New chiral gamino alcohols 1-4 were synthesized and applied in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol with up to 94.0% enantiomeric excess.
Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator t...Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator to monomer ratio. Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TGA), and scanning electron microscopy (SEC) techniques were used to characterize the structure, thermal stability, and surface morphology of the obtained product, respectively. Grafting of MMA onto silk increased the thermal stability of silk. The FTIR spectrum and SEM images provided further evidence that MMA has been successfully grafted onto the silk fiber. A peak ascribed to the C=O stretching vibration of MMA was detected in the FTIR spectrum of grafted silk fiber, which was not present in the spectrum of pure silk fiber. Moreover, the SEM images illustrated the increase in diameter and surface roughness of grafted silk compared with pure silk. Lastly, the dyeing performance of the modified silk was significantly increased.展开更多
Three chiral N-ferrocenylmethylaminoalcohols were synthesized from readily available natural L-valine, leucine and phenylanine, and used as chiral ligands in the enantioselective addition of diethylzinc to aldehydes.
A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been investigated.Using 10 mol%of this chiral catalyst,secondary alcohols can be obtained in u...A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been investigated.Using 10 mol%of this chiral catalyst,secondary alcohols can be obtained in up to 87%yield and 99.5%ee under mild conditions.展开更多
Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived G-amino alcohols were synthesized from commercially available LDOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and s...Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived G-amino alcohols were synthesized from commercially available LDOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and showed different catalytic activities （up to 86% ee）. The solvent played an important role in the enantioselective process. The transition state models were proposed to explain the reversion of the product configuration.展开更多
Readily available 2-methylquinoline derived chiral ligands 1 and 2 have been applied in the enantioselective addition of diethylzinc to aldehydes with up to 91.4% ee being recorded.
Optically active trans-(1S,2S)-1-substituted-2-(N,N-dialkylamino)-1-indanol derivatives have been prepared and used in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol in good yield with up to 9...Optically active trans-(1S,2S)-1-substituted-2-(N,N-dialkylamino)-1-indanol derivatives have been prepared and used in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol in good yield with up to 93.1% enantiomeric excess.展开更多
Four 1, 2,3,4-tetrahydro - β - c arboline amino acid esters with a heterocycle at the C- 1position were used as chiral ligands in the enantioselective addition reactions. The differentpositions of the heteroatoms gav...Four 1, 2,3,4-tetrahydro - β - c arboline amino acid esters with a heterocycle at the C- 1position were used as chiral ligands in the enantioselective addition reactions. The differentpositions of the heteroatoms gave different effects, and medium but opposite enantioselectivitywas recorded.展开更多
The optical active alkyne-bridged Mo-Co heterometal complexes are synthesized by the chiral phase transfer catalyst (N-benzylcinchorin chloride) induced metal exchange reaction. The complex is used as catalyst to prom...The optical active alkyne-bridged Mo-Co heterometal complexes are synthesized by the chiral phase transfer catalyst (N-benzylcinchorin chloride) induced metal exchange reaction. The complex is used as catalyst to promote the asymmetric addition of diethylzinc to benzaldehyde. The ee value of the product alcohol is 5.7%, which illustrates the asymmetric induction of the tetrahedral framework chirality in asymmetric catalysis reaction for the first time.展开更多
A series of novel N,O-type chiral ligands derived from enantiopure inherently chiral calix[4]arenes containing quinolin-2-yl-methanol moiety in the cone or partialcone conformation have been synthe-sized and character...A series of novel N,O-type chiral ligands derived from enantiopure inherently chiral calix[4]arenes containing quinolin-2-yl-methanol moiety in the cone or partialcone conformation have been synthe-sized and characterized. Moreover,they have been applied to the catalytic asymmetric addition of diethylzinc to benzaldehyde,which represents the first example that the inherently chiral calixarene can be used as the chiral ligands for the catalytic asymmetric synthesis.展开更多
