Synthesis Of Nitrogenous Organic Small Molecules With Benzynes: Dipole Cycloaddition And Insertion Reactions Of C-N Double Bond

Benzyne is an important synthetic intermediate, which has high reactivity due to the extremelyunstable triple bond of benzyne molecular. Inserting aromatic ring into molecular rapidly and synthesizingvariety of benzoheterocycle efficiently, benzyne chemistry is attracting more and more synthetic organicchemist`s attentions.In this thesis, we study the benzyne [3+2] cycloaddition with1,3-dipolar and latent depole, andinsertion reactions with carbodiimide species. We attempt to explore different types of benzyne reactionand expand the reaction scope, offer an novel method to synthesize similar compounds.The main results were outlined as below:Synthesis of dihydrobenzoisoxazoles from benzynes and sugar-derived nitrones: Benzyne [3+2]cycloaddition with sugar-derived nitrones affords good yields of dihydrobenzoisoxazolidines. This reactionextends the current scope of benzyne cycloaddition with nitrones, and the products have potential value ofbiomedicine.Aryne Cycloaddition with3-Oxidopyridinium Species: Kobayashi benzyne precursor was used todevelop the [3+2] cycloaddition of arynes with3-oxidopyridinium species. The reaction offers abicyclo[3.2.1] skeleton under mild conditions. A [7+2] cycloaddition mode with a subsequent pyridinering-opening event has also been observedThe insertion reactions of arynes to C-N doublebonds of carbodiimide species: The insertion reactionsof arynes to C-N doublebonds of carbodiimide species afford good yields of p-N substituded benzamide compounds. This reaction extends the current scope of benzyne insertion reactions, offers a novel methodto the synthesis of p-N substituded benzamide compounds.