【作者】 李慧；

【导师】 郭灿城；

【作者基本信息】 湖南大学 ， 化学工程与技术， 2021， 博士

【摘要】 烯烃（包括其衍生物）是常见的有机化合物,是合成化学中的重要原料。烯烃可以通过取代反应、氧化反应、加成反应等转化成其它的线性化合物。与此同时,烯烃还能与其它化合物发生环化反应得到环状化合物,深受化学工作者的重视并得到了广泛的研究。几十年以来,大量有关烯烃参与的分子间环化合成环状分子特别是合成六元环状化合物的工作已经被报道。尽管如此,开发新的烯烃分子间环化反应合成六元环状化合物的研究工作仍然是必要的。基于前人的研究工作及自身的兴趣,本课题选取2-芳基丙烯为底物之一,探索不同条件下,2-芳基丙烯参与的新环化反应,从而合成一系列六元环状化合物。主要研究内容如下:1.发展了碘单质-二甲亚砜体系下两分子2-芳基丙烯之间合成1-萘甲醛的[4+2]环化反应。这是第一例以2-芳基丙烯作为C4供体合成芳香醛的报道,为稠环芳香醛的合成提供了新的路线。该反应利用二甲亚砜作氧化剂,在碘单质的促进下,先将2-芳基丙烯氧化成不饱和醛,然后两分子不饱和醛之间进行[4+2]环化和脱羰基化,得到4-芳基-1-萘甲醛。通过该反应,以较高的产率获得了一系列的4-芳基-1-萘甲醛化合物。同时,还研究了取代基位置对反应结果的影响。得到了16种2,3-二芳基-1H-茚酮。2.开发了K₂S₂O₈促进的2-芳基丙烯,醛和二甲亚砜之间合成2H-吡喃类化合物的[3+2+1]环化反应。这是第一次基于无杂原子的三原子供体的[3+2+1]环化构建含氧杂环骨架的报道,成功建立了新的合成3,6-二氢-2H-吡喃类化合物的方法。在这个反应过程中,涉及了两个C-C键和一个C-O键的形成。通过该反应以中等到较高收率合成了28种2,4-二取代-3,6-二氢-2H-吡喃。通过一系列控制实验及文献,我们提出了该[3+2+1]环化反应的可能机理:在过硫酸钾的促进下,2-芳基丙烯与二甲亚砜之间经过C-H活化和脱甲硫基化形成1,3-丁二烯,再与醛进行[4+2]环加成最终得到3,6-二氢-2H-吡喃。3.发展了碘单质促进的2-芳基丙烯,二甲亚砜和两分子醋酸铵之间合成嘧啶类化合物的[3+1+1+1]环化反应。这是第一例使用2-芳基丙烯作为C3供体合成嘧啶类化合物的报道,为一步合成5-芳基嘧啶提供了新的方法。这一过程涉及了四个C-N键的形成。首先,通过优化实验得到了该环化反应的最适宜条件,并在最优条件的基础上利用该反应合成了一系列5-芳基嘧啶类化合物。最后,我们通过一系列控制实验及文献,提出了该[3+1+1+1]环化反应的可能机理。4.开发了K₂S₂O₈促进的2-芳基丙烯,甲基酮和二甲亚砜之间合成环己烯类化合物的[3+1+1+1]环化反应。据我们所知,这是第一个以二甲亚砜作为双重碳砌块合成六元碳环的例子,也是第一次以[3+1+1+1]环化反应构建环己烯骨架的报道。在这一环化反应中涉及了四个C-C键的形成。2-芳基丙烯为环己烯分子提供三个碳原子,甲基酮为环己烯分子提供一个碳原子,二甲亚砜作为双重的碳供体为环己烯分子提供两个碳原子。在最优条件下,一系列的2-芳基丙烯和甲基酮类化合物能够转化为相应的环己烯类化合物。同时,该反应还能合成螺环环己烯类化合物。最后,通过一系列控制实验,对该[3+1+1+1]环化反应提出了可能的机理。更多还原

