Neighboring Groups Are Applied In The Organic Synthesis

In organic reactions, the reactivity could be affected by different substituted groups in the same molecular through the electrical and bulky factors, however, these groups don't participate the reactions directly, to the opposite, in some other reactions, the neighboring groups of the reaction centre participate the main reaction when it goes on, which is so called "Neighboring-Group Participation" and has been extensively explored especially in recent years. In the reactions participated by neighboring- groups, configurations maintenance, rearrangement and cyclization are reachable other than the reaction rate enhancment.In this dissertation, we described the neighboring-group participations in organic reactions using nitrogen-participated cyclization and sulfur-participated dibromization as examples.Firstly,We explored the nitrogen-participated cyclization reactions using oximes as the substrates and synthesized substituted pyrroles were obtained by mixing the oxime and anhydride in DMA under 80℃.Secondly, We researched the dibromization using sulfur as a neighboring group in sulfur-bearing propargylalcohol, which was participated by CuBr₂ under 80℃in acetonitrile and provided a convenient method to obtain dibromized alkynes from sulfured propargylalcohol.