One-pot sequential diprop-2-ynylation and cycloaddition: An efficient synthesis of novel N,N-bis(1,2,3-triazol-4-yl) methylarylamines starting from primary amines

Abstract

A facile, one-pot synthesis strategy for the tertiary arylamines bearing N,N-bis(1,2,3-triazol-4-yl)methyl structure has been developed by sequential diprop-2-ynylation of primary amines with propargyl bromide in the presence of calcium hydride in DMF and [3?+?2] “click” cycloaddition with organic azides promoted by cupric acetate in the mixed DMF-H₂O media. This protocol provides some features, such as high efficiency and regioselectivity, easy operation, and moderate to good product yield (56–84%) with a wide substrate scope under mild conditions.     

四种Keggin型多酸纳米材料的制备及其吸附有机染料的性能

以4种Keggin型多酸作为原料(分别为H₃PW₁₂O₄₀·36H₂O(简写为PW₁₂^a)、H₃PMo₁₂O₄₀·34H₂O(简写为PMo₁₂^a)、H₄SiW₁₂O₄₀·35H₂O(简写为SiW₁₂^a)和H₄GeW₁₂O₄₀·40H₂O(简写为GeW₁₂^a)),采用表面活性剂智能化控制的软化学法制备了相应的4种Keggin型多酸纳米材料,分别为Ag₃PW₁₂O₄₀·36H₂O(简写为PW₁₂^b)、Ag₃PMo₁₂O₄₀·34H₂O(简写为PMo₁₂^b)、Ag₄SiW₁₂O₄₀·35H₂O(简写为SiW₁₂^b)和Ag₄GeW₁₂O₄₀·40H₂O(简写为GeW₁₂^b)。采用IR、UV-Vis、XRD和SEM表征多酸的结构和纳米粒子的形貌。在室内黑暗条件下,100mg样品可在5min内把20mg·L^-1的100mL亚甲基蓝(MB)染料溶液脱色,使其变为接近无色,吸附效率最高可达96.3%,吸附效率大小为PMo₁₂^b >PW₁₂^b >GeW₁₂^b >SiW₁₂^b。相同条件下,100mg样品使20mg·L^-1的100mL罗丹明B(RhB)染料溶液30min内脱色完全,脱色效率最高可达96.1%,吸附效率大小为PW₁₂^b >PMo₁₂^b >SiW₁₂^b >GeW₁₂^b。说明该4种多酸纳米材料具有较高的吸附有机染料性能。     

A simple selective protocol for continuous two-stage fluorescent sensing of both MeHg and anti-MeHg agents in living cells

Methylmercury (MeHg⁺) is one of the most toxic mercury species targeting human nervous systems, and deficiency of a convenient and precise appraisal model for anti-MeHg⁺ treatment greatly slows down the step of developing clinically useful anti-MeHg⁺ agents. A simple visualization model has been demonstrated in this work for selective sensing of both MeHg⁺ and anti-MeHg⁺ agents in two continuous stages of one experiment in living cells, using a newly developed fluorescent pyrrolcoumarin probe. The developed sensing protocol shows great potential in the future applications of screening and evaluation of anti-MeHg⁺ agents.     

Co(S1-xSex)2系统中的铁磁量子相变

针对Co(S1-xSex)2系统在x=0.11附近发生的铁磁金属到顺磁金属相变,制备了一系列不同Se替代浓度的多晶样品.通过对其结构和电阻率-温度ρ(T)关系的系统观测,结果发现,样品铁磁相变温度TC随着Se替代浓度x值的增加,以(1-x)1/2关系单调下降,其二级铁磁相变转变为一级相变;在临界浓度x=0.11附近,其ρ(T)关系由Fermi液体行为转变为非Fermi液体行为.作者认为,Co(S1-xSex)2系统在x=0.11附近发生的是一种量子相变,在该量子相变点附近零温度下的自旋量子涨落导致其ρ(T)关系的反常行为.     

Synthesis of a new conformation-constrained L-tyrosine analogue as a potential scaffold for SH2 domain ligands

The enantioselective synthesis of a new tricyclic tyrosine analogue is reported. This conformation-constrained SH2 domain ligand scaffold 2 was designed on the basis of the natural ligand, whose structure contains the elements of a tyrosine moiety having chi(1) and chi(2) angles constrained to values observed for a phosphotyrosyl (pTyr) residue bound to the p56(lck) SH2 domain. It represents a unique, highly constrained amino acid, which may be of value in signal transduction studies. Three key steps, an asymmetric tandem Michael addition, an intramolecular Friedel-Crafts reaction, and an intramolecular Mannich reaction, were successfully applied in the presented synthetic route.     

Synthesis of a new stable conformationally constrained 2,7-anhydrosialic acid derivative

A stereoseletive synthesis of 2,7-anhydrosialic acid derivative 18 was achieved from d-glucono-delta-lactone. A highly syn-selective addition of Grignard reagent to theN-benzylimine 8 served as a key step.     

Chemical Biology Studies on Molecular Diversity of Annonaceous Acetogenins

Annonaceous acetogenins, isolated from the Annonaceae plants, have been attracting worldwide attention in recent years due to their biological activities, especially as growth inhibitors of certain tumor ceils [ 1 ]. They have been shown to function by blocking complex I in mitochondria [2] as well as ubiquinone-linked NADPH oxidase in the cells of specific tumor cell lines, including some multidrug-resistant ones [3]. These features make these acetogenins excellent leads for the new antitumor agents. In our previous work, the compounds 1a to 1d (Figure 1), which relies on structure simplification while maintaining all essential functionalities of the acetogenins, was in vitro tested against several human solid tumor cell lines and showed interesting cell selectivity [4]. All four analogues show remarkable activity against the HCT-8 and HT-29 cell lines, while compound 1c was found the best [4bi. In order to further investigate the effects of key structural features, a convergent parallel fragments assembly strategy was developed [4e]. In addition, the biological relevancies of typical annonaceous acetogenin mimetics were also studied [4f].     

液芯波导阵列芯片检测血清及尿液中的β2-微球蛋白

提出了一种液芯波导免疫分析阵列芯片的检测系统,结合光强差技术提高了ELISA的灵敏度,HRP的线性范围为1×10-10~9×10-10g/L,检出限为3.0×10-11g/L,RSD小于1%(c=3×10-10g/L,n=11),线性范围的下限与检出限均比普通的光度法下降了100倍,将其应用于血清和尿液中β2-微球蛋白的免疫分析,与标准方法所得结果相符。