Study On The Reaction Catalyzed By Ga(Ⅲ) Reagents

Gallium triflate is a stable reusable Lewis acid catalyst. It can easily dissolve in polar solvents such as CH3CN, MeOH, EtOH and water. Gallium tris(dodecylsulfate) is a Lewis acid-surfactant combined catalyst. As a Lewis acid, it could activate the substrate; as a surfactant, it could occur micelle-forming and promote the aqueous reaction.This thesis contains three parts. Firstly, we studied the catalytic properties of gallium triflate, which could efficiently catalyzed the condensation of o-phenylenediamines and propargyl esters to form new 1, 5-benzodiazepines in good yields. The unsaturated bond in 1, 5-benzodiazepine only exists in the form of carbon-carbon double bond rather than the common form of carbon-nitrogen double bond. Secondly, we proved that Gallium triflate is also high efficient to catalyze the formation of quinoxaline and its derivatives from 1,2-diamines and 1,2-diketones in excellent to quantitative yields. The reactions proceeded with 1 mol% catalyst in ethanol at room temperature and the catalyst could be recycled for at least 10 times. Finally, we used Gallium tris(dodecylsulfate) to catalyze the C3-regioselective addition of propargyl esters with indoles to form bis-indolyl esters in excellent to quantitative yields. The reaction proceeded well in water without any organic solvents.The structures of products were all confirmed by 1H NMR, 13C NMR and HRMS spectra.