HClO₄ And HClO₄-SiO₂ Catalyzed Addition Of β-Dicarbonyl Compounds To Alcohols And Alkenes And TfOH-SiO₂ Catalyzed Addition Of Sulfonamides To Alkenes

In this thesis, the direct additions ofβ-diketones to secondary alcohols or alkenes have been achieved using perchloric acid (HClO4) as the catalyst in low catalytic loading (lmol%). The HClO4-catalyzed reactions could be conveniently conducted in air with undried solvents and majority of the substrate gave more than 85%yields. Moreover, when HClO4 was absorbed onto silica gel, the silica gel-supported HClO4-catalyzed heterogeneous additions also proceeded smoothly to give similar or even better results in comparison with the homogenous ones. The supported catalyst could be readily recovered by filtering method and reused for 4 runs. Furthermore, the mechanism for the HClO4 catalyzed-addition of theβ-diketone to alcohol was investigated thoroughly through experiments and the SN1 mechanism was established ambiguously.Highly efficient hydroamination reactions of sulfonamides, benzamide with inactivate olefins catalyzed by readily available and inexpensive silia gel-supported TfOH was achieved for the first time. The silica gel-supported TfOH catalyzed addition reactions could be conveniently conducted in air with unpredried solvent in catalytic loading (5mol%). The supproted catalyst could be readily recovered and reused for 6 runs with maitained reactivity and yields, and each yield of the reaction in run is more than 95%. These processes gave more than 80%yields for the addition reaction of various sulfonamides with alkenes.