Development Of New Synthetic Methodologies For Complicated Nitrogen-containing Heterocycles

Nitrogen-containing heterocycles,with diverse structural features,are widely distributed in Nature.They not only serve as the core parts of natural alkaloids,but also exist in other unnatural biologically interesting compounds,including many marketed pharmaceuticals.For their important roles in life,synthesis of the high-value nitrogen-containing heterocyclic compounds is of great importance to help various advanced studies associated with nitrogen-heterocycles.This dissertation was divided into three parts,including synthesis methods of two kinds of nitrogen-containing heterocyclic compounds,and the study on total synthesis of a Lycopoudium alkaloid.The first section studied the light-driven olefin hydrosilylation,and successfully expanded to the light-driven alkyne hydrosilylation.Furthermore,we designed and implemented a radical cascade cyclization for the quick synthesis of multi-substituted piperidines based on diene hydrosilylation.In the second section,a gram-scale organocatalytic enantioselective Michael addition of 2-nitrocyclohexanone to acrolein has been developed,and successfully applied to a concise two-step synthesis of(S)-1-azaspiro[4.5]decan-6-one.The third section explored a new total synthesis of lycopodium alkaloid:Lycopladine D,based on a light-driven[2+2]cycloaddition of an enol intermediate in the 10membered nitrogen heterocycle.We successfully synthesized the 10-membered ring intermediate,and attempted the crucial[2+2]cycloaddition reaction.The subsequent synthesis is underway in this laboratory.