近年来紫杉醇的合成研究进展

紫杉醇和多烯紫杉醇是目前销量最大的临床抗癌药物.近年来围绕紫杉醇所进行的高水平研究仍然层出不穷.综述了2008年以来紫杉醇的合成研究进展,主要涉及紫杉醇6-8-6骨架的构建、环系的合成以及侧链的制备.     

多组分反应合成紫杉醇侧链及其在合成紫杉醇衍生物中的应用

以水、重氮乙酸酯、芳香醛和芳香胺为原料,在单一催化剂Cu(OTf)2的作用下成功实现了一例基于羟基叶立德捕捉的四组分反应,一步构建了α-羟基-β-氨基酸酯类化合物骨架,并通过进一步的化学转化高效地合成了紫杉醇噁唑烷型侧链.此外,将所得侧链与紫杉醇母核、卡巴他赛母核对接,成功合成了14个紫杉醇衍生物,并在随后的抗肿瘤细胞活性测试中,发现了多个活性优异的新型化合物.将多组分反应方法学与应用相结合,开发了一种高效合成紫杉醇侧链衍生物的方法,并成功地将其应用到紫杉醇衍生物的半合成中,为该类化合物的构效关系研究提供了一种新途径,具有潜在的应用价值.     

铈对悬浮培养南方红豆杉细胞可溶性蛋白和紫杉醇合成动态的影响

研究Ce4 对悬浮培养南方红豆杉细胞可溶性蛋白和紫杉醇合成的动态影响,Ce4＋对可溶性蛋白合成和细胞活力的影响存在“分区和分叉现象,低浓度Ce4 (0.010mmol.L^-1)可显著提高可溶性蛋白的合成强度和细胞活力,高浓度Ce4 (5.00mmol.L^-1)对细胞表现为强伤害作用,适宜浓度Ce4 (1.00mmol.L^-1)在短期内可大幅度提高紫杉醇的合成速度,达到最高积累。     

紫杉醇及其修饰物的光谱研究

紫杉醇 (paclitaxel,商品名 Taxol)是二萜类化合物 [1] ,对多种肿瘤细胞模型有特殊疗效 .由于它在水中极难溶 (<0 .0 0 4 mg/m L ) ,影响了临床应用 ,有大量关于合成紫杉醇衍生物的研究 ,试图找到增大紫杉醇水溶性的途径 .我们曾用血清白蛋白修饰紫杉醇 ,使其水溶性有一定程度提高 [2 ] .本文对紫杉醇及其修饰产物进行紫外和荧光光谱研究 ,希望找到一种测定紫杉醇修饰的方法 ,并对修饰物的结构进行了讨论 .1　材料和方法1 .1　试剂和仪器　牛血清白蛋白 (Bovine serum albumin,BSA)为电泳纯 ,购自中国医学科学院血液研究所 .紫杉醇购自天…     

抗癌药物紫杉醇的全合成-Nicolaou法全合成紫杉醇的剖析

介绍和剖析了用Nicolaou法全合成紫杉醇的方法,包括合成的战略和路线,关键反应和保护基的应用等.     

紫杉醇化学半合成进展

综述了以 1 0 -去乙酰巴卡亭Ⅲ和 1 0 -去乙酰紫杉醇为前体的紫杉醇化学半合成     

紫杉醇全合成

评论了紫杉醇合成了合成战略，合成路线，逆合成分析及展望，参考文献９篇。     

苯基-硅胶色谱介质的合成及其在紫杉醇提纯中的应用

 以硅胶为基质 ,γ 氨丙基三乙氧基硅烷 (APTS)为连接臂 ,用 4种方法合成了苯基反相液相色谱介质。探讨了APTS 硅胶的合成条件 ,比较了这 4种介质用于紫杉醇纯化的分离效果 ,其中气相法合成的介质可使紫杉醇的纯度达到 77 4% ,回收率在 90 %以上。     

镧、铈对红豆杉细胞生长及紫杉醇合成与释放的影响

研究镧、铈对东北红豆杉悬浮细胞生长及紫杉醇合成与释放的影响。结果表明，当发酵液中稀土浓度较高时，均能明显改变东北红豆杉细胞的生长模式，使细胞生长的延迟期与对数期缩短，平稳期消失，并于衰亡期出现生物量的周期性振荡；在细胞生长的对数期加入稀土化合物能显著提高东北红豆杉细胞合成与释放紫杉醇的量；在加入稀土化合物的同时，补加碳源，有利于细胞合成紫杉醇。     

合成紫杉醇-奥曲肽偶联物的新方法

以紫杉醇丁二酸酯为原料,二苯基-N-琥珀酰亚胺磷酸酯为催化剂,合成了中间体N-羟基丁二酰亚胺紫杉醇丁二酸酯(3);3与游离奥曲肽偶联得紫杉醇-奥曲肽偶联物,纯度98%,其结构经ESI-MS确证。     

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.