Studies On The Multicomponent Reactions Based Phenylglyoxal

Heterocyclic compounds are ubiquitous in natural products, pharmaceuticals and biologically active alkaloids. The creation of diverse and complex heterocyclic compounds from readily available starting materials is a challenging project in synthetic chemistry for both academia and the pharmaceutical industry. One of the most promising approaches is based on multicomponent reactions(MCRs), which are defined as complex product formation via “one-pot” processes involving three or more reactants. Multicomponent reaction processes avoid the isolation and purification of intermediates, minimize solvent waste, maximize the yield of the final product. Phenylglyoxal is widely used in multicomponent reactions(MCRs) in virtue of its high reactivity and multiple reaction sites. In this thesis, some novel heterocyclic compounds have been synthesized by multicomponent reactions(MCRs) using phenylglyoxal as starting material. This thesis consists of the following three important parts:In the first part, the progress of study on multicomponent reactions(MCRs) based phenylglyoxal in the last few years has been mainly introducedIn the second part, a simple and efficient one-pot construction of highly functionalized indolizine derivatives via a diethylamine-catalyzed three-component reactions of arylglyoxals, cyclic 1,3-diones, and 5-aminopyrazoles under microwave irradiation is described. This new method has the advantages of mild reaction conditions, readily available starting materials, wide substract diversity and short reaction time. The structures of the products were characterized by IR, 1H NMR, 13 C NMR and HRMS. The structure of compound 4k was further confirmed by X-ray diffraction analysis.In the third part, a series of highly functionalized hexahydrofuro[2,3-b]furan derivatives has been synthesized via the three-component reaction of phenylglyoxal, 5-aminopyrazoles and dimedone(or barbituric acid) catalyzed by dimethylamine in ethanol. The key features of this reaction are mild reaction conditions, readily available starting materials, operational simplicity, high bondforming efficiency and environmental friendliness. The structures of the products were characterized by IR, 1H NMR, 13 C NMR and HRMS. The structure of compound 5a was further confirmed by X-ray diffraction analysis.