A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition m...A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .展开更多
Four monoalkyl esters of isoalkylphosphonic acids have been studied for the chromatographic separation of rare earths (RE).The relationship between distribution ratios and acid concentration of the eluants for samariu...Four monoalkyl esters of isoalkylphosphonic acids have been studied for the chromatographic separation of rare earths (RE).The relationship between distribution ratios and acid concentration of the eluants for samarium and ytterbium has been explored.The characteristics of these extractants loaded onto macroreticular poly (methyl methacrylate) resin beads for the separation of lanthanum,cerium,praseodymium and neodymium have been compared.Among the extractants studied,mono(1-methylheptyl) ester of isooctylphosphonic acid was found to be the best for RE separation.The acidity for separation is lower than any known P-containing extractants for the same purpose.For instance,with 1.73 mol·L^(-1) nitric acid as eluent,thulium,ytterbium and lutetium can be separated quantitatively.The extractant-loaded resins possess high column efficiency with good kinetic characteristics.The extraction mechanism was also explored.展开更多
New structural phospholipids 1.3-cyclic monoalkyl(acyl)-rac-glycerothiophosphates of uridine were synthesized. The strategy for the synthesis is using hexaethylphosphorous triamide, activated by a catalytic amount of ...New structural phospholipids 1.3-cyclic monoalkyl(acyl)-rac-glycerothiophosphates of uridine were synthesized. The strategy for the synthesis is using hexaethylphosphorous triamide, activated by a catalytic amount of iodine, as the phosphorylating reagent. Their structures were confirmed by (1)HNMR, (31)PNMR, IR and elemental analysis.展开更多
A series of N-monoalkyl aromatic amines are synthesized in high yields from corresponding nitroarene derivatives,aldehydes,and ammonium formate in the presence of Pd/C as a catalyst through one-pot operations at room ...A series of N-monoalkyl aromatic amines are synthesized in high yields from corresponding nitroarene derivatives,aldehydes,and ammonium formate in the presence of Pd/C as a catalyst through one-pot operations at room temperature. Both the conversion and selectivity of the process are above 80%. Optimum reaction conditions are investigated,and it is found that the optimum molar ratio of nitroarene derivatives to ammonium formate and the optimum weight ratio of nitroarene derivatives to Pd/C are 1/4 and 1/0.10,respectively. These experiments provide a novel access for N-monoalkyl aromatic amines with advantages of simplicity,high selectivity,and environmental benignity.展开更多
The 1-O-monoalkyl glycerol ethers(MAGEs) were initially viewed as the biomarkers for sulfate-reducing bacteria(SRB) mediating anaerobic oxidation of methane in the marine environments. However, limited information is ...The 1-O-monoalkyl glycerol ethers(MAGEs) were initially viewed as the biomarkers for sulfate-reducing bacteria(SRB) mediating anaerobic oxidation of methane in the marine environments. However, limited information is known about their distribution in terrestrial and other aquatic settings including soils, fresh water lakes, and cave sediments, which may obscure our understanding of their biological sources. Here we found that MAGEs were ubiquitous but differed obviously in distributional pattern among those environments. The surface soils are dominated generally by i C15:0-MAGE, followed by n C16:0-MAGE whereas the lake sediments show the opposite, resulting in significantly higher i C15:0/n C16:0 ratios in soils than in lake sediments. The cave deposits are characterized by considerably higher proportions of branched MAGEs than the former two environments. The logarithm of i C15:0/a C15:0 ratio shows a significant negative correlation with soil p H, likely reflecting an adaptation of microbial cell membrane to change in the ambient proton concentration. The MAGE profiles in cultured bacteria cannot fully explain the MAGE distribution in all the samples analyzed. Therefore, MAGEs in soil, lake sediments, and cave deposits likely have additional biological source(s) other than SRB and cultured MAGE-producing bacteria. The difference in MAGE pattern among environments is likely to be attributed to change in microbial communities.展开更多
文摘A new and simple route for the synthesis of α,β-unsaturated ketones via cleavage of the C-C(O)C single bond of monoalkylated β-diketone has been described. The reaction was catalyzed by copper, a cheap transition metal in a weakly basic medium (K<sub>3</sub>PO<sub>4</sub>) at room temperature. To carry out this study, we first had to synthesize the monoalkylated β-diketones 1. Afterwards, α,β-unsaturated ketones 2 were obtained with high yields around 80%. Finally, all the products were characterized by 1H NMR, 13C NMR, and HRMS spectra. .