A series of new optically active [2-（1-hydroxyalkyl）pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermedia...A series of new optically active [2-（1-hydroxyalkyl）pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermediate was obtained. They were then applied to catalyze enantioselective addition of diethylzinc to arylaldehydes with enantioselectivity up to 99%. The effects of the ligand structures on the enantioselectivity were also studied.展开更多
A series of C_2-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial L-phenylalanine.All of the new compounds have been fully characterized by IR,~1H NMR,^（13）C NMR,MS spectra and el...A series of C_2-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial L-phenylalanine.All of the new compounds have been fully characterized by IR,~1H NMR,^（13）C NMR,MS spectra and elemental analyses.The chiral thioureas were used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc,the corresponding sec-alcohols were gained with excellent enantioselectivities（up to 87.1%ee） and high yields（up to 76.7%） after the conditions were optimized.展开更多
Several novel chiral sulfonamide ligands based on （1R,2S,4R,5S）-1,4-diamino-2,5-dimethylcyclohexane skele- ton have been synthesized and their application in the enantioselective addition of diethylzinc to aldehydes...Several novel chiral sulfonamide ligands based on （1R,2S,4R,5S）-1,4-diamino-2,5-dimethylcyclohexane skele- ton have been synthesized and their application in the enantioselective addition of diethylzinc to aldehydes was in- vestigated in the presence of Ti（Oipr）4. The effect of ligands, temperature and the loading amount of ligands was studied. Under optimized conditions, enantioselective addition of diethylzinc with various aryl aldehydes and aliphatic aldehydes proceeded smoothly and afforded chiral secondary alcohols in up to 88% ee.展开更多
Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl](L*)was obtained by taking off the protecting groups of poly[(S)-3-vinyl-2,2'-bis(methoxymethoxy)-1,1'-binaphthyl](poly-1).L*was proved to keep a stable ...Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl](L*)was obtained by taking off the protecting groups of poly[(S)-3-vinyl-2,2'-bis(methoxymethoxy)-1,1'-binaphthyl](poly-1).L*was proved to keep a stable helical con-formation in solution.The application of helical L*in the asymmetric addition of diethylzinc to aldehydes has been studied.The catalytic system employing 10 mol%of L*and 150 mol%of Ti(OiPr)_(4) was found to promote the addi-tion of diethylzinc to a wide range of aromatic aldehydes,giving up to 99%enantiomeric excess(ee)and up to 93%yield of the corresponding secondary alcohol at 0℃.The chiral polymer can be easily recovered and reused with-out loss of catalytic activity as well as enantioselectivity.展开更多
Three 2-{(3R,7aS)-1,1-disubstituted-tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-3-yl}phenols have been synthesized from salicylaldehyde and amino alcohols derived from L-proline,and used as ligands hi enantioselective add...Three 2-{(3R,7aS)-1,1-disubstituted-tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-3-yl}phenols have been synthesized from salicylaldehyde and amino alcohols derived from L-proline,and used as ligands hi enantioselective addition of diethylzinc to aldehydes,the ee values of obtained secondary alcohols were found in the range of 0-90%.展开更多
Easily available chiral ketones were employed for the synthesis of optically active pyridyl alcohols, which were applied in the asymmetric diethylzinc addition to aldehydes, up to 89.4% e.e. was obtained using D-fruct...Easily available chiral ketones were employed for the synthesis of optically active pyridyl alcohols, which were applied in the asymmetric diethylzinc addition to aldehydes, up to 89.4% e.e. was obtained using D-fructose-derived pyridyl alcohol.展开更多
Chiral ligand (R)-N, N'-Bis(2-hydroxy-3,5-di- tert-butyl-aryl-methyl)-1, 1'-binaphthalene-2,2'-diamine derived from the reduction of Schiff base (R)-2,2'-bis (3,5-di-tert-butyl-2-hy-droxybenzylideneami...Chiral ligand (R)-N, N'-Bis(2-hydroxy-3,5-di- tert-butyl-aryl-methyl)-1, 1'-binaphthalene-2,2'-diamine derived from the reduction of Schiff base (R)-2,2'-bis (3,5-di-tert-butyl-2-hy-droxybenzylideneamino)-1, 1'-binaphthyl with LiAIH(4) is fairly effective in the asymmetric addition reaction of diethylzinc to aldehydes by which good yields (46%-94%) of the corresponding sec-alcohols can be obtained in moderate ee (51%-79%) with R configuration for a variety of aldehydes.展开更多
基金Hong Kong Polytechnic University for the financial support.
