(S)-3,5-bistrifluoromethylphenyl ethanol is a key chiral intermediate for the synthesis of NK-1 receptor antagonists. Enantioselective synthesis of (S)-3,5-bistrifluoromethylphenyl ethanol was successfully performed i...(S)-3,5-bistrifluoromethylphenyl ethanol is a key chiral intermediate for the synthesis of NK-1 receptor antagonists. Enantioselective synthesis of (S)-3,5-bistrifluoromethylphenyl ethanol was successfully performed in high enantiomeric excess (e.e.) through asymmetric reduction of 3,5-bis(trifluoromethyl) acetophenone catalyzed by Candida tropicalis 104 cells. The influence of some key reaction parameters such as substrate concentration, co-substrate and its concentration, biomass and reaction time was examined, respectively. The results showed that these factors obviously influence the yield, but the optical purity of the prepared product remains intact. The opti-mum conditions for the preparation of (S)-3,5-bistrifluoromethylphenyl ethanol were found to be as follows: sub-strate concentration 50 mmol?L?1; 50 g·L-1 of maltose as co-substrate; wet cell concentration 300 g·L-1; reaction for 30 h. Under above optimal conditions, the maximum yield for (S)-3,5-bistrifluoromethylphenyl ethanol reached 70.3% with 100% of product e.e.展开更多
in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidatio...in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidation of S(IV) is obtained. On the basis of the investigation of thecatalytic effects of Mn(II) and Fe(III) on the oxidation of S(IV), it has been elucidated that thecatalytic activity of Mn(II) is greater than that of Fet(III), and that Mn(II) and Fe(III) do not havea significant synergic effect on the catalytic oxidation of S (IV). The catalytic oxidation andautooxidation of S(IV) in unbuffered solution was also explored in the presence of light. The resultsshow that the reaction is first order with respect to S(IV) concentrations, the reaction rate increaseswith increasing light intensity and the concentrations of Fe(III) and Mn(II), and that the photoas-sisted catalytic activity of Fe(III) is greater than that of Mn(II).展开更多
Complexes[Ln(L)(Cl_2]Cl·3H_2O (Ln =La, Pr, Nd,Sm,Eu,Gd,Dy,Er and Lu)and[Lu(L)(H_2O)(NO_3 )_2]NO_3(L=N,N'-diethyltriglycollic dianilide)have been prepared in the nonaqueous medium,the new complexes of which ha...Complexes[Ln(L)(Cl_2]Cl·3H_2O (Ln =La, Pr, Nd,Sm,Eu,Gd,Dy,Er and Lu)and[Lu(L)(H_2O)(NO_3 )_2]NO_3(L=N,N'-diethyltriglycollic dianilide)have been prepared in the nonaqueous medium,the new complexes of which have been characterized by means of elemental analysis,conductivity measurements,IR spectra,￣1H NMR spectra and TG-DTA techniques.In all the complexes,the organic ligand showed tetradentate behaviour.The structure analysis of [Lu (L) (H_2O) (NO_3 )_2]NO_3 showed that the lutetiurn atom is nine-coordinated by one tetradentate ligand , two bidentate nitrate groups and one water molecule with the following mean bond lengths:Lu O (etheric),0.2396;Lu O (carbonyl),0.2245;Lu O(nitrate),0.2397;Lu O(water),0.2296 nm.展开更多
Fifteen M(S2COR)n complexes were prepared.According to the data provided by IR,UV-Vis absorption spectrometry and X-ray diffraction,this paper covers the relationship between molecular structures of xanthate complexes...Fifteen M(S2COR)n complexes were prepared.According to the data provided by IR,UV-Vis absorption spectrometry and X-ray diffraction,this paper covers the relationship between molecular structures of xanthate complexes and their absorption spectra and a criterion of chelate stability is also proposed.The stability mechanism of xanthate chelates and related rules were investigated.展开更多
A kind of generalization of the Curve Type Node Configuration is given in this paper, and it is called the generalized node configuration CTNCB in Rs(s > 2). The related multivariate polynomial interpolation proble...A kind of generalization of the Curve Type Node Configuration is given in this paper, and it is called the generalized node configuration CTNCB in Rs(s > 2). The related multivariate polynomial interpolation problem is discussed. It is proved that the CTNCB is an appropriate node configuration for the polynomial space Pns(s > 2). And the expressions of the multivariate Vandermonde determinants that are related to the Odd Curve Type Node Configuration in R2 are also obtained.展开更多
基金Supported by the National＇Natural Science Foundation of China （21076193） and Foundation of Zhejiang Key Developing Discipline of Pharmacy （20100609）.
