Multicomponent reactions and ionic liquids: a perfect synergy for eco-compatible heterocyclic synthesis

Abstract

The efficiency of a chemical synthesis can be nowadays measured, not only by parameters like selectivity and overall yield, but also by its raw material, time, human resources and energy requirements, as well as the toxicity and hazard of the chemicals and the protocols involved. The development of multicomponent reactions (MCRs) in the presence of task-specific ionic liquids (ILs), used not only as environmentally benign reaction media, but also as catalysts, is a new approach that meet with the requirements of sustainable chemistry. The aim of this tutorial review is to highlight the synergistic effect of the combined use of MCRs and ILs for the development of new eco-compatible methodologies for heterocyclic chemistry.

Ammonium- and Phosphonium-Based Ionic Liquid: Green and Reusable Catalysts

“…Isambert et al [47] described the development of multicomponent reactions in the presence of task-specific ILs for the new eco-compatible methodologies for heterocyclic chemistry as environmentally benign reaction media as well as catalysts.…”

Synthesis, characterization and antimicrobial studies of new 2-(2-chloroquinolin-3-yl)-3-(substituted phenyl/pyridinyl)quinazolin-4(3H)-one derivatives using l-proline as a catalyst

“…For that, we have used microwave-assisted organic synthesis (Perreux and Loupy, 2001;Xu and Guo, 2004;Varma, 1999, Gnana Ruba Priya et al, 2011Zhang et al, 2009) in addition to conventional heating, multicomponent reactions (MCR) rout (Mossetti et al, 2011;Siddiqui et al, 2011;Bhuiyan et al, 2012;Isambert et al, 2011;Tang et al, 2010) and Lproline as an efficient acidic catalyst (Pan et al, 2009, Kumar et al, 2006. Therefore, the entitled compounds 4a-m and 5a-m were synthesized starting from isatoic anhydride 1, aromatic or heterocyclic amines 2a-m, 2-chloro-3-formylquinoline 3 and L-proline as a catalyst using MCR via both conventional and microwave heating in a high efficiency as shown in Scheme 1.…”

Synergy Effects in the Chemical Synthesis and Extensions of Multicomponent Reactions (MCRs)—The Low Energy Way to Ultra-Short Syntheses of Tailor-Made Molecules

“…Suitable solvents for MCRs are alcohols such as methanol and ethanol, water [125][126][127] and ionic liquids (ILs) [128][129][130][131][132][133], PEG-based ILs [134]. Unconventional solvents [135] such as trifluoroethanol [136] were also investigated.…”