Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characte...Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characterized by using 1H NMR,13C NMR,MS,and X-ray single crystal diffraction techniques.The results indicate that only axially chiral enantiomers were observed in the single crystal structures of products 1 and 3 synthesized from achiral amino alcohols;Using racemic amino alcohol((±)-2-aminopropanol)as the raw material,only axial chiral isomers were observed in the single crystal structure of product 2,and no racemic isomer was found.The crystal structure of product 4 based on chiral amino alcohol((S)-valinol)contains non axial chiral isomers and S-type isomers.However,the other two optically pure amino alcohols((S)-phenylpropanol,(R)-phenylpropanol)can only obtain optically pure axially chiral and chiral products 5 and 6,respectively,maintaining the configuration of the raw amino alcohol and no non axial chiral isomer is observed.The product using(±)-2-aminobutanol as the raw material cannot be determined for its absolute configuration as a single crystal of the product has not been obtained.展开更多
基金supported by Guizhou Province College Students Innovation Project(S202310666114)the Student Program of Minzu Normal University of Xingyi(23XYXS28)Guizhou Province Qianxinan Prefecture Science and Technology Bureau project(2022-1-24).
文摘Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characterized by using 1H NMR,13C NMR,MS,and X-ray single crystal diffraction techniques.The results indicate that only axially chiral enantiomers were observed in the single crystal structures of products 1 and 3 synthesized from achiral amino alcohols;Using racemic amino alcohol((±)-2-aminopropanol)as the raw material,only axial chiral isomers were observed in the single crystal structure of product 2,and no racemic isomer was found.The crystal structure of product 4 based on chiral amino alcohol((S)-valinol)contains non axial chiral isomers and S-type isomers.However,the other two optically pure amino alcohols((S)-phenylpropanol,(R)-phenylpropanol)can only obtain optically pure axially chiral and chiral products 5 and 6,respectively,maintaining the configuration of the raw amino alcohol and no non axial chiral isomer is observed.The product using(±)-2-aminobutanol as the raw material cannot be determined for its absolute configuration as a single crystal of the product has not been obtained.
