Study On The Synthesis Of 2-Oxindoles By Free Radical Addition/Cyclization Process

Oxindoles are one of the most important nitrogen-containing heterocyclic compounds,which are widely existed in natural alkaloids and bioactive drug molecules.In recent years,the addition/cyclization reaction of N-arylacrylamides with C-,N-,P-,and S-based radicals have been developed,which provide a range of important approaches toward oxindoles.In this dissertation,the addition/cyclization reaction of N-aryl acrylamides with multi-chloride methyl radical and methyl radical are studied.A metal-free radical addition/cyclization reaction of N-aryl acrylamides with CHCl₃or CH₂Cl₂as radical source in the presence of K₃PO₄?3H₂O as base,benzoyl peroxide(BPO)as oxidant is developed,which affords 14 examples of trichloromethylated 2-oxindoles and 6 examples of dichloromethylated 2-oxindoles in30%-83%yields,including 6 new compounds.A Fe-catalyzed methyl radical addition/cyclization reaction of N-aryl acrylamides with DMSO as methyl radical source in the presence of H₂O₂as oxidant is developed,which affords 19 examples of 3-ethyl-oxindoles and 2 examples of isoquinoline-dione in 25%-83%yields,including 6 new compouds.It is propitious to the reaction with the low concentration and continuous addition of hydrogen peroxide.