Studies On The Desulfitative Amination Of Benzoxazole And Annulation Of Aldehydes With Alkynes

In recent years, much attention has been paid in thetransition-metal-catalyzed desulfitative cross-coupling reactions. Thedesulfitative amination reactions are powerful and versatile routes to theformation of C-N bonds. Indenone frameworks are ubiquitous inpharmaceutical and material science. Thus, it is very necessary tosynthesize these compounds. This dissertation will focus on thedesulfitative amination and annulation of aldehydes. it is consisted of twoparts:In part one, the recent research progress on thetransition-metal-catalyzed desulfitative cross-coupling reactions wasreviewed. We developed palladium-copper-catalyzed desulfitativeamination of benzo[d]oxazole with sulfamoyl chlorides. It tolerates aseries of functional groups. Finally, we investigated the preliminary mechanism.In part two, we summarized the recent research progress on theannulation of alkynes. A rhodium-catalyzed direct annulation ofaldehydes with alkynes leading to indenones is described. We tested thereaction of benzaldehyde with diphenyl ethyne. The in situ temporalinstallation of acetylhydrazine enables the annulation of the ortho areneC-H bond with alkynes to form ketone hydrazone, which transforms toindenone by protonation. This procedure is simple and easy to operate. Inaddition, It has a good functional groups compatibility. Moreover, themechanism was studied.