Ni-Catalyzed Reductive Cross-Coupling Of Unactivated Alkyl Bromides And Total Synthesis Of Sacidumlignan D

This thesis aims at Ni-Catalyzed reductive cross-coupling of unactivated alkyl bromides and its applications in organic synthesis. It consists of the following three chapters.Chapter 1:Several transition-metal-catalyzed C-C couplings of unactivated alkyl halides are summarized briefly, with the emphasis on Ni-catalyzed reactions. And the influence of the ligands on this type of cross-coupling is also discussed in detail. Cross-coupling of alkyl halides with organometallic reagent that is generated in situ, and direct reductive couplings are highlighted in the last section.Chapter 2:A Ni-Catalyzed intermolecular reductive cross-coupling reaction of unactivated alkyl bromides and aryl iodides at room temperature has been developed in our group and successfully extended to less explored intramolecular versions and tandem cyclization-intermolecular cross-coupling. Highly stereoselective (or stereospecific) synthesis of linear-fused perhydrofuro[2,3-b]furan (pyran) and spiroketal skeletons allows rapid access to these useful building blocks, which would be potentially valuable in the synthesis of relevant natural products. A rational explanation for the formation of contiguous stereogenic centers is given.Chapter 3:Sacidumlignan D is a lignan with an unprecedented and rearranged tetrahydrofuran skeleton. Its isolation, structure identification and previous synthetic studies are described. In this work, efficient total synthesis of (±)-sacidumlignan D has been successfully achieved employing Ueno-Storkradical cyclization of a-bromo acetal as a key step.