【作者】 陈国飞；

【导师】 麻生明； 傅春玲；

【作者基本信息】 浙江大学 ， 有机化学， 2010， 博士

【摘要】 我们小组在金属催化的官能团化联烯的环化反应和亲电加成环化方面已经进行了一系列的研究,基于这样的基础,我的博士论文主要是围绕着缺电子联烯的化学展开,研究了2,3-联烯酸酯,1,2-联烯酮的亲电反应和2,3-联烯酸,2,3-联烯酰胺的偶联环化反应,实现其反应的选择性调控,此外还研究了2,3-联烯酰胺,炔酰胺与二氧化碳的环化反应。1.在2,3-联烯酸酯与苯硒氯的亲电加成反应的研究中,发现水在体系中发挥了重要的作用。通过条件的控制,可以高选择性地得到亲电环化的产物和亲电加成-氧化的产物。2.在1,2-联烯酮与碘的亲电关环反应的研究中,发现3-位单取代的1,2-联烯酮可以生成呋喃类化合物,而3-位双取代的1,2-联烯酮则生成2-羟基-2,5-二氢呋喃类化合物；同时在研究中发现全氟烷基取代的联烯酮比常规烷基取代的联烯酮有更高的反应活性,得到的产物的产率也比较高。3.在顾振华博士工作的基础上,研究了2,3-联烯酸与贫电子炔烃的环化偶联反应：(1)当贫电子炔烃是炔酮时,反应首先得到双键顺反比例很差的混合物,通过在DMSO溶液中加热可以完全转化到热力学稳定的反式产物,发展了一种一锅法高选择性地制备E构型的4-位羰基乙烯基取代的2(5H)-呋喃酮类化合物的方法；(2)当贫电子炔烃是炔酸酯时,通过条件的控制,可以主要得到与一分子炔酸酯关环偶联的产物；(3)当贫电子炔烃是炔基膦酸二酯时,反应得到顺反单一的与一分子炔基膦酸二酯关环偶联的产物。4.在2,3-联烯酰胺的关环反应的研究中,实现了其自身双分子关环偶联反应,在反应体系中碱的加入是反应成功的关键；还发展了其与炔丙醇碳酸酯偶联生成Z构型的β-联烯基呋喃酮亚胺类化合物的方法,初步的机理研究表明这个反应是零价钯启动的。由于位阻的原因,这两个反应中2,3-联烯酰胺都是氧进攻关环得到呋喃酮亚胺类化合物。5.在二氧化碳固定的研究中,发展了2,3-联烯酰胺与二氧化碳反应制备1,3-噁嗪-2,4-二酮类化合物的方法,该方法简单方便,不需要催化剂,只需常压的二氧化碳。在此基础上,顺利地实现了炔酰胺与二氧化碳的反应,如果在体系中加入NIS,NBS等亲电试剂,还可以得到三分子反应的产物。更多还原

【Abstract】 Great efforts have already been made on the cyclization of functionalized allene in our group. Based on these research findings, the main theme of my dissertation is on the cyclization reaction of electron-deficient allenes, including electrophilic addition cyclizations of 2,3-allenoates and 1,2-allenyl ketones and coupling cyclization reactions of 2,3-allenoic acids and 2,3-allenamides. The chemoselective control of these reactions has been achieved. Besides, the fixation of carbon dioxide with 2,3-allenamides and alkynamides has also been developed.1. In the electrophilic addition reaction of 2,3-allenoates with PhSeCl, water was proved to be the crucial factor in control of chemoselectivity. Butenolides and 4-oxo-2(E)-alkenoates could be obtained respectively with high selectivity by adjusting reaction conditions.2. Furans or 2,5-dihydrofuran-2-ols could be obtained in the electrophilic cyclization reaction of 1,2-alkenyl ketones with iodine when different substrates were used. Allenyl prerfluoroalkyl ketones showed higher reactivity and gave higher yields as compared to ordinary allenyl alkyl ketones.3. Coupling cyclization reactions of 2,3-allenoic acids in the presence of electron-deficient alkynes were continuously studied based on the research of Dr. Zhenhua Gu. When alkynones were used as substrates, a one-pot synthesis of E-4-(3’-oxo-1’-alkenyl)-2-(5H)-furanones was established. Though a mixture of Z/E isomers was obtained in the first step, it could be converted to the thermodynamically stable E isomer by heating in DMSO. When propiolates served as the substrates, a 1:1 adduct product could be formed by controlling reaction conditions. For alkynyl phosphonate, only E isomer of the 1:1 adduct product was observed.4. We have developed a PdCl2/NaI/K2CO3-catalyzed highly stereoselective homodimeric coupling-cyclization reaction of 2,3-allenamides. The addition of K2CO3 plays an important role in this transformation. Additionally, we have established a protocol of the Pd-catalyzed coupling reaction of 2,3-allenamides with propargylic carbonates affordingβ-allenyl furanamines. Preliminary mechanism study showed that this reaction was probably initiated by the Pd(0) species. Furanamine-type products were obtained indicating that both of the two reactions proceeded through the O-attack pathway.5. In the fixation and transformation of carbon dioxide, we developed a very simple and mild protocol for the reaction of carbon dioxide with 2,3-allenamides. In the absence of metal catalyst, the starting materials were converted into 1,3-oxazine-2,4-diones with a CO2 balloon. On the basis of this report, the fixation of carbon dioxide with 2-alkynamides was also established. Meanwhile, a one pot three-component reaction of alkynamides, CO2 and electrophilic agents such as NIS and NBS was developed to afford halogen-substituted oxazoles.更多还原