Synthetic Studies Of Vincorine And The Study On The Synthesis Of Aspidosperma Alkaloids Skeleton By Rhodium-Catalyzed Aza-vinyl Carbene

This thesis mainly focused on the synthetic studies toward the indole alkaloid vincorine and the synthesis of aspidosperma alkaloids skeleton via Rhodium-catalyzed aza-vinyl carbine cyclizations. It consists of the following two parts:Chapter1. The synthesis of indole alkaloid VincorineA brief introduction of Vincorine including its separation, structure, biological activities and some synthetic studies are given. Our synthetic campaingn toward this molecule begin with the commercially available5-methoxytryptamine. A series of operations such as Suzuki coupling reaction, intramolecular Diels-Alder reaction were employed as the key steps for the total synthesis of Vincorine. The key intermediate of vinyl indole amide (1-58) was successfully prepared; however the precursor of IMDA reaction was failed to be synthesized so as to the critical IMDA reaction has never been tested in our work.Chapter2. Synthesis of Aspidosperma Alkaloids Skeleton via Rhodium-Catalyzed Aza-vinyl Carbene cyclization.Introductions about monoterpenoid indole alkaloids, especially the Aspidosperma alkaloids including their synthetic studies have been extensively summarized. A series of stable and readily accessible N-sulfonyl1,2,3-triazoles as carbene precursors are employed in our research to build the indoline tetracyclic core skeleton of the Aspidosperma alkaloids via a intramolecular sulfonyl triazole isomerization/[3+2] dipolar cycloaddition cascade. Over ten different analogs of aspidoserma alkaloid were successfully synthesized using this stategy. This novel protocol proves to be more practical and efficient to construct several of indole alkaloid skeletons which might have a wide range of applications in the synthesis of this kind of natural products.