Premium
Design of Water Stable 1,3‐Dialkyl‐ 2‐Methyl Imidazolium Basic Ionic Liquids as Reusable Homogeneous Catalysts for Aza‐Michael Reaction in Neat Condition
Author(s) -
Boruah Kabita,
Borah Ruli
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.201900187
Subject(s) - ionic liquid , catalysis , thermogravimetric analysis , acrylonitrile , cationic polymerization , chemistry , piperidine , proton nmr , hydroxide , michael reaction , ionic bonding , nuclear chemistry , organic chemistry , inorganic chemistry , polymer chemistry , ion , polymer , copolymer
In this study, new members of mono cationic basic ionic liquids were synthesized as water stable viscous liquid consisting of 1, 3‐dialkyl‐2‐methyl imidazolium cation and acetate (or hydroxide) anion. Their structures were determined using 1 H NMR, 13 C NMR, FT‐IR and elemental analysis. Thermogravimetric analysis displayed maximum stabilities of six ionic liquids up to 260 °C. The UV‐Vis technique was employed to determine their comparable Hammett basicity order. Thermally stable five ionic liquids with less moisture content showed their catalytic activities by formation of 85–97% yields of β‐amino carbonyl compound for the model Aza‐Michael reaction of piperidine and acrylonitrile in neat condition with 2 and 5 mol % of catalysts for 5–15 min at room temperature. The optimized two catalysts [dbIm]OH and [daIm]OAc were reused efficiently with slight loss of activity for four cycles after the 1 st run.