Ni（HCO3）2 with unique phase and high crystallinity was synthesized with urea hydrolysis. The as-prepared samples were well characterized in detail. N2 adsorption and desorption result manifests a high surface area o...Ni（HCO3）2 with unique phase and high crystallinity was synthesized with urea hydrolysis. The as-prepared samples were well characterized in detail. N2 adsorption and desorption result manifests a high surface area of 99.03 m2/g with a pore size of 7.8 nm. Scanning electron microscopy （SEM） and particle size distribution reveal that the diameters of the formed pellets are uniform. Thermogravimetry （TG） analysis result shows that 500 ℃ could be the appropriate temperature for converting Ni（HCO3）2 precursors into NiO via a thermal decomposition process. CO2 and NH3 temperature-programmed desorption results show that Ni（HCO3）2 has explicit acid-base sites. Transmission electron microscopy （TEM） results vividly indicate that the pellets are aggregated by hexagonal platelets and possess porous structures. Ni（HCO3）2 can efficiently catalyze the one-step synthesis of benzoin ethyl ether from benzaldehyde and ethanol, with the conversion ofbenzaldehyde up to 57.5% and nearly 100% selectivity of benzoin ethyl ether.展开更多
The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investi...The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.展开更多
An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored. Cu-Fe-hydrotalcite was firstly successfully s...An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored. Cu-Fe-hydrotalcite was firstly successfully synthesized over Jahn-Teller effect of Cu^2＋. The catalytic test result showed that Cu-Fe-hydrotalcite could be used as a good catalyst in the synthesis of benzoin isopropyl ether. The highest conversion of ben- zaldehyde was 59.7% and the selectivity of benzoin isopropyl ether was nearly 100%. By this new method, not only was the cyanide poisoning avoided, but also the synthesis of benzoin isopropyl ether could be completed in one step instead of traditional two steps with both condensation and etherification.展开更多
Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within...Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.展开更多
The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The hi...The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 39.6% and 100% respectively at ambient temperature and pressure. The effects of structures of the bridge group R in the ligands on the dioxygen affinities and catalytic activities to epoxidize styrene were also investigated.展开更多
Using heavy-atom-containing xanthene dyes,benzoins can be quanti- tatively prepared by photosensitized reduction from benzils with triethyla- mine.It is an important supplement to'benzoin condensation',asp.for...Using heavy-atom-containing xanthene dyes,benzoins can be quanti- tatively prepared by photosensitized reduction from benzils with triethyla- mine.It is an important supplement to'benzoin condensation',asp.for those benzoins with electron-donating substituents.展开更多
Benzoin condensation is an important carbon-carbon bond-forming reaction. The benzoin reaction with good yield, high enantioselectivity and broad substrate scope is highly desired in organic synthesis. The intermolecu...Benzoin condensation is an important carbon-carbon bond-forming reaction. The benzoin reaction with good yield, high enantioselectivity and broad substrate scope is highly desired in organic synthesis. The intermolecular benzoin condensation catalyzed by bifunctional N-heterocyclic carbenes has been investigated, and the corresponding α-hydroxyketones were obtained with yields up to 76% and enantioselectivities up to 99% ee.展开更多
基金Project(50872086)supported by the National Natural Science Foundation of ChinaProject(2012021006-3)supported by the Natural Science Foundation of Shanxi Province,China+1 种基金Project(2012L022)supported by Special/Youth Foundation of Taiyuan University of Technology,ChinaProject(20120321033-02)supported by Science and Technology Research of Shanxi Province,China
文摘Ni（HCO3）2 with unique phase and high crystallinity was synthesized with urea hydrolysis. The as-prepared samples were well characterized in detail. N2 adsorption and desorption result manifests a high surface area of 99.03 m2/g with a pore size of 7.8 nm. Scanning electron microscopy （SEM） and particle size distribution reveal that the diameters of the formed pellets are uniform. Thermogravimetry （TG） analysis result shows that 500 ℃ could be the appropriate temperature for converting Ni（HCO3）2 precursors into NiO via a thermal decomposition process. CO2 and NH3 temperature-programmed desorption results show that Ni（HCO3）2 has explicit acid-base sites. Transmission electron microscopy （TEM） results vividly indicate that the pellets are aggregated by hexagonal platelets and possess porous structures. Ni（HCO3）2 can efficiently catalyze the one-step synthesis of benzoin ethyl ether from benzaldehyde and ethanol, with the conversion ofbenzaldehyde up to 57.5% and nearly 100% selectivity of benzoin ethyl ether.
基金This work was supported by the National Natural Science Foundation of China （No.21333012 and No.21425313） and the National Basic Research Program of China （No.2013CB834602）.
文摘The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.
基金support from the National Natural Science Foundation of China (50872086)the Natural Science Foundation of Shanxi Province(2008011018)
文摘An efficient synthesis of benzoin isopropyl ether with benzaldehyde and propanol in the presence of heterogeneous recyclable Cu-Fe-hydrotalcite catalyst has been explored. Cu-Fe-hydrotalcite was firstly successfully synthesized over Jahn-Teller effect of Cu^2＋. The catalytic test result showed that Cu-Fe-hydrotalcite could be used as a good catalyst in the synthesis of benzoin isopropyl ether. The highest conversion of ben- zaldehyde was 59.7% and the selectivity of benzoin isopropyl ether was nearly 100%. By this new method, not only was the cyanide poisoning avoided, but also the synthesis of benzoin isopropyl ether could be completed in one step instead of traditional two steps with both condensation and etherification.
基金We thank the financial support from the National Natural Science Foundation of China.(No.20172038)
文摘Benzoin condensation promoted efficiently in three imidazolium based room tempera- ture ionic liquids [bmim]Br, [bmim]BF4 and [Bnmim]BF4 is reported for the first time. Benzoins were obtained in up to 91% yield within less than 30 min under mild conditions.
文摘The oxygenation constants of transition-metal complexes with benzoin Schiff bases were measured and these complexes were first employed as models for mimicking monooxygenase in catalytic epoxidation of styrene. The highest conversion and selectivity were up to 39.6% and 100% respectively at ambient temperature and pressure. The effects of structures of the bridge group R in the ligands on the dioxygen affinities and catalytic activities to epoxidize styrene were also investigated.
文摘Using heavy-atom-containing xanthene dyes,benzoins can be quanti- tatively prepared by photosensitized reduction from benzils with triethyla- mine.It is an important supplement to'benzoin condensation',asp.for those benzoins with electron-donating substituents.
基金supported by the National Natural Science Foundation of China (20602036)the Ministry of Science and Technology of China (2009ZX09501-018) and the Chinese Academy of Sciences.
文摘Benzoin condensation is an important carbon-carbon bond-forming reaction. The benzoin reaction with good yield, high enantioselectivity and broad substrate scope is highly desired in organic synthesis. The intermolecular benzoin condensation catalyzed by bifunctional N-heterocyclic carbenes has been investigated, and the corresponding α-hydroxyketones were obtained with yields up to 76% and enantioselectivities up to 99% ee.
