四环素C-2位Mannich反应的研究

报道了四环素C-2位与伯胺、仲胺反应形成Mannich碱的简便方法:四环素盐酸盐在甲醇和水溶液中与伯胺反应,生成二级Mannich碱;四环素在叔丁醇中与仲胺反应,生成三级Mannich碱。合成了10个化合物,其中8个未见报道,并对所合成化合物的结构进行了表征。     

对-甲苯乙酮与芳香醛和芳香胺的Mannich反应

Mannich反应是合成新化合物的重要方法 [1] ,其对应的产物 Mannich碱常常具有广泛的生物活性 [2 ] .文献报道 ,对 -甲苯乙酮的 Mannich碱具有抑癌 [3]和麻醉拮抗 [4 ]等生物活性 ,但是文献中对 -甲苯乙酮 Mannich碱的合成却是从胺交换法 [5] 、酮交换法 [6] 、查耳酮与胺的 Michael加成[7] 、Schiff碱与酮的缩合 [8～ 14 ] 、β-内酰胺与有机锂的亲核裂解 [15] 等间接方法得到的 .即使是从直接法合成 ,一般也是甲醛参与的 Mannich反应 .虽然芳香醛和芳香胺同时参与的 Mannich反应已有报道 [16] ,但对 -甲苯乙酮与芳香醛和芳香胺直接进行…     

斯德酮与芳香胺的Mannich反应

3－（4－甲基苯甲酰基乙基）斯德酮和3－（3－羟基－3－苯基丙基）斯德酮 可以与芳香胺发生Mannich反应，得到斯德酮与芳香胺的Mannich碱。     

芳香胺参加的Mannich反应——3-芳氨基-3-苯基-1-(4-溴苯基)丙酮的合成

文献报道过芳香胺与苯甲醛生成的Schiff碱可在少量相应的芳香胺盐酸盐或浓盐酸催化下制备Mannich碱(Ⅰ),所用的Schiff碱系事先合成,且产率较低(15-68.9％)。本文报导用4-溴苯乙酮、苯甲醛和芳香胺在少量浓盐酸催化下能直接发生Mannich反应,     

黄芩苷元的Mannich反应

利用天然产物黄芩苷元（baicalein)在A环8－位碳上进行Mannich反应，合成 了11个新的Mannich碱化合物。反应温和，产物易纯化，收率达80％以上。同时考 察了伯胺与甲醛配比为1：2时，产物为二氢苯并E嗪类化合物和黄芩苷元A环上5－ ，6－，7－位羟基对8－位氢进行Mannich反应活性的影响。并对Mannich碱化合物 2b和2j进行盐酸成盐4b和4j，初步考察了它们的溶解度与黄芩苷元的差别。     

姜黄素Mannich碱的合成及抑菌活性

为了寻求杀菌剂的新的先导化合物,用姜黄素、甲醛和仲胺发生Mannich反应得到8个新的姜黄素Mannich碱衍生物,其结构经IR,1H NMR,13C NMR,MS和元素分析所表征.初步抑菌实验结果表明,所有姜黄素Mannich碱衍生物与姜黄素对比,对枯草杆菌、金黄色葡萄球菌、大肠杆菌、青霉、黑霉有更好的抑菌效果.这些结果表明含有哌嗪环的姜黄素Mannich碱抑制霉菌的活性明显(16.88~21.34 mm).     

2-胺甲基环十二烷酮酯类化合物的合成及其生物活性研究

环十二烷酮衍生物;Mannich碱;反应;2-胺甲基环十二烷酮酯类化合物的合成及其生物活性研究     

查尔酮Mannich碱衍生物的合成与AChE抑制活性研究

以柚皮苷为原料,经酸催化水解、O-甲基化或O-异戊烯基化反应、碱催化的开环反应合成了天然查尔酮卡瓦胡椒素A(1)和查尔酮异戊烯基醚衍生物2;然后以查尔酮1和2为底物,分别通过Mannich反应对其3'位进行了胺甲基化修饰,合成了14个未见文献报道的新型查尔酮Mannich碱衍生物3~16.所合成化合物的结构已由核磁共振谱、红外光谱和质谱所证实,并对所合成的查尔酮及其Mannich碱衍生物进行了乙酰胆碱酯酶(AChE)抑制活性测试,结果发现查尔酮Mannich碱衍生物3~5,9具有良好的AChE抑制活性.     

苯骈咪唑-N-Mannich碱与苯乙酮的交换反应

Mannich反应是在有机合成中广泛采用的反应,是甲醛与胺及含有活性氢的分子(如甲基酮等)发生缩合反应,是制备β-胺基酮类的方便方法.但一般认为芳香胺不能参加这个反应,因此,可先制成脂肪胺的Mannich碱,然后用芳香胺交换来制备β-芳胺基酮^[1-5].     

多硝基甲烷Mannich碱稳定性的理论研究

用MNDO SCF-MO方法全优化了系列多硝基甲烷Mannich碱的几何构型, 计算了它们的电子结构。在胺、醛组分相同时, 标题物>N-CH2-Y的特征键CH2-Y的键级随酸组分亲核性的增强而增大。该CH2-Y键级较小是造成Mannich碱在溶液中不稳定的重要原因。C-NO2键的键级在分子中较小, 可能是热或光解等受激分解的引发键, 从电子结构特征上阐明了以硝仿为酸组分的Mannich碱稳定性较差的原因。     

Synthesis of Mannich Bases of Meldrum's Acid and Its 5-Substituted Derivatives

Mannich bases of Meldrum's acid and its 5-substituted derivatives were synthesized using aminomethyl acetate or diaminomethane and acetic anhydride as aminomethylating agent.     

