排序方式: 共有7条查询结果,搜索用时 15 毫秒
1
1.
Aminolytic kinetic resolution (AKR) of trans-stilbene oxide and trans-beta-methyl styrene oxide proceeded smoothly under microwave irradiation using chiral dimeric and polymeric Cr(III) salen complexes as efficient catalysts, giving regio-, diastereo-, and enantioselective anti-beta-amino alcohols in high yields (49%) and chiral purity (ee up to 94%) in case of 4-methylaniline within 2 min. The kinetic resolution system is approximately five times faster than traditional oil bath heating at 70 degrees C and 420 times faster than the reaction conducted at room temperature with concomitant recovery of respective chirally enriched epoxides (ee, 92%) in excellent yields (up to 48%). The catalyst 1 worked well in terms of enantioselectivity than the catalyst 2, but both the catalysts were easily recovered and reused five times with the retention of its efficiency. 相似文献
2.
Xu Zhenggang Jiang Kangkang Yang Yue Shakeel A. Soomro Wang Tianyu Li Chenhao Yang Shen Zhao Yunlin Yang Guiyan 《Restoration Ecology》2024,32(3):e14065
Cadmium (Cd) pollution poses a serious threat to various ecosystems, and phytoremediation is an alternate method for developing the soil health. To better utilize phytoremediation for Cd-contaminated soil remediation, the ginkgo leaves, pine needles, and Eucommia bark were mixed and naturally fermented to obtain Ginkgo biloba–Pinus massoniana–Eucommia ulmoides (GPE) Jiaosu and Jiaosu residue, whose effects on Broussonetia papyrifera planted in Cd-contaminated soil were evaluated. The results showed that the contents of the protein, phenolic, vitamin E, and alcohol of GPE Jiaosu were 4400 ± 0.46, 0.22 ± 0.01, 0.88 ± 0.24, and 4.63 ± 0.25 μL/mL, accordingly, with fine antioxidant activity. The soil pH, electrical conductivity content, organic carbon, total nitrogen, total phosphorus, alkali-hydrolyzable nitrogen, available phosphorus, and Cd concentration were all significantly (p < 0.05) modified. The chlorophyll content of B. papyrifera was increased by using Jiaosu residue in 12 hours, while the promotion effect of Jiaosu appeared in the later stage (60 days). The Cd tolerance physiological indexes such as malondialdehyde content and antioxidant enzymes' activity were all regulated. Applying the Jiaosu residue, the Cd in stems was decreased by 72.61% under 1000 mg/kg Cd treatment. These results suggested that GPE Jiaosu and Jiaosu residue can improve the properties of Cd-contaminated soil, promote the Cd tolerance of B. papyrifera, and affect the Cd migration. The current study provides a new bioremediation method using the Jiaosu and Jiaosu residue as Cd environmental remediation materials in a recyclable pathway, which is a circular and healthy development concept that integrates economic, ecological, and social significance. 相似文献
3.
Thaís Augusto Marinho Carmen Luci Rodrigues Lopes Sheila Araújo Teles Nádia Rúbia Silva Reis Megmar Aparecida dos Santos Carneiro Andreia Alves de Andrade Regina Maria Bringel Martins 《Memórias do Instituto Oswaldo Cruz》2013,108(4):519-522
The prevalence of hepatitis C virus (HCV) in a population of
recyclable waste collectors (n = 431) was assessed using a cross-sectional
survey in all 15 cooperatives in the city of Goiânia, Central-West Brazil. The
HCV prevalence was 1.6% (95% confidence interval: 0.6-3.6) and a history of
sexually transmitted infections was independently associated with this
infection. HCV RNA (corresponding to genotype 1; subtypes 1a and 1b) was
detected in five/seven anti-HCV-positive samples. Although the study population
reported a high rate (47.3%) of sharps and needle accidents, HCV infection was
not more frequent in recyclable waste collectors than in the general Brazilian
population. 相似文献
4.
Chiral polymeric Mn(III) salen complexes were used efficiently for oxidative kinetic resolution of racemic secondary alcohols at room temperature. High chiral purity (ee; >99%) was achieved for the oxidative kinetic resolution of racemic secondary alcohols with 0.6 mol % catalyst loading in 60 min. The catalyst was easily recycled for five successive catalytic experiments. 相似文献
5.
Recyclable polymeric 1 and dimeric 2 chiral Mn(III) salen complexes catalyzed enantioselective cyanosilylation of various ketones in the presence of triphenylphosphine oxide as an additive proceeded smoothly at room temperature, providing excellent yields (up to 98%) and enantiomeric excess (up to 86%) of respective cyanohydrin trimethylsilyl ether. For most of the substrates, the Catalyst 1 showed slightly better reactivity and enantioselecitivity than the Catalyst 2 nevertheless both the catalysts were easily recovered and reused four times with the retention of their efficiency. 相似文献
6.
7.
1