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摘要氮杂环卡宾性质独特，它是一类具有优良研究前景和极高应用价值的仿生有机催化剂。它的某些金属配合物具有特定的用途，例如用于抑制微生物、真菌和病毒的生长，使用有效的氮杂环卡宾的配合物甚至可以用于治疗癌细胞。随着研究的发展，氮杂环卡宾越来越受到化学家的重视。47224
本篇论文主要研究内容为氧气参与下氮杂环卡宾/Lewis酸不对称催化α,β-不饱和醛与1,3-二羰基化合物的反应。在氧化剂的选择中，我们尝试用绿色环保的氧气代替那些比较昂贵的化学氧化剂，在不同的催化剂作用下希望能得到较好的结果。解决的关键问题是，怎样的催化条件是高效的，然后在最优条件下改变底物来确认其底物的适应情况。
N-Heterocyclic carbenes (NHCs) have special characteristics. It’s a kind of biomimic organic catalysts which has good research prospects and high value. Some metal complex has its specific properties, e.g., for inhibiting the growth of microorganisms, fungi and viruses. Use a valid heterocyclic carbene complexes can even be used to treat cancer. With the development of research on NHC carbene, more and more attentions were attacted by chemists all over the world.
In this thesis, an enantioselective NHC-catalyzed aerobic annulation of α,β-unsaturated aldehydes with 1,3-dicarbonyls was investigated, leading to the formation of chiral 2H-pyran-2-ones in high yields and enantioselectivities. Different solvents, bases and additives were screened, and finally we found the best reaction condition. With the optimum condition in hand, we then explored the substrate scope, and the desired products were obtained in good to excellent yields and enantioselectivities with different substitution groups. In this study, air was selected as the oxidant instead of the very expensive BPO under optimized reaction conditions, which is cheap, green and environment friendly.
毕业论文关键词：氮杂环卡宾；不对称有机催化； 2H-吡喃-2-酮； Lewis酸
Keyword: N-Heterocyclic carbenes; Asymmetric organocatalysis; 2H- pyran-2-one; Lewis acid
摘 要 2
目 录 3
第一章 绪论 4
1.1 引言 4
1.2 氮杂环卡宾的发展简述 4
1.2.1氮杂环卡宾催化安息香缩合反应 6
1.2.2 氮杂环卡宾催化Stetter反应 6
1.2.3 Breslow中间体 7
1.3 手性2H-吡喃-2-酮 7
1.4 氮杂环卡宾催化的其它底物的反应 8
1.5 总结 9
第二章 实验部分 10
2.1 方案设计 10
2.1.1 溶剂的筛选 10
2.1.2 碱的筛选 10
2.1.3 添加剂的筛选 10
2.1.4 催化剂的筛选 10
2.1.5 底物扩展 11
2.1.6 其他条件 11
2.2 实验部分 11
2.2.1 实验所用仪器 11
2.2.2 实验所用试剂 11
2.2.3 反应方程式 12
2.2.4 实验过程 12
第三章 结果与讨论