4α-甲基-5α-胆甾烷的合成及中间体立体化研究

4-甲基甾烷类化合物是一类广泛存在于原油、油页岩中的生物标志化合物。4α-甲基-5α-胆甾烷(4)的合成已有文献报道。我们用与     

哒嗪酮类α1-肾上腺素受体拮抗剂的合成和生物活性研究

将苯(氧)乙胺和苯氧烷胺类α1-肾上腺素受体拮抗剂中的苯(氧)乙胺、苯氧烷胺片段引入哒嗪酮类化合物中,设计、合成了30个新的含哒嗪酮环的α1-肾上腺素受体拮抗剂．所有新化合物的结构均经1H NMR,IR,HRMS确证．生物活性测试表明28个目标物对α1-肾上腺素受体有较好的拮抗作用(pA2>6．00),化合物6o,6p,6q,6v,6x,6y,10c,10d的pA2值>7．00．     

1-硝基-4-芳基-3-丁烯酮类化合物的合成方法研究

4-芳基取代丁烯酮类化合物可用于合成香料、电镀、杀虫驱虫等方面,因其结构特性还可作为药物合成的中间体.本文通过α-硝化的二硫缩烯酮与芳醛在碱的催化下发生缩合反应,并脱去硫环,得到一系列1-硝基-4-芳基-3-丁烯酮类化合物.本文利用新的合成方法向4-芳基取代丁烯酮的1-位引入了硝基,使该碳原子具有更强的活性,该类化合物...     

3-羟基哌啶氮α-碳负离子的形成及α-羟烷化反应

合成了（S）-3-羟基哌啶苯硫醚化合物6作为3-羟基哌啶氮α-碳负离子手性合成子（B）的合成等效体.化合物6经羟基去质子现场保护、萘锂（LN）还原锂化形成手性哌啶醇双负离子中间体B.双负离子B可被质子淬灭得到还原产物2a 而与羰基化合物反应则得到α-羟烷化产物12～17和少量还原产物2a.该反应具有很高的环上2,3-位非对映立体选择性 与非对称的羰基化合物反应产生新手性中心的立体选择性从50：50到77：23.     

具有分子内氢键的有机化合物的合成Ⅰ.——α-二氯乙酰胺基-β-羟基-隣羟基-对硝基苯丙酮及其有关的化合物

1.本文叙述自邻氨基-对硝基乙苯开始分别经过九步或八步反应,合成α-二氯乙酰胺基-β-羟基-邻羟基对硝基苯丙酮(Ⅲ)和α-二氯乙酰胺基-β-羟基-邻甲氧基对硝基苯丙酮(Ⅳ),以及一些有关的化合物。 2.硝基化合物Ⅲ及Ⅳ均可以低亚硫酸钠还原成相应的氨基化合物,α-二氯乙酰胺基-β-羟基-邻羟基-对氨基苯丙酮(Ⅴ)和α-二氯乙酰胺基-β-羟基-邻甲氧基-对氨基苯丙酮(Ⅵ)。 3.曾试验邻羟基-对硝基苯甲醛与对硝基苯甲醛,及邻羟基-对硝基苯乙酮与邻甲氧基对硝基苯乙酮等两对化合物的抗菌效力。结果凡有氢键钳合结构的化合物均有较强的抗菌作用。 4.曾试验化合物Ⅲ,Ⅳ,Ⅴ,Ⅵ及其相应的去羟甲基化合物ⅩⅩ,ⅩⅪ,ⅩⅩⅧ和ⅩⅩⅨ对金色葡萄球菌,枯草杆菌,大肠杆菌和副伤寒菌B型的抑制作用。在此等化合物中(除去Ⅴ),凡有酚基与羰基形成钳合结构的化合物均有比较强的抗菌作用。化合物Ⅲ对金色葡萄球菌的抑制效力接近于氯霉素,但对革兰氏阴性菌的效力低于氯霉素;这种不一致的现象可能是Ⅲ的抗菌作用机理与氯霉素不同。     

3-羟基-6-腙及6-羰基-3-腙胆甾烷的合成及抗肿瘤活性评估

以胆甾醇为原料,通过不同的合成方法,制备得到8个新的具有3-羟基-6-腙及3个6-羰基-3-腙结构的胆甾烷腙衍生物,所有合成化合物都通过了IR,NMR及HRMS的结构表征.另外,采用人肝癌细胞(Bel-7404)及胃癌细胞(SGC-7901)对合成化合物的抗肿瘤活性进行了研究,结果表明所合成的3-羟基-6-腙胆甾烷衍生物对所测试的肿瘤细胞株表现出明显的生长增殖抑制活性,本研究结果为甾体抗肿瘤药物的合成研究提供了有用的参考.     

16α-溴-17-羟基对映贝壳杉烷类化合物的合成

本文合成了7和8两种作为环化前体的16α-溴-17-羟基对映贝壳杉烷类化合物. SeO~2氧化烯丙基化合物10不能得到烯基醛化合物11, 但可得到一个13-乙酰基重排反应产物12.     

3-间硝基苯基/对硝基苯基-6-芳基-1,2,4-三唑并[3,4-b]-1,3,4-噻二唑衍生物的合成

报道了以3-间硝基苯基/对硝基苯基-4-氨基-5-巯基-1,2,4-三唑与芳酸在磷酰氯的作用下,合成了16个标题化合物,并研究了合成反应的条件。观察了部分标题化合物对金黄色葡萄球菌和大肠杆菌有明显的抑菌作用。     

4-氨基-5-氰基-6-烷胺基吡啶衍生物的合成与生物活性

采用六水合硝酸锌作催化剂、少量的乙醇钠为助催化剂,使用无水乙醇作为溶剂,将2-氰基-3-烷胺基-3-氨基-丙烯腈(N,N-缩醛)与β-二羰基化合物一步关环生成了一系列目标化合物4-氨基-5-氰基-6-烷胺基吡啶衍生物.通过1H NMR,IR,EI-MS,元素分析等方法对所合成的化合物进行了结构表征.代表化合物2-甲基-4-氨基-5-氰基-6-乙醇胺基-3-乙氧羰基吡啶经单晶X衍射证实了结构.对合成的多取代吡啶衍生物化合物作了初步的农药活性测试,测试结果表明:所合成的多取代吡啶衍生物部分化合物表现出较好的杀菌活性,同时也对油菜和稗草具有一定的除草活性.     

α-羰基烯酮式环二硫代缩醛化学(V)——β,β-1,3-亚丙二硫基-α,β-不饱和芳酮类化合物的合成

β,β-二烷硫基-α,β-不饱和酮类化合物作为一类具多反应中心的活泼中间体在有机合成中的应用,近20年来已引人注目并进行了深入广泛的研究~[1,2].以往的研究大多是针对β,β-二甲硫基-α,β-不饱和酮类化合物1进行的,而对结构相近的β,β-1,3-亚丙二硫基-α,β-不饱和酮类化合物2的研究较少.对于1类的合成,所用碱的选择至关重要~[1].实验证明叔丁醇钠和叔丁醇钾~[3～5]在1类的合成中效果较好.前文~[6]曾以六甲基二硅氨基锂(LHMDS)为碱高     

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%.     

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.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

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.     

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.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.