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A Facile and Green Pathway for One‐Pot Multicomponent Synthesis of Functionalized Spiroxyindoles using Caffeinium Hydrogen Sulfate as a Catalyst.
Author(s) -
Agarwal Shalini,
Kidwai Mazaahir,
Nath Mahendra
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.201900121
Subject(s) - malononitrile , knoevenagel condensation , catalysis , hydrogen sulfate , domino , combinatorial chemistry , chemistry , yield (engineering) , one pot synthesis , organic chemistry , cascade reaction , materials science , ionic liquid , metallurgy
This paper demonstrates an efficient, green and convenient strategy for the synthesis of densely functionalized biologically important spiroxyindoles. This facile step economic synthetic protocol involves one‐pot three component condensation of functionalized isatins, malononitrile and C−H activated carbonyl compounds in the presence of Caffeinium hydrogen sulfate (CHS) as a green acid catalyst to afford various spiroxyindole derivatives via domino Knoevenagel‐Michael‐cyclization sequence. This environmentally benign protocol provides various advantages viz operational simplicity, excellent yield processing, cost‐effectiveness and short reaction time. High selectivity, broad substrate scope, recyclability of the catalyst and isolation of final products via simple filtration and recrystallization procedure are the prominent features of the presented methodology.