| Nitrogen-containing molecules are ubiquitous in natural products,synthetic intermediates,pharmaceuticals,and functional materials.Indole is a very common class of N-containing heterocyclic compounds,and its C3 functionalized compounds are widely present in various natural products and pharmaceutically active molecules.The raw materials of indole compounds are easy to prepare and are important for organic intermediates in organic synthesis.The amination reaction of indole compounds has attracted great interest of many organic researchers.In this dissertation,azo-indoles and fused quinoxalines compounds were synthesized by inexpensive Iron（III）-catalyzed C3-H amination of indoles.This study is divided into two parts:In the first part,the amination-dehydrogenation cross-coupling reaction of 2-aryl indoles and phenylhydrazines under the catalysis of Iron（III）was developed to synthesize indole azo-compounds.The effects of different temperatures,solvents and metal catalysts on the formation of indole azo-compounds were discussed.This reaction had the advantages of broad substrate scope and tolerates a wide range of functional groups.It was found by experiments that 2-aryl indoles or phenylhydrazines bearing electron-donating or electron-withdrawing groups could afford indole azo-compounds in good to excellent yields.Fluorescence experiments showed that some of the synthesized indole azocompounds had good fluorescence emission.This method provides a new and efficient way to synthesize azo-based fluorescent material molecules.In the second part,an Iron（III）catalyzed amination reaction of 2-arylindoles with o-phenylenediamines and a tandem diazotization reaction were studied to synthesize fused quinoxalines derivatives in moderate to good yields.We optimized the reaction conditions with various acid,temperature,catalysts and other conditions.We also studied the applicability of the substrates,and found that the reaction had the advantages of mild reaction conditions,simple operation,and good functional group compatibility.At the same time,the obtained fused quinoxalines compounds can be introduced with luminescent groups through simple chemical transformations,and the synthesized fluorescence emission wavelength can reach more than 670 nm.This strategy not only provides an efficient method for the synthesis of fused quinoxalines derivatives,but also lays the foundation for the synthesis of fused quinoxalines fluorescent dye molecules. |
