Base Promoted New Radical Reactions

Our research group devotes to exploring new reactions via the transition-metal-free self-hydride transferring strategy.In previous work,we have developed functionalization of alcohols,which can highly efficient deirct amination and olefination with alcohols in the prescence of base.In the mechanism study we found that some new reactions are free radical process.Base on those studies,the synthesis methodology and reaction mechanism based on base-promoted new reactions have been intensively studied.The main contents are listed below:(1)The methodology of highly efficient phenanthroline-tert-butoxide-catalyzed transition-metal-free allylic isomerization of alcohols and amines has been developed.In this process,only catalytic amount of phenanthroline-tBuONa is empolyed.On the basis of systematic experimental study including kinetic study,EPR,deuterium-labelling experiments as well as control experiments,a plausible reaction mechanism involving a radical pathway has been proposed.Furthermore,we developed a highly efficient direct Wittig olefination of allylic alcohols.(2)The selective hydrogenation and boronation of aryl halides are developed.Dehalogenation of aryl halides using benzyl aldehydes as hydrogen sources and borylation of aryl halides promoted by 1,10-phenanthroline have been developed.A radical pathway via benzoyl radical has been established based on the experimental evidence including kinetic study,KIE,trapping reactions,and control reactions.As know,for the first time,aldehydes are used as hydrogen source.(3)The addition of carbon radicals to substituted carbonyls including aldehydes and ketones via a cascade radical addition/cyclization reaction have been developed,it can highly efficient synthesis benzofuran.Based on studying of mechanism,we developed the highly efficient method for synthesis of indole by radical addition to imine.