BORON-ACTIVATED CYCLOADDITIONS AND RELATED REACTIONS

根据最近的发现， 区域选择性和立体选择性，以及许多独特的特性 的乙烯基硼烷的Diels-Alder反应，该建议旨在开发一种 各种硼活化的环加成和相关反应。朝向 为此，主要目的是开发新的和有用的乙烯基硼烷 和相关的Diels-Alder亲二烯体。第二个目标是扩大 展示了与乙烯基硼烷的狄尔斯-阿尔德反应的范围，包括 高度官能化的二烯的使用和立体化学的研究 分子内反应，以获得足够广泛的基础， 这些反应的知识，以允许其在复杂的使用规划 合成。 另一个目标是推广最近的一项发现， 硼烷可以催化二烯与未活化的 乙炔。在以下方面略有改善 我们的催化反应 提供工业上可用的工艺。拟议的工作还将继续 发展实用的不对称反应。 最后，最近发现的第二个硼激活的周环 反应，烯丙基硼化的烯烃，提出了一个巨大的和不同的直接 与烯烃反应的实用性，以及许多有用的新合成方法 基于烯丙基硼化产物的二次转化。是 建议广泛研究烯丙基硼化的范围，目标是 充分发展这种新的独特的碳-碳键形成反应。 这项建议中与健康有关的工作来自一个诚实的 对多种药用合成方法的影响 重要的天然和人工物质。

On the basis of recent discoveries demonstrating the high reactivity, regioselectivity, and stereoselectivity, and many unique characteristics of Diels-Alder reactions of vinylboranes, this proposal aims to develop a variety of boron-activated cycloadditions and related reactions. Toward that end, a primary objective is to develop new and useful vinylboranes and related Diels-Alder dienophiles. A second objective is to broaden the demonstrated scope of Diels-Alder reactions with vinylboranes, including the use of highly functionalized dienes and a study of the stereochemistry of intramolecular reactions, in order to gain sufficiently broad-based knowledge of these reactions to allow the planning of their use in complex syntheses. Another goal is to generalize a recent discovery that small amounts of boranes can catalyze Diels-Alder reactions of dienes with unactivated acetylenes. Modest improvements in our catalytic reaction could furnish industrially usable processes. The proposed work will also pursue the development of practical asymmetric reactions. Finally, recent discoveries with a second boron-activated pericyclic reaction, the allylboration of alkenes, suggest a huge and varied direct utility of reactions with alkenes, and many useful new synthetic methods based on secondary conversions of the allylboration products. It is proposed to extensively study the scope of allylborations with the goal of fully developing this new and unique carbon-carbon bond forming reaction. The health-relatedness to the work in this proposal derives from an honest impact on methods for the synthesis of a wide variety of medicinally important natural and artificial substances.