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Construction of Polycycles Using Palladium-Catalyzed α-Arylation Reaction toward Carbonyl Group

利用钯催化的羰基 α-芳基化反应构建多环

基本信息

批准号：
10672014
负责人：
MURATAKE Hideaki
金额：
$ 1.47万
依托单位：
Research Foundation Itsuu Laboratory
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

In the last decade, organometallic chemistry, especially organopalladium chemistry has made a marked advance. While a great number of palladium-catalyzed arylation and vinylation reactions have been investigated, most of which involve olefins (Heck reaction), organo-tin compounds (Stille reaction), or organo-borane compounds (Suzuki reaction) as terminators.Exploitation of other functional groups as the terminator is expected to enable expanded application. Recently, the intermolecular palladium-catalyzed α-arylation reaction of ketone was reported by three groups of US and Japan. At the same time, we also reported independently its intramolecular version to form benzene-annulated bridged- spirocycloalkanones employing a bis(triphenylphosphine)palladium(II) chloride-cesium carbonate-with or without triphenylphosphine catalyst system.Our catalyst system was found to be applicable to properly designed substrates bearing a formyl or nitro terminating group. Arylation toward the formyl group occurred at the α-position (α-arylation) or at the carbonyl carbon (carbonyl-arylation) depending on the structure of the substrates and on the reaction solvent. The α-arylated secondary nitro group was partially transformed to ketone, whereas the tertiary nitro group was partially eliminated to a styrene type of olefin.Now, we can get various types of carbocycles employing the above intramolecular arylation conditions. They bear the useful functional groups, ketone, formyl, and nitro groups. We are now engaged in the synthetic investigation of Hetisan type of aconite alkaloids using the above cyclization reaction.

近十年来，有机金属化学，特别是有机钯化学取得了显著的进展。钯催化的芳基化和乙烯基化反应已有很多研究，但大多数反应都是以烯烃（Heck反应）、有机锡化合物（Stille反应）或有机硼烷化合物（Suzuki反应）为终止剂，利用其它官能团作为终止剂有望扩大应用范围。近年来，美国和日本的三个研究小组报道了钯催化的分子间酮的α-芳基化反应。同时，我们还独立报道了其分子内版本，使用双（三苯膦）氯化钯（II）-碳酸铯-在有或没有三苯膦催化剂体系的情况下，形成苯环桥连螺环烷酮。我们的催化剂体系被发现适用于适当设计的带有甲酰基或硝基封端基团的底物。根据底物的结构和反应溶剂，在α-位（α-芳基化）或羰基碳（羰基-芳基化）发生朝向甲酰基的芳基化。α-芳基化的仲硝基部分转化为酮，而叔硝基部分被消除为苯乙烯型的烯烃，利用上述分子内芳基化反应条件，可以得到各种类型的碳环化合物。它们带有有用的官能团，酮，甲酰基和硝基。利用上述环合反应，我们正在进行合梯散型乌头生物碱的合成研究。