Topomerization of [9] annulen anion （1） and its 2-fluoro-, 2-chloro- and 2- bromo-defivatives （2, 3 and 4, respectively） are studied at the HF/6-31G＊ and B3LYP/6-31 1＋＋G＊＊ levels of theory. The relative ease ...Topomerization of [9] annulen anion （1） and its 2-fluoro-, 2-chloro- and 2- bromo-defivatives （2, 3 and 4, respectively） are studied at the HF/6-31G＊ and B3LYP/6-31 1＋＋G＊＊ levels of theory. The relative ease of topomerization is dependent on the charge distribution and planarity of the ground state and the transition state of 9-membered rings as well as the size and electronegativity of halogen substituent. Consequently, the endo-2-halo-[9] annulen anion topomers become unstable and easily convert to related exo-topomers. Hence, according to the DFT calcu- lations, the order of topomerization energy barrier for endo = exo topomerization is lendo 〉 2endo 〉 3endo.展开更多
When ethyl 3-fluoroalkyl-3-haloacrylate was treated with excess CH2N2,1-methyl-3-ethoxycarbonyl-4-fluoroalkylpyr azoles(3)and 1-methyl-5-ethoxycarbonyl-4-fluoroalkylpyrazoles(4)were obtained with a ratio of 90-95:10-5...When ethyl 3-fluoroalkyl-3-haloacrylate was treated with excess CH2N2,1-methyl-3-ethoxycarbonyl-4-fluoroalkylpyr azoles(3)and 1-methyl-5-ethoxycarbonyl-4-fluoroalkylpyrazoles(4)were obtained with a ratio of 90-95:10-5 in good yield.展开更多
In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media....In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media.The procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.展开更多
According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C ...According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the struc- ture-activity relationship was discussed based on the antibacterial results.展开更多
An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environme...An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environmentally clean and safe procedure, which involved insitu generation of the active halogen in presence of alkali halides. Cationic surfactants such as cetyltrimethylammoniumbromide (CTAB) and cetyltrimethylammoniumchloride (CTAC) were found to facilitate efficiency of halogenation in aqueous media.展开更多
文摘Topomerization of [9] annulen anion （1） and its 2-fluoro-, 2-chloro- and 2- bromo-defivatives （2, 3 and 4, respectively） are studied at the HF/6-31G＊ and B3LYP/6-31 1＋＋G＊＊ levels of theory. The relative ease of topomerization is dependent on the charge distribution and planarity of the ground state and the transition state of 9-membered rings as well as the size and electronegativity of halogen substituent. Consequently, the endo-2-halo-[9] annulen anion topomers become unstable and easily convert to related exo-topomers. Hence, according to the DFT calcu- lations, the order of topomerization energy barrier for endo = exo topomerization is lendo 〉 2endo 〉 3endo.
文摘When ethyl 3-fluoroalkyl-3-haloacrylate was treated with excess CH2N2,1-methyl-3-ethoxycarbonyl-4-fluoroalkylpyr azoles(3)and 1-methyl-5-ethoxycarbonyl-4-fluoroalkylpyrazoles(4)were obtained with a ratio of 90-95:10-5 in good yield.
基金the Guangdong Natural Science Foundation(No.8151063201000016)the National Natural Science Foundation of China(No.20672046) for financial support
文摘In the presence of diethyl 1,4-dihydro-2,6-dimethylpyridine-3,5-dicarboxylate（DHP） and a catalytic amount of potassium iodide,severalα-halo ketones were easily reduced to the corresponding ketones in acetone media.The procedure presented here showed several merits such as short reaction time,practical experimental and isolated procedure,and excellent yields of products.
基金Supported by the National Natural Science Foundation of China(Nos.20976135,21176194)
文摘According to the superposition principle of reinforcement of biological activities, 24 novel 1,4- disubstituted phenyl-5-（halo-2-hydroxyphenyl）imino-l,2,3-triazoles was synthesized and characterized by 1H NMR, ^13C NMR, elemental analysis and IR. All the target compounds were screened for their antibacterial potential in vitro against Monilia albican, Escherichia coli and Staphylococcus aureus. It was shown that all the compounds possessed efficient antibacterial activities at a concentration of 0.1 mg/mL, even at a concentration of 0.01 mg/mL, some of the compounds still exhibited antibacterial activities against Escherichia coli and Monilia albican. At last, the struc- ture-activity relationship was discussed based on the antibacterial results.
文摘An efficient and greener protocol for the synthesis of 1-halo-naphthols by the action of hydrogen peroxide and alkali metal halides in aqueous micellar media is been described in the present work. This is an environmentally clean and safe procedure, which involved insitu generation of the active halogen in presence of alkali halides. Cationic surfactants such as cetyltrimethylammoniumbromide (CTAB) and cetyltrimethylammoniumchloride (CTAC) were found to facilitate efficiency of halogenation in aqueous media.
