（S）-（1-Benzylpyrrolidin-2-yl）diphenylmethanol and cinchonine were evaluated as promotors in the asymmetric additions of phenylacetylene to ketones, in order to prepare chiral propargylic alcohols. Good yields （up...（S）-（1-Benzylpyrrolidin-2-yl）diphenylmethanol and cinchonine were evaluated as promotors in the asymmetric additions of phenylacetylene to ketones, in order to prepare chiral propargylic alcohols. Good yields （up to 89%） and moderate enantioselectivities （up to 77.9% ee） were achieved. Addition of Ti（OPr-i）4 can significantly improve the enantioselectivity of the reaction.展开更多
A new kind of optically active polymer bearing chiral amino alcohol was prepared by means of graft. The resulting grafted polymer was obtained as follows. First, the carbonyl of optically active helical poly（menthyl ...A new kind of optically active polymer bearing chiral amino alcohol was prepared by means of graft. The resulting grafted polymer was obtained as follows. First, the carbonyl of optically active helical poly（menthyl vinyl ketone）（poly-MVK） was reduced to hydroxyl group with lithium aluminum hydride as a reductant to yield poly（1-menthyl-2-propen-1-ol）（poly-MPO）. Second, the hydroxyl group of poly-MPO reacted with epichlorohydrin to yield methyloxirane-loading poly-MPO[（poly-MPO）-MO]. Third, the（poly-MPO）-MO reacted with amine to pro- duce optically active polymer bearing chiral amino alcohol[（poly-MPO）-APO]. The （poly-MPO）-APO was applied to the asymmetric addition of phenylacetylene to aromatic ketone. Good enantioselectivities were achieved and the catalyst could be recovered and reused 5 times with unchanged enantioselectivity and slightly decreased activity.展开更多
Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among t...Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.展开更多
A new chiral cyclic β-amino alcohol (R)- 1 -(l '-amino-2'-naphthylethyl)-cyclopentanol2, which had notbeen reported previously, was prepared from (R) - 3 - (2 - naphthy1 )- alanine 3.
Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and t...Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.展开更多
Reduction of prochiral ferrocenyl ketones 2a-e in the presence of 10 mol% of chiral beta -amino alcohols 4a-b provides 1-ferrocenyl alcohols 1a-e in high yields (> 85%) with high optically purity (e.e. up to 96%).
Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the co...Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the conversion process. They are the reversible imine formation, the internal resonance assisted Hydrogen Bonding (RAHB) and the additional hydrogen bonds between the amino acids and the heterocylic moiety of the pendant groups. The conversion efficiency of all the receptors was found to be comparable with those of the receptors reported earlier.展开更多
A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino a...A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.展开更多
An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycycli...An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.展开更多
Vicinal amino alcohols are a class of important motifs in pharmaceuticals,natural products as well as wide application in asymmetric catalysis（Scheme 1（a））.It is no doubt that development of efficient methods to a...Vicinal amino alcohols are a class of important motifs in pharmaceuticals,natural products as well as wide application in asymmetric catalysis（Scheme 1（a））.It is no doubt that development of efficient methods to access them has been a prominent research topic in the past decades.展开更多
文摘（S）-（1-Benzylpyrrolidin-2-yl）diphenylmethanol and cinchonine were evaluated as promotors in the asymmetric additions of phenylacetylene to ketones, in order to prepare chiral propargylic alcohols. Good yields （up to 89%） and moderate enantioselectivities （up to 77.9% ee） were achieved. Addition of Ti（OPr-i）4 can significantly improve the enantioselectivity of the reaction.
基金Supported by the National Natural Science Foundation of China（No.21172186） and the Higher Education Doctoral Science Foundation of China（No.20134301110004）.