【Abstract】 Alkenes（including their derivatives）are common organic compounds and are important raw materials in synthetic chemistry.Alkenes could be converted into other linear compounds through substitution,oxidation and addition reactions.At the same time,alkenes could also undergo annulation reactions with other compounds to obtain cyclic compounds,which have received great attention an d been widely studied.Over the decades,a large number of works on the synthesis of cyclic compounds,especially six-membered cyclic compounds,by annulation involving alkenes have been reported.Even so,the research on the development of new intermolecu lar annulation strategies involving alkenes for the synthesis of six-membered cyclic compounds is still necessary.In this paper,2-arylpropene was taken as one of the reactants to explore new annulation reactions involving 2-arylpropene to synthesize a series of six-membered cyclic compounds under different conditions.The main contents are described as follows:1.A[4+2]annulation reaction between two 2-arylpropene to 1-naphthalaldehyde in the I₂-DMSO system was developed.This is the first example of the synthesis of aromatic aldehydes using 2-arylpropene as four-carbon donor,which provided a new route for the synthesis of polycyclic aromatic aldehyde.In this annulation,DMSO was used as oxidant,2-arylpropene been oxidized toα,β-unsaturated aldehydes in the presence of iodine.Then,[4+2]annulation and then aromatization between twoα,β-unsaturated aldehydes happened,and given 4-aryl-1-naphthalaldehyde.A series of4-aryl-1-naphthaldehyde compounds were synthesized with high yields by this annulation.Meantime,the effect of position of substituent groups in 2-arylpropene on the reaction was also investigated.And 16 examples of 2,3-diaryl-1H-inden-1-ones were obtained.2.A K₂S₂O₈-promoted[3+2+1]annulation to 2H-pyran motif between2-arylpropene,aldehyde and DMSO was exploited.This is the first[3+2+1]annulation strategy based on the heteroatoms-free tri-atom donor to construct oxo-heterocyclic skeleton,which successfully established a new approach for the synthesis of 3,6-dihydro-2H-pyrans.This annulation involves the formation of two C-C bonds and a C-O bond.28 examples of 3,6-dihydro-2H-pyrans were synthesized with medium to high yields by this annulation.Based on the results of controlled experiments and literature,a possible mechanism was proposed which contains C-H activation,demethylsulfidation,and cycloaddition.3.A I₂-promoted[3+1+1+1]annulation reaction to pyrimidine units between2-arylpropene,DMSO and two ammonium acetates was developed.This is the first report of the synthesis of pyrimidines using 2-arylpropylene as tri-carbon atom donor,which provides a new approach for the synthesis of 5-arylpyrimidines in one-pot.This annulation involves the formation of four C-N bonds.Firstly,the optimum reaction condition of this reaction was obtained according to the experiments.A nd a series of2-arylpropenes were applied to this annulation reaction under the optimal condition,acquired the corresponding pyrimidine compounds.Finally,a possible mechanism for this[3+1+1+1]annulation process was proposed by the controlled experiments.4.A K₂S₂O₈-promoted[3+1+1+1]annulation to cyclohexene among2-arylpropene,methyl ketone and two DMSO was exploited.To the best of our knowledge,this is the first example of the synthesis of six-membered carbocycle using DMSO as a double carbon block and the first report of the construction of cyclohexene skeleton by[3+1+1+1]annulation reaction.In this reaction,2-arylpropene served as tri-carbon donor,methyl ketone served as single car bon source,and DMSO was as dual carbon synthon to the cyclohexene framwork.This annulation involves the formation of four C-C bonds.Under optimal conditions,a series of 2-arylpropylenes and methyl ketones can be converted to corresponding cyclohexenes.Meanwhile,spirocyclohexene compounds can be synthesized by this reaction,which shows the potential application in pharmaceutical chemistry.Finally,based on a series of controlled experiments,a possible mechanism was proposed for this[3+1+1+1] annulation reaction.更多还原