Study On The Application Of Functionalized Ionic Liquids And Its Derivatives In Organic Reactions

With the increasing human activities and the growing serious ecological environment, energy shortages and global warming have caused a serious impediment to social sustainable development. Green chemistry has become the frontier of the development of chemical science. Ionic liquids as a new class of medium provides a source of innovation for breaking through the green engineering, brings new opportunities for solving energy and environmental problems, has become one of the focus of green chemistry. In recent years, a number of researchers have a great interest in development and application of ionic liquid, especially the functionalized ionic liquid and its derivatives in organic synthesis.Ionic liquids have received considerable attention as an attractive alternative to the traditional organic solvents. The increased interest for their investigation is mainly due to their unique properties, such as chemical and thermal stability, high polarity, negligible vapor pressure, high electrical conductivity. In addition, the miscibility of ionic liquids with organic solvents or water can be tuned by the choice of different cations and anions.This thesis mainly focuses on the synthesis and applications of a novel functionalized ionic liquid and its derivatives in organic reactions. The thesis includes the following aspects:1. Ionic liquid supported-Schiff bases have been synthesized by the condensation of ionic liquid [2-aemin][PF6] with aromatic aldehydes at room temperature without any catalyst and solvent. All products have characterized by IR, NMR, elemental analysis and X-ray diffraction.2. The Suzuki-Miyaura reaction of aryl halide with arylboronic acid was catalyzed by the ionic liquid-supported Schiff base/Pd catalytic system. The protocol has the merits of short reaction time, excellent yields, reusability of the catalyst.3. Synthesis of heterocyclic compounds catalyzed by functionalized ionic liquids and its derivates(1) 2-Amino-3-cyano-4-aryl-7,7-dimethyl-5-oxo-4H-5,6,7,8-tetrahydrobenzo[b] pyrans are synthesized by use of aromatic aldehyde, malononitrile and dimedone via mutlicomponent reaction employing task-specific ionic liquid [2-aemin][PF6] as organocatalyst with good to excellent yields. This methodology has the merits of short reaction time, excellent yields, easy post-processing.(2) A novel pyran derivatives were synthesized via sequential process of Suzuki coupling, Knoevenagel condensation and Michael addition reactions by using ionic liquid supported-Schiff base and task-specific ionic liquid [PhCH2Me2N+CH2CH2NMe2]Cl- as catalysts. All products have characterized by IR, NMR, elemental analysis and X-ray diffraction.