文摘A new kind of optically active polymer bearing chiral amino alcohol was prepared by means of graft. The resulting grafted polymer was obtained as follows. First, the carbonyl of optically active helical poly（menthyl vinyl ketone）（poly-MVK） was reduced to hydroxyl group with lithium aluminum hydride as a reductant to yield poly（1-menthyl-2-propen-1-ol）（poly-MPO）. Second, the hydroxyl group of poly-MPO reacted with epichlorohydrin to yield methyloxirane-loading poly-MPO[（poly-MPO）-MO]. Third, the（poly-MPO）-MO reacted with amine to pro- duce optically active polymer bearing chiral amino alcohol[（poly-MPO）-APO]. The （poly-MPO）-APO was applied to the asymmetric addition of phenylacetylene to aromatic ketone. Good enantioselectivities were achieved and the catalyst could be recovered and reused 5 times with unchanged enantioselectivity and slightly decreased activity.
基金This work was funded by the National Natural Science Foundation of China (No. 20301009)
文摘Chiral amino acids and their corresponding amino alcohols bearing camphoric backbone were prepared from D-（＋）-camphoric imide and characterized by infrared, elemental analysis, ESI-MS, and NMR measurements. Among them, one intermediate （1S,3R）-3-amino-2,2,3- trimethyl cyclopentane-1-carboxylic acid hydrochloride 3 was structurally elucidated by X-ray diffraction techniques. Versatile intermolecular hydrogen bonding interactions observed in its packing structure result in a two-dimensional framework.
文摘Enantiomers of four amino alcohols were resolved by ion-pair chromatography with (+)-10-camphorsulphonic acid as chiral counter ion. Studies of the influence of the mobile phase composition, the solute structure and the mobile phase flow-rate on separation are presented. Under the optimized conditions enantiomeric propanolol, norephedrine, metropolol and salbutamol were separated using dichloromethane-1-pentanol (97:3 v/v) as mobile phase on Lichrospher-100-DIOL column.
文摘Reduction of prochiral ferrocenyl ketones 2a-e in the presence of 10 mol% of chiral beta -amino alcohols 4a-b provides 1-ferrocenyl alcohols 1a-e in high yields (> 85%) with high optically purity (e.e. up to 96%).
文摘Four binol based pyrrole carboxamide chiral receptors has been synthesized and effectively used as a Chirality Conversion Reagent (CCR) for underivatized amino acids. Three points of interactions take place for the conversion process. They are the reversible imine formation, the internal resonance assisted Hydrogen Bonding (RAHB) and the additional hydrogen bonds between the amino acids and the heterocylic moiety of the pendant groups. The conversion efficiency of all the receptors was found to be comparable with those of the receptors reported earlier.
基金the National Natural Science Foundation of China(Nos.20472026 and 20525206)Chang Jiang Scholar Program of the Ministry of Education, China.
文摘A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.
基金supported by the National Natural Science Foundation of China(21632003,21871116,22071085,U22A20390)the Fundamental Research Funds for the Central Universities(lzujbky-2023-stlt01)the 111 Program from the Ministry of Education of China。
文摘An asymmetric catalytic strategy in photocatalysis utilizing a chirality-induced approach through an organocatalytic/photoredox relay catalysis strategy is successfully achieved for the rapid construction of polycyclic compounds containing vicinal amino alcohols in a one-pot protocol. This methodology facilitates the efficient synthesis of diverse substituted polycyclic tetrahydroquinoline and benzofuran-derived vicinal amino alcohols, each containing five consecutive chiral centers, with high yields,excellent diastereoselectivities and enantioselectivities(up to 95% yield, >20:1 dr and 98% ee), under mild reaction conditions driven by sequential bifunctional squaramide organocatalyst-catalyzed [4+2] annulation and photocatalyst-catalyzed ketyl radical addition cyclization reaction process. Furthermore, investigations into the stereoselectivity mechanism and high-resolution mass spectrometry(HRMS) experiments on free radical trapping have provided evidence for elucidating the detailed mechanism of chirality-induced processes and chiral intermediate conversions in this procedure.
文摘Vicinal amino alcohols are a class of important motifs in pharmaceuticals,natural products as well as wide application in asymmetric catalysis（Scheme 1（a））.It is no doubt that development of efficient methods to access them has been a prominent research topic in the past decades.
