摘要许多天然产品和合成试剂中都存在丙二烯。这种手性烯烃具有两个正交烯烃,因此具有一个独特的架构,这种构型使得丙二烯能合成有价值的中间体,试剂 [1]和对映选择性的催化剂。[2]因此,这种手性非外消旋丙二烯的制备有非常重要的研究意义。Hoveyda组近期发表了一篇文章报道了一个非常新颖有效的方法来合成学活性三取代丙二烯。[3] 在天然产物的合成中也提到了该方法,包括分子间自由基链加成和分子间-分子内自由基串联加成反应,联烯进行分子间自由基链加成反应时, 自由基对联烯的加成既可发生在中间碳原子上, 也可发生在末端碳原子上, 主要取于所形成中间体的稳定性、 空间效应、电负性和溶剂等因素也有影响。一般以碳为中心的自由基(如CH3·, CCl3· 等)易进攻末端碳原子, 而以杂原子为中心的自由基(如Br·, RS·, ArSO2·等)易进攻联烯的中心碳原子,联烯及其衍生物也易与烯烃、联烯、烯炔和乙烯酮进行[2+2] 环加成反应, 还可以与卡宾环丙烷化, 这些反应都是通过自由基机理进行的。75231
Allenes appear in many natural products and synthetic reagents。The two orthogonal olefins of chiral allenes create a unique architecture, which renders allenes valuable syntheticintermediates, reagents,[1] and enantioselective catalysts。[2] For these reasons, the preparation of chiral non-racemic allenes has remained a topic of significant interest。 A recent report from the Hoveyda group describes an innovative and effect approach to optically active trisubstituted allenes。[3] The application in natural product synthesis is also described 。Substituted allenes undergo rather facile radical chain addition reactions 。Attack by a radical species can occur ateither the central or the terminal C atom。In the case of addition , the preferred route is generally that forming thepossibly more stable free-radical intermediates 。The steric effect , electronegativity and solvent effect shoulde also beconsidered 。In general , carbon-centered free radicals such as CH3· and CCl3·add mostly to the terminal carbon atomwhile heteroatom-based free radicals such as Br·, RS·, ArSO2· and R3Sn· add preferentially to the central carbonatom 。Substituted allenes can undergo a variety of [ 2 +2] cycloaddition reactions with alkenes , allenes , enynes and ketenes and also undergo a cyclopropanation with carbenes via a biradical mechanism 。
毕业论文关键词:关键词1不对称催化; 关键词2手性丙二烯; 关键词3铜;关键词4对映选择性烯丙基取代; 关键词5 N-杂环卡宾 关键词6 联烯;关键词7 自由基;关键词8加成反应
Keyword: 英文关键词1 asymmetric catalyst; 英文关键词2chiral allene; 英文关键词3copper; 英文关键词4 enantioselective allylic substitution; 英文关键词5N-heterocyclic carbenes 英文关键词6 allene ,英文关键词7 radical ,英文关键词8 addition reaction ,
目 录
1 引言 6
2 实验部分 8
2。1实验试剂 8
2。2实验仪器 8
2。3几种合成联烯的方案的介绍 8
2。4本实验采用的联烯合成过程 11
2。4。1带苯基的联烯合成过程 11
2。4。2带甲基的联烯合成过程 14
2。4。3 带氢原子的联烯合成过程 15
2。5含乙酸乙酯联烯化合物的合成 16
2。6联烯化合物在合成中的应用