石香薷中两个新黄酮甙的研究

石香薷中两个新黄酮甙的研究郑尚珍，孙丽萍，沈序维王毅（西北师范大学化学系，兰州，７３００７０）（中国科学院兰州化学物理研究所）关键词石香薷，唇形科，黄酮甙唇形科植物石香薷（ＭＯｓｌａｃｈｉｎｅｎｓｉｓＭａｘｉｍ）作为中药，用来治疗暑湿感冒、头痛、腹痛...     

四种药用香薷植物中多种微量元素分析

对高原香薷、萼果香薷、密花香薷、细穗香薷等四种药用香薷植物中的17种微量元素含量进行了测定和分析。结果表明,4种香薷植物中常量元素以K含量最高,其次为Ca、Mg、Na;必需微量元素中以Cu、Fe、Mn元素的含量为高;非必需微量元素As、Hg、Pb、Cd、Sb含量较低,从重金属元素的角度考虑,使用所测定的4种香薷植物是安全的。     

有效合成5—硝基呋喃烯衍生物

报道了一种有效合成５－硝基呋喃烯衍生物的方法。在常温、弱碱Ｋ２ＣＯ３存在下（ｔｒａｃｅＨ２Ｏ），５－硝基呋喃亚甲基溴化钾盐与芳醛反应，高产率、高立体选择性地得到５－硝基呋喃烯衍生物。     

噻吩基和呋喃基四硫富瓦烯的合成及电化学性质

提供了一种合成噻吩基和呋喃基四硫富有瓦烯（ＴＴＦ）的方法，并用其合成了３种未见文献报道的噻吩基ＴＴＦ（Ⅶａ，Ⅷｂ，Ⅶｃ）和２种呋喃基ＴＴＦ（Ⅶｄ１，Ⅶｄ２）研究这些化合物的循环伏安行为及有关电化学性质，制得了一种Ⅶｂ与ＴＣＮＱ反应生成的电荷转移络合物，讨论了噻吩基ＴＴＦ和呋喃基ＴＴＦ在产物构型和电化学性质方面的差别。     

α-呋喃酯类化合物在EI电离条件下的质谱特征

总结和归属了α－呋喃甲酸酯、α－呋喃甲醇酯、α－呋喃丙烯酸酯以及α－呋喃环在电子电离质谱（ＥＩＭＳ）中的主要裂解方式和特征,给出各化合物主要碎片离子的来源和结构。上述３类不同α－呋喃酯在ＥＩＭＳ中的基峰离子分别为９５、８１和１２１。α－呋喃离子是３类α－呋喃酯的共同碎片离子,由其裂解产生的２９、３８和４１的碎片离子也是３类α－呋喃酯的共同特征离子     

取代苯基呋喃甲酸长链烷基酯的合成及生物活性

取代苯基呋喃甲酸长链烷基酯的合成及生物活性司宗兴＊孙亚秋汪海涛（中国农业大学应用化学系北京１０００９４）关键词苯基呋喃甲酸酯，合成，杀菌活性１９９６－０６－１７收稿，１９９６－１２－０５修回取代芳基呋喃甲酸是一类很好的活性基团，它的酯在医学上用做镇痛...     

乙醇胺合三（2－呋喃基）硼烷的分子和晶体结构

标题化合物乙醇胺合三（２－呋喃基）硼烷Ｃ＿（１４）Ｈ＿（１６）ＢＮＯ（Ｍｒ＝２７３．１０）的晶体属单斜晶系，空间群为Ｐ２＿１／ｃ，晶胞参数ａ＝１０．０５３（２），ｂ＝８．２１１（９），ｃ＝１６．５０９（２），β＝９５．０９°，Ｖ＝１３５７．３（７），Ｚ＝４，Ｄ＿ｃ＝１．３３ｇ／ｃｍ￣３，μ（ＭｏＫα）＝０．９０１ｃｍ￣（－１）。结构的偏离因子Ｒ＝０．０４５，Ｒ＿ｗ＝０．０４９。结构测定表明，呋喃环对硼原子的π电子反馈导致Ｂ─Ｃ键长极明显地缩短。由此可解释呋喃环与硼成键时所特有的共生倾向。     

呋喃甲酸酯与三氯乙醛缩合反应研究

系统地研究了呋喃甲酸酯与三氯乙醛的缩合反应规律，提出了路易斯酸催化该反应的机制。当呋喃酸酯：无水三氯乙醛：三氯化铝（摩尔比）为２：１：１时，在６０～７０℃下反应６ｈ双分子缩合产物的收率为５３～７５％。     

乙醇胺合三（2－呋喃基）硼烷的分子和晶体结构

标题化合物乙醇胺合三（２－呋喃基）硼烷Ｃ＿（１４）Ｈ＿（１６）ＢＮＯ（Ｍｒ＝２７３．１０）的晶体属单斜晶系，空间群为Ｐ２＿１／ｃ，晶胞参数ａ＝１０．０５３（２），ｂ＝８．２１１（９），ｃ＝１６．５０９（２），β＝９５．０９°，Ｖ＝１３５７．３（７），Ｚ＝４，Ｄ＿ｃ＝１．３３ｇ／ｃｍ￣３，μ（ＭｏＫα）＝０．９０１ｃｍ￣（－１）。结构的偏离因子Ｒ＝０．０４５，Ｒ＿ｗ＝０．０４９。结构测定表明，呋喃环对硼原子的π电子反馈导致Ｂ─Ｃ键长极明显地缩短。由此可解释呋喃环与硼成键时所特有的共生倾向。     

5－O－苯甲酰基－2，3－二脱氧－3－硝基－D－呋喃戊糖甲苷的合成研究

５－Ｏ－苯甲酰基－２，３－二脱氧－３－硝基－Ｄ－呋喃戊糖甲苷的合成研究史达清，周龙虎，高原，戴桂元（徐州师范学院化学系，徐州，２２１００９）关键词呋喃戊糖苷，Ｄ－木糖，异构化，合成５－Ｏ－苯甲酰基－２，３－二脱氧－３－硝基－Ｄ呋喃戊糖甲苷１是合成河豚...     

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%.     

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.     

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.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.     

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.