Synthesis Of N-Heteroaromatics Via Electrochemical Oxidation Of Ketoximes And Hydrazones

Nitrogen-containing organic molecules are very important in chemistry,biology,and material fields.The development of efficient and sustainable nitrogen-containing heterocyclic construction reactions has been a research hotspot in the field of organic synthesis.Oxime and hydrazone are easy to obtain,and using them as raw materials to synthesize nitrogen-containing heterocycles is a good method.In this dissertation,oxime and hydrazone are oxidized by electrochemical means to generate iminoxyl radicals and diazonium compounds respectively.Then,phenanthridine derivatives and[1,2,3]triazole[1,5-a]pyridine derivatives were synthesized by cycloaromatization.This dissertation is divided into the following sections mainly:In the first part,the synthesis of phenanthridines and phenanthridine N-oxides was realized by electrochemical oxidation of ketoxime.Iminoxyl radical was generated through electrolysis,followed by the addition of iminoxyl radical to the aromatic ring and oxidative aromatization.Interestingly,when Pt is used as the cathode,phenanthridine N-oxides can be selectively obtained;when Pb is used as the cathode,phenanthridine derivatives can be selectively obtained.The method,which is green and efficient,also has a good functional compatibility,and only produce hydrogen as a by-product.(?)In the second part,we use hydrazone of 2-acylpyridine derivatives to synthesize[1,2,3]triazole[1,5-a]pyridine by direct electrolysis.Hydrazones are oxidized to diazo compounds in the process,followed by undergoing intramolecular ring closure.This synthesis method does not need additional oxidant and metal catalyst,which is also suitable for "one pot" synthesis.(?)...