Several new calixcrowns were synthesized and characterized. The transport of Ca 2+ ion was investigated through a bubbling pseudo emulsion liquid membrane with these calixcrowns, the parent calixarenes ( n ...Several new calixcrowns were synthesized and characterized. The transport of Ca 2+ ion was investigated through a bubbling pseudo emulsion liquid membrane with these calixcrowns, the parent calixarenes ( n =4, 6, 8) and the ester, acid derivatives of calixarene as mobile carriers. The effects of the initial concentrations of Ca 2+ ion in the source phase and the initial pH difference (ΔpH) between the receiving phase and the source phase were studied. The results suggest that there are two different transport mechanisms. The transports using calixarenes and their ester, acid derivatives as carriers represent a proton coupled co transport with a flow of protons in the opposite direction, while the transports using the calixcrowns as carriers exhibit the characteristics of an anion coupled co transport with a flow of anion in the same direction.展开更多
Calix[4] (aza) crowns containing amide groups 3a—d were synthesized by the reactions of calix[4]arene (la) or p-tert-butylcalix[4]arene (1b) with N, N′-ethylenebis(2-chloroacetamide) (2a) or N, N′- 1,2-ethylenebis ...Calix[4] (aza) crowns containing amide groups 3a—d were synthesized by the reactions of calix[4]arene (la) or p-tert-butylcalix[4]arene (1b) with N, N′-ethylenebis(2-chloroacetamide) (2a) or N, N′- 1,2-ethylenebis (2-chloroacetamide) (2b) by one step procedure in yields of 85—-90%. Calix[4]-(aza) crowns 4a—b could be obtained by the reduction of 3a—b with LiAlH4 in yields of 51 and 67%, respectively. The nitration of 3a or 3c afforded new chromogenic calix[4]arenes 5a bearing two nitrophenol moieties and 5c bearing one nitro-phenol and one quinone moiety, respectively. The ipso-nitration's of 3b and 3d were also studied. Both gave the products containing one nitro phenol and one quinine moiety. Moreover, a very interesting calix[4]arene derivative 5d containing one cyclohexadienone moiety was also separated as the main product when 3d was ipso-nitrated.展开更多
Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase and amidase containing microbial whole-cell catalyst, at 10 ℃ and with the use of methanol as a co-solvent, nitrile and amide biotransformations produc...Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase and amidase containing microbial whole-cell catalyst, at 10 ℃ and with the use of methanol as a co-solvent, nitrile and amide biotransformations produce 2S-1,4-benzodioxane-2-carboxamide and 2R-1,4-benzodioxane-2-carboxylic acid in high yields with excellent enantioselectivity.展开更多
文摘Several new calixcrowns were synthesized and characterized. The transport of Ca 2+ ion was investigated through a bubbling pseudo emulsion liquid membrane with these calixcrowns, the parent calixarenes ( n =4, 6, 8) and the ester, acid derivatives of calixarene as mobile carriers. The effects of the initial concentrations of Ca 2+ ion in the source phase and the initial pH difference (ΔpH) between the receiving phase and the source phase were studied. The results suggest that there are two different transport mechanisms. The transports using calixarenes and their ester, acid derivatives as carriers represent a proton coupled co transport with a flow of protons in the opposite direction, while the transports using the calixcrowns as carriers exhibit the characteristics of an anion coupled co transport with a flow of anion in the same direction.
基金Project (Nos. 29602010, 29772037) supported by the National Natural Science Foundation of China.
文摘Calix[4] (aza) crowns containing amide groups 3a—d were synthesized by the reactions of calix[4]arene (la) or p-tert-butylcalix[4]arene (1b) with N, N′-ethylenebis(2-chloroacetamide) (2a) or N, N′- 1,2-ethylenebis (2-chloroacetamide) (2b) by one step procedure in yields of 85—-90%. Calix[4]-(aza) crowns 4a—b could be obtained by the reduction of 3a—b with LiAlH4 in yields of 51 and 67%, respectively. The nitration of 3a or 3c afforded new chromogenic calix[4]arenes 5a bearing two nitrophenol moieties and 5c bearing one nitro-phenol and one quinone moiety, respectively. The ipso-nitration's of 3b and 3d were also studied. Both gave the products containing one nitro phenol and one quinine moiety. Moreover, a very interesting calix[4]arene derivative 5d containing one cyclohexadienone moiety was also separated as the main product when 3d was ipso-nitrated.
基金Project supported by the Major State Basic Research Development Program （No. 2003CB716005）, the Ministry of Science and Technology, the National Science Foundation of China, and the Chinese Academy of Sciences.
文摘Catalyzed by Rhodococcus erythropolis AJ270, a nitrile hydratase and amidase containing microbial whole-cell catalyst, at 10 ℃ and with the use of methanol as a co-solvent, nitrile and amide biotransformations produce 2S-1,4-benzodioxane-2-carboxamide and 2R-1,4-benzodioxane-2-carboxylic acid in high yields with excellent enantioselectivity.
