Development and Application of New Asymmetric Cycloaddition Reactions

利用新的区域选择性和立体选择性路易斯酸催化烯烃和炔与1,4-苯醌、1,4-苯醌二亚胺和烷氧- α， β -不饱和烯酮的形式环加成反应，研究合成高取代二氢苯并呋喃、二氢吲哚、双环{3.2.1}辛酮和环丁烷的新方法。利用手性Ti（IV）催化剂探索和开发这些新方法的对映体变体，许多方法提供高对映体纯度的产品。产品的结构构成了许多类生物活性分子的全部或部分基本框架，手性环丁烷也可用于制备具有有趣性质的新型棒状聚合物。特定靶标包括：特定的血小板活化因子受体拮抗剂、抗白血病剂瑞格酰胺、抗真菌剂、桂花苷、代表性的新木质素和棘果霉醛。一种结构上有趣的天然产物。此外，还计划合成几种2-和3-芳基-2,3-二氢苯并呋喃及其氮类似物，即2-和3-芳基-2,3-二氢吲哚。有了这笔奖金，有机合成计划将支持堪萨斯大学托马斯·a·恩格勒博士的研究。这些研究将基于利用手性Ti（IV）基试剂的新方法探索不对称分子的新途径。这种新的合成方法将有利于生物化学和医学以及化学工业的研究。

The investigation of a new approach to the synthesis of highly substituted dihydrobenzofurans, dihydroindoles, bicyclo{3.2.1}octenones and cyclobutanes will be made utilizing novel regio- and stereoselective Lewis acid catalyzed formal cycloaddition reactions of alkenes and alkynes with 1,4-benzoquinones, 1,4-benzoquinonediimides and alkoxy-alpha, beta-unsaturated enones. The exploration and development of enantiospecific variants of these new methods utilizing chiral Ti(IV) catalysts is planned and many provide the products in high enantiomeric purity. The structures of the products form all, or part of, the basic framework of many classes of biologically active molecules and chiral cyclobutanes may also be useful in the preparation of novel rod shaped polymers with interesting properties Specific targets include kadsurenone, a specific platelet-activating factor receptor antagonist, recaglamide, an antileukemic agent, viniferin, an antifungal agent, guianin, a representative neolignan, and acanthodoral, a structurally interesting natural product. In addition, syntheses of several 2-and 3-aryl-2,3-dihydrobenzofurans and their nitrogen analogs, i.e. 2-and 3-aryl-2,3-dihydroindoles, are planned. %%% With this award, the Organic Synthesis Program will support the research of Dr. Thomas A. Engler at the University of Kansas. The studies will explore new routes to asymmetric molecules based on new methods utililzing chiral Ti(IV) based reagents. The new synthetic methodology should benefit research in biochemistry and medicine, as well as in the chemical industry.