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Effective and Sustainable Access to Quinolines and Acridines: A Heterogeneous Imidazolium Salt Mediates C–C and C–N Bond Formation
Author(s) -
Gisbert Patricia,
AlbertSoriano María,
Pastor Isidro M.
Publication year - 2019
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/ejoc.201900880
Subject(s) - chemistry , catalysis , quinoline , acridine , salt (chemistry) , tandem , combinatorial chemistry , chalcone , heterogeneous catalysis , solvent , organic chemistry , green chemistry , chloride , ionic liquid , materials science , composite material
Quinoline and acridine derivatives have been prepared using a functionalized imidazolium salt as heterogeneous catalyst. Different ketones have been coupled with 2‐aminobenzaldehydes and 2‐aminoaryl ketones under solvent‐free conditions, employing 1,3‐bis(carboxymethyl)‐imidazolium chloride as a catalyst. The protocol is simple and effective for the synthesis of a variety of nitrogen containing heterocycles (> 35 examples) with moderate to excellent yields (up to 96 %), being possible to perform the reaction in preparative scale. Additionally, 3‐acetylquinolines have been transformed, under solvent‐free conditions, into quinolyl chalcone derivatives by means of the same catalyst. Thus, the catalytic system mediates both reactions effectively in a tandem procedure. Furthermore, the catalyst is easily separated from the reaction mixture and can be reused without loss of activity (up to 8 cycles) which remarks its sturdiness. The E‐factors are in the range of 14–23, both for the formation of quinolines and for the tandem reaction, which demonstrates the sustainability of the protocols described.