Zinc-Grafted Functionalized SBA-15: A Novel and Highly Efficient Heterogeneous Mesoporous Catalyst for the One-Pot Synthesis of Tetrahydrobenzo[a]xanthenes

In this work, a novel type of zinc-grafted functionalized mesoporous silica catalyst (SBA-15/EDAB-ZnII) was synthesized through the immobilization of zinc acetate on the modified surface of SBA- 15 with ethyl 3,4-diaminobenzoate as an organic linker. Characterization of the newly synthesized heterogeneous mesoporous catalyst was successfully accomplished using different techniques. The as-synthesized mesocatalyst revealed a superb catalytic activity towards the one-pot synthesis of a wide verity of tetrahydrobenzo[a]xanthene derivatives. This protocol involved the three-component reactions of various aldehydes, 2-naphthol, and dimedone, under mild reaction conditions. The most promising features which highlight the presented approach are: furnishing a very important class of pharmaceutically and biologically active products in excellent yields (85-97%) within short reaction times (10-50 minutes), mildness of the reaction conditions (temperature of 90⁰ C, without using any additive), using solvent free media and more importantly convenient catalyst reusability for at least seven successive runs without any appreciable loss of its activity. The characteristics of the present methodology make this reaction proper for scale-up and commercialization.

کلیدواژه ها:

Mesoporous Silica Catalyst ، SBA-15/EDAB-ZnII ، Tetrahydrobenzo[a]xanthenes ، Green Chemistry ، One-pot Reaction.