121st General Meeting of the KCS

Type Oral Presentation
Area Oral Presentations of Young Scholars in Organic Division
Room No. Halla Hall B
Time THU 10:15-:
Code ORGN.O-6
Subject Synthesis of 2-Substituted Quinolines from 2-Aminostyryl Ketones Using Iodide as a Catalyst and Its Application to On-water Synthesis
Authors So Young Lee, Jiye Jeon, Cheol-Hong Cheon*
Department of Chemistry, Korea University, Korea
Abstract Quinolines are common building blocks found in biologically and pharmacologically active compounds. Particularly, 2-substituted quinolines are of importance since they display interesting biological activities and been utilized as key building blocks in materials science. One of the conventional methods for the synthesis of 2-arylquinolines involves the intramolecular cyclization of (E)-2-aminochalcones. However, this method generally requires additional steps to convert (E)-alkene into (Z)-isomer via either photoisomerisation or the use of a stoichiometric amount of chemical reagents, such as iodine and selenium, in the presence of a base. We hypothesized that 2-arylquinolines could be prepared from 2-aminochalcones in the presence of iodide as a nucleophilic catalyst. Conjugate addition of iodide to 2-aminochalcones would lead to β-iodoketones, which undergo intramolecular imine formation affording dihydroquinoline intermediates. Following elimination of iodide provided the desired 2-arylquinolines. Based on this hypothesis, we developed a novel method for 2-arylquinolines starting from 2-aminochalcones in the presence of a catalytic amount of Iodide. Furthermore, we could expand this reaction in water as a reaction media. Since water is the unique the cheapest abundant solvent available from nature, non-toxic to the environment, easy product isolation by simple phase separation, the development of novel on-water reaction has received considerable attentions from the chemical society. Thus, we further extended this protocol for the on-water synthesis of quinolines from 2-aminostyryl ketones. By using water-insoluble properties of 2-aminochalcone and 2-arylquinoline, the quinoline products could be easily isolated from the reaction mixture.
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