Scandium triflate-catalyzed intramolecular Friedel-Crafts acylation with Meldrum's acids: insight into the mechanism

The intramolecular Friedel-Crafts acylation of arenes with Meldrum's acid derivatives catalyzed by Sc(OTf)₃ was reported as a mild and general entry into functionalized 1-indanones. Mechanistic investigations were undertaken to determine the rate-determining step in the acylation sequence using Meldrum's acid, as well as to examine the role of the Lewis acid catalyst. Enolizable Meldrum's acid derivatives react via an acyl ketene intermediate under thermal conditions, while quaternized Meldrum's acid derivatives are thermally stable and only act as effective Friedel-Crafts acylating agents in the presence of a Lewis acid catalyst. The acylation was postulated to proceed through direct acylation of a Lewis acid-activated carbonyl. In the catalytic Friedel-Crafts acylation of Meldrum's acids, triflic acid appeared to be the active catalytic species, with Sc(OTf)₃ serving as a very mild and convenient reagent for its delivery.     

Synthesis of unsymmetrical methylene derivatives of benzopyran‐4‐ones from mannich bases

The formation of methylene‐bis derivatives of benzopyran‐4‐ones from their Mannich bases was studied. On these grounds, unsymmetrical methylene derivatives have been synthesized by reacting Mannich bases of benzopyran‐4‐ones with structurally related compounds lacking the dialkylaminomethyl group.     

Acyclic chiral amines and amino acids as inexpensive and readily tunable catalysts for the direct asymmetric three-component Mannich reaction

The direct three-component asymmetric Mannich reaction catalyzed by acyclic chiral amines or amino acids is presented. Simple acyclic chiral amines and amino acids--such as alanine-tetrazole (9), alanine, valine, and serine-catalyzed the three-component asymmetric Mannich reactions between unmodified ketones, p-anisidine, and aldehydes with high chemo- and stereoselectivity, furnishing the corresponding Mannich bases with up to >99 % ee. This study demonstrates that the whole range of amino acids in nature, as well as nonproteogenic amino acid derivatives, can be considered in the design and tuning of novel, inexpensive organocatalysts for the direct asymmetric Mannich reaction.     

Bioactive heterocyclic analogs of the antitumor drug,podophyllotoxin

3,4-Methylenedioxyphenol (sesamol) condenses with pyrrolidine and aromatic aldehydes to yield Mannich bases of type 4 . The Mannich bases react readily with ketonic reagents to form pyrrolidinylbenzopyran derivatives which provide a simple route to antimitotic and bioactive heterocyclic analogs of the anti-cancer drug, podophyllotoxin.     

异色满酮-4及其衍生物的合成(Ⅰ)

在异色满酮-4的合成中改变了介质,合成了异色满酮-4的五种O-酰基肟、六种Mannich碱、四种3-位亚甲基取代物和六种同嘧啶及吡唑并合的衍生物,并对于部分异色满酮-4的Mannich碱进行了药理试验。     

An enantioselective ketene-imine cycloaddition method for synthesis of substituted ring-fused 2-pyridinones

Previously, a method for the stereoselective synthesis of beta-lactams, starting from 2H-Delta(2)-thiazolines and Meldrum's acid derivatives, has been reported from our laboratory. We now report a new method for the synthesis of optically active, highly substituted ring-fused 2-pyridinones. This was discovered when 2-alkyl-Delta(2)-thiazolines and Meldrum's acid derivatives were treated with HCl(g) in benzene at 5 --> 78 degrees C. Further refinement of the synthetic protocol revealed that use of 1,2-dichloroethane as solvent at 0 --> 64 degrees C led to the desired 2-pyridinones in good yields and with excellent enantioselectivity. Use of these conditions allowed preparation of 2-pyridinones from several different Delta(2)-thiazolines and Meldrum's acid derivatives and may be a general route to 2-pyridinones.     

A New Investigation of Mannich Reaction

Mannich reaction is widely used for the synthesis of many kinds of compounds1. In the synthesis of the derivatives of styryl ketonic Mannich bases, a one-pot method is used, in which ketone, secondary-amine hydrochloride, paraformaldehyde are refluxed together in alcohol2,3. In most cases the normal Mannich product MA is obtained. But when certain amine is used as the reactant, a side-product IM, instead of MA is obtained. MS and 1HNMR data indicate that compound IM is a new type of Man…     

Synthesis and Reactivity of Mannich Bases. XVIII. Reaction of Dithiocarbamic Acid Salts With Mannich Bases Derived from Ortho-Hydroxyacetophenones

The reaction of Mannich bases derived from ortho-hydroxyacetophenones with N,N-dialkyldithiocarbamic acid salts result in the formation of the corresponding dithiocarbamic acid esters via an amine moiety replacement when the process is conducted in cold water. Attempts to carry out the synthesis in refluxing ethanol-water mixture led to the insertion of carbon sulfide at the C—N bond in Mannich bases. N-Aryldithiocarbamic acid salts afforded on reaction with the above-mentioned Mannich bases only bis-(2-(2-hydroxybenzoyl)ethyl)thioethers.     

New aminoalkyl and vinyl derivatives of pyridine and quinoline

New bases have been obtained by the Mannich reaction from 2-methyl-5-vinylpyridine and from 2,4-dimethylquinoline. Decomposition of quaternary salts of these bases has yielded previously unknown vinyl derivatives of pyridine and quinoline.