New inorganic–organic hybrid materials based on SBA-15 molecular sieves involved in the quinolines synthesis

In this paper we report on the first mesoporous catalyst based on SBA-15 incorporating simultaneously basic and acid functions able to promote the Friedländer reaction between 2-aminoaryl ketones and ethyl acetoacetate leading to quinolines 1 with high yields. From 2-aminobenzophenone (3a) it is possible to prepare quinoline 1a with the highest selectivity (86%) as compared with other mesoporous acidic catalysts. In contrast, the reaction catalyzed by amine-grafted SBA-15 yielded selectively (98%) the corresponding quinolone 2a in accordance with our previous results. Experimental results have been justified by theoretical calculations as function of the stability of reaction intermediate species, which could be involved in the process.