Studies On The Iminoxyl/Hydrazonyl Radicals-Participated Reactions

This thesis deals with studies on the iminoxyl and hydrazonyl radicals-promoted cyclization and cascade cyclization reactions.It consists of five chapters:In the first chapter,a brief introduction of the classes,structures,properties and applications in organic reactions of the heteroatom-centered radicals has been briefly reviewed,especially for the iminoxyl and hydrazonyl radicals.In the second chapter,a cascade radical cyclization/addition/cyclization sequence for the synthesis of isoxazoline-functionalized phenanthridines was reported,by using ?,?-unsaturated ketoximes and 2-arylphenylisonitriles as the readily accessible starting materials and TBAI(tetrabutylammonium iodide)and TBHP(tert-butyl hydroperoxide)as a cheap,efficient and pratical catalytic oxidative system for the initiation of iminoxyl radicals from ?,?-unsaturated ketoximes.In the third chapter,we developed a novel iminoxyl radical-promoted cascade oxyalkylation/alkylarylation of unactuated alkenes and activated alkenes.By using this protocol,isoxazoline-tethered oxindoles were successfully obtained by a one-pot reaction of ?,?-unsaturated ketoximes with N-Arylacrylamides as the substrates and t-BuOOH as the sole oxidants under mild and metal-free conditions.In the fourth chapter we report a novel and efficient iminoxyl radical-promoted oxyalkenylation of unactivated alkenes for the systheisis of vinyl substituted isoxazolines using?,?-unsaturated ketoximes and vinyl acid as the starting materials and Cu(OAc)2/DTBP as an oxidation system.In the fifth chapter,we presented a novel and efficient method for the generation in situ of azoalkenes from ketohydrazones mediated by TEMPO(2,2,6,6-tetramethylpiperidine-1-oxyl radical),and its application to the synthesis of tetrahydropyridazine derivatives via aza-Diels-Alder reaction with alkenes.