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New Development of One-electron Transfer Reaction - Application to the Total Synthesis of Biologically Active Natural Products -

一电子转移反应新进展-在生物活性天然产物全合成中的应用-

基本信息

批准号：
13640530
负责人：
YODA Hidemi
金额：
$ 2.24万
依托单位：
Shizuoka University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13640530/
关键词：
Samarium radical imide lactam reductive coupling alkaloid indolizidine natural product インドリジジン

项目摘要

Structurally complex alkaloidal sugar mimics with a nitrogen in the ring have been isolated from plants and microorganisms and inhibit various glycosidases in a reversible and competitive manner. Since such glycosidase inhibitors proved to have the potential to produce antiviral, insect antifeedant, antidiabetic, and anticancer effects as well as immune modulatory properties, they have held considerable interest in the context of the synthesis of nitrogen-containing natural products.Towards the carbonyl group of imides, on the other hand, two reactions, i.e., an intramolecular Barbier-type reaction of some N-iodoalkyl cyclic imides and a coupling reaction of acyclic imides such as N-acyllactams with carbonyl compounds are known. In this connection we have also recently reported the first pinacolic cross-coupling reaction between phthalimides and carbonyl compounds and its application to the complete stereoselective deoxygenation. However, the lack of studies concerning the reactivity of samarium (II) compounds towards simple amides is surprising except in some special cases. This should be attributed to their low reactivity.Herein we described the first nitrogen-carbon (hetero) coupling reaction between lactams and aldehydes mediated by SmI_2 to provide N-α-hydroxyalkylated lactams and its application to the short synthesis of biologically active indolizidine alkaloids, (-)-δ-coniceine, (+)-5-epiindolizidine 167B and (+)-lentiginosine in addition to the formal synthesis of an isoindolobenzazepine alkaloid, chilenine.

从植物和微生物中分离出了环中含氮的结构复杂的类糖化合物，它们以可逆和竞争的方式抑制各种糖苷酶。由于此类糖苷酶抑制剂被证明具有产生抗病毒、昆虫拒食、抗糖尿病和抗癌作用以及免疫调节性质的潜力，因此它们在含氮天然产物的合成方面具有相当大的兴趣。已知一些N-碘代烷基环状酰亚胺的分子内Barbier型反应和无环酰亚胺如N-酰基内酰胺与羰基化合物的偶联反应。在这方面，我们最近还报道了邻苯二甲酰亚胺和羰基化合物之间的第一个频哪醇交叉偶联反应及其在完全立体选择性脱氧中的应用。然而，除了在一些特殊情况下，缺乏有关钐（II）化合物对简单酰胺的反应性的研究是令人惊讶的。本文首次报道了SmI_2介导的内酰胺与醛的氮-碳（杂）偶联反应，得到N-α-羟烷基化内酰胺，并将其应用于生物活性吲哚里西啶生物碱（-）-δ-康尼因，（+）-5-表吲哚里西啶167 B和（+）-扁豆碱核苷，以及一种异吲哚苯并氮杂生物碱chilenine的正式合成。