基金The project supported by the National Natural Science Foundation of China
文摘Four monoalkyl esters of isoalkylphosphonic acids have been studied for the chromatographic separation of rare earths (RE).The relationship between distribution ratios and acid concentration of the eluants for samarium and ytterbium has been explored.The characteristics of these extractants loaded onto macroreticular poly (methyl methacrylate) resin beads for the separation of lanthanum,cerium,praseodymium and neodymium have been compared.Among the extractants studied,mono(1-methylheptyl) ester of isooctylphosphonic acid was found to be the best for RE separation.The acidity for separation is lower than any known P-containing extractants for the same purpose.For instance,with 1.73 mol·L^(-1) nitric acid as eluent,thulium,ytterbium and lutetium can be separated quantitatively.The extractant-loaded resins possess high column efficiency with good kinetic characteristics.The extraction mechanism was also explored.
文摘New structural phospholipids 1.3-cyclic monoalkyl(acyl)-rac-glycerothiophosphates of uridine were synthesized. The strategy for the synthesis is using hexaethylphosphorous triamide, activated by a catalytic amount of iodine, as the phosphorylating reagent. Their structures were confirmed by (1)HNMR, (31)PNMR, IR and elemental analysis.
基金Supported by the National Natural Science Foundation of China (Grant No. 20876148)
文摘A series of N-monoalkyl aromatic amines are synthesized in high yields from corresponding nitroarene derivatives,aldehydes,and ammonium formate in the presence of Pd/C as a catalyst through one-pot operations at room temperature. Both the conversion and selectivity of the process are above 80%. Optimum reaction conditions are investigated,and it is found that the optimum molar ratio of nitroarene derivatives to ammonium formate and the optimum weight ratio of nitroarene derivatives to Pd/C are 1/4 and 1/0.10,respectively. These experiments provide a novel access for N-monoalkyl aromatic amines with advantages of simplicity,high selectivity,and environmental benignity.
基金supported by the National Basic Research Program of China(Grant No.2011CB808800)the National Natural Science Foundation of China(Grant No.41330103)the"111"Project(Grant No.B08030)
文摘The 1-O-monoalkyl glycerol ethers(MAGEs) were initially viewed as the biomarkers for sulfate-reducing bacteria(SRB) mediating anaerobic oxidation of methane in the marine environments. However, limited information is known about their distribution in terrestrial and other aquatic settings including soils, fresh water lakes, and cave sediments, which may obscure our understanding of their biological sources. Here we found that MAGEs were ubiquitous but differed obviously in distributional pattern among those environments. The surface soils are dominated generally by i C15:0-MAGE, followed by n C16:0-MAGE whereas the lake sediments show the opposite, resulting in significantly higher i C15:0/n C16:0 ratios in soils than in lake sediments. The cave deposits are characterized by considerably higher proportions of branched MAGEs than the former two environments. The logarithm of i C15:0/a C15:0 ratio shows a significant negative correlation with soil p H, likely reflecting an adaptation of microbial cell membrane to change in the ambient proton concentration. The MAGE profiles in cultured bacteria cannot fully explain the MAGE distribution in all the samples analyzed. Therefore, MAGEs in soil, lake sediments, and cave deposits likely have additional biological source(s) other than SRB and cultured MAGE-producing bacteria. The difference in MAGE pattern among environments is likely to be attributed to change in microbial communities.
基金Supported by the National Natural Science Foundation of China(20476046 and 20776069)the Key Natural Science Foundation for Univer-sities of Jiangsu Province(06KJA53012)the Program for Changjiang Scholars and Innovative Research Team in Universities(PCSIRT 0732)
