SYNTHESIS VIA TRANSITION METAL COMPLEXES

通过过渡金属络合物合成

• 批准号: 3306287
• 负责人: THOMAS Stuart LIVINGHOUSE
• 金额: $ 11.12万
• 依托单位: MONTANA STATE UNIVERSITY - BOZEMAN
• 依托单位国家: 美国
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-08-01 至 1996-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3306287
• 关键词: catalyst; chemical synthesis; ligands; metal complex; phosphines; stereoisomer; catalyst; chemical synthesis; ligands; metal complex; phosphines; stereoisomer

The development of new asymmetric catalysts for important synthetic reactions constitutes a significant and longstanding challenge. Aside from the relatively few transformations for which impressive enantioselectivities are obtainable using axially dissymmetric bisphosphines related to BINAP, there are numerous reactions in which only modest levels of enantioselection can be achieved with this class of ligands. Accordingly, there is presently a need for new, complementary classes of homochiral bisphosphines for asymmetric synthesis. Part I of this proposal is concerned with the design and synthesis of three new "families" of electronically and sterically differentiated bisphosphines in which the resident chirality exists at phosphorus. Subsequent to their preparation, these ligand classes will be systematically evaluated in asymmetric variations of Rh(I) catalyzed [4 + 2], [2+2+] and hydroboration reactions as well as alkene hydrocyanations catalyzed by Ni(0) and Pd(0). It is expected that the new homochiral ligands described herein will find numerous applications as enantioselective modifiers for other transformations catalyzed by transition metal complexes. Over the past three years, the Principal Investigator and his co-workers have been investigating several new annulation reactions mediated by group IV metal complexes. During the course of these studies, several novel coupling reactions were discovered which proceed with a high degree of chemo and stereoselectivity in many relatively simple model substrates. The focus of the studies described in Part II of this proposal will be the extension of our successes in this area to the group IV templated synthesis of several biologically active target structures. The molecules of interest not only possess a diverse spectrum of pharmacological activities but will also serve as operational models by which the crucial issues of stereo, regio, and chemocontrol associated with group IV mediated coupling processes can be evaluated. As a consequence of this investigation, the utility of these new reactions for effecting practical chemical synthesis of medicinally important compounds will be revealed.

重要合成的新型不对称催化剂的开发 反应构成了一个重大且长期存在的挑战。 旁边 从相对较少的转变来看 使用轴向对称性可获得对映选择性 双膦与BINAP有关，有许多反应 只有此类只能实现适中的对映选择水平 配体。 因此，目前需要新的 异磷的互补类别的互补类别 合成。 该提案的第一部分与设计有关 电子和空间的三个新“家族”的合成 居民手性存在的分化双膦 磷。 在准备后，这些配体课将 在RH（I）催化的不对称变化中进行系统评估 [4+2]，[2+2+]和水合反应以及烷烃 Ni（0）和PD（0）催化的氢氰基化。 期望 本文所述的新的同卵配体将发现许多应用 作为其他转换的对映选择性修饰符 过渡金属配合物。 在过去的三年中，首席调查员及其同事 一直在研究由 IV组金属配合物。 在这些研究过程中，有几个 发现了新的耦合反应，以高度进行 在许多相对简单的模型中的化学和立体选择性 基材。 第二部分中描述的研究重点 提案将是我们在该领域取得成功的延伸到小组的 静脉注射了几种生物活性靶点结构的模板合成。 感兴趣的分子不仅具有多种多样的光谱 药理活动，但也将作为运营模型 立体声，Regio和化学控制相关的关键问题 使用IV组介导的耦合过程可以评估。 作为 调查的结果，这些新反应的实用性 实现对药物重要化合物的实用化学合成 将被揭示。