Synthetic Approach for Novel Fluorine Substituted <i>α</i>-Aminophosphonic Acids Containing 1,2,4-Triazin-5-One Moiety as Antioxidant Agents

Novel fluorine substituted α-amino phosphonic acids containing 1,2,4-triazin- 5-one (6a-f) have been obtained from fluoroacylation of 6-(2&prime;-amino-5&prime;-nitrophenyl)-3-thioxo-1,2,4-triazin-5(4H)-one (1) followed by ammonilysis to give the corresponding 3-amino-derivative 3. Condensation of compound 3 with nitro/halogenated aromatic aldehydes yielded the Schiff bases 4. The simple addition of diethyl phosphonate to compound 4 produced the α-amino phosphonates 5. Acidic hydrolysis of compound 5 produced the fluorine substituted α-amino acids derivatives 6. Structures of the new compounds have been established with the help of elemental analysis and spectral measurements. Also, the products evaluated as antioxidants, where the fluorinated α-amino phosphonic acids 6 are more active than the other synthesized systems.

Synthesis and Fungicidal Activity of （E）-5-[1-（2-Oxo- 1 -oxaspiro[4,5]dec/non-3-en-3-yl）ethylidene]-2- aminoimidazolin-4-one Derivatives

The novel fungicidal agents, （E）-5-[1-（2-oxo-l-oxaspiro[4,5]dec/non-3-en-3-yl）ethylidene]-2-aminoimidazolin- 4-one derivatives, were designed and synthesized in moderate to excellent yields in four steps using a-hydroxyketone and diketene as raw materials and characterized by HR-ESI-MS, 1H NMR and X-ray diffraction. The preliminary bioassay showed that some of these compounds, such as 5e, 6a, 6e, and 7h exhibit 87.8%, 91.3%, 89.9% and 87.8% inhibition rates against Sclerotinia scleotiorum, 3b, 3c, 4c and 7h exhibit 96.4%, 92.5%, 90.3% and 76.9% inhibition rates against Phytophthora capsici at the concentration of 50 μg/mL, respectively. These compounds exhibited significant fungicidal activities against S. scleotiorum and P. capsici with EC50 values of 2.56 --11.60 μg/mL, and compounds 6e and 7h exhibited weak inhibition against the spore germination of S. scleoti- orum, while the spore germination ofP. capsici was strongly inhibited by compound 7h solution. Scanning electron microscopy （SEM） and transmission electron microscopy （TEM） observation indicated that compound 7h had a significant impact on the structure and function of the hyphal cell wall ofP. capsici mycelium.

Recent advances on controllable and selective catalytic oxidation of cyclohexene

Because of multiple potential reaction sites and variable oxidation depths,oxidation of cyclohexene can lead to a mixture of products with different oxidation states and functional groups,such as 7-oxabicyclo[4.1.0]heptane,trans/cis-cyclohexane-1,2-diol,cyclohex-2-en-1-ol,cyclohex-2-en-1-one,and even adipic acid.These products are broadly and abundantly used intermediates in the chemical industry;therefore,controllable oxidation reactions for cyclohexene that can selectively afford the targeted products are synthetically valuable for applications in both the academy and industry,thus becoming the aim of synthetic and catalytic chemists in the field.Many reports on selective oxidation of cyclohexene have recently appeared in the literature because of its significance.This short review summarizes the recent advances on this subject,and the contents are mainly classified based on the chosen oxidants.We hope that this review can provide a useful guide for controllable and selective catalytic oxidation of cyclohexene for interested readers from both the academy and industry.

Co-Catalyzed Dehydrogenation Claisen Condensation of Secondary Alcohols with Esters

Comprehensive Summary Catalytic dehydrogenation,with its exceptional atom economy and chemoselectivity,offers a highly desirable yet challenging approach for converting multiple environmentally friendly alcohols into crucial molecules.Furthermore,the utilization of catalysts based on abundant elements found on Earth for alcohol dehydrogenation to produce acryl ketone holds significant promise as a versatile strategy in synthesizing key building blocks for numerous pharmaceutical applications.The present study describes a practical Co-catalyzed cascade dehydrogenative Claisen condensation of secondary alcohols with esters,facilitating the synthesis of a wide range of 3-hydroxy-prop-2-en-1-ones.We introduce a catalytic system based on novel and scalable indazole NNP-ligands coordinated to cobalt for efficient dehydrogenations of secondary alcohols,and propose a plausible reaction mechanism supported by control experiments and labeling studies.Notably,it allows for the streamlined synthesis of multiple pharmaceuticals in one-pot.

川赤芍的化学成分分离鉴定

目的:研究川赤芍的化学成分。方法:取川赤芍(30 kg),用95%乙醇回流提取4次,提取液过滤后合并,减压浓缩得浸膏,将浸膏加水混悬后依次用石油醚、二氯甲烷、乙酸乙酯、正丁醇进行萃取,得到相应的5个部位,石油醚部分、二氯甲烷部分、乙酸乙酯部分、正丁醇部分和水部分。各部位分别采用硅胶,Sephadex LH-20,ODS柱色谱及中压制备液相,高压制备液相等方法对其进行分离纯化,得到的化合物用红外、质谱、核磁共振谱等波谱技术进行鉴定。结果:从川赤芍中分离纯化得到16个化合物,分别鉴定为(1S,5R,6R)-1,8-dihydroxypin-2-en-4-one (1),(2-hydroxyl)-phenyl-methyl-β-D-xylopyranoside(2),flufuran (3),6’-O-vanillylpaeoniflorin (4),2,5-二羟基肉桂酸甲酯(5),(1S,2S,5R,6R)-1,8-dihydroxypin-4-one (6),palbinone (7),4-O-甲基芍药苷(8),4-O-乙基芍药苷(9),苯甲酰氧化芍药苷(10),苯甲酸(11),没食子酸(12),没食子酸甲酯(13),没食子酸乙酯(14),β-谷甾醇(15),1,2,3,4,6-O-五没食子酰葡萄糖(16)。结论:其中,化合物1,2为新的天然化合物,化合物3为首次从芍药属中分离得到,化合物4~7为首次从该植物中分离得到。