Iron And Cobalt Catalyzed 1,2-Acyl Migration Reaction Of ?-Azido Ketone

This thesis deals with base transition-metal-catalyzed 1,2-acyl migration of azido ketones and the rearrangement of azide amides.It consists of the following parts:The first chapter is a literature review on the organic azide-involved amination reactions,where recent progress on the transition metal-catalyzed C–H amination reactions and the rearrangement of organic azides is briefly introduced.The following two chapters describe my work for the master's degree,which are summarized as follows:?1?The iron-catalyzed 1,2-acyl migration reaction of?-azido ketones was investigated by using three different catalytic systems:a)iron phosphine complex?1,2-phenylenebis[diphenyl]phosphine iron complex??Fe?dpbz?Br₂?,b)FeBr₂/Et₃N,and c)1,1'-bis?diphenylphosphino?ferrocene?dppf?.Our result shows that Fe?dpbz?Br₂ and dppf are highly effective for the acyl migration of2-azido-2,3-dihydro-1H-inden-1-ones,but they did not work well when applied to?-azido-?-ketoesters.The catalytic system of FeBr₂/Et₃N,on the other hand,exhibited a broader catalytic scope.A variety of?-azido ketones and?-azido-?-ketoesters can be converted to the corresponding enamides in good yields under the catalysis of FeBr₂/Et₃N.Overall,these conditions are superior to those previously reported in terms of reaction temperature,catalyst amount,and substrate applicability.Besides iron catalysts,cobalt complexes were also tested preliminarily for their application to the reactions.The reactions provide a simple effective means for the preparation of enamides.?2?The possibility of reducing azides to aminyl radicals under the conditions of cobalt and copper catalysis were preliminarily explored.It was found that by using[Cu?bcp??Xantphos?]PF₆ as photocatalyst,2-azido-N,N-diphenylpropionamide can be converted to N-phenyl-2-?phenylamino?propanamide via reduction and phenyl migration in a yield of 27%.The phenyl migration is proposed to involve the participation of the aminyl radical intermediate.Although the yield was only moderate,this result demonstrates that aminyl radicals can be generated from azides via single eletron reduction.