布朗斯特酸催化的亚胺极性反转反应 和手性环丁烯的合成

   手性布朗斯特酸催化作为一种重要的催化模式，以其绿色、高效的特性成功实现了诸多不对称催化反应，在医药和合成化学等领域中展现出较高的应用价值。因此，基于手性布朗斯特酸的催化模式受到科研工作者越来越多的关注和研究。一方面，发生极性反转后的醌亚胺可作为新型高效的、便捷合成的氮源亲电试剂，可应用于C-N键的构建，便于制备复杂的生物活性分子；另一方面，手性环丁烯不仅是构建药物活性分子或天然产物的核心骨架，还能进一步衍生化组装成其他复杂分子片段，其不对称合成具有较高的学术研究价值和应用前景。但目前关于布朗斯特酸催化的醌亚胺的不对称亲电反应和手性环丁烯的合成仍处于初步研究阶段。因此，本论文以手性布朗斯特酸为催化剂，探索了两种不对称催化反应类型，高收率、高立体选择性地实现了两类手性化合物的合成，主要内容如下：

   利用醌亚胺极性反转的策略，本文开发了手性磷酸催化1-萘胺的不对称亲电胺化反应，实现了稳定C-N轴的直接构建，以较好的反应收率和优异的对映选择性合成了C-N轴手性N-芳基磺酰胺化合物。该反应具有较好的底物普适性（39个例子，最高可达97%收率和97% ee），丰富了醌亚胺的极性反转反应在不对称催化领域中的应用，也为含C-N轴手性N-芳基磺酰胺化合物的高效不对称合成提供了新途径。

   利用小环具有较大环张力的特性，本文还开发了手性N-三氟磷酰胺催化二环[1.1.0]丁烷的不对称异构化反应，以较好的反应收率和对映选择性合成了一系列手性环丁烯化合物（39个例子，最高可达97%收率和96% ee），为高效构建手性环丁烯提供了新思路。此外，手性环丁烯可作为平台分子，通过环加成反应得到多种具有生物活性片段的手性二环[3.2.0]庚烷衍生物与二环[2.1.0]戊烷衍生物。手性环丁烯产物的进一步衍生化也体现了该反应具有重要的实用意义。

        As an important catalytic mode, organocatalysis has successfully been applied in many asymmetric reactions with its green and highly efficient characteristics, and has shown high application value in the fields of medicine and synthetic chemistry. Therefore, the catalytic model based on chiral Brønsted acid has attracted great attention by researchers. On one hand, the umpolung of iminoquinones, as a kind of novel, efficient and accessible nitrogen source electrophiles, has been applied to the construction of C-N bonds for the rapid and convenient preparation of complex structures. On the other hand, chiral cyclobutenes are not only the core frameworks of pharmaceutical active molecules or natural products, but also can be further derived and assembled into other complex molecular fragments, which has high academic research value and potential application. However, the research on asymmetric electrophilic reactions of iminoquinones and organocatalytic synthesis of chiral cyclobutenes are still in the preliminary stage. In this thesis, two kinds of asymmetric catalytic reactions were explored under chiral Brønsted acid catalysis, and the synthesis of chiral compounds was achieved with high yields and enantioselectivities. The main contents include:

         In this thesis, chiral phosphoric acid (CPA)-catalyzed asymmetric electrophilic amination of 1-naphthylamines has successfully been achieved by the strategy of umpolung of iminoquinones, which leads to the direct construction of stable C-N axis. This protocal exhibited broad substrate scope, affording C-N axially chiral N-arylsulfonamides with moderate to high yieds and high enantioselectivities (39 examples, up to 97% yield and 97% ee). This methodology enriches the asymmetric application of umpolung reaction of iminoquinones, and also offers a novel approach to facilitate the highly efficient asymmetric construction of C-N axially chiral N-arylsulfonamides.

        Meanwhile, due to the high ring strain energy of small rings, the asymmetric isomerization of bicyclo[1.1.0]butane catalyzed by chiral N-trifluorophosphoramide (NTPA) was achieved, in which stable chiral cyclobutene compounds were obtained with good to high yields and enantioselectivities (39 examples, up to 97% yield and 96% ee), providing a new path for the construction of chiral cyclobutenes. In addition, chiral cyclobutenes can be used as a kind of platform molecules to rapidly synthesize other complex structures through cycloaddition reaction to obtain a variety of bioactive fragments of chiral bicyclo[3.2.0]heptane and bicyclo[2.1.0]pentane. The further derivatization of chiral cyclobutene also shows that the reaction has important practical significance.

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