【作者】 刘霄；

【导师】 马玉道；

【作者基本信息】 山东大学 ， 无机化学， 2011， 博士

【摘要】 手性配体的结构是不对称催化反应取得成功的一个重要因素,而根据反应特点进行新型配体的设计与合成一直是不对称催化反应中研究的重点。中心手性、轴手性、面手性和螺手性是构建手性配体的基本手性因素。面手性[2.2]环仿(PCP)类化合物是平面手性配体的一个典型代表,从上世纪九十年代末开始,这类化合物作为一类崭新的手性配体应用到不对称催化的研究逐渐增多,面手性在现代金属有机化学均相催化中扮演着越来越重要的作用。[2.2]环仿是由两个平行并对立而且发生了扭曲变形的的苯环通过两个乙撑基连接的三维型的芳香分子。由于其特殊的结构特点也常常用于研究跨环立体效应和电子效应的优良载体。近年来,[2.2]环仿常常用于构建人工光合作用的体系,作为一种特殊的共价型连接基,与许多其他连接基团如(乙炔基、苯基等)有着不同的性质和特殊的作用。基于以上原因,以及我们一直以来对于[2.2]环仿化学的研究兴趣,我们设计并合成了一系列基于面手性[2.2]环仿的螺手性化合物,并尝试将其应用于手性催化。另外还研究了面手性[2.2]环仿这一特殊的芳香化合物与另一种特殊芳香化合物卟啉的Suzuki反应条件。然后我们以此反应为基础合成了由[2.2]环仿桥连的卟啉-花二酰亚胺三聚体及其类似物,并研究了这一体系的光致电子转移与能量传递过程。本论文的内容主要有以下几个方面：第一部分,基于面手性[2.2]环仿的螺手性大环亚胺的合成及性质。设计并合成了一系列基于[2.2]环仿的螺手性大环亚胺,并对其进行了表征,确定了其螺手性。在我们合的目标化合物中,4-氨基-12-溴[2.2]环仿和4,12-二氨基[2.2]环仿是重要的结构单元,也是合成目标化合物的关键中间体。对于这两个化合物的合成及拆分我们采用了我们实验室所发现的方法。4-氨基-12-溴-[2.2]环仿的一个重要特点是其空间结构可以较容易地加以修饰。氨基与乙酸酐反应得到的乙酰胺可以进一步进行重氮化反应,再进行烷基化后可获得各种醚。在室温条件下,以四氢呋喃为溶剂,4,12-二氨基[2.2]环仿以及由不同醚链连接的的氨基[2.2]环仿衍生物和乙二醛水溶液反应,可得到相应的合环的亚胺。通过X-射线单晶衍射我们确定了4,12-二氨基[2.2]环仿反应后生成的四亚胺的螺手性。然后以四亚胺为标准,通过比旋光度以及圆二色谱的测定确定了其余化合物的螺手性。第二部分,基于面手性[2.2]环仿的卟啉衍生物的合成与表征。合成了一系列基于面手性[2.2]环仿的卟啉化合物,研究了两种特殊的芳香化合物[2.2]环仿与卟啉的Suzuki反应条件。复杂结构的卟啉化合物用经典的方法进行合成时步骤比较繁琐而且产率较低,而采用Suzuki反应可以很好的解决官能团的适配性这一问题。我们在卟啉硼酸嚬呐醇酯与溴代[2.2]环仿的Suzuki反应中,筛选了各种溶剂与碱,发现体系中所用碱的碱性强弱对这一反应起到了至关重要的作用,而K3PO4·3H2O的碱性在这一反应中比较合适。第三部分,由[2.2]环仿连接的卟啉-花二酰亚胺三聚体的光致电子转移和能量传递。以上述Suzuki反应为基础合成了由[2.2]环仿及其他连接基(苯基、联苯)桥连的卟啉与花二酰亚胺衍生物相连的D-A体系化合物,并通过稳态紫外可见吸收光谱,荧光光谱研究了化合物的光物理性质。稳态紫外可见吸收光谱表明：在基态,体系各组分之间没有明显的相互作用。荧光光谱表明了苝二酰亚胺向卟啉分子高效的光致能量传递和卟啉分子向花二酰亚胺分子之间的光致电荷转移。更多还原

