Design of Metal Artificial Enzymes and the Application to Fine Organic Synthesis

金属人工酶的设计及其在精细有机合成中的应用

基本信息

批准号：
11440184
负责人：
MARUOKA Keiji
金额：
$ 10.3万
依托单位：
KYOTO UNIVERSITY (2000)Hokkaido University (1999)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

项目摘要

Alkyl halides, especially iodides and bromides, are frequently utilized as precursors to generate various carbon-centered radicals in organic synthesis. The usefulness of these halo derivatives in radical reactions has been demonstrated in numerous synthetic examples and often reviewed in the chemical literature. There is, however, inevitable drawback to the use of such reactive alkyl halides for radical reactions, and this is mainly due to the troublesome intervention of internal and/or external nucleophiles (e.g., alkoxides, amines, cyanide, enolates, etc.). To overcome this intrinsic problem, we initiated the search for a reactive alkyl iodide equivalent which is stable for ordinary nucleophilic attack. Herein we wish to report that ο-(ο-iodophenyl)phenylthio derivatives are highly effective with various functional group compatibility for rapid generation of carbon radicals under mild conditions. This approach expands the scope of radical chemistry, since a variety of nucleophilic t … More hiolations (thioacetalization, conjugate addition, epoxide opening, etc.) using arythiol can be readily combined with the present radical generation process. In addition to ο-(ο-iodophenyl)phenylthio derivatives, ο-[(E)-2-Trimethylsilyl-2-iodovinyl]phenylthio derivatives have been also introduced as effective precursors for the generation of carbon centered radicals even in the presence of certain nucleophiles ; this provides useful information about the structural requirement for inducing an efficient anchimeric effect under mild conditions.The above mentioned chemistry led us to investigate the possibility of generating desired carbanion species by the utilization of such anchimeric effect. Taking both the versatility and the availability with the limitation of structural types into account, we focused on the combined use of ο-(ο-iodophenyl)phenylselenenyl or tellurenyl derivatives and commercially available alkyllithiums, expecting that various alkyllithium reagents could be efficiently prepared through the initial Li-halogen exchange and subsequent translocation of the resulting anion. The synthetic utility as well as the limitation were evaluated in the in situ trapping reaction with carbonyl compounds. Less

烷基卤化物，特别是碘化物和溴化物，经常被用作有机合成中产生各种碳中心自由基的前体。这些卤代衍生物在自由基反应中的用途已在许多合成实例中得到证明，并且经常在化学文献中进行综述。然而，使用这种反应性烷基卤进行自由基反应不可避免的缺点，这主要是由于内部和/或外部亲核试剂（例如醇盐、为了克服这一内在问题，我们开始寻找对普通亲核攻击稳定的反应性烷基碘化物等价物。在此我们希望报告邻-(邻-碘苯基)苯硫基衍生物。与各种官能团相容，在温和条件下快速生成碳自由基，这种方法扩展了自由基化学的范围，因为各种亲核试剂。 …更多使用芳硫醇的硫醇化（硫缩醛化、共轭加成、环氧化物开环等）可以很容易地与目前的自由基生成过程结合。除了 ο-(ο-碘苯基)苯硫基衍生物外，ο-[(E)-2-。三甲基甲硅烷基-2-碘乙烯基]苯硫基衍生物也被引入作为有效前体，即使在存在某些亲核试剂；这提供了有关在温和条件下诱导有效的嵌合效应的结构要求的有用信息。上述化学使我们研究通过利用这种嵌合效应产生所需碳负离子物种的可能性。考虑到结构类型的限制，我们重点研究了ο-(ο-碘苯基)苯基硒基或碲基衍生物与市售的组合使用烷基锂，期望通过最初的锂-卤素交换和随后产生的阴离子的移位可以有效地制备各种烷基锂试剂，并在与羰基化合物的原位捕获反应中评估了合成实用性和局限性。