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分子的自分类性在乙酰甲基碳键联成烯新反应中的应用

Application of Molecular Self-Sorting Property in Novel Carbon-Carbon Bond-Forming Reaction via Coupling of Acetyl Methyl Carbon

【作者】 殷国栋

【导师】 吴安心;

【作者基本信息】 华中师范大学 , 有机化学, 2008, 博士

【摘要】 环境友好、简便高效和原子经济的方法是有机合成发展的必然趋势。串级反应和多组分反应就是考虑原子经济性、高效率和绿色化学等要求而迅速发展起来的可以一锅多步合成复杂目标化合物的一类新颖的合成策略。集群分子的自分类行为在自然和生命体系中是一个很普遍的现象,它是在复杂的体系中分子间相互作用的一种区别自我和非自我的能力。本论文以分子的自分类行为为切入点而提出了一种新的多线路串级并联的合成反应策略——自分类串级反应,以此建立了芳基乙酮(或α,β-不饱和甲基酮)二聚偶联成碳碳双键的反应,并在此基础上实现了一系列硫甲基取代五元杂环化合物的合成;此外,在研究该反应的机理过程中建立了羰基化合物的碘化和芳香酮转化为芳基羧酸酯的方法。具体内容如下:第一章,碳碳键的形成可以说是构筑有机分子骨架最重要的反应,我们根据反应底物中C-H键的碳杂化类型(sp、sp2及sp3)概述了分子间碳碳键偶联的主要方式,并引入分子的自分类性,提出了本论文的设想和研究思路。第二章,基于对集群分子自分类现象的认识,建立了一种与传统的串级反应和多组分反应明显不同的反应模式——自分类串级反应,实现了在CuO/I2/DMSO体系中芳基乙酮二聚偶联成碳碳双键产物2-硫甲基-2-烯-1,4-二酮Ⅱ-5,并通过4-氯苯乙酮和2-乙酰基噻吩两种底物间的交叉偶联反应对其反应机理进行了验证。所有化合物都通过了1H NMR,13C NMR,IR和MS表征,且(Z)-Ⅱ-5、(E)-Ⅱ-5和(Z)-Ⅱ-12的结构也得到了X-ray单晶衍射的进一步证实。第三章,首先通过经典的羟醛缩合反应制备了12种α,β-不饱和甲基酮Ⅲ-2,并实现了在CuO/I2/DMSO条件下分子间sp3甲基碳直接偶联成烯Ⅲ-3,其中化合物(E)-Ⅲ-3e的结构得到了X-ray单晶衍射的验证。第四章,以SnCl2/AcOH/HCl为反应条件通过串级反应将不饱和1,4-二酮Ⅱ-5有效地转化为关环后的产物3-硫甲基-2,5-二芳基三取代的呋喃Ⅳ-16。用液溴处理Ⅳ-16或用30%的HBr-AcOH溶液直接与Ⅱ-5反应后都生成了4-溴-3-硫甲基-2,5-二芳基四取代的呋喃Ⅳ-19。在乙醇中用Raney Ni进行脱硫甲基处理Ⅳ-16以很好的分离收率得到了2,5-二芳基呋喃Ⅳ-20。接下来我们以KI/HCl体系实现了Ⅱ-5中碳碳双键选择性还原为饱和的1,4-二酮Ⅳ-22,在酸性条件下用HCOONH4处理Ⅳ-22后得到了Paal-Knorr胺环化产物3.硫甲基-2,5-二芳基吡咯Ⅳ-23,而用Lawesson’s试剂处理后则得到3-硫甲基-2,5-二芳基噻吩Ⅳ-24。所有合成的化合物都通过了波谱表征,且Ⅳ-16b和Ⅳ-22c得到了X-ray单晶衍射的证实。第五章,以CuO/I2组合体系,在回流的甲醇中有效实现了羰基化合物的α-碘化反应。通过对反应机理的探讨,我们发现氧化铜在反应中通过随机自分类起着多重角色的作用。第六章,在第三章和第五章的研究基础上,以CuO/I2组合体系,实现了α,β-不饱和酮α’位置的选择性碘化,而碳碳双键和芳环并不受其影响。本章首次系统性地研究了α,β-不饱和酮向重要的中间体α,β-不饱和α’-碘代酮的直接转化。第七章,在碘、吡啶和碳酸钾的醇介质中,有效地实现了将芳基(或杂芳基)甲基酮、β-酮酸酯或三氟甲基取代的β-二酮直接转化为相应的芳基羧酸酯,机理表明反应过程中伴随着碳碳键的裂解。

