Radical-mediated Difunctionalization Of Unactivated Olefins And Alkynes

In the field of organic chemistry,the research of unsaturated bond difunctionalization,in particularly,olefins and alkynes,emerges in endlessly.Difunctional reaction can build two or more C-C bond or C-X bond in one step.This strategy can shorten the reaction path significantly,and provide a convenient mean of the synthesis and modification of natural products,drug molecules.About the research of difunctionalization,in general,researchers use transition metal catalysis or photocatalysis.However,most reported difunctional reactions contrapose activated olefin and alkynes(such as aryl,carbonyl,or heteroatom-substituted olefin and alkynes)rather than inert.During the study of my Master degree,I focus on resolving these difficults by means of intramocular cyano migration.The dissertation is divided into the four sections.The first part summarizes the research works about functionalization of olefins and alkynes by metal catalysis or radical pathway.Besides,the basis and significance of my project is introduced in this part.The second part introduces the research work of Cyanotrifluoromethylthiolation of Unactivated Olefins through Intramolecular Cyano Migration.A broad range of vicinal CF3 Ssubstituted alkyl nitriles are gained in good yields under mild reaction conditions.This reaction possesses wide applicability,and various functional groups have strong compatibility.The third part introduces the research work of Cyanotrifluoromethylthiolation of unactivated dialkyl-substituted alkynes via cyano migration.Taken advantage of the strategy of intramolecular cyano migration,the reaction proceeds stereoselectively to deliver the E-olefinic products.A variety of tetrasubstituted trifluoromethylthiolated acrylonitriles are afforded in modest to good yields.The last part introduces the research work of synthesis of 1,8-dicarbonyl compounds through intramolecular cyano 1,4-migration strategy and the three-membered ring alcohol ring opening.Under the condition of photocatalysis and oxidant,the three-membered ring alcohol opens its ring,and then add to olefins,after five-membered ring transition state,then radical intermediate is oxidized and experiences deprotonation.Finally,the 1,8-diketone is obtained.This method can synthesize easily various kinds of complex 1,8-dicarbonyl compounds.