从肌苷简便合成腺苷

在不改变骨架的前提下提出一种从肌苷通过官能团转换制备腺苷的工艺方法,总收率可达62%。肌苷在醋酸钠存在下与醋酸酐发生酯化反应以92%的收率得到2′,3′,5′-三乙酰肌苷,其化合物经吡啶和三氯氧磷处理形成吡啶盐溶液,未分离直接在40℃、0.25～0.30MPa压力下进行氨解反应以67%产率制得腺苷。腺苷结构经1HNMR、MS测试技术确证。这种简便的腺苷合成方法可适合于工业化生产。     

原料气中添加CO对CO_2在铜基催化剂上加氢反应的促进作用(英文)

研究了CO2在Cu－Zn－Al催化剂上的加氢合成甲醇反应。发现在原料气中添加少量的CO可提高甲醇的选择性和收率。TPD和TPSR结果表明,CO占据催化剂表面部分活性位并抑制CO2的逆水煤气转换,促进了甲醇的生成。     

新型染料敏化剂三苯基咪唑丙烯酸的合成及其光电性能

以苯偶姻、苯甲醛和丙二酸为原料经3步反应合成了新型三苯基咪唑系染料敏化剂(TPIA),其结构经1H NMR,13C NMR,IR和MS表征,并分析了咪唑的环化反应机理。将TPIA用于染料敏化太阳能电池染料敏化剂,表明TPIA具有良好的光电转换性能,TPIA的乙醇饱和溶液吸附敏化光阳极24 h的DSSC光电转换效率为1.90%,填充因子为74.5%。     

锕系端基亚胺金属有机化合物研究进展

在过去的30多年中,锕系端基亚胺金属有机化合物因其具有独特的结构特征以及在基团转换与催化方面的潜在应用而受到人们的广泛研究,并取得了一些很好的成果.目前,锕系端基亚胺金属有机化合物已成为金属有机化学领域中一个引人注目的研究热点.这篇综述主要介绍了锕系端基亚胺金属有机化合物在合成及反应性能方面的研究进展.     

单萜吲哚生物碱Alstonerine的合成研究进展

Alstonerine属于单萜吲哚生物碱,除其结构很有特征外,还报道对两株人肺癌细胞具有细胞毒性,因此,它自然就成为合成化学的重要目标.已经有多种合成策略用于构建这个结构体系:包括Pictet-Spengler反应和Dieckmann缩合反应、烯烃复分解关环反应、膦配体催化的[4+2]关环/Friedel-Craft环化、氮杂-Diels-Alder反应/分子内Heck反应、Pauson-Khand反应等.本工作根据构建环系的不同反应系统总结了Alstonerine的合成方法.大部分合成反应步骤较多,适合工业生产的有效合成方法还有待于进一步探索.     

基于刻蚀反应的纳米结构空心化（英文）

中空纳米材料的可控合成使其在催化、能量转换与储存、生物医药等领域具有广阔的应用前景.本专论旨在揭示刻蚀反应对纳米结构空心过程的关键影响.讨论了通过增强纳米粒子表面在刻蚀液中的相对稳定性来精确操纵中空化过程的策略,主要关注3种刻蚀策略,包括硬模板法、氧化还原辅助中空法和表面钝化自模板法.最后,对基于刻蚀反应的纳米结构空心化可控合成未来的发展方向进行了展望.     

高分子量PPV的合成、掺杂及导电性

高分子量的聚对苯乙炔（ＰＰＶ）是从单体１．４一二氯甲基苯合成,后者聚合产生水溶性铳盐,此时,对于ＰＰＶ的转换可用二甲硫醚和盐酸的热消除反应,从水溶液中成膜。用ＩＲ、ＵＶ－Ｖｉｓ、ＴＧＡ分析研究了消除反应。ＰＰＶ膜具有良好的机械性能,而且可能是由于ｎ－和ｐ－型杂质得到的材料具有的导电性近似于这些高掺杂聚乙炔。中间聚电解质的转换率对于ＰＰＶ可能是一种调整,并且这些掺杂膜的导电性,可能与平均共轭长度有关     

新型2-硫杂-5-氮杂双环[2.2.1]庚-3-酮衍生物的合成

以反式-4-羟基-L-脯氨酸为原料,经氮烷基化、酯化、磺酰化、硫代乙酸钾反应构型转换、水解酯基、缩合和成盐反应合成了5个新型的(2S,4S)-5-烷基-2-硫杂-5-氮杂双环[2.2.1]庚-3-酮衍生物,其结构经1H NMR和MS表征。     

无外相的葡聚糖凝胶的合成

本文研究了无外相的葡聚糖凝胶的合成方法以及有关的催化剂用量,糖液浓度,反应时间,反应温度,交联剂用量和不同分子量的葡聚糖与合成凝胶的性能关系,并确定了最佳反应条件,从而制得了性能类似国外同类产品Sephadex的凝胶。     

微波干法有机合成研究进展

摘要：本文综述了近年来微波无溶剂有机合成如保护与脱保护反应,缩合反应,成环反应,氧化—还原反应,加成反应,酰化反应,偶联反应及水解反应的进展。参考文献36篇。     

Synthesis of 1,3‐Amino Alcohols by Hydroxy‐Directed Aziridination and Aziridine Hydrosilylation

We describe an approach to N‐tosyl 1,3‐amino alcohols that consists of a diastereoselective aziridination reaction of acyclic allylic alcohols and an unprecedented regioselective hydrosilylation of α‐hydroxy aziridines. The products contain up to three contiguous stereocenters. Computational studies outline key aspects of the aziridination mechanism, which is different and more intricate than anticipated.     