【Abstract】 Environmentally friendly,simple,highly efficient and atomic-economic method is developing trend of organic synthetic chemistry.Considering of atomic-economy,highly efficiency and green chemistry,tandem reaction and multicomponent reaction strategies have been rapidly developed in recent years.Sometimes,complicated compounds can be obtained in one-pot and multi-step reaction via these synthetic strategies.Self-sorting behavior of molecular cluster-the ability to efficiently distinguish between self and nonself-is common property in complicated system.A novel synthetic reaction strategy-self-sorting tandem reaction which is a parallel tandem reaction pattern-is presented based on molecular self-sorting property in this thesis.Accordingly,an efficient carbon-carbon double bond-forming reaction from aryl methyl ketones(orα,β-unsaturated methyl ketones) is developed and a series of methylthio substituted five-numbered heterocycles are synthesized.In addition,new methods for iodination of carbonyl compounds and for convertion of aromatic ketones to the corresponding arenecarboxylic esters are found during the investigation of reaction mechanism.The main content is as follows:In chapter 1,carbon-carbon bond-forming is the most important reaction for the construction of organic molecules framework.Intermolecular carbon-carbon coupling pattern is summarized acorrding to the hybridized type of C-H bonds(sp,sp2 and sp3) and molecular self-sorting behavior is introduced.Subsequently,we put forward our design idea and research topics based on the above review.In chapter 2,on the basis of self-sorting behavior of molecular cluster,self-sorting tandem reaction which is different from classical tandem reaction and multicomponent reaction,has been presented for the first time.Accordingly,2-(methylthio)-2-butene-1,4-dionesⅡ-5 are prepared from aryl methyl ketones in the presence ofcopper(Ⅱ) oxide,iodine and dimethyl sulfoxide.The success of cross-coupling reaction of 4-chloroacetophenone with 2-acetylthiophene supports a hypothetical self-sorting tandem reaction mechanism.These 1,4-diketones are characterized by 1H NMR,13C NMR,IR and MS.In addition,compounds(Z)-Ⅱ-5,(E)-Ⅱ-5 and(Z)-Ⅱ-12 are further confirmed by X-ray single crystal diffraction.In chapter 3,twelveα,β-unsaturated methyl ketonesⅢ-2 are synthesized via classical aldol condensation reaction.Carbon-carbon double bond productsⅢ-3 are obtained via coupling of sp3 C-H bonds of two methyl groups in the presence of copper(Ⅱ) oxide,iodine and dimethyl sulfoxide. compound(E)-Ⅲ-3e is further confirmed by X-ray single crystal diffraction. In chapter 4,1,4-diketonesⅡ-5 are readily converted into the corresponding 3-methylthio 2,5-diaryl trisubstituted furansⅣ-16 in good yields in the presence of SnCl2/AcOH/HCl through a domino process.4-Bromo-3-methylthio 2,5-diaryl tetrasubstituted furansⅣ-19 are obtained either by the treatment of furansⅣ-16 with molecular bromine or of diketonesⅡ-5 with 30%hydrogen bromide in acetic acid solution in one pot.Removal of the methylthio group is accomplished by the treatment ofⅣ-16 with Raney Ni in ethanol which affords diaryl substituted furansⅣ-20 in excellent isolated yield.Selective reduction of the double bond of compoundsⅡ-5 by KI/HCl leads to the formation of the saturated 1,4-diketonesⅣ-22.3-Methylthio-2,5-diaryl substituted pyrrolesⅣ-23 and thiophenesⅣ-24 are synthesized by the reaction ofⅣ-22 with HCOONH4 or Lawesson’s reagent respectively via the Paal-Knorr cyclization reaction.These synthesized compounds are identified by spectral analysis andⅣ-16b andⅣ-22c are confirmed by X-ray single crystal diffraction.In chapter 5,in refluxing methanol,aromatic ketones are transformed into the correspondingα-iodo ketones in good yields by the combination of copper(Ⅱ) oxide and iodine.The reaction mechanism shows that copper(Ⅱ) oxide plays a multiple role through random self-sorting.In chapter 6,on the basis of chapters 3 and 5,an efficient approach toα,β-unsaturatedα’-iodo ketones fromα,β-unsaturated ketones by selective iodination at theα’-position without effect on the double bond and the aromatic ring in the presence of copper(Ⅱ) oxide/iodine is described.This is the first systematical investigation of the synthesis of important intermediatesα,β-unsaturatedα’-iodo ketones directly fromα,β-unsaturated ketones.In chapter 7,it is found that aromatic methyl ketones,β-ketoesters,and trifluoromethyl-β-diketones can be directly converted to arenecarboxylic esters via carbon-carbon bond cleavage reaction in the presence of eopper(Ⅱ) oxide,iodine,pyridine,and potassium carbonate in alcoholic media.

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