无溶剂条件下的不对称催化反应

本文综述了近年来在无溶剂条件下进行的一些不对称催化反应的进展, 着重介绍了无溶剂条件下的不对称Aldol反应、环氧化合物不对称开环反应、外消旋环氧化合物的拆分、不对称Diels-Alder反应、金属有机试剂对醛酮的不对称加成反应、不对称氢化反应、不对称氢甲酰化反应、不对称烯烃复分解反应、不对称Michael加成反应、不对称氧化反应、不对称Friedel-Crafts反应等, 同时展望了无溶剂不对称催化反应的研究前景。     

手性膦小分子催化不对称反应的研究进展

手性膦小分子催化的不对称反应是目前研究的热点之一,该类反应具有反应时间短、条件温和、催化活性高、环境友好等优点,符合绿色化学发展方向.对手性膦小分子催化的不对称Morita-Baylis-Hillman反应、Morita-Baylis-Hillman加成物的烯丙基位立体选择性取代反应、环加成反应、酯化反应,γ-加成反应以及其它重要的不对称反应进行简要的评述.     

高分子支载的金鸡纳生物碱催化剂在不对称催化反应中的应用进展

综述了近年来高分子支载的金鸡纳生物碱催化剂在不对称双羟基化反应、不对称Michael加成反应、活性亚胺的不对称烷基化反应以及潜手性酮的不对称还原反应中的应用及最新进展。     

有机催化不对称Michael加成反应

有机催化的不对称合成反应是目前研究最为活跃的领域之一. 不对称Michael加成反应是合成众多重要的手性合成子和药物中间体的有效手段. 目前报道的催化Michael加成反应的有机催化剂主要有脯氨酸及其衍生物、手性咪唑啉酮、手性(硫)脲、金鸡纳碱衍生物等. 对各类有机催化剂在有机催化不对称Michael加成反应中的应用, 以及不对称诱导反应的机理、催化剂分子结构及反应条件对其催化活性和不对称诱导作用的影响进行了评述.     

轴向手性膦氮配体及其在不对称催化合成中的应用

本文较为详细地综述了轴向手性膦氮配体合成及其在不对称烯丙基取代反应、不对称1,4－共轭加成反应及不对称硼氢化反应中的应用。     

手性氨基酸酰胺催化剂的发现及研究进展

自从L-脯胺酰胺被发现能高效催化不对称aldol反应以来,手性氨基酸酰胺催化剂的设计及不对称催化研究一直受到关注。特别是“烯胺-双氢键”模型的提出为设计新型有机小分子催化剂提供了理论依据,使催化剂的结构设计趋于多样化。本文重点总结了含有单氢键给体、双氢键给体及多氢键给体的氨基酸酰胺催化的不对称催化反应,主要包括不对称直接aldol反应、Mannich反应、Michael加成反应、环加成反应、串联环化反应、Biginelli反应等方面的研究进展。     

手性季鏻盐相转移催化剂在不对称反应中的应用

手性相转移催化是不对称催化领域的重要分支之一,扮演着越来越重要的角色。本论文综述了几类新型手性季鏻盐催化剂的设计合成,及其在催化不对称Henry反应、不对称氢磷酰化反应、不对称烷基化反应、不对称Michael加成反应、不对称Mannich反应、不对称aldol反应、不对称质子化反应及不对称胺化反应中的催化活性和对映选择性,重点介绍了不同催化剂和反应底物之间立体效应和电子效应的影响,并对手性季鏻盐催化剂的发展进行了展望。     

手性磺酰胺有机小分子催化剂在不对称催化反应中的应用进展

有机小分子催化的不对称合成反应是目前研究最为活跃的领域之一.综述了磺酰胺类衍生物作为小分子催化剂在不对称反应(Michael加成反应、Mannich反应、羟醛缩合反应等)中的应用,讨论了磺酰胺中NH的酸性以及氢键性质在不对称催化反应中的的作用.     

氮杂环卡宾催化烯酮与N-酰基偶氮化合物的[4＋2]环加成反应

烯酮的不对称环加成反应是合成手性杂环化合物的高效方法．近来,中国科学院化学研究所叶松等发展了手性氮杂环卡宾（NHC）催化的烯酮的不对称环加成反应新方法,实现了烯酮分别与亚胺、醛及仅肛不饱和酮反应,     

有机磷试剂在不对称反应中的应用

由于其结构多样性,有机磷化合物作为配体、催化剂、辅助剂、添加剂、底物以及试剂等在不对称反应中均获得了成功的应用,从而使有机磷试剂在不对称反应研究领域占有举足轻重的地位.本文全面介绍了本课题组近几年来围绕有机磷试剂在不对称反应中的应用,在醛的不对称硅氰化反应、内消旋环氧烷不对称开环反应、潜手性酮的不对称硼烷还原、不对称Friedel-Crafts烷基化、对映选择Mitsunobu、不对称aza-Morita-Baylis-Hillman、不对称aza-Henry以及硝基烯的不对称Michael加成反应等方面所取得的一些研究结果.     

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.     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.