Multicomponent catalytic asymmetric aziridination of aldehydes

The first multicomponent catalytic asymmetric aziridination reaction is developed to give aziridine-2-carboxylic esters with very high diastereo- and enantioselectivity from aromatic and aliphatic aldehydes. This new method pushes the boundary of the aziridination reaction to substrates that failed with preformed imines.     

Stereochemical aspects of the iodine(III)-mediated aziridination reaction of some cyclic allylic carbamates

[reaction: see text] The iodine(III)-mediated aziridination reaction of an indolyl-substituted carbamate requires a Rh(II) catalyst and proceeds by a metallonitrene intermediate. Stepwise addition across the indole pi-bond followed by Rh(II) detachment generates a metal-free zwitterion, which ultimately leads to the observed products. In contrast, intramolecular aziridination of several cycloalkenyl carbamates does not require a Rh(II) catalyst and occurs via an iminoiodinane intermediate.     

Guanidinium ylide mediated aziridination: identification of a spiro imidazolidine-oxazolidine intermediate

We successfully isolated a spiro imidazolidine-oxazolidine intermediate in the reaction of guanidinium ylide mediated aziridination using alpha-bromocinnamaldehyde. X-ray crystallographic analysis unambiguously revealed that the stereogenic centers of the spiro intermediate were in a trans configuration. The role of the spiro compound as an intermediate in the aziridination reaction was confirmed by observation of its smooth chemical conversion into aziridine products.     

NBS‐Mediated Aziridination between Styrenes and Amides under Transition Metal‐Free Conditions

An efficient and simple protocol for N‐bromosuccinimide (NBS)‐mediated styrenes aziridination using amides as the nitrenoid source has been developed. This aziridination affords desired products in moderate to good yields without using transition metal catalyst under very mild reaction condition.     

N-tosyloxycarbamates as a source of metal nitrenes: rhodium-catalyzed C-H insertion and aziridination reactions

The rhodium-catalyzed decomposition of N-tosyloxycarbamates to generate metal nitrenes which undergo intramolecular C-H insertion or aziridination reaction is described. Aliphatic N-tosyloxycarbamates produce oxazolidinones with high yields and stereospecificity through insertion in benzylic, tertiary, and secondary C-H bonds. Intramolecular aziridination occurs with allylic N-tosyloxycarbamates to produce aziridines as single diastereomers. The reaction proceeds at room temperature using a rhodium catalyst and an excess of potassium carbonate and does not require the use of strong oxidant, such as hypervalent iodine reagents. A rhodium nitrene species is presumably involved, as both reactions are stereospecific.     

Practical aziridinations II: electronic modifications to poly(pyrazolyl)borate-copper catalysts

A significant influence of the electronic features of poly(pyrazolyl)borate ligands on the efficiency of the copper-catalyzed aziridination reaction has been noted. Electron-deficient, bidentate di(pyrazolyl)borates in conjunction with copper(II) chloride generated the most effective catalyst system for the aziridination of a variety of olefins.     

Iron(III) porphyrin catalyzed aziridination of alkenes with bromamine-T as nitrene source

[reaction: see text] Iron(III) porphyrin complexes Fe(Por)Cl are effective catalysts for aziridination of alkenes using bromamine-T as the nitrene source. The catalytic system can operate under mild conditions with alkenes as limiting reagents. The aziridination reaction is general and suitable for a wide variety of alkenes, including aromatic, aliphatic, cyclic, and acyclic olefins, as well as alpha,beta-unsaturated esters. For 1,2-disubstituted olefins, the reactions proceeded with moderate to low stereospecificity.     

Copper-nitrenoid formation and transfer in catalytic olefin aziridination utilizing chelating 2-pyridylsulfonyl moieties

We have developed an efficient protocol for copper-catalyzed olefin aziridination using 5-methyl-2-pyridinesulfonamide or 2-pyridinesulfonyl azide as the nitrenoid source. The presence of a 2-pyridyl group significantly facilitates aziridination, suggesting that the reaction is driven by the favorable formation of a pyridyl-coordinated nitrenoid intermediate. Using this chelation-assisted strategy, synthetically acceptable yields of aziridines could be obtained with a range of aryl olefins even in the absence of external ligands. Importantly, a large excess of olefin is not required. X-ray crystallography, ESI-MS, Hammett plot analysis, kinetic studies, and computational undertakings strongly support that the observed aziridination is driven by internal coordination.     

Aryl iodide mediated aziridination of alkenes

[reaction: see text] Aryl iodide mediated aziridination of a variety of alkenes with N-aminophthalimide under mild conditions (m-CPBA, K2CO3, CH2Cl2, 25 degrees C) was achieved in moderate to good yields (up to 94%). By recovering the aryl iodide, a recyclable system is developed with product yield over 79% attained for the aziridination of trans-1,2-diphenylethylene.