四氢叶酸辅酶模型的合成及甲基取代的一碳单元转移反应

本文报道了甲基取代的甲酸态的四氢叶酸辅酶模型--碘化1, 2-二甲基-3-对氯苯磺酰基咪唑啉的合成。研究了模型与单官能团亲核体(苯胺、对氯苯胺、对硝基苯胺)和双官能团亲核体(邻苯二胺、邻氨基酚、乙二胺)作用, 转移甲基取代的一碳单元的反应。     

四氢叶酸辅酶结构和性能的模拟及取代一碳单元转移反应的研究

本工作模拟了四氢叶酸辅酶的结构和反应性能, 合成了模型化合物碘化1, 2-二甲基-3-对甲氧苯磺酰基咪唑啉, 研究了模型化合物与单官能团亲核体、双官能团亲核体相作用, 以甲酸、甲醛氧化态转移取代一碳单元[≡C-CH~3, =C(CH~3)CH~2NO~2]的反应, 部分反应生成了咔啉类生物碱衍生物和其它杂环类化合物。     

甲基取代的甲酸态的四氢叶酸辅酶模型的合成及其取代碳单元转移反应

以乙二胺和乙酰胺为原料,经4步反应合成了碘化1,2-二甲基-3-间(或对)-硝基苯磺酰基咪唑啉(2a,2b),以2a和2b作为甲基取代的甲酸态四氢叶酸辅酶模型,同单亲核中心的氮亲核体(对甲苯胺,对甲氧基苯胺等)和碳亲核体(丙二腈)反应得到次乙基单元(CH₃-C>)转移的中间体产物;与双亲核中心的亲核体(邻苯二胺,邻氨基酚)反应得到次乙基单元完全转移的产物。     

甲基取代的甲酸态的四氢叶酸辅酶模型的合成及其取代碳 …

以乙二胺和乙酰胺为原料，经４步反应合成了碘化１，２－二甲基－３－间（或对）－硝基苯磺酰基咪唑啉（２ａ，２ｂ）以２ａ和２ｂ作为甲基取代的甲酸态四氢叶酸辅酶模型，同单亲核中心的氮亲核体（对甲苯胺，对甲氧基苯胺等）和碳亲核体（丙二腈）反应得到次惭基单元（ＣＨ３－Ｃ≤）转移的中间体产物，与双亲核中心的亲核体（邻苯二胺，邻氨基酚）反应得到次乙基单元完全转移的产物。     

四氢叶酸模型化合物咪唑啉盐的基团转移反应

合成了2种四氢叶酸辅酶模型化合物咪唑啉盐7和8. 它们与双官能团亲核体作用, 分别完全转移了3个和5个碳单元; 化合物7与单官能团亲核体作用, 部分转移了3个碳单元; 以部分转移产物化合物17作为四氢叶酸甲醛态模型, 与胺类反应实现了带硝基的4个碳单元的完全转移; 并研究了模型化合物7的还原反应. 这些反应模拟并扩展了四氢叶酸辅酶在生物体内转移一碳单元的功能, 产生了几种新的合成方法和试剂, 可以应用于有机合成中.     

四氢叶酸辅酶模型化合物的研究Ⅱ .碘化 1 ,2 -二甲基 - 3-芳磺酰基 -△~2 -咪唑啉的一碳单元转移反应

四氢叶酸辅酶模型化合物与邻苯二胺、乙二胺、邻氨基酚作用则得到相应的一碳单元转移,而与芳胺、丙二腈碳负离子以及苯基溴化镁反应分别生成辅酶模型化合物的衍生物。讨论了其可能的一碳单元转移机制。     

N,N,N'-不同基团三取代乙二胺衍生物的简便合成

以2-取代咪唑啉为起始原料,经过磺酰化反应,得到磺酰基咪唑啉2a-2e,然后进行甲基化反应得到1,2,3-三取代咪唑啉碘盐3a-3e。化合物3在室温下经过水解反应或还原反应,可得到两类不同基团N,N,N'-三取代乙二胺衍生物4或5。该反应具有条件温和、副产物少、产物得率高和后处理简单等优点,提供了一种有效的三步合成不同基团N,N,N'-三取代乙二胺衍生物的新方法。所合成产物通过NMR、IR和元素分析方法进行了结构确证。     

四氢叶酸辅酶模型化合物的研究：Ⅱ.碘化1,2—二甲基—3—芳磺酰基—△^ …

四氢叶酸辅酶模型化合物与邻苯二胺、乙二胺、邻氨基酚作用则得到的相应的一碳单元转移，而与芳胺、丙二腈碳负离子以及苯基溴化镁反应分别生成辅酶模型化合物的衍生物。讨论了其可能的一碳单元转移机制。     

四氢叶酸辅酶模型化合物的研究I.碘化 1 ,2 -二甲基 - 3-芳磺酰基 -△~2 -咪唑啉的合成及其性质

合成了四氢叶酸辅酶甲酸态的3个模型化合物,即碘化1,2-二甲基-3-芳磺酰基(芳基=p-CH3C6H4,C6H5,p-ClC6H4)-△2-咪唑啉,研究了其还原和水解反应。     

苯并咪唑盐与胺类化合物的加成-水解反应研究

四氢叶酸辅酶在生物体内的生物合成过程中的作用是转移不同氧化态的一碳单元.本课题组曾首次提出并报道了苯并咪唑盐作为四氢叶酸辅酶的模型化合物,并研究了该模型化合物与多种格利雅试剂和丙二酸二乙酯碳负离子等反应,实现了一碳单元的转移反应,为许多醛、酮和β-羰基酸等有机化合物提供了仿生合成新方法[1,2].本文对苯并咪唑盐与亲核试剂胺类化合物的加成-水解反应进行了研究,提出了苯并咪唑盐的另一种新反应,为一些酰胺类化合物提供了一种未见文献报道的重要仿生合成新方法.     

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.