离子液体[bmim]Cl/AlCl_3催化5-氰基吲哚酰化反应

5-氰基吲哚与4-氯丁酰氯之间的傅-克酰化反应使用路易斯酸之类的催化剂(如AlCl3、FeCl3),反应产物复杂,无法分离出期望的产物5-氰基-3-(4-氯丁酰基)吲哚。在离子液体[bmim]Cl/AlCl3中,进行5-氰基吲哚与4-氯丁酰氯间的傅-克酰化反应,则反应的主产物是5-氰基-3-(4-氯丁酰基)吲哚,产物结构通过质谱与核磁共振氢谱表征。考察了[bmim]Cl/AlCl3中AlCl3与[bmim]Cl间的摩尔比以及[bmim]Cl/AlCl3与5-氰基吲哚的摩尔比对该酰化反应的影响。结果表明,当n(AlCl3)∶n([bmim]Cl)=2.5∶1,n([bmim]Cl/AlCl3)∶n(5-氰基吲哚)=2∶1,室温下反应24 h,最大产率71.7%。     

胆酸甲酯羟基酰化反应活性研究

以甲基丙烯酰氯、甲基丙烯酸酐和甲基丙烯酸作酰化剂,研究了胆酸甲酯分子中羟基的反应活性.结果显示,与三种活性不同的酰化试剂作用时,胆酸甲酯分子甾体骨架上三个仲羟基的相对反应活性不同.     

胆酸酯及其甲基丙烯酸衍生物的制备

以HCl为催化剂,合成了脂肪族二元醇单胆酸酯(2~5)。运用甲基丙烯酰氯和甲基丙烯酸酐作酰化试剂,三乙胺作缚酸剂,4-(二甲氨基)吡啶作催化剂,合成了分子中含有不同数量甲基丙酰基的胆酸衍生物(6~9)。实验结果表明,当用甲基丙烯酰氯作酰化剂时,2~5分子中羟基的反应活性顺序是:CH2-OH>3-OH>12-OH>7-OH。     

无溶剂合成酰基二茂铁的新方法

以二茂铁为原料,乙酸酐、丙酸酐、丁酸酐和苯甲酸酐为酰化剂,45%~47%三氟化硼乙醚溶液为催化剂,无溶剂合成了4种酰基二茂铁,总产率81%~92%,其结构经¹H NMR和¹³C NMR确证。     

胆酸甲酯(甲基)丙烯酰基衍生物的合成

以(甲基)丙烯酰氯为酰化剂,三乙胺做缚酸剂合成了分子中含有1~3个(甲基)丙烯酰基的胆酸衍生物。结果显示,以酰氯作酰化试剂,胆酸甲酯分子中3个羟基的反应活性顺序是:C3-OH>C12-OH>C7-OH。     

无溶剂条件下ZnBr2催化醇与苯甲酸酐的酰化反应

以溴化锌为催化剂,在无溶剂条件下实现了醇与苯甲酸酐的酰化反应,部分产物经NMR和IR表征。     

α-乙酰基二硫缩烯酮α碳原子的酰化反应

进行了α-乙酰基二硫缩烯酮与酰氯的酰化反应. 以干燥的二氯甲烷为溶剂, 在四氯化钛催化下, α-乙酰基环二硫缩烯酮(1)可与脂肪及芳酰氯(2)反应, 在化合物1的α-碳原子上发生酰化反应, 以较高的产率生成各种α-乙酰基-α-酰基二硫缩烯酮(3).     

用高浓度杂多酸溶液催化苯甲醚与乙酸酐的酰化反应

芳香化合物经Friedel-Crafts酰化反应制备药物和香料中间体芳香酮是近年来人们感兴趣的课题^[1-4]。用于该反应的传统催化剂是Lewis酸金属氯化物。由于反应过程中催化剂可与酰化试剂羧基产物形成配合物,因而催化剂用量大,且所形成的配合物水解后产生大量废液。为了减少环境污染,人们已成功地用分子筛催化剂代替传统催化剂催化芳香化合物的酰化反应^[5-7]。其中包括用分子筛催化各种芳香化合物与乙酸酐的酰化反应^[8]。我们已经研究了用杂多酸－乙酸浓溶液催化异丁烷与丁烯的烷基化反应^[9,10],以及烯烃与羧酸的直接酯化反应^[11]。本文将报道杂多酸－乙酸浓溶液对苯甲醚与乙酸酐酰化反应的催化活性。     

在氯化亚锡存在下2,3-二甲基-2-丁烯与乙酐的催化酰化反应

一种新的催化剂,SnCl2·2H2O,已用于2,3-二甲基-2-丁烯与乙酐的酰化反应来制备高产率的3,3,4-三甲基-4-戊烯-2-酮 (TMP). 发现SnCl2·2H2O是室温下2,3-二甲基-2-丁烯与乙酐进行酰化反应的有效催化剂. 考察了催化剂用量、乙酐用量、反应时间和溶剂的加入等因素对该酰化反应的影响. 发现当催化剂/2,3-二甲基-2-丁烯摩尔比在0.30/1和 0.60/1之间、反应时间为2 h时,所得酰化产品的产率最高. 该酰化反应进行到完全所需的时间取决于催化剂用量和乙酐用量. 在需要加入溶剂的情况下,二氯甲烷或氯仿是一种合适的溶剂.     

Nafion功能化介孔催化剂上苯甲醚/苯甲酰氯酰基化反应研究

苯甲醚/苯甲酰氯的酰基化产物4-甲氧基二苯甲酮是多种精细化工产品的重要中间体. 本工作主要介绍了Nafion负载型SBA-15, SBA-16及Me-SBA-15介孔超强酸催化剂的制备及其在苯甲醚/苯甲酰氯酰基化反应中的应用. 实验结果表明, 单位时间单位Nafion活性位上的苯甲酰氯转化数高于传统HBeta沸石和硫酸氧化锆, 且载量的增加能显著提高酰基化催化性能. 甲基修饰的Me-SBA-15介孔材料明显改善了催化剂表面的疏水性能, 有效减缓了多聚芳烃副产物的生成, 反应的转化率得到大幅提高. 相对一维孔道结构的介孔SBA-15而言, 三维笼状结构的SBA-16对反应物及产物分子具有更好的扩散性能, 该结构优势由酰基化反应的高初始活性得以充分体现. 在整个反应过程中, 该类催化剂对4-甲氧基二苯甲酮具有专一的选择性.     

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.