文摘New chiral gamino alcohols 1-4 were synthesized and applied in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol with up to 94.0% enantiomeric excess.
文摘Methyl methacrylate (MMA) was grafted onto silk fiber in a one-step emulsion system using a diethylzinc and 1,10-phenanthroline complex. The reaction conditions were investigated by varying temperature and initiator to monomer ratio. Fourier transform infrared (FTIR) spectrum, thermogravimetric analysis (TGA), and scanning electron microscopy (SEC) techniques were used to characterize the structure, thermal stability, and surface morphology of the obtained product, respectively. Grafting of MMA onto silk increased the thermal stability of silk. The FTIR spectrum and SEM images provided further evidence that MMA has been successfully grafted onto the silk fiber. A peak ascribed to the C=O stretching vibration of MMA was detected in the FTIR spectrum of grafted silk fiber, which was not present in the spectrum of pure silk fiber. Moreover, the SEM images illustrated the increase in diameter and surface roughness of grafted silk compared with pure silk. Lastly, the dyeing performance of the modified silk was significantly increased.
文摘Three chiral N-ferrocenylmethylaminoalcohols were synthesized from readily available natural L-valine, leucine and phenylanine, and used as chiral ligands in the enantioselective addition of diethylzinc to aldehydes.
文摘A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been investigated.Using 10 mol%of this chiral catalyst,secondary alcohols can be obtained in up to 87%yield and 99.5%ee under mild conditions.
文摘Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived G-amino alcohols were synthesized from commercially available LDOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and showed different catalytic activities （up to 86% ee）. The solvent played an important role in the enantioselective process. The transition state models were proposed to explain the reversion of the product configuration.
文摘Readily available 2-methylquinoline derived chiral ligands 1 and 2 have been applied in the enantioselective addition of diethylzinc to aldehydes with up to 91.4% ee being recorded.
文摘Optically active trans-(1S,2S)-1-substituted-2-(N,N-dialkylamino)-1-indanol derivatives have been prepared and used in the asymmetric addition of diethylzinc to aldehydes to give sec-alcohol in good yield with up to 93.1% enantiomeric excess.
文摘Four 1, 2,3,4-tetrahydro - β - c arboline amino acid esters with a heterocycle at the C- 1position were used as chiral ligands in the enantioselective addition reactions. The differentpositions of the heteroatoms gave different effects, and medium but opposite enantioselectivitywas recorded.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 29871061).
文摘The optical active alkyne-bridged Mo-Co heterometal complexes are synthesized by the chiral phase transfer catalyst (N-benzylcinchorin chloride) induced metal exchange reaction. The complex is used as catalyst to promote the asymmetric addition of diethylzinc to benzaldehyde. The ee value of the product alcohol is 5.7%, which illustrates the asymmetric induction of the tetrahedral framework chirality in asymmetric catalysis reaction for the first time.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20625206 & 20372064)the National Basic Research Project (Grant Nos. 2007CB808000 & 2008CB617501), and the Chinese Academy of Sciences
文摘A series of novel N,O-type chiral ligands derived from enantiopure inherently chiral calix[4]arenes containing quinolin-2-yl-methanol moiety in the cone or partialcone conformation have been synthe-sized and characterized. Moreover,they have been applied to the catalytic asymmetric addition of diethylzinc to benzaldehyde,which represents the first example that the inherently chiral calixarene can be used as the chiral ligands for the catalytic asymmetric synthesis.
基金Project supported by the National Natural Science Foundation of China （No. 20172047） and the Education Commission of Henan Province.
文摘A series of new optically active [2-（1-hydroxyalkyl）pyrrolidino]methylferrocenes were conveniently prepared from commercially available L-proline and ferrocenecarboxylic acid. The crystal structure of key intermediate was obtained. They were then applied to catalyze enantioselective addition of diethylzinc to arylaldehydes with enantioselectivity up to 99%. The effects of the ligand structures on the enantioselectivity were also studied.
