Metal chlorides supported on chiral mesoporous silica (MClx/CMS) as highly active Lewis acid catalyst for the selective hydroamination of cyclohexene

Abstract

Metal chlorides supported on chiral mesoporous silica (MClx/CMS) as solid acid catalysts were prepared, characterized and their catalytic performance in hydroamination of cyclohexene was evaluated. A series of MClx/CMS catalysts were prepared by wet impregnation with various types of metal chlorides (NiCl2, CuCl2, AlCl3, CoCl2, FeCl3, ZnCl2) on CMS support and further heat treated at mild temperature. The supported catalysts showed catalytic synergistic effect (∼60% of conversion) and 100% selectivity in hydroamination of cyclohexene under mild reaction condition (60°C). Furthermore, the influence of reaction parameters and supports on activity of the catalyst was also investigated. The MClx/CMS catalysts can be recovered for reuse for several runs with little reactivity loss (∼5%) and easily handled under the described reaction conditions.