Study On The C–N Bond Formation Catalyzed By Ga(Ⅲ) Reagents

In the last decade, Gallium trichloride and Gallium triflate have been widely applied in the organic synthesis. Gallium trichloride is a kind of mild, high selective and high efficient catalysts. Gallium triflate is a stable reusable Lewis acid catalyst, which can easily dissolve in polar solvents such as CH3CN, MeOH, EtOH and water. Gallium perchlorate is never reported to catalyze organic reactions, but our study disclosed that it is an efficient catalyst for some intersting reactions.This thesis contains three parts. Firstly, we studied the catalytic properties of gallium perchlorate, which could efficiently catalyze the condensation of o-phenylenediamines andα-bromoketones to afford 2-substituted quinoxalines in good yields. The mild reaction conditions, convenient manipulation and short reaction time were notable advantages of this method. Secondly, we proved that Gallium perchlorate was also high efficient to catalyze the formation of quinoxaline and its derivatives from 1,2-diamines andα-hydroxyketones. Finally, polysubstituted pyrroles were readily synthesized via a one-pot solvent-free three-component coupling reaction of amines, 1,3-dicarbonyl compounds and nitroalkenes catalyzed by Gallium perchlorate under mild conditions.The structures of products were all confirmed by 1H NMR, 13C NMR and HRMS spectra.