Studies On The Cyclization Reactions Of Alkynyl-imides

Heterocyclic compounds and their derivatives are becoming increasingly important due to their wide range of applications in organic synthesis, material chemistry and medicinal chemistry. During the last decades, studying and synthesizing these compounds have attracted the interest of organic chemists worldwide. In this thesis we choose alkynyl-imide derivatives as starting materials to prepare multi-functionalized heterocyclic compounds by using different synthetic strategies.The dissertation mainly includes three parts:Part â… :base catalyzed sequence of propargyl-allenyl isomerization and aza-electrocyclization:1. In chapter 1, we presented a sequence of propargyl-allenyl isomerization and aza-electrocyclization for the facile synthesis of poly-functionalized quinolines. With the advantage of mild reaction conditions and high yield, this protocol offers an alternative way to prepare poly-functionalized quinolones.Part â…¡:acyl electrophiles and Selectfluor promoted cascade reaction of alkynyl-imide derivatives:2. Chapter 3 and chapter 4 describe the development of a facile protocol to a highly functionalized amidoallenylium by treatment of alkynylimine with acyl bromide in dichloromethane, which may give tetrasubstituted allene intermediates and yield furans, pyrroles, thiophenes, benzofurans, benzothiophenes, hydrindenes and isoindolines. 3. Polycyclic skeletons are present in numerous important compounds, such as synthetic intermediates and target molecules of biological interest. In chapter 5, a Selectfluor-promoted construction of polycyclic skeletons with high synthetic efficiency was developed.Part â…¢:Cu(â… )-catalyzed cyclization of alkyne imines:4. In the last chapter, a novel efficient route to 3-halogen substituted quinoline derivatives through Cu(â…¢)-mediated cyclization of alkyne imines was introduced.