Studies On Iminoxyl Radical-Involved Cascade Reactions

Radical cascade reactions are efficient strategy in organic reactions.Thus,they are widely studied and applied by chemists.In these reactions,carbon-centered radical was studied in many times.On the contrary,heteroatom-centered radical was researched rarely.Iminoxyl radical is one of the important heteroatom-centered radical.And chemists have already synthesized many compounds by iminoxyl radical.However,iminoxyl radical-promoted cascade reactions with internal olefins or vinyl azides have not been reported.This thesis is devoted to iminoxyl radicals-promoted cascade reactions.It consists of three parts.The first part introduces the structures and properties of iminoxyl radicals.Moreover,the application of iminoxyl radicals in organic synthesis was also introduced in this part.The second part describes iminoxyl radical-promoted tandem reactions: efficient synthesis of isoxazoline-functionalized ketene dithioacetals from unsaturated oximes and internal olefins.In this reaction,internal olefins,that is,?-oxoketene dithioacetals,and unsaturated oximes were used as the substrates and TBPB as the commercial available oxidant,along with tandem intramolecular/intermolecular C(sp3)-O/C(sp3)-C(sp2)bond formation.The third part describes iminoxyl radical-participated cascade reactions: oxyalkylation/nitroalkylaton of alkenes of unsaturated oximes with vinyl azides.These reactions were carried out by employing Mn(OAc)3·2H2O as oxidant and MeCN as solvent,30 oC as reactions tempreture under an argon atmosphere for 4 hours.These reactions synthesized isoxazoline-functionalized compounds and cyclic nitrone--functionalized compounds.These substrates are readily accessible in these reactions.This protocol is characterized by a broad substrate scope,mild conditions,handy procedure and excellent yields.