摘要 過渡金屬催化的合成方法是現代有機合成中最重要的工具。尤其利用易於獲得的π-組成分子進行碳-氫鍵官能化,更是在單一步驟合成天然產物與生物活性骨架中一種相當有吸引力的方法。它是一種不管原子使用效率或步驟效率都相當高的方法,被高度推崇為綠色過程。因此, 本論文描述了三個新的專注在過渡金屬催化的碳-氫鍵官能化反應與重烯的新反應。為了方便和更好的理解,論文分為三章。這三章分別描述了銠(III)和鈷(III)催化的碳-氫鍵官能化和與重烯的環化反應。 第1章描述銠(III)金屬催化2-羥基或2-氨基苯甲醛與重烯進行[4+1]環化反應。 反應通過醛碳-氫鍵活化,重烯的插入和親核加成,然後進行β-氫脫去反應,以優異的產率提供官能基化的3-香豆冉酮和3-二氫吲哚酮。 第2章討論酚輔助鈷(III)金屬催化2-乙烯基苯酚與重烯進行碳-氫鍵官能化,以提供[5+1]環化產物。 反應通過乙烯基之碳-氫鍵活化,重烯插入和不尋常的分子內位向選擇性苯氧基加成,然後進行β-氫脫去反應,以優異的產率提供2,2-二取代的2H-苯並吡喃。 另外,這是在鈷催化的碳-氫鍵活化反應中,重烯類物質首次用作偶聯物。 第3章解釋了鈷(III)金屬催化N-苯基乙醯胺與重烯進行[3+3]環化反應。 反應通過芳香碳-氫鍵活化,重烯插入反應,然後進行β-氫脫去反應和1,4-加成反應,以優異的產率提供官能化的1,2-二氫喹啉。 而沒有環化的二烯中間體的分離則清楚地解釋了反應途徑。
ABSTRACT Transition-metal catalyzed synthetic methods are the most important tools of modern organic synthesis. Particularly, direct C–H functionalization by utilizing readily available π-components is an attractive methodology to synthesize natural products and bioactive skeletons in a single step. It is an atom- and step-economical method which is highly urged as one of the green processes. In this regard, this thesis describes three new reactions that focus on the transition-metal catalyzed C–H bond functionalization reactions with allenes. For convenience and better understanding, the thesis is divided into three chapters. These three chapters describe Rh(III) and Co(III)-catalyzed C–H bond functionalization and annulation reactions with allenes. Chapter 1 describes a Rh(III)-catalyzed [4+1] annulations of 2-hydroxy- and 2-aminobenzaldehydes with allenes. The reaction proceeds via aldehyde C–H bond activation, allene insertion and nucleophilic addition followed by β-hydride elimination to afford functionalized 3-coumaranones and 3-indolinones in excellent yields. Chapter 2 deals about Co(III)-catalyzed phenolic OH-assisted C–H bond functionalization of 2-vinylphenols with allenes to afford [5+1] annulation product. The reaction proceeds via vinylic C–H bond activation, allene insertion and unusual intramolecular regioselective phenoxide addition followed by β-hydride elimination to afford 2,2-disubstituted 2H-chromenes in excellent yields. This is the first time that allenes have been used as the coupling partners in cobalt-catalyzed C–H activation reactions. Chapter 3 explains about a Co(III)-catalyzed [3+3] annulation of N-Phenylacetamides with Allenes. The reaction proceeds via aromatic C–H bond activation, allene insertion, followed by β-hydride elimination and 1,4-addition reaction affords a functionalized 1,2-dihydroquinolines in excellent yields. Isolation of acyclic diene intermediate clearly explains the reaction pathway.