Study On Hydrazonyl Radical And Iminoxyl Radical Participated Functionalization Of Olefins

Free radical is a very important reaction intermediate.In recent decades,the radicals participated the electrophilic,nucleophilic and cyclization reactions have been widely used in organic synthesis.Especially,it shows unique simplicity and efficiency in synthesis of complex molecules.Hydrazone radicals and iminoxyl radicals as a new class of nitrogen,oxygen free radicals,the cyclization of heterocyclic compounds for the synthesis and application provides a new way of thinking and methods.This thesis is divided into four chapters according to the work of my PhD.The main contents are as follows:Chapter 1: This chapter is divided into two parts: A)The properties of some free radicals commonly used in this paper are described,such as free radical classification,generation,reaction type and cyclization rules and so on.B)The properties of hydrazone radicals and the recent progress in the heterocyclic compounds involved in hydrazone radicals were introduced.Chapter 2: Hydrazone Radicals Promoted Vicinal Difunctionalization of Alkenes and Trifunctionalization of Allyls: Synthesis of Pyrazolines and Tetrahydropyridazines.We found that phenylhydrazone free radical is a kind of typical ? radical by calculation.We use the easily prepared ?,?-unsaturated hydrazone and ?,?-unsaturated hydrazine for the synthesis of pyrazolines and tetrahydropyridazines through C-N forming 5-exo-trig and 6-exo-trig cyclization and tandem 1,5-H-shift/5-exo-trig cyclization.In the reactions,and consequently,oxyamination,diamination of nunactivated alkenes,and dioxyamination and triamination of allyls can be realized.Chapter 3: Transition From ? Radical to ? Radical: Substituent-Tuned Cyclization of Hydrazonyl Radicals.We have demonstrated for the first time that hydrazonyl radicals,which generally exhibit ?-electronic structures,can be tuned to s radicals by attaching a trifluoroacetyl or trichloroacetyl group to the N1 atom.In this way,both the N1 and the N2 atom become reactive radical centers.Under the indicated reaction conditions,?,?-and ?,?-unsaturated N-trifluoroacetyl and N-trichloroacetyl hydrazones readily underwent the corresponding C-N1 and C-N2 bondforming 5-exo-trig cyclization to afford structurally important pyrazolines and azomethine imines in high yields.Chapter 4: Hydrazonyl Radical-Participated Tandem Reaction: A Strategy for the Synthesis of Pyrazoline-Functionalized Oxindoles.In this reaction,a novel and efficient metal as well solvent-free protocol has been developed for the synthesis of structurally novel pyrazoline-functionalized oxindoles via tandem cyclization/addition/ cyclization sequence,via a tandem intra-/intermolecular C-N/C-C/C-C bond formation.Chapter 5: Cu(II)Catalyzed Iminoxyl Radicals Participated Azidamination and Diazidamination of Unactivated Olefins: Synthesis of Azide/Diazide substituted Cyclic Nitrone.A novel iminoxyl radicals participated azidamination and diazidamination of unactivated olefins to synthesize azide and diazide substituted cyclic nitrone catalyzed by Copper(II)has been developed.The stable Zhdankin reagent was used as an efficient azide radical source.The method can achieve regioselective difunctionalization and trifunctionalization of unactivated olefins in good to excellent yields,through a switch between base and no base controlling the degree of azidation.At the same time,a quaternary carboncenter was generated during applications of the methodology for the synthesis of diazide substituted cyclic nitrone.