Selective Reactions Of Seven-membered Cyclic Imines Dibenzo-1,4-oxazepines With Indoles And Diazoacetates Catalyzed By Acid

Dibenzo-1,4-oxazepines are a class of seven-membered heterocyclic compounds with two heteroatoms of N and O,which play an important role in organic synthetic chemistry and pharmaceutical science.In this paper,the nucleophilic addition reactions of Br?nsted acid catalyzed seven-membered cyclic imine dibenzo-1,4-oxazepine with indoles and diazoacetates have studied.High selectivities have been achieved to obtaine different structures of dibenzo-1,4-oxazepine compounds.1.Aza-Friedel-Crafts reaction of dibenzo-1,4-oxazepines with indoles catalyzed by acid.The aza-Friedel-Crafts reaction of seven-membered cyclic imine dibenzo-1,4-oxazepines and indoles was studied with Br?nsted acid as catalyst.After optimization of reaction conditions,trifluoroacetic acid was choosed as the best catalyst.The chemical selectivity of the reaction system can be effectively controlled by changing different solvents,and the yields of mono-indole addition products 3 were obtained in high yield with 31%-98% in THF,the yields of bis-indole addition products 4 were obtained in high to good yields with 36%-99% in DCM.Then we further reacted with the indole of the mono-substituted products with the different substituents to give the asymmetric indole derivatives 5 in high yield with 23%-99%.2.Reaction of dibenzo-1,4-oxazepines with diazoacetates catalyzed by chiral phosphoric acidThe specific chemical selectivity and high enantioselective reaction of diazoacetates with seven-membered cyclic imines were achieved by using chiral phosphoric acid as a catalyst.Chemical selectivity can be efficiently controlled by using the different ester moieties of diazoacetates.While ethyl diazoacetate was used as a substrate,the 1,2-addition to C=N bond was observed to afford ?-amino-?-diazoesters in high yield with 45%-95%(up to 89% ee).While phenyl diazoacetate was used as a substrate,the [1+2] cycloaddition was observed to afford aziridine compounds in high yield with 76%-92%(up to 89% ee).