NH2SO3H-SiO2 as a new water-compatible, recyclable heterogeneous catalyst for the synthesis of novel (α,β-unsaturated) β-amino ketones via aza-Michael reaction

摘要

NH2SO3H-SiO2/water as a novel catalytic system was used for the synthesis of (α,β-unsaturated) β-amino ketones via aza-Michael reaction at reflux conditions. The methodology was of general applicability and the catalyst exhibited activity up to five cycles. The catalyst was characterized for the first time using FT-IR, X-ray diffraction and scanning electron microscopic-energy dispersion analytical X-ray. The stability of the catalyst was evaluated by differential scanning calorimetry and TGA/differential thermal analysis. High efficiency of the catalyst along with its recycling ability and the rather low loading demonstrated in reactions are the merits of the presented protocol.