Two Wang resin-supported （1R,2R）-（＋）-1,2-DPEN（DPEN=diphenylethylenediamine） catalysts were synthesized from cyanuric chloride and trimesoyl chloride, respectively. These two catalysts were characterized by FTIR...Two Wang resin-supported （1R,2R）-（＋）-1,2-DPEN（DPEN=diphenylethylenediamine） catalysts were synthesized from cyanuric chloride and trimesoyl chloride, respectively. These two catalysts were characterized by FTIR, TGA and elemental analysis. The results demonstrated that （1R,2R）-（＋）-1,2-DPEN was successfully bonded to the surface of Wang resin through the amido linkage. Subsequently, the asymmetric Michael addition of acetone to β-nitrostyrene was employed to evaluate their catalytic performance. It was found that the catalyst generated from trilnesoyl chloride exhibited much better catalytic behavior than our previously reported catalyst, likely attributed to the multiple hydrogen-bond interaction between β-nitrostyrene and amide group, which made the catalytic transition intermediates more stable. Under the optimal conditions, 76.1% β-nitrostyrene conversion and 93.8% enantioselectivity were obtained. Finally, the generality of this catalyst was examined with Michael additions of acetone to β-nitroolefms and excellent enantioselectivities（91.9% to 99.9%） were achieved.展开更多
A simple and efficient asymmetric synthesis of the sex pheromone of the southern corn rootworm is discribed. The key step is the asymmetric Michael addition of enoylsultam with virtually complete asymmetric induction(...A simple and efficient asymmetric synthesis of the sex pheromone of the southern corn rootworm is discribed. The key step is the asymmetric Michael addition of enoylsultam with virtually complete asymmetric induction( e.e. %>99%)展开更多
With solid phase organic synthesis method(SPOS), polymer-bound N-enoylprolinol(4) was prepared by the attachment of N-enoylprolinol(3) to Merrifield resin and was used for asymmetric Michael additions for the first ti...With solid phase organic synthesis method(SPOS), polymer-bound N-enoylprolinol(4) was prepared by the attachment of N-enoylprolinol(3) to Merrifield resin and was used for asymmetric Michael additions for the first time. The enantiomeric excess obtained by this method is increased as compared with that obtained by the corresponding solution phase reactions.展开更多
Asymmetric conjugated addition of allylcopper reagents derived from an allyl Grignard reagent and CuBr·Me_2S to chiralα,β-unsaturated N-acyl oxazolidinones has been achieved.The synthetic procedure was applied ...Asymmetric conjugated addition of allylcopper reagents derived from an allyl Grignard reagent and CuBr·Me_2S to chiralα,β-unsaturated N-acyl oxazolidinones has been achieved.The synthetic procedure was applied to the preparation of the key intermediate of the novel nonbenzodiazepine hypnotic drug,ramelteon.展开更多
gHighly optically active 4-substituted-2(5H)-furanones 6a—6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(5H)-furanone (4a), which was conveniently...gHighly optically active 4-substituted-2(5H)-furanones 6a—6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(5H)-furanone (4a), which was conveniently prepared starting from 2-furaldehyde under mild conditions. The products were identified on the basis of their sat-isfactory elemental analysis and spectroscopic data of IR, UV, 1H NMR, 13C NMR and mass spectra. The stereo-chemistry and absolute configuration of this type of compounds were established by the X-ray crystallographic study. The reaction provided a short and efficient synthesis of the interesting highly optically active 4-substituted-2(5H)-furanones containing an active pyrimidine and a purine base group.展开更多
基金Supportted by the National Natural Science Foundation of China（No.21476163）.
文摘Two Wang resin-supported （1R,2R）-（＋）-1,2-DPEN（DPEN=diphenylethylenediamine） catalysts were synthesized from cyanuric chloride and trimesoyl chloride, respectively. These two catalysts were characterized by FTIR, TGA and elemental analysis. The results demonstrated that （1R,2R）-（＋）-1,2-DPEN was successfully bonded to the surface of Wang resin through the amido linkage. Subsequently, the asymmetric Michael addition of acetone to β-nitrostyrene was employed to evaluate their catalytic performance. It was found that the catalyst generated from trilnesoyl chloride exhibited much better catalytic behavior than our previously reported catalyst, likely attributed to the multiple hydrogen-bond interaction between β-nitrostyrene and amide group, which made the catalytic transition intermediates more stable. Under the optimal conditions, 76.1% β-nitrostyrene conversion and 93.8% enantioselectivity were obtained. Finally, the generality of this catalyst was examined with Michael additions of acetone to β-nitroolefms and excellent enantioselectivities（91.9% to 99.9%） were achieved.
文摘A simple and efficient asymmetric synthesis of the sex pheromone of the southern corn rootworm is discribed. The key step is the asymmetric Michael addition of enoylsultam with virtually complete asymmetric induction( e.e. %>99%)
基金Supported by the National Natural Science Foundation of China(No.2 9872 0 12 )
文摘With solid phase organic synthesis method(SPOS), polymer-bound N-enoylprolinol(4) was prepared by the attachment of N-enoylprolinol(3) to Merrifield resin and was used for asymmetric Michael additions for the first time. The enantiomeric excess obtained by this method is increased as compared with that obtained by the corresponding solution phase reactions.
基金the Shanghai Municipal Natural Science Foundation(No10ZR1409600)
文摘Asymmetric conjugated addition of allylcopper reagents derived from an allyl Grignard reagent and CuBr·Me_2S to chiralα,β-unsaturated N-acyl oxazolidinones has been achieved.The synthetic procedure was applied to the preparation of the key intermediate of the novel nonbenzodiazepine hypnotic drug,ramelteon.
基金Project supported by the National Natural Science Foundation of China (No. 29672004).
文摘gHighly optically active 4-substituted-2(5H)-furanones 6a—6j were obtained in good yields with de≥98% by the tandem Michael addition/elimination reaction of chiral 3-bromo-2(5H)-furanone (4a), which was conveniently prepared starting from 2-furaldehyde under mild conditions. The products were identified on the basis of their sat-isfactory elemental analysis and spectroscopic data of IR, UV, 1H NMR, 13C NMR and mass spectra. The stereo-chemistry and absolute configuration of this type of compounds were established by the X-ray crystallographic study. The reaction provided a short and efficient synthesis of the interesting highly optically active 4-substituted-2(5H)-furanones containing an active pyrimidine and a purine base group.
