Constructions Of Many N-heterocyclic Compounds Via Tandem Reactions

Heterocyclic compounds, in particular nitrogen-containing heterocyclic compounds, are the molecular skeleton structure of many natural products and drugs. The nitrogen-containing heterocyclic compounds have been widely applied in the fields of pharmaceutical, chemical industry and so on. The tandem reactions have been applied as a powerful approach for the construction of nitrogen-containing heterocyclic compounds. Isoquinoline alkaloids are the major important natural alkaloids with diverse structural skeletons. This thesis is focused on tandem reaction for the generation a series of nitrogen-containing heterocyclic compounds which potentially exhibit remarkable biological activities.Firstly, the efficient synthesis of 1-amino-isoquinoline-N-oxides are generated under mild conditions through a silver(I) and copper(I) co-catalyzed reaction of 2-alkynylbenzaldoxime with secondary amines. During the reaction process, a silver-catalyzed 6-endo cyclization and a copper(I)-catalyzed C-H bond activation are involved.Secondly, a novel and efficient route for the synthesis of 1-(trifluoromethyl)isoquinolines via a copper(II)-catalyzed tandem reaction of isoquinoline-N-oxides with Togni’s Reagent is developed. The reaction proceeds smoothly in wild conditions, leading to the corresponding products in good yields. The trifluoromethyl group could be easily introduced in the 1-position of isoquinoline under mild conditions.