Studies On The Metal-Catalyzed Radical Cyclization And Unstrained Heterocycles-Opening Reactions

Heterocyclic skeletons are widely distributed in drugs and complex natural molecules.Therefore,chemists have been working hard to develop efficient,green and convenient strategies for the synthesis of heterocyclic backbones or the modification of heterocycles via site-selective ring-opening functionalization.This thesis mainly explores the metal catalyzed oxidative free radical reaction in the following two aspects: in the first part,the copper catalyzed oxidative cyclization of hydrazonyl and iminoxyl radicals onto intramolecular olefins is realized,and a series of heterocyclic compounds with important structures have been synthesized;in the second part,the silver catalyzed oxidative site selective ring-opening functionalization of the unstrained nitrogen-containing heterocycles is realized.The thesis contains six chapters:Chapter 1: This chapter begins with an overview of free radical classification,initiation method,reaction type,cyclization and ring-opening rules.Then,three different processes in metal-catalyzed oxidative radical reaction are described.Finally,the recent progresses in metal catalyzed oxidative cyclization of hydrazonyl / iminoxyl radicals and ring-opening of unstrained heterocycles involved free radicals are reviewed.Chapter 2: The oxyamination and diamination of internal olefins of ?,?-and ?,?-unsaturated ketoximes with electron rich aryl and aliphatic amines have been developed via Cu-catalyzed oxidative cyclization of iminoxyl radicals.By using this strategy,many structurally diverse amino-featured isoxazolines and cyclic nitrones can be prepared conveniently and efficiently.It is worth noting that di-tert-butyl peroxide(DTBP)or air at atmospheric pressure can be used as the terminal oxidant for this tactic.Chapter 3: The aminoacyloxylation of unactivated alkenes of unsaturated hydrazones with manifold carboxylic acids has been achieved by Cu-catalyzed oxidative cyclization reaction of hydrazonyl radicals.A variety of structurally significant acyloxyl-featured pyrazolines and tetrahydropyridazines are efficiently prepared.Significantly,various carboxyl-containing drugs and bioactive molecules participated very well in this transformation.Chapter 4: Based on the previous work of our laboratory,the aminoalkenylation and aminoacyloxylation of unactivated alkenes of ?,?-unsaturated ketoximes are selectively achievedbycopper-catalyzed / copper and TBAI co-catalyzedoxidativecyclization reaction of iminoxyl radicals.A series of useful acyloxyl or vinyl-containing cyclic nitrones are synthesised by this method.Chapter 5: Ag-catalyzed oxidativesite-selective ring-opening and C-C bond transformation of unstrained cyclic imines has been developed for the preparation of potential bioactive distal aminoalkyl-containing quinones.A variety of peptides containing proline residues are compatible with this strategy.Chapter 6: Summary and prospect.