Synthesis Of Imidazo[1,2-a]pyridines Fused Sulfur Derivatives And Indolines

Imidazo[1,2-a]pyridines are a group of very important heterocycles possessing diverse biological activity. Their structural motif can be found in several marketed drugs, such as anxiolytic alpidem and saripidem and in drugs used for the treatment of insomnia and brain disorders zolpidem. Their antiviral, antiparasitic, antibacterial, anti-inflammatory properties are also well documented. Besides the pharmacological importance, imidazo-[1,2-a]pyridines exhibit interesting optical properties. Not surprisingly, methodology of their synthesis has attracted significant attention. However, reports about the synthetic methodologies of imidazo[1,2-a]pyridines fused sulfur derivatives are still unusual. Thus the research via C-S bonds formation approach for synthesis of sulfur derivatives possessing potential application value is a very promising field. Indolines are important building blocks in a vast number of biologically active natural products1 and pharmacologically active compounds. Numerous synthetic methodologies have been developed for recent years. Most of these approaches to construct indolines were focused on transition-metal-catalyzed C-N or C-C bond formation. However, because of the high catalyst loading demand and heavy metals residue in some of these processes, the application is restricted. Therefore,exploration of transition-metal-free approaches for the synthesis of indolines possesses vital significance in the drug synthesis.The dissertation includes two parts of work:(1) copper catalyzed synthesis of imidazo[1,2-a]pyridines fused sulfur derivatives by constructing C-S bond.(2) transition-metal-free synthesis of indolines. The contents of this dissertation are summarized as follow:1. In the presence of Cu I-I2, the preparation of imidazo[1,2-a]pyridines fused sulfur derivatives via copper-catalyzed double C-S bonds formation was firstly developed in good yields. Fluorescence spectrum and ultraviolet spectrum test showed that the compound has good optical properties. 2. Herein, a efficient method for catalytic regioselective sulfenylation of imidazopyridines was described in the presence of Cu(OAc)2-O2. A class of novel thioether compounds were synthesized at the same time. The nontoxic and readily available metal sulfides is a sulfur sources for the coupling partners. 3. A transition-metal-free and mild cyclization of N-(ortho-chloromethyl)aryl amides with iodonium ylides were used for the synthesis of indolines. The synthesis method has the advantages of moderate reaction condition and relatively higher productivity.