基金Open-Ended Fund of the State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology
文摘A series of C_2-symmetric and asymmetric chiral thiourea derivatives were synthesized from commercial L-phenylalanine.All of the new compounds have been fully characterized by IR,~1H NMR,^（13）C NMR,MS spectra and elemental analyses.The chiral thioureas were used as chiral ligands in the catalytic enantioselective ethylation of aldehydes with diethylzinc,the corresponding sec-alcohols were gained with excellent enantioselectivities（up to 87.1%ee） and high yields（up to 76.7%） after the conditions were optimized.
基金Project supported by ttae National Natural Science Foundation of China （No. 20672053）, the Science Foundation of Zhejiang Province （No. Y407081） and the National Basic Research Program of China （No. 2007CB925103）.
文摘Several novel chiral sulfonamide ligands based on （1R,2S,4R,5S）-1,4-diamino-2,5-dimethylcyclohexane skele- ton have been synthesized and their application in the enantioselective addition of diethylzinc to aldehydes was in- vestigated in the presence of Ti（Oipr）4. The effect of ligands, temperature and the loading amount of ligands was studied. Under optimized conditions, enantioselective addition of diethylzinc with various aryl aldehydes and aliphatic aldehydes proceeded smoothly and afforded chiral secondary alcohols in up to 88% ee.
基金National Natural Science Foundation of China(No.21172186)Doctor Student Research Foundation of Chinese Education Ministry(No.20134301110004)for financial support of this work.
文摘Poly[(S)-3-vinyl-2,2'-dihydroxy-1,1'-binaphthyl](L*)was obtained by taking off the protecting groups of poly[(S)-3-vinyl-2,2'-bis(methoxymethoxy)-1,1'-binaphthyl](poly-1).L*was proved to keep a stable helical con-formation in solution.The application of helical L*in the asymmetric addition of diethylzinc to aldehydes has been studied.The catalytic system employing 10 mol%of L*and 150 mol%of Ti(OiPr)_(4) was found to promote the addi-tion of diethylzinc to a wide range of aromatic aldehydes,giving up to 99%enantiomeric excess(ee)and up to 93%yield of the corresponding secondary alcohol at 0℃.The chiral polymer can be easily recovered and reused with-out loss of catalytic activity as well as enantioselectivity.
基金Project supported by the Key Laboratory of Organic Syntheses,Jiangsu Province(No.T2109102).
文摘Three 2-{(3R,7aS)-1,1-disubstituted-tetrahydro-1H-pyrrolo[1,2-c][1,3]oxazol-3-yl}phenols have been synthesized from salicylaldehyde and amino alcohols derived from L-proline,and used as ligands hi enantioselective addition of diethylzinc to aldehydes,the ee values of obtained secondary alcohols were found in the range of 0-90%.
基金Project (Nos. 29790127 and 29872045) supported by the National Natural Science Foundation of China.
文摘Easily available chiral ketones were employed for the synthesis of optically active pyridyl alcohols, which were applied in the asymmetric diethylzinc addition to aldehydes, up to 89.4% e.e. was obtained using D-fructose-derived pyridyl alcohol.
基金theMajorStateBasicResearchDevelopmentProgram (No .G2 0 0 0 0 480 0 7)andtheNationalNaturalScienceFoundationofChina (No .2 0 0 2 5 2 0 6 )
文摘Chiral ligand (R)-N, N'-Bis(2-hydroxy-3,5-di- tert-butyl-aryl-methyl)-1, 1'-binaphthalene-2,2'-diamine derived from the reduction of Schiff base (R)-2,2'-bis (3,5-di-tert-butyl-2-hy-droxybenzylideneamino)-1, 1'-binaphthyl with LiAIH(4) is fairly effective in the asymmetric addition reaction of diethylzinc to aldehydes by which good yields (46%-94%) of the corresponding sec-alcohols can be obtained in moderate ee (51%-79%) with R configuration for a variety of aldehydes.
