Study On Selective Derivatization Of 3-Aryl Indazole

Indazole is an important fused aromatic heterocyclic system containing benzene ring and pyrazole ring.It is an important nitrogen-containing heterocyclic skeleton in organic and pharmaceutical chemistry.Indazole derivatives exhibit a wide range of biological properties,such as anti-inflammatory,antibacterial,antifungal and antitumor.In particular,indazole-based conjugated aromatic systems and fused aromatic ring compounds were wildly utilized in drugs and material sciences.Consequently,intensive attention has been continuously drawing upon their synthetic methodology.In addition,iodonium ylides as inexpensive and readily available hypervalent iodine reagents show good thermal stability,safety,solubility in common organic solvent,and have been widely used in organic synthesis.Thus,many progress have been made in C-H activation and insertion into iodonium-ylide-derived carbenoid for synthesis of fused aromatic compounds.On the other hand,as an electron-deficient olefin,maleimide is widely used as an alkylation reagent for Michael addition reaction.And,maleimide derivatives are well known for their unique photophysical properties and potent pharmaceutical activities.Consequently,tremendous effort has been devoted to synthesis maleimide-containing compounds.This thesis focuses on the development methods for stage-derivative of indazole for the construction of indazole-containing derivatives.The main contents are as follows:In part one,we developed a route for access for indazole fused dihydrophenanthridinones.Acid-controlled Rh（III）-catalyzed C-H activation of 3-arylindazoles and annulation with hypervalent iodonium ylides,afforded a wide range of dihydroindazolo[2,3-f]phenanthridin-5（6H）-ones.The synthesized products exhibit good photophysical properties,which indicates their potential applications in the fields of new fluorescent.Moreover,the products were obtained without tedious column chromatography,only simply filtration and washing with methanol.Furthermore,the catalyst system can be recycled for reusing at least eight times with excellent yield,which may allow this method to have potential into industrial production.In part two,we described a methodology for the synthesis of indazole-maleimide hybrid compounds.The Ag⁺reacted firstly with indazole to form Ag-indazole trinuclear complex Lewis acid[（3-phenylindazole）Ag]₃,Which catalyzed indazoles selective N¹-aza-Michael addition to maleimide for the synthesis of indazole-maleimide hybrid compounds.This method has a wide substrate range and medium to excellent yield.