SILOXANE COUPLINGS AND NATURAL PRODUCT SYNTHESIS

描述：（申请人摘要）本研究的长期目标是 确定钯催化交叉偶联的范围和限制 与烯丙基酯和芳基衍生物的高价硅氧烷。这 方法可以作为Stille和Suzuki耦合的替代方案 在天然产物领域具有几个局限性的协议 合成.在这项研究中，芳基，乙烯基和烯丙基硅氧烷的反应， 将研究各种衬底。此外，评价 用于与芳基氯交叉偶联的新钯催化剂及其用途 用于交叉偶联反应的不对称形式的手性配体将 进行。一旦确定了耦合方法的范围， 硅氧烷方法将用于抗肿瘤化合物的全合成。 抗生素（+）-泛司他丁和抗有丝分裂剂（-）-秋水仙碱。

DESCRIPTION: (Applicant's Abstract) The long term goal of this research is to determine the scope and limitations of the palladium-catalyzed cross-coupling of hypervalent siloxanes with allylic ester and aryl derivatives. This methodology could serve as an alternative to Stille and Suzuki coupling protocols that have several limitations in the field of natural product synthesis. In this study, the reactions of aryl, vinyl, and allyl siloxanes with a variety of substrates will be investigated. In addition, evaluation of new palladium catalysts for cross-couplings with aryl chlorides and the use of chiral ligands for an asymmetric version of the cross-coupling reaction will be undertaken. Once the scope of the coupling methodology has been determined, the siloxane methodology will be employed for the total synthesis of the antitumor antibiotic (+)-pancratastatin and the antimitotic agent (-)-colchicine.