Studies On Catalytic Synthesis Of Trans-Oxazolines By Br?nsted Acid

Oxazoline is an important class of nitrogen-containing heterocyclic compounds,widely existing in a variety of natural products,pharmaceutical molecules and biologically active compounds.In this paper,the application and synthesis of oxazoline compounds are introduced.Moreover,a new method for synthesis of trans-oxazoline catalyzed by Br?nsted acid is studied.In the first chapter,we briefly introduced the application of oxazoline compounds in biomedicine,asymmetric catalysis and some other fields.We slso have summarized the previous work on the synthesis of oxazoline:1.Methods of Synthesizing oxazoline compounds using?-amino alcohol;2.Methods of synthesizing oxazoline compounds by intramolecular cyclization;3.Other methods of synthesizing oxazoline compounds.In the second chapter,we briefly introduced the development process of sulphur ylide and the rapid development of sulfoxonium ylides chemistry in recent years.Most of the chemical reactions of sulfoxonium ylides are explored using metal catalysis.Through research,we have developed a new method for synthesizing tri-substituted trans-oxazolines using HClO₄ as a catalyst as well as N-vinylamide and sulfoxonium ylides as starting materials.This[4+1]cyclization reaction constructed by C-C and C-O bonds has a wide substrate adaptability(all aryl,heterocyclic,and alkyl groups are applicable),high diastereoselectivity(dr>20:1)and yield.