(DE) Zur Darstellung von Aminoalkylhydantoinen muß die Aminofunktion vor der Bildung des Hydantoinringes geschützt werden. Da die Schutzgruppe jedoch insbesondere für spätere enzymatische Reaktionen, bei denen die entsprechenden Aminosäuren freigesetzt werden, wieder aufwendig zu entfernen ist, wird ein einfaches Verfahren zur Darstellung der Aminoalkylverbindungen gesucht. Zur Darstellung von Verbindungen der allgemeinen Formel (I) oder (II), worin X für Alkylen und Y für Wasserstoff oder Alkyl steht, wird eine säurelabile Aminoschutzgruppe verwendet. Diese Schutzgruppe kann schon während des säurekatalysierten Hydantoinringschlusses abgespalten werden, da bei diesem Teilschritt keine Konkurrenzreaktion der freigesetzten Aminofunktion mehr eintritt. Darstellung von D- und L-Antipoden natürlicher oder nichtnatürlicher Aminosäuren.(EN) In order to prepare aminoalkylhydantoins, the amino function must be protected before the formation of the hydantoin ring. Since the protective group is difficult to remove again, however, in particular for subsequent enzymatic reactions in which the corresponding aminoacids are liberated, a simple method of preparing aminoalkyl compounds was sought. The invention calls for an acid-labile amino-protecting group to be used in the preparation of compounds of general formula (I) or (II) in which X is alkylene and Y is hydrogen or alkyl. This protective group can even be split off during the acid-catalysed hydantoin ring closure since, during this step, no competing reactions of the freed amino function take place. The method disclosed is suitable for use in the preparation of optically opposite D- and L-forms of natural and synthetic aminoacids.(FR) L'invention concerne un procédé de préparation d'aminoalkylhydantoïnes et d'aminoalkyle-$g(a)-aminoacides. Pour obtenir des aminoalkylhydantoïnes, la fonction amino doit être protégée avant la formation du composé cyclique hydantoïne. Comme le groupe protecteur est toutefois difficile à enlever à nouveau, notamment pour des réactions enzymatiques au cours desquelles les acides aminés correspondants seront libérés, l'invention se propose de mettre au point un procédé de préparation de composés aminoalkyle. Pour obtenir des composés de la formule générale (I) ou (II) où X désigne des alkyles et Y l'hydrogène ou l'alkyle, on utilise un groupe protecteur amino acido-labile. Ce groupe protecteur peut être éliminé dès la cyclisation de l'hydantoïne à catalysation acide, car dans cette étape partielle, il ne se produit plus de réaction concurrentielle de la fonction amino libérée. L'invention concerne en outre la préparation d'antipodes D et L d'acides aminés naturels ou non naturels.
为了合成
氨基丁基
丙烯酰胺-氢酰胺二元Sometimes, it is essential to add a counter-ions, especially when working with weak acids, bases, or buffer systems. The techniques involved in bis-amide chemistry are a major part of organic synthesis. By combining bis-amides with acid or base, it's sometimes possible to design compounds with extended conjugation that cannot be easily made from aliphatic or aromatic systems. widened conjugated systems have several advantages, including more efficient reaction sequences, greater ease of synthesis and pure度, and the possibility for other operations such as Cr abstraction. For instance, the combination of bis-p-airkylideneamides with 4-nitrobenzoic acid can result in bis-spier derivatives that are more likely to react than sp-inosins. This is because the additional electron-withdrawing groups on the aromatic ring accelerate the reaction. The resonan(zement of these groups also extends to product stability. Furthermore, bis-amide chemistry is often applied for the synthesis of products with multiple aryl substituents. For example, the combination of bis-p-alkylideneamides with 2,4,6-trinitrophenol can lead to the formation of nitrogen-containing condensed heterocycles, such as imidazoles and pyrazoles, which have unique reactivity and are useful as ligands or in drug design. Moreover, bis-amides can also be utilize to synthesize macrocyclic compounds. Such as bis-acetamides reacting with trifluoroacetate ion to form macrocyclic acetamides, which can subsequently undergo Claisen cyclization to give macrocyclic ketenes. These relevant reactions will be elucidate in detail in Chapter 3. Additionally, it's important to note that these counter-ions can sometimes lead to unexpected product formations. For example, certain bis-amides might still react even when the counter-ion is not present, showing their versatility. While bis-amide chemistry has many applications, it is vital to understand its mechanistic and other underlying principles to exploit its full potential。中文翻译:为了合成
氨基乙
酸酯类化合物及其衍
生物,通常需要添加反离子,尤其是当使用弱酸、弱碱或缓冲系统时。二酰胺
化学中的技术是有机合成的重要组成部分。通过将二酰胺与酸或碱结合,有时可以设计出具有延长共轭的化合物,这样的化合物无法通过线性或芳香系统合成。具有延长共轭优势的化合物有几个优点,包括更高效的反应序列、合成上的更大灵活性和纯度,以及可能的其他操作如Cr抽象。例如,将二-二键酰胺与4-
硝基苯酸反应可以得到双-//:化合物的二-//:衍
生物,这些衍
生物更容易反应 than sp-inosins。这是因为这些衍
生物上的额外吸电子基团加速了反应,而且这些基团所带来的共振也使产物更加稳定。此外,二酰胺
化学还可用于多个取代基苯环化合物的合成。例如,二-二键酰胺与2,4,6-三硝基
酚的组合可以形成含有氮的浓缩环状杂环,如imidazoles和pyrazoles,这些化合物具有独特的活性,常被用作配位体或药物设计中。此外,二酰胺还可以用于合成大环化合物。例如,二- acetamides与trifluoroacetate离子反应以形成大
环酸氨,随后会发生Cllaisen环化反应以生成大环酮。这些相关反应将在第3章详细阐述。此外,反离子有时也会带来意外的产物形成。例如,某些二酰胺仍然会发生反应,即使反离子不存在,显示其多面性。尽管二酰胺
化学有许多应用,但理解其机理和其他basic principles是开发其潜力所必需的。