质粒DNA催化Henry反应的研究

发布时间：2018-07-28 13:45

【摘要】：Henry反应是形成碳-碳键的重要反应之一,可以为许多化合物的合成提供中间体,具有广泛的应用价值。目前报道的Henry反应的催化剂主要有手性胍、硫脲衍生物或者金鸡纳碱衍生物等,反应溶剂大多数是有机溶剂,对环境有很大的危害。所以,绿色催化剂的开发渐渐成为研究重点。近几年来,DNA作为化学反应的催化剂逐渐引起广泛的关注,主要因为反应大多在水相中发生,且与铜离子络合物偶联后能达到较高的对映选择性,既满足了生产需要,也保护了环境。DNA分子一直以来被认为是体内遗传信息的载体,但随着对它的深入研究,科学家们对DNA分子的认识已渐渐从生物领域拓展到化学合成领域。目前,已经发现DNA可以催化很多经典的化学反应,例如:狄尔斯-阿尔德反应,Michael加成反应等。常用的DNA催化剂有鲑鱼精DNA,人体端粒末端G-四联体,小牛胸腺DNA以及人工合成的单链DNA。本实验在此基础上尝试了用未经修饰的质粒DNA催化Henry反应,并与鲑鱼精DNA作为对比。首先,我们选择纯水作为反应溶剂;其次,从溶剂、底物摩尔比、反应温度、反应时间和金属离子等方面对反应进行了优化,结果表明质粒DNA催化反应发生20 min后产率就可以达到97%,催化效率远远高于鲑鱼精DNA,而且在连续使用十次后,依然能够保持100%的催化活力。除此之外,本实验还研究了不同取代基对质粒催化Henry反应的影响,分别用不同的硝基烷烃和不同取代基的苯甲醛进行反应,结果表明,对于硝基烷烃,空间位阻越大,越不容易发生反应;对于不同取代基的苯甲醛,带有吸电子基团的芳香醛更容易发生反应,而苯甲醛,对羟基苯甲醛和对甲氧基苯甲醛,则不容易发生Henry反应。本实验不仅展示了未经修饰的质粒DNA具有催化高产率的Henry加成反应的能力,还为未来DNA杂交催化剂提供了新的选择。这说明不仅只有鲑鱼精DNA或者人体端粒末端G-四联体可以作为杂交催化剂的生物骨架,质粒DNA也具有这个潜能,而且质粒DNA还具有较高的催化效率。
[Abstract]:Henry reaction is one of the important reactions to form carbon-carbon bonds, which can provide intermediates for the synthesis of many compounds. At present, the catalysts for Henry reaction are mainly chiral guanidine, thiourea derivatives or cinchonabine derivatives, and most of the reaction solvents are organic solvents, which are harmful to the environment. Therefore, the development of green catalyst has gradually become the focus of research. In recent years, DNA as a catalyst for chemical reactions has attracted wide attention, mainly because the reactions are mostly in water phase and can achieve high enantioselectivity after coupling with copper ion complexes, which can meet the needs of production. DNA molecules have been regarded as carriers of genetic information in vivo, but with the further study of DNA molecules, scientists have gradually expanded their understanding of DNA molecules from the biological field to the field of chemical synthesis. At present, it has been found that DNA can catalyze many classical chemical reactions, such as Dils-Alder reaction and Michael addition reaction. Common DNA catalysts include salmon sperm DNA, human telomere terminal G-quadruplex, calf thymus DNA and synthetic single-stranded DNA. On this basis, the unmodified plasmid DNA was used to catalyze the Henry reaction, which was compared with salmon essence DNA. Firstly, pure water was chosen as the reaction solvent; secondly, the reaction was optimized in terms of solvent, molar ratio of substrate, reaction temperature, reaction time and metal ions. The results showed that the yield of plasmid DNA catalytic reaction could reach 97% after 20 min, the catalytic efficiency was much higher than that of salmon sperm DNA, and 100% catalytic activity could be maintained after 10 times of continuous use. In addition, the effect of different substituents on the Henry reaction catalyzed by plasmids was studied. Different nitroalkanes and benzaldehyde with different substituents were used respectively. The results showed that the steric hindrance of nitroalkanes increased. For benzaldehyde with different substituents, aromatic aldehydes with electron-absorbing groups are more likely to react, while benzaldehyde, p-hydroxybenzaldehyde and p-methoxybenzaldehyde are not susceptible to Henry reaction. This experiment not only showed that the unmodified plasmid DNA had the ability to catalyze the Henry addition reaction with high yield, but also provided a new choice for the future DNA hybridization catalyst. This indicates that not only salmon sperm DNA or human telomere terminal G-quadruplex can be used as the biological skeleton of hybrid catalyst, but also plasmid DNA has this potential, and plasmid DNA also has high catalytic efficiency.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O621.251

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