【作者】 孙云；

【导师】 赵康；

【作者基本信息】 天津大学 ， 应用化学， 2008， 博士

【摘要】 官能团化的烯胺在有机化学领域占有十分重要的地位,它们在药物设计及多种具有生物活性物质的合成中扮演了不容忽视的角色。α,β-脱氢氨基酸和α-烯胺酮(后者也被称为α,β-脱氢氨基酸衍生物)作为这个大家庭的成员,不仅其骨架结构频繁出现在天然产物及具有生物活性的物质结构中,而且它们能够参与多种有机反应,是有机合成领域有用的合成子。鉴于二者在有机化学中的广泛应用,对其合成方法的研究也越发重要。根据文献报道的成熟的合成方法,我们从经济易得的原料出发制备了研究反应所需的多种带有不同取代基的α-溴代羰基化合物和N-烷氧基酰胺。本论文以α-溴代羰基化合物和N-烷氧基酰胺为反应底物,利用N-O键在碱性条件下易于断裂的特点,通过优化反应条件找到了一锅法制备α,β-脱氢氨基酸和α-烯胺酮的温和有效的方法。运用此方法,我们得到了一系列结构丰富的以一种构型为主的产物,发现了该类反应的一些反应规律。通过单晶X射线衍射、NOE实验以及文献调研确定这些化合物为Z式构型。最后我们对合成的一系列α,β-脱氢氨基酸衍生物碳碳双键的还原进行了方法学研究,发现了操作简便、反应条件温和、价廉高效的TMSCl/KI/MeCN还原体系。利用该体系还原α,β-脱氢氨基酸衍生物的反应尚未见报道,我们对其可能的反应机理进行了推测。多种不同结构的α,β-脱氢氨基酸衍生物在此还原体系下以非常好的收率得到了相应的还原产物,这些新化合物的结构得到了核磁波谱的确证。更多还原

【Abstract】 Functionalized enamines have played a very important role in the drug design and synthesis of a variety of different structures which possess biological activities. As members of this family,α,β-dehydroamino acids andα-ketoenamines (also referred to asα,β-dehydroamino acid derivatives) occur as frequent frameworks in natural products and biologically active compounds. They can participate in various organic reactions and thus they are useful synthons in organic synthesis. In virtue of the wide application ofα,β-dehydroamino acids andα-ketoenamines in organic chemistry, there is still a need to develop facile and practical synthetic methods for their preparation.According to the process already reported in the literature, theα-bromo ketones and hydroxamates with various different substituents were prepared from inexpensive starting materials.Herein we disclose a mild and efficent one-pot synthetic strategy for the preparation ofα,β-dehydroamino acid derivatives through the reactions ofα-bromocarbonyl compounds with hydroxamates due to the easy cleavage of nitrogen-oxygen bond under basic conditions. A series of compounds with a single isomer were predominately generated via this method, and thus some rules of this reaction has been found out. The geometry of the products has been confirmed as Z-configuration based on single-crystal X-ray analysis, NOE experiment and a comparison with the previous literature.The reduction of carbon-carbon double bond ofα,β-dehydroamino acid derivatives was investigated. It was found that TMSCl/KI/MeCN was a simple, efficient, mild and inexpensive reductive system and it was used to reduceα,β-dehydroamino acid derivatives for the first time. Variousα,β-dehydroamino acid derivatives were reduced in excellent yields under this condition. The structures of these new compounds were confirmed by NMR spectra.更多还原