cascade conversion process. Moreover, this protocol is applicable to the production of a wide range of renewable isoindolinone derivatives and commercial medicines in excellent yields (>92%) and is suitable for gram-scale reactions.
Sugar aromatization: the efficient conversion of bio-furanics to versatile renewable isoindolinones is achieved by a self-stabilized cycloaromatization strategy. |
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Bibliography: | Electronic supplementary information (ESI) available. CCDC For ESI and crystallographic data in CIF or other electronic format see DOI 2209873 2165682 2179840 and 2165681 , https://doi.org/10.1039/d2gc04786a |
ISSN: | 1463-9262 1463-9270 |
DOI: | 10.1039/d2gc04786a |