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Bridged Alkyl Ionic Liquid‐Catalyzed Tandem Reaction for Synthesis of Spiro[4 H ‐pyran‐3,3′‐oxindoles] in Aqueous Ethanol Solution
Author(s) -
Li ChengBin,
Huang LuShan,
Wu RunShi,
Xu DaZhen
Publication year - 2019
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201803905
Subject(s) - ionic liquid , catalysis , pyran , aqueous solution , chemistry , alkyl , oxindole , solvent , environmentally friendly , tandem , organic chemistry , ethanol , green chemistry , combinatorial chemistry , materials science , composite material , ecology , biology
A new class of bridged alkyl ionic liquids has been successfully developed and they are shown to be efficient catalysts for the synthesis of a wide range of densely functionalized spiro[4 H ‐pyran‐3,3′‐oxindole] derivatives. With only 1 mol% catalyst, all the reactions underwent smoothly in aqueous ethanol solution at ambient temperature and afforded the corresponding products in good to excellent yields within a short reaction time. This is a simple and green protocol with significant advantages such as the use of environmentally friendly solvent, mild conditions, easy work up, no chromatographic separation, and applicability for large‐scale synthesis. The catalyst could be reused eight times at least.