【Abstract】 The structure of the chiral ligands is an important factor in asymmetric catalysis, and the synthesis of new ligands according to the characteristics of the asymmetric catalysis reaction has been the key point of the research. Central chirality, axial chirality, planar chiral and helical chiral are the basic factors for the construction of chiral ligands. Compounds derived from [2.2]paracyclophane (PCP) are typical representatives of planar chiral ligand, and these compounds had been widely used in asymmetric catalysis as a new class of chiral ligands since 1990s. Planar chiral has been playing more and more important roles in homogeneous catalysis in modern chemistry.[2.2]paracyclophane (PCP) is a three-dimensional aromatic molecule with rigid arrangement of parallel, eclipsed benzene rings connected by the ethylene. Due to its special structural features, molecules based on PCP have been designed to mimic through-space delocalization of excited energy, probe intramolecular charge transfer across the transannular gap and understand the global transannularπ-πinteractions. In recent years, molecules based on PCP are often used to build artificial photosynthesis system as a special spacer different from many other groups such as acetylene, benzene, etc.For these reasons, and our interest in cyclophane chemistry, we designed and synthesized a series of helical compounds based on PCP, and try to apply it to asymmetric catalysis. We also studied Suzuki reaction conditions between the two kinds of particular aromatic compounds PCP bromides and porphyrin boronate. Then Novel bisporphyrin-perylene triad dyes composed of a perylene tetracarboxylic diimide (PDI) and tetraphenylporphyrin (free-base porphyrin (H2TPP) or zinc porphyrin (ZnTPP)) linked by a [2.2]paracyclophane moiety have been prepared. Structurally related compounds bearing a biphenyl or a p-terphenyl spacer have also been prepared. Photoinduced electron and energy transfer in porphyrin-perylene diimide triads were determined.The main content of the thesis was shown as follows: 1. Synthesis of cyclophanes with planar and helical chirality derived from [2.2]paracyclophane.Macrocyclic imines based on PCP were synthesized and characterized, and the absolute helicity of the imines were determined. In our synthetic pathway to the helical macrocyclic imines, the compounds 4-amino-12-bromo[2.2]paracyclophane and 4,12-diamino[2.2] paracyclophane are the key structural elements. We adopted our own methods discovered by our lab for the synthesis and resolution of the two compounds. One of the important characteristics of the two compounds is the fact that they are easily tunable in their steric profile. Suzuki-Miyaura coupling with arylboronic acids under PdCl2(dppf) catalysis gave the sterically hindered amino[2.2]paracyclophanes in good to excellent yields (85-99%). The acetamides preparedby the reaction of amino group with acetic anhydride can further diazotization to get variety of phenols and then ether. Treatment of the substituted amino[2.2] paracyclophanes with aqueous glyoxal in THF at room temperature gave corresponding imines in essentially quantitative yield. The absolute helicity of the tetraimine prepared from 4,12-diamino[2.2] paracyclophane was determined according to the X-ray single crystal diffraction. Then the absolute helicity of the other imines were also determined by the specific rotation and CD spectra.2. Preparation of [2.2]paracyclophanyl porphyrins.A facile synthetic approach for the preparation of planar chiral porphyrins derived from [2.2]paracyclophane was described. The conditions of Suzuki reaction between the two special aromatic compounds PCP and porphyrins were studied. Traditional method to the porphyrin includes condensation of pyrroles and aldehydes in refluxing propionic acid, and some unusually elaborated unsymmetrical porphyrins couldn’t be prepared in this way. Palladium-catalyzed cross-coupling reactions that employ halogenated porphyrins and arylboronates have provided a facile synthetic approach for the modular preparation of porphyrin macrocyles. K3PO4·3H2O was found to be a mild and effective base with the catalyst of PdCl2(dppf) acted as effective catalytic system for the cross-coupling reaction between PCP bromides and porphyrin boronate. The method reported here may be used as a novel alternative for preparation of chiral porphyrin derivatives.3. Photoinduced energy and electron transfer in porphyrin-perylene diimide symmetric triads linked by [2.2]paracyclophane.Novel bisporphyrin-perylene triad dyes composed of a perylene tetracarboxylic diimide (PDI) and tetraphenylporphyrin (free-base porphyrin (H2TPP) or zinc porphyrin (ZnTPP)) linked by a [2.2]paracyclophane moiety have been prepared based on the above Suzuki reaction. Structurally related compounds bearing a biphenyl or a p-terphenyl spacer have also been prepared as references. The photophysical properties of these compounds are investigated by steady state electronic absorption and fluorescence spectra. The ground state absorption spectra reveal no significant interactions between the porphyrin moieties and PDI in the ground state. The fluorescence spectra suggest high efficient energy transfer from PDI to porphyrin. The energy transfer is not affected by the spacer between the porphyrin and PDI.更多还原