鎳鋁雙金屬做連鎖反應烯烴異構化與碳-氫官能基化之反應性研究

Abstract

在本論文中，我們利用鎳金屬-碳烯催化系統，活化1-甲基-1氫-苯並咪唑 (1-methyl-1H-benzimidazole) 與其衍生物的C2位碳氫鍵，並引入各種烯烴同時進行雙鍵的異構化反應 (isomerization) 及碳-氫鍵催化加成反應的連鎖反應 (Tandem reaction)。反應條件中，藉由不同的配位基 (ligand)和路易士酸 (Lewis acid) 的添加，可以產生不同位向的產物。反應中若不添加路易士酸，則反應物苯丙烯 (allybenzene) 會先進行雙鍵異構化反應再進行碳-氫鍵加成反應，進而得到分支結構產物;但若將配位基改成立體障礙較大的配位基且添加路易士酸，則可得到直鍊結構的產物。此反應的重點在於烯烴類的雙鍵異構化反應，我們也運用相關的實驗結果來推測出此異構化反應與碳氫鍵活化反應的連鎖反應過程，證明了此分支與直鍊產物的反應機制。我們將此方法運用在芳香環衍生物或各類烯烴的催化上都可以得到不錯的產率及選擇性，此研究對於未來發展藥物、天然物、材料的合成上，都是一個展新且高效率的方法。

In this thesis, tandem alkene isomerization and C-H functionalizaton of N-methylbenzimidazole by nickel catalysts was developed. We obtained different products by adding different ligands and Lewis acids. In the absence of Lewis acid, we obtained branched-chain derivatives of benzimidazole due to occurrence of olefin isomerization in this system. On the other hand, we obtained linear-chain derivatives of benzimidazole by adding Lewis acid and bulky ligand. We speculated that olefin isomerization process is faster than C-H bond activation without addition of Lewis acid to obtain the branched products, which was demonstrated by GC analysis. From GC analysis and kinetic isotope experiments, the plausible mechanism of this tandem catalysis was proposed. This study described the first Ni-promoted prototype reaction based on integrating C-H activation of various heteroarenes with isomerization of allylarenes, which provided a novel route for synthesizing the related pharmaceutical drugs, nature products and materials.