取代均三氮杂苯氧基苯氧丙酸酯的合成及其除草活性

以三聚氯氰、二乙胺及2-(4-羟基苯氧基)丙酸酯为原料,经2步取代反应合成了2个新的取代均三氮杂苯氧基苯氧丙酸酯(4a和4b),其结构经1H NMR, IR和元素分析表征.生物活性测试结果表明,4对双子叶杂草苘麻有较好的除草活性.     

1-(三氟甲基)-1,2-苯碘酰-3(1H)-酮在芳杂环上三氟甲基化的应用研究

以1-(三氟甲基)-1,2-苯碘酰-3(1H)-酮为三氟甲基源,并以2-氨基-5-溴吡啶为三氟甲基化底物,采用响应面分析法对合成工艺进行了分析优化,确定了最佳反应条件为:反应时间4 h,催化剂用量0.16 eq,反应温度50℃.经过3次验证实验,其平均收率为87％.最后继续合成了多个三氟甲基杂环芳香胺,且化合物结构经1...     

N-[4-(三氟甲氧基)苯基]氨基甲酸苯酯的合成

以三氟甲氧基苯为起始原料，经硝化、加氢还原和酰化反应合成了N-[4-(三氟甲氧基)苯基\]氨基甲酸苯酯，总收率84.6%，纯度98.9%，其结构经¹H NMR和MS（ESI）确证。     

环保增塑剂柠檬酸三(2-乙基)己酯的合成

以柠檬酸和2-乙基己醇为原料,用结晶硫酸高铈为催化剂合成环保增塑剂柠檬酸三(2-乙基)己酯,考察了反应温度、催化剂用量、醇酸摩尔比、反应时间等因素对反应结果的影响,对合成的产品进行了红外光谱分析。实验结果表明,硫酸高铈催化合成柠檬酸三(2-乙基)己酯的最佳反应条件为n(2-乙基已醇)∶n(柠檬酸)=3.60∶1,催化剂用量为柠檬酸质量的1.5%,反应时间为90 m in,反应温度为150℃~160℃,在最佳反应条件下,柠檬酸三(2-乙基)己酯收率在98%以上。     

福司氟康唑杂质——2-(2,4-二氟苯基)-1-(1H-1,2,4-三氮唑-1-基)-3-(4H-1,2,4-三氮唑-4-基)-2-丙基磷酸二氢酯的合成

以1,3-二氟苯为起始原料,依次经傅－克酰基化,1H-三氮唑取代,环氧化,胺解,4H-三氮唑环化,磷酸酯化和钯碳加氢反应等7步反应合成了福司氟康唑的主要杂质--2-(2,4-二氟苯基-1-(1H-1,2,4-三氮唑-1-基)-3-(4H-1,2,4-三氮唑-4-基)-2-丙基磷酸二氢酯,纯度98%,总收率7.8%,其结构经¹H NMR确证。     

多官能团化的1,5-苯并二氮杂■类化合物的绿色合成

1,5-苯并二氮杂■类化合物是一类具有重要生物或药理活性的七元氮杂环化合物,酯基、羧基、酰基、芳基等均是其活性基团.在室温(25℃)下以醛羰基化合物或二羰基化合物、3-丁炔-2-酮、取代的邻苯二胺为原料,无水乙醇为溶剂,磁性纳米铁酸钴(CoFe₂O₄)为催化剂/无催化剂条件下三组分串联反应一锅绿色合成34种COR、COOR或COOH取代的1,5-苯并二氮杂■类化合物,产率最高可达90%,并提出了催化串联合成反应机理.该串联反应历经迈克尔加成反应、亲核加成反应、脱水反应、分子内的亚胺-烯胺环合反应、质子转移等反应过程,一个反应体系内合成了多官能团化的1,5-苯并二氮杂■化合物,实现了温和条件下,一个反应体系中在苯并二氮杂■的七元环上同时引入活性的酰基、酯基或羧基等多个活性基团.该方法的优势在于合成方法新颖、原子经济、目标化合物产率及选择性较高,实现了反应过程的绿色化,为绿色合成苯并氮杂■类化合物提供了新思路.     

三(4-乙酰氨基苯基)甲烷的合成

以三苯甲烷为原料,经硝化、还原和乙酰化反应合成了一种新型三芳基甲烷——三(4-乙酰氨基苯基)甲烷,纯度99.74,总收率50.6%,其结构经1H NMR,FT-IR和元素分析表征。     

增感剂DPO的合成工艺研究

以苯亚磺酸钠和氯乙酸乙酯为起始原料,首先合成苯砜乙酸乙酯(Ⅰ);再与由1,1,3,3-四甲氧基丙烷与二乙胺反应得到的N,N-双乙基胺-1,3-二丙烯醋酸盐反应,得5-二乙基氨基-2-苯磺酰基-2,4-戊二烯乙酸乙酯(Ⅱ)中间体;最后与正辛醇酯交换得到目标产物5-二乙基氨基-2-苯磺酰基-2,4-戊二烯乙酸辛酯(DPO)。考察了溶剂的种类对制备化合物Ⅰ和投料比、反应温度对制备化合物Ⅱ的影响,并且通过重结晶法纯化DPO产品,最终可使产品DPO收率达到69.58%、产品纯度大于99.50%,并通过LC-MS和1H NMR对产品及中间产品进行了结构分析与确证。     

2-乙酰基-6-三甲基硅基苯基三氟甲磺酸酯的合成

以2-三甲基硅基苯酚为原料,经甲酰化、酯化、亲核加成和氧化反应首次合成了3-乙酰基苯炔的前体——2-乙酰基-6-三甲基硅基苯基三氟甲磺酸酯,总收率35%,其结构经1H NMR和13C NMR确证。     

氯化磷酸二苯酯的合成和结构表征

以苯酚、三氯氧磷为原料,以无水三氯化铝为催化剂合成了氯化磷酸二苯酯;采用正交试验研究了反应温度、反应时间、催化剂用量和原料配比对反应收率的影响,确定了最佳工艺条件;并利用红外光谱和核磁共振谱表征了产物的结构.结果表明,影响反应收率的几种因素的排序为:反应温度>原料配比>催化剂用量>反应时间;最佳反应条件为:温度70℃、反应时间15h、原料配比(n苯酚∶n三氯氧磷)2∶1、催化剂用量0.8g(相对于苯酚的质量分数为4.25%).与此同时,采用加水后处理方法可以提高产品收率和可操作性.     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.