杂双金属复合物ZABDP催化芳香酮与芳香醛的直接不对称Aldol反应

合成了新型的手性铝/锌杂双金属复合物(R,S,S)-3,3'-二[(N-二苯基脯氨醇)甲基]-2,2'-二羟基-1,1'-联萘酚铝/锌复合物(ZABDP).在催化芳香酮与芳香醛的羟醛缩合(Aldol)反应中,该复合物中的铝作为路易斯酸活化醛,锌的烷氧化物作为Br?nsted碱,使苯乙酮形成活性锌的烯醇化物,2种金属的应用使得芳香醛与芳香酮的直接不对称Aldol反应顺利进行,反应的对映选择性最高达90%,产率最高达99%.     

手性口恶唑硼烷酮催化不对称Aldol反应的研究

以廉价易得的手性氨基酸为原料合成了一系列氮磺酰化氨基酸配体,并将之与硼烷原闰制备成手性恶唑硼烷酮催化苯甲醛与烯醇硅醚的不对称Aldol反应,获得了较好的效果。对各种影响反应结果的因素进行了讨论,并对其不对称诱导机理进行了探讨。结果表明D-苯基甘氨酸衍生的手性恶唑硼烷酮催化剂对这种反应的催化效明显好于L-缬氨酸、L-亮氨酸、L-异亮氨酸等其它脂肪侧链氨基酸衍生的恶唑硼烷酮催化剂。其所得产物的化学产率和ee值分别为38.7%和81.7%。     

联二萘酚衍生手性二胺催化的不对称Aldol反应

在10 mol%手性二胺和10 mol%手性磷酸的催化下,苯乙酮及其衍生物与三氟丙酮酸甲酯完成Aldol反应,得到80%的产率和73%ee的对映体过量产物,其结构经1H NMR和13C NMR表征.     

苯并呋喃-2,3-二酮和丙酮的不对称Aldol反应

以脯氨酸作为催化剂催化苯并呋喃-2,3-二酮与丙酮的不对称Aldol反应, 高选择性地合成了一系列3位含有手性季碳中心的苯并呋喃酮类化合物.     

手性伯胺催化的不对称Aldol反应

<正>Aldol反应被认为是现代有机合成中最有效的形成碳碳键的方法之一[1],应用此反应可以合成含有两个立体中心的β-羟基羰基化合物。自从2000年List教授发现脯氨酸可以催化分子间的不对称Aldol反应以来[2],越来越多的科学家开始致力于寻找高效的有机催化剂。     

不对称催化Henry反应研究进展

Henry反应是一类重要的有机反应. 按照反应中使用催化剂的种类, 分金属络合物催化、有机小分子催化、酶催化、非均相负载催化四大类, 详细介绍了不对称催化Henry反应的研究进展.     

L-脯氨酸催化的不对称Aldol缩合反应实验设计

介绍了L-脯氨酸催化的对硝基苯甲醛与丙酮的不对称Aldol反应的实验设计。室温反应2 h后,柱层析得到（R）-4-（4-硝基苯基）-4-羟基-2-丁酮,利用手性高效液相色谱测试得到产物的ee值。学生实验结果显示,收率范围为53%~74%,对映选择性范围为62%~69%。本实验方案将Aldol反应的研究成果设计成综合性实验,不仅强化训练了学生基本的实验技能和操作,同时拓宽了知识面,培养了学生分析问题、解决问题等方面的综合能力。     

氯甲基化聚苯乙烯负载修饰L-脯氨酸催化不对称Aldol反应研究

以氯甲基化聚苯乙烯为载体,分别以氨基胍、三聚氰胺和4,4′-二氨基苯磺酰苯胺(DASA)为连接臂,合成了三种负载修饰L-脯氨酸催化剂,并且将其用于催化不对称Aldol反应,探索了溶剂和底物对其催化性能的影响,并考察了其重复使用性能.结果表明,DASA负载修饰L-脯氨酸催化剂具有较好的催化活性和选择性,相应的最高产率达83%,e.e.值达86%.     

脯氨酸催化的不对称Aldol反应的研究进展

不对称合成是手性药物制备的核心环节,A ldol反应是重要的形成C—C键的反应之一,在全合成中有广泛应用.脯氨酸的两个异构体均价廉易得,作为一个非金属不对称催化试剂,它催化的不对称A ldol反应立体选择性高,有很好的应用前景.本文就近二十年来脯氨酸催化A ldol反应的机理,溶剂效应,最新进展三方面进行了介绍.     

手性恶唑硼烷酮催化不对称ALDOL反应进展

本文论述了手性恶唑硼烷酮在催化不对称ａｌｄｏｌ反应中的应用,讨论了反应机理。     

Coinage Metal-Catalyzed Asymmetric Reactions of ortho-Alkynylaryl and Heteroaryl Aldehydes and Ketones

Coinage metals have become the metal of choice due to their excellent catalytic activity in organic transformation processes. Combining various chiral ligands and coinage metals became a productive area of research and access to heterocyclic derivatives according to an efficient and sustainable manner. This review was devoted to the various recently developed coinage metal-catalyzed domino processes of ortho-alkynylaryl and heteroaryl aldehydes and ketones leading to functionalized heterocycles. Various gold chiral complexes were presented, and methods of preparations of chromenes along with indoles were covered. Ag-chiral complexes are also prone to interesting activities such as cyclization followed by reduction and functionalization with enolizable ketones or (diazomethyl)phosphonate. Asymmetric Cu-catalyzed domino cyclization and asymmetric transfer hydrogenation reactions efficiently led to functionalized chromenes. Some remarkable examples involving copper associated with ruthenium in the context of a cyclization and asymmetric hydrogenation process were also presented.     

Solvent-Free Crossed Aldol Condensation of Ketones with Aromatic Aldehydes Mediated by Magnesium Hydrogensulfate

Summary.  Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions in solution do not proceed satisfactorily. Corresponding authors. E-mail: p-salehi@cc.sbu.ac.ir Received September 20, 2001. Accepted (revised) January 16, 2002     

Solvent-Free Crossed Aldol Condensation of Ketones with Aromatic Aldehydes Mediated by Magnesium Hydrogensulfate

 Crossed aldol condensations of ketones with aromatic aldehydes are carried out efficiently in the presence of magnesium hydrogensulfate under solvent-free conditions in good to excellent yield without the occurrence of any self-condensation. Similar reactions in solution do not proceed satisfactorily.     

Solvent-Free Crossed Aldol Condensation of Cyclic Ketones with Aromatic Aldehydes Assisted by Microwave Irradiation

Summary. A fast alumina-promoted crossed aldol-condensation reaction of aldehydes and cyclic ketones under microwave irradiation is described. This process is simple, efficient, and environmentally benign and proceeds in fairly high yield without any self-condensation.     

Microwave Irradiated Reactions of N-Phenacylpyridinium Chloride with Aromatic Aldehydes and Ketones

Pyridinium cations show a great variety of synthetic applications,due to the aromatic character of the pyridine heterocycle, to its basicity, and the electron-attracting influence of the nitrogen atom1-3. N-phenacylpyridium bromide in the presence of base…