Study On Visible Light-Driven Radical Addition Reactions Of Alkenes

Radical addition reactions constitute a general method for the carbon-carbon bond and carbon-hetero atom bond construction.The recent application of visible light photocatalysis has greatly expanded the scope of radical addition of alkenes in organic synthesis.This thesis explores the copper-catalyzed atom transfer radical cyclization of unsaturated halides and the anti-Markovnikov hydroazidation of alkenes under the condition of visible light irradiation.It comprises the following three chapters:The first chapter describes the advances of atom transfer radical addition（ATRA）reactions of alkenes.This type of reactions has great value for the synthesis of small organic molecules as well as macromolecules.As in most cases copper catalysis is used for this purpose,this chapter mainly reviews the progress made on copper-catalyzed ATRA reactions.The reactions under other conditions are also briefly introduced.The second and third chapters describe the author’s research work during the period of the graduate study.It is summarized as follows:The copper-catalyzed atom transfer radical cyclization reaction of unsaturated organic bromides and iodides were investigated under visible light irradiation.A variety of copper（I）complexes were examined for their effectiveness as catalyst.The complexes tested include:a)1,10-phenanthroline monohydrate/bisphosphine complexes;b)bipyridine/bisphosphine complexes;c)carbene/bipyridine complexes;d)bisphosphine complexes.It was found that the 1,10-phenanthroline monohydrate/bisphosphine copper complexes can effectively promote the investigated reactions,whereas other types of catalysts are much less effective under the current ccircumstance.A new protocol for visible light-induced anti-Markovnikov hydroazidation of alkenes was developed by using organic dye Eosin Y as photocatalyst and TMSN₃as the azide source.The reaction has a wide scope;a variety of differently substituted alkenes can be azidated by using this protocol.