1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in re...1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.展开更多
1,3-Dibromo-5,5-dimethylhydantoin（DBDMH） was found to be a new and efficient nitrogen/halogen source for the aminobromination of ethyl a-cyanocinnamate derivatives catalyzed by K3PO4. The reaction afforded the amino...1,3-Dibromo-5,5-dimethylhydantoin（DBDMH） was found to be a new and efficient nitrogen/halogen source for the aminobromination of ethyl a-cyanocinnamate derivatives catalyzed by K3PO4. The reaction afforded the aminobrominated products in high yields at room temperature, and the full regiospecificity of all the products were achieved. A possible pathway involving a Michael addition for this aminobromination was suggested.展开更多
The reaction of β,β-dicyanostyrene derivatives（l） with 1,3-dibromo-5,5-dimethylhydantoin（DBDMH） was systematicly studied. The reaction could generate different products when promoted by different mild bases. Whe...The reaction of β,β-dicyanostyrene derivatives（l） with 1,3-dibromo-5,5-dimethylhydantoin（DBDMH） was systematicly studied. The reaction could generate different products when promoted by different mild bases. When the reaction was promoted by NaOAc（100%, molar ratio to compound 1）, β,β-dicyanostyrene derivatives could be directly converted into corresponding α,β-dehydroamino derivatives in good to excellent yields in one-pot. When the reaction was promoted by K3PO4（80%, molar ratio to compound 1）, the corresponding α,β-dehydroamino and double-α,β-dehydroamino compounds were simultaneously obtained and the total conversion of β,β-dicyanostyrene derivatives was up to 90% or higher.展开更多
基金the University of Guilan Research Council for the partial support
文摘1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.
基金Supported by the Natural Science Foundation of Shaanxi Province, China（No.2009JM2001）, the Innovation FoundatiOn of Pastgraduate Cultivation of Shaanxi Normal University, China（No.2008CXB009） and the Fundamental Research Funds for the Central Universities of China（No.GK261001095）.
文摘1,3-Dibromo-5,5-dimethylhydantoin（DBDMH） was found to be a new and efficient nitrogen/halogen source for the aminobromination of ethyl a-cyanocinnamate derivatives catalyzed by K3PO4. The reaction afforded the aminobrominated products in high yields at room temperature, and the full regiospecificity of all the products were achieved. A possible pathway involving a Michael addition for this aminobromination was suggested.
基金Supported by the Natural Science Foundation of Shaanxi Province, China（No.2009JM2001）, the Innovation Foundation of Postgraduate Cultivation of Shaanxi Normal University, China（No.2008CXB009） and the Fundamental Research Funds for the Central Universities of China（No.GK261001095）.
文摘The reaction of β,β-dicyanostyrene derivatives（l） with 1,3-dibromo-5,5-dimethylhydantoin（DBDMH） was systematicly studied. The reaction could generate different products when promoted by different mild bases. When the reaction was promoted by NaOAc（100%, molar ratio to compound 1）, β,β-dicyanostyrene derivatives could be directly converted into corresponding α,β-dehydroamino derivatives in good to excellent yields in one-pot. When the reaction was promoted by K3PO4（80%, molar ratio to compound 1）, the corresponding α,β-dehydroamino and double-α,β-dehydroamino compounds were simultaneously obtained and the total conversion of β,β-dicyanostyrene derivatives was up to 90% or higher.
