The concise building of the spiroketal core of acortatarin-type alkaloids as potential therapeutic agents in diabetic nephropathy was established in four steps,through a tandem N-alkylation/hemiacetalization between p...The concise building of the spiroketal core of acortatarin-type alkaloids as potential therapeutic agents in diabetic nephropathy was established in four steps,through a tandem N-alkylation/hemiacetalization between pyrrole units and the corresponding halo alcohols generated by convenient halomethylation of chiral lactones from natural aldoses.展开更多
Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic ...Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic sulfur reagent followed by insertion of Zn into disulfide and nucleophilic thiolation, providing straightforward access to a wide range of alkyl sulfides with broad substrate scope. A neutral TMEDA-ligated four-coordinated zinc thiolate with tetrahedra geometry was synthesized, isolated and fully characterized by NMR, IR and X-ray analysis. More importantly, the chemical reactivity of this active intermediate has been investigated, enabling the construction of C-Se, C-Te, Sb-S and Bi-S bonds to prepare valuable sulfur-containing molecules and beyond.展开更多
To the Editor： Sulfur dioxide （SO2） is one of the main air pollutants, which is formed when sulfur-containing fuel is burned In some special situation, people may be exposed to high concentration of SO,, such as an...To the Editor： Sulfur dioxide （SO2） is one of the main air pollutants, which is formed when sulfur-containing fuel is burned In some special situation, people may be exposed to high concentration of SO,, such as an accident of SO2 tank leakage, mine blast, smoke of gunpowder in a war, and smoke of volcanic eruption, which may be harmful to the persons who are exposed to it. Many studies have indicated that SO, exposure increases morbidity and mortality. SO, can not only produce a variety of adverse pulmonary effects, such as bronchitis and airway hyperresponsiveness but also have harmful effects on other systems and organs. It is associated with increased risk of acute myocardial infarction, and inhalation of SO, can cause injury in brain including stroke. The expressions of oncogenes and tumor suppressor genes in lung and liver of rat were affected by exposure to SO2 and benzo（a）pyrene. The expressions of apoptosis-related genes can be augmented and the apoptosis of the cells was induced in liver, lung, and brain of rats exposed to SO2.展开更多
基金the“Hundred Talents Project”of Chinese Academy of Science and“High-end Science and Technology Talents Program”’of Yunnan Province(2011HA008)。
文摘The concise building of the spiroketal core of acortatarin-type alkaloids as potential therapeutic agents in diabetic nephropathy was established in four steps,through a tandem N-alkylation/hemiacetalization between pyrrole units and the corresponding halo alcohols generated by convenient halomethylation of chiral lactones from natural aldoses.
基金the National Science Foundation of China(22001051)Zhejiang Provincial Natural Science Foundation of China(LY23B020002)for financial supportfunding from the STU Scientific Research Foundation for Talents(NTF20022)。
文摘Zinc-promoted umpolung thiolation of alkyl electrophiles with masked sulfur transfer reagents in the absence of nickel or copper catalysis is described. This protocol proceeds via a SET process of Zn to electrophilic sulfur reagent followed by insertion of Zn into disulfide and nucleophilic thiolation, providing straightforward access to a wide range of alkyl sulfides with broad substrate scope. A neutral TMEDA-ligated four-coordinated zinc thiolate with tetrahedra geometry was synthesized, isolated and fully characterized by NMR, IR and X-ray analysis. More importantly, the chemical reactivity of this active intermediate has been investigated, enabling the construction of C-Se, C-Te, Sb-S and Bi-S bonds to prepare valuable sulfur-containing molecules and beyond.
文摘To the Editor： Sulfur dioxide （SO2） is one of the main air pollutants, which is formed when sulfur-containing fuel is burned In some special situation, people may be exposed to high concentration of SO,, such as an accident of SO2 tank leakage, mine blast, smoke of gunpowder in a war, and smoke of volcanic eruption, which may be harmful to the persons who are exposed to it. Many studies have indicated that SO, exposure increases morbidity and mortality. SO, can not only produce a variety of adverse pulmonary effects, such as bronchitis and airway hyperresponsiveness but also have harmful effects on other systems and organs. It is associated with increased risk of acute myocardial infarction, and inhalation of SO, can cause injury in brain including stroke. The expressions of oncogenes and tumor suppressor genes in lung and liver of rat were affected by exposure to SO2 and benzo（a）pyrene. The expressions of apoptosis-related genes can be augmented and the apoptosis of the cells was induced in liver, lung, and brain of rats exposed to SO2.