文摘(S)-3,5-bistrifluoromethylphenyl ethanol is a key chiral intermediate for the synthesis of NK-1 receptor antagonists. Enantioselective synthesis of (S)-3,5-bistrifluoromethylphenyl ethanol was successfully performed in high enantiomeric excess (e.e.) through asymmetric reduction of 3,5-bis(trifluoromethyl) acetophenone catalyzed by Candida tropicalis 104 cells. The influence of some key reaction parameters such as substrate concentration, co-substrate and its concentration, biomass and reaction time was examined, respectively. The results showed that these factors obviously influence the yield, but the optical purity of the prepared product remains intact. The opti-mum conditions for the preparation of (S)-3,5-bistrifluoromethylphenyl ethanol were found to be as follows: sub-strate concentration 50 mmol?L?1; 50 g·L-1 of maltose as co-substrate; wet cell concentration 300 g·L-1; reaction for 30 h. Under above optimal conditions, the maximum yield for (S)-3,5-bistrifluoromethylphenyl ethanol reached 70.3% with 100% of product e.e.
文摘in absence of light, the reaction kinetics of Mn(II) and Fe(III)-atalyzed oxidation ofS(IV) in unbuffered and buffered solutions were studied. An activation energy of 77.4kJ . mol￣(-1) forthe Mn(II)catalyzed oxidation of S(IV) is obtained. On the basis of the investigation of thecatalytic effects of Mn(II) and Fe(III) on the oxidation of S(IV), it has been elucidated that thecatalytic activity of Mn(II) is greater than that of Fet(III), and that Mn(II) and Fe(III) do not havea significant synergic effect on the catalytic oxidation of S (IV). The catalytic oxidation andautooxidation of S(IV) in unbuffered solution was also explored in the presence of light. The resultsshow that the reaction is first order with respect to S(IV) concentrations, the reaction rate increaseswith increasing light intensity and the concentrations of Fe(III) and Mn(II), and that the photoas-sisted catalytic activity of Fe(III) is greater than that of Mn(II).
文摘Complexes[Ln(L)(Cl_2]Cl·3H_2O (Ln =La, Pr, Nd,Sm,Eu,Gd,Dy,Er and Lu)and[Lu(L)(H_2O)(NO_3 )_2]NO_3(L=N,N'-diethyltriglycollic dianilide)have been prepared in the nonaqueous medium,the new complexes of which have been characterized by means of elemental analysis,conductivity measurements,IR spectra,￣1H NMR spectra and TG-DTA techniques.In all the complexes,the organic ligand showed tetradentate behaviour.The structure analysis of [Lu (L) (H_2O) (NO_3 )_2]NO_3 showed that the lutetiurn atom is nine-coordinated by one tetradentate ligand , two bidentate nitrate groups and one water molecule with the following mean bond lengths:Lu O (etheric),0.2396;Lu O (carbonyl),0.2245;Lu O(nitrate),0.2397;Lu O(water),0.2296 nm.
文摘Fifteen M(S2COR)n complexes were prepared.According to the data provided by IR,UV-Vis absorption spectrometry and X-ray diffraction,this paper covers the relationship between molecular structures of xanthate complexes and their absorption spectra and a criterion of chelate stability is also proposed.The stability mechanism of xanthate chelates and related rules were investigated.
基金the Science and Technology Project of Jiangxi Provincial Department of Education([2007]320)
文摘A kind of generalization of the Curve Type Node Configuration is given in this paper, and it is called the generalized node configuration CTNCB in Rs(s > 2). The related multivariate polynomial interpolation problem is discussed. It is proved that the CTNCB is an appropriate node configuration for the polynomial space Pns(s > 2). And the expressions of the multivariate Vandermonde determinants that are related to the Odd Curve Type Node Configuration in R2 